MODERATE QUAKES IN GREENLAND SEA; CENTRAL ALASKA

 

EARTHQUAKE SUMMARY FOR JULY 22, 2021

 

The strongest earthquake in the world today was an M 5.5 in the Greenland Sea. It was not reported felt in this remote area. It may have been promoted by the minor geomagnetic storm at high latitudes which occurred today, the strongest in more than a month. This summary noted this possibility as:

 

"The geomagnetic field saw disturbed conditions today. The AP level was 11.  High latitude geomagnetic field  saw minor storm conditions with AP 28. This is the strongest geomagnetic disturbance at high latitudes in more than a month and could bring enhanced seismicity at high latitudes in the next several days." (July 22, 2021)

 

A slightly smaller event at this epicenter in the Greenland Sea occurred on March 23, 2021. At the time this summary noted:

 

"The M 5.3-5.4 in the Greenland Sea is the largest in that area within about 300 km of this epicenter since an M 5.6 on February 8, 2018 and prior to that an M 6.5 on March 5, 2009." (March 24, 2021)

 

Forecast 135599 had expected today's event within about 100 km was likely around July 21.

 

O: 23JUL2021 04:05:38  79.8N    3.1E Mw=5.5  EMSC   GREENLAND SEA                

P: 21JUL2021 135599    79.0N    7.0E 4.0-5.8 AAAAA  Arctic Ocean Region        

 

The strongest earthquake in the U.S. or Canada today was an M 4.7 in Central Alaska. NEIC reported maximum intensity IV at Eielson AFB with intensity II-III in Fairbanks, North Pole, Healy, Delta Junction, Clear and Anderson, Alaska. Like the event in the Greenland Sea this may have been promoted by the strong geomagnetic disturbance today at high latitudes. An M 4.4 also occurred south of this South of  Alaska in the Unimak Island region. These events had been expected between July 18 and 26 within about 100 km of these epicenters. The M 4.7 near Fairbanks is the strongest within about 150 km of that epicenter since an M 4.8 on February 17, 2007. An M 5.5 hit about 250 km southwest of this on April 8, 2021. 

 

O: 23JUL2021 04:20:19  64.5N  146.8W mb=4.7  EMSC   CENTRAL ALASKA               

P: 18JUL2021 135593    63.3N  145.0W 3.2-5.2 BBAAA  Central Alaska             

P: 26JUL2021 135848    63.1N  144.7W 3.2-5.1 BBAAA  Central Alaska             

 

The M 4.4 south of Alaska is the strongest within about 150 km of that epicenter since an M 4.5 on March 28, 2021.  It had been expected to occur within about 100 km around July 24.

 

O: 22JUL2021 13:12:31  53.6N  162.8W mb=4.4  EMSC   SOUTH OF ALASKA              

P: 24JUL2021 135840    54.3N  162.7W 3.5-5.1 AAAAA  Unimak Islands, Aleutians  

 

Other high latitude seismicity occurred in northern Russia with a series of moderate quakes in Mongolia, Kamchatka and Northwestern Sakha.

 

O: 22JUL2021 07:45:30  51.3N  100.4E mb=3.9  EMSC   RUSSIA-MONGOLIA BORDER REGION

P: 21JUL2021 135584    51.0N   98.0E 3.0-4.4 AABAA  So. Siberia                

 

O: 22JUL2021 16:02:51  53.7N  158.4E mb=4.0  EMSC   NEAR EAST COAST OF KAMCHATKA 

P: 25JUL2021 135829    51.0N  158.0E 4.0-5.7 BBAAA  Kamchatka                   

 

O: 22JUL2021 11:44:06  55.6N  162.0E mb=4.5  EMSC   NEAR EAST COAST OF KAMCHATKA 

P: 28JUL2021 135827    54.0N  162.0E 4.0-5.4 CBAAA  E. of Kamchatka            

 

O: 22JUL2021 18:34:43  72.4N  125.3E mb=4.0  EMSC   NORTHWESTERN SAKHA, RUSSIA   

 

STRONG QUAKE SHAKES PANAMA AND COSTA RICA

 

EARTHQUAKE SUMMARY FOR JULY 21, 2021

 

The strongest earthquake in the world today occurred in the area south of Panama with M 6.7. It was widely felt with strong intensity in Panama. NEIC reported intensity VIII (with damage) in Panama at Boqueron and VII in Burica, Puerto Armuelles; V in La Concepcion, David, Progreso; IV in Finca, Bagala, Las Lomas and Ouiteno. A series of moderate aftershocks were also felt in the area. At M 6.7 this is the strongest earthquake in the world since the M 7.4 in Qinghai, China on May 21, 2021. The only earthquakes with M>=6.7 within about 250 km of this epicenter in the past 30 years occurred about 250 km to the north on August 20, 1999 and about 200 km to the south on March 31, 1999. Today's activity follows a series of moderate and large earthquakes in the area as noted in the previous issue of this summary:

 

"The series of earthquakes in Panama and Costa Rica also continued today. This has included an moderate quakes in Costa Rica on July 14, 2021 and an M 6.1 south of Panama on July 17 as noted at the time in this summary:

 

 

"The strongest earthquake in the world today was an M 6.1 south of Panama. NEIC reported it was felt with maximum intensity IV in Panama at Cerro Sombrero; IV in San Andres and II-III in Puerto Armuelles, Guarumal, Pedregal, David, Quiterio, Tole, Petrerillos and Golfito, Panama.  This is the strongest event in the area south of Panama within about 200 km since an M 6.6 on January 7, 2015. An M 6.2 also occurred about 200 km north of today's epicenter on June 26, 2019.

Forecast 135406 had expected today's event within about 50 km was likely

around July 19." (July 17, 2021, July 21, 2021)

 

Forecasts 135652 and 135406 had expected today's activity was likely within about 100 km between July 19 and 25.

 

O: 21JUL2021 21:15:14   7.4N   82.9W Mw=6.7  EMSC   SOUTH OF PANAMA              

O: 22JUL2021 02:51:05   7.2N   83.0W mb=4.7  EMSC   OFF COAST OF COSTA RICA

O: 21JUL2021 22:25:58   7.4N   82.7W mb=4.9  EMSC   SOUTH OF PANAMA

O: 21JUL2021 21:34:39   7.8N   82.8W mb=4.7  EMSC   SOUTH OF PANAMA

O: 21JUL2021 21:55:35   8.2N   82.9W ML=4.0  EMSC   PANAMA-COSTA RICA BORDER REGION

P: 25JUL2021 135652     7.0N   82.0W 3.5-6.1 BAAAA  Costa Rica                 

P: 19JUL2021 135406     7.0N   82.0W 3.5-5.2 AAAAA  Costa Rica                 

 

An earthquake of M 5.9 also occurred in the series in the Bismarck Sea, Indonesia today. This is the strongest event in this sequence to date. Earthquakes of M 5.7 and 5.8 hit the area on July 19. At the time this summary noted:

 

"The M 5.8 in the Bismarck Sea occurred near local solar midnight and may have been promoted by high tidal stresses which maximize near this hour and by geomagnetic effects from the moderate geomagnetic storm of two days ago. The last earthquake of equal or greater magnitude in the Bismarck Sea occurred as an M 6.1 on April 27, 2021 about 150 km to the west of today's epicenter. An M 6.3 also occurred in this area on February 7, 2021. Forecast 135420 had expected today's activity in the Bismarck Sea within about 50 km of these epicenter was likely around July 19." (July 19-20, 2021)

 

Like the activity on July 19, the mainshock today of M 5.9 also occurred  within minutes of local solar midnight and was likely promoted by high tidal stresses. These may have been enhanced by high tides associated with the coming full moon as this epicenter is near the maximum longitude for these tides as described in this summary:

 

 

"The full moon will arrive on July 24 at 02:37 UT. Longitudes which are at local solar midnight at this time are near 40 West and those at local solar noon near 140 East. These include, in the west, the Atlantic Ocean basin and in the east, the western Pacific subduction zone including Japan and portions of Eastern Indonesia. These areas are currently active and could see a strong earthquake in the next week." (July 20-21, 2021)

 

 

O: 21JUL2021 14:26:01   3.4S  146.7E Mw=5.9  EMSC   BISMARCK SEA

O: 21JUL2021 23:07:46   3.2S  146.7E mb=4.8  EMSC   BISMARCK SEA                 

P: 19JUL2021 135420     3.0S  146.0E 4.0-5.4 AAAAA  New Ireland                

 

The strongest earthquake in the U.S. or Canada today was an M 4.4 off the coast of Northern California. NEIC reported it was felt along the coast of Northern California with intensity II-III in Petrolia, Ferndale, Rio Dell, Fortuna, Carlotta, Eureka, Baside, Arcata and McKinleyville. NEIC reported an aftershock of M 2.8 off northern California  was felt with intensity II-III in the area(s) of northern California in Arcata and Redwood City. This event, the third largest in the area in the past year (after events of M 4.5 and 4.7 on January 12 and March 30, 2021), appears to be an aftershock of the M 5.1 which hit this epicenter on July 18. At the time this summary noted in this regard:

 

 

"Today's event is the largest in this area off the coast of Northern California in more than a year. Similar events have last occurred in the area as an M 5.2 on March 18, 2020, an M 5.8 on March 9, 2020 and an M 4.6 on June 23, 2019 after a four year lull following an M 5.7 on September 3, 2016. Forecast 135552 had expected today's event within about 25 km was likely in mid-July." (July 18, 2021)

 

 

O: 21JUL2021 10:36:37  40.4N  124.9W ML=2.6  EMSC   OFFSHORE NORTHERN CALIFORNIA

O: 21JUL2021 12:25:57  40.5N  124.7W ML=2.5  EMSC   OFFSHORE NORTHERN CALIFORNIA 

O: 21JUL2021 10:05:30  40.3N  124.4W ML=3.8  EMSC   OFFSHORE NORTHERN CALIFORNIA 

O: 21JUL2021 10:05:30  40.3N  124.4W ML=4.4  ANSS   OFFSHORE NORTHERN CALIFORNIA

P: 15JUL2021 135552    40.2N  124.2W 2.5-4.4 CAAAA  Off Coast of No. Calif     

 

MODERATE QUAKES IN TRISTAN DA CUNHA; PAKISTAN

 

EARTHQUAKE SUMMARY FOR JULY 20, 2021

 

The most unusual earthquake located in the world today was an M 5.0 in the area of the South Atlantic near Tristan da Cunha. It was not reported felt in this remote area. The last earthquake within about 300 km of today's epicenter with M>=5 occurred as a series (M 5.0, 5.4, 5.2) on January 15, 2021 and prior to that an M 5.9 on August 31, 2020.

 

O: 21JUL2021 02:19:04  35.4S   15.8W mb=5.0  EMSC   TRISTAN DA CUNHA REGION      

 

An M 5.1 also occurred in Pakistan today.  NEIC reported this earthquake of M 5.1 in Pakistan was felt with intensity II-III in the area(s) of Pakistan with V in Jampur, IV in Rajanpur, Dajal, and Muzaffargarh, Punjab and II-III in Dera Ghazi and Kashmor.  The only earthquake within about 250 km of this event with M>=5.1 in the past year was an M 5.5 about 300 km to the northwest on November 14, 2020. The last within 250 km were of M 5.2 on June 17, 2018 and an M 5.3 on October 23, 2015. Forecast 135470 had expected this epicenter would be active around July 17.

 

O: 20JUL2021 23:54:26  29.3N   70.1E Mw=5.1  EMSC   PAKISTAN                     

P: 17JUL2021 135470    29.0N   68.0E 3.5-4.9 BABAA  Pakistan                   

 

Moderate, but not unusual earthquakes of M 5.1 and 5.2 also occurred today in Indonesia and Mindanao, Philippines. An active swarm in Sulawesi, Indonesia today included several M 4.1 events and may expand in coming days. These had been expected within about 150 km in forecasts 135404 and 135412 in mid-July.

 

O: 20JUL2021 20:26:46   5.6N  126.8E Mw=5.2  EMSC   MINDANAO, PHILIPPINES        

P: 19JUL2021 135404     7.0N  126.0E 4.0-5.4 ABAAA  Central Philippines        

 

O: 21JUL2021 04:33:35   7.5S  128.3E mb=5.1  EMSC   KEPULAUAN BARAT DAYA, INDONESI

P: 17JUL2021 135412     8.0S  128.0E 4.0-5.6 BAAAA  Banda Sea                  

 

O: 21JUL2021 05:39:03   2.9S  119.4E ML=4.1  EMSC   SULAWESI, INDONESIA

O: 20JUL2021 21:40:29   2.9S  119.3E ML=4.1  EMSC   SULAWESI, INDONESIA           

P: 16JUL2021 135401     0.0N  120.0E 4.0-5.4 BCAAA  Celebes Sea                

 

An earthquake of M 4.4 in the Ryukyu Islands today continued moderate seismicity in that area. It was reported by JMA to have been lightly felt in Okinawa, Japan. This activity appears to be related to the passage of  Typhoon In-Fa through the area as previously noted in this summary:

 

"Typhoon In-Fa continued today south of Honshu, Japan with winds up to 115 kts. It is expected to track to the northwest reaching the Central Ryukyu Islands and Taiwan around July 21. Some seismic enhance is likely in these areas at that time." (July 18-21, 2021)

 

Forecast 135472 had expected this event was likely in mid-July within about

50 km of today's epicenter.

 

O: 20JUL2021 13:33:56  25.8N  128.3E mb=4.4  EMSC   RYUKYU ISLANDS, JAPAN        

P: 16JUL2021 135472    26.0N  129.0E 4.0-5.6 BAAAA  Ryukyu Islands             

 

The series of earthquakes in Panama and Costa Rica also continued today. This has included an moderate quakes in Costa Rica on July 14, 2021 and an M 6.1 south of Panama on July 17 as noted at the time in this summary:

 

 

"The strongest earthquake in the world today was an M 6.1 south of Panama. NEIC reported it was felt with maximum intensity IV in Panama at Cerro Sombrero; IV in San Andres and II-III in Puerto Armuelles, Guarumal, Pedregal, David, Quiterio, Tole, Petrerillos and Golfito, Panama. This is the strongest event in the area south of Panama within about 200 km since an M 6.6 on January 7, 2015. An M 6.2 also occurred about 200 km north of today's epicenter on June 26, 2019.

Forecast 135406 had expected today's event within about 50 km was likely around July 19." (July 17, 2021)

 

 

O: 21JUL2021 03:28:59   9.8N   81.1W ML=3.9  EMSC   PANAMA                        

P: 19JUL2021 135406     7.0N   82.0W 3.5-5.2 ACAAA  Costa Rica                 

 

NEIC reported the earthquake of M 3.9 in Costa Rica was felt with intensity II-III in the area(s) of Costa Rica at Saltrillos, San Antonio (V); San Jose, San Rafael (IV) and Pattara, San Felipe, Tobosi, Curridabat, San Pedro and Escazu, San Jose.

 

O: 20JUL2021 23:57:14   9.8N   84.1W mb=3.9  EMSC   COSTA RICA                   

P: 19JUL2021 135406     7.0N   82.0W 3.5-5.2 ACBAA  Costa Rica                 

 

MODERATE QUAKES SHAKE SOUTHWEST PACIFIC

 

EARTHQUAKE SUMMARY FOR JULY 19, 2021

 

The largest earthquakes in the world today were an M 5.7 and  M 5.8 in the Bismarck Sea. It was preceded by an M 5.0 foreshock. NEIC reported these events were strongly felt with intensity up to VIII in Lorengau Manus, Papua New Guinea. An M 5.7 also shook the region of New Britain today.  The M 5.8 in the Bismarck Sea occurred near local solar midnight and may have been promoted by high tidal stresses which maximize near this hour and by geomagnetic effects from the moderate geomagnetic storm of two days ago. The last earthquake of equal or  greater magnitude in the Bismarck Sea occurred as an M 6.1 on April 27, 2021 about 150 km to the west of today's epicenter. An M 6.3 also occurred in this area on February 7, 2021. Forecast 135420 had expected today's activity in the Bismarck Sea within about 50 km of these epicenter was likely around July 19.

 

O: 19JUL2021 19:42:33   3.3S  146.7E mb=5.0  EMSC   BISMARCK SEA

O: 19JUL2021 20:30:41   3.3S  146.5E Mw=5.7  EMSC   BISMARCK SEA

O: 19JUL2021 20:24:39   3.5S  146.4E ML=4.6  EMSC   BISMARCK SEA

O: 19JUL2021 20:57:06   3.6S  147.0E ML=4.7  EMSC   BISMARCK SEA

O: 19JUL2021 15:22:32   3.3S  146.9E Mw=5.8  EMSC   BISMARCK SEA                  

O: 19JUL2021 20:00:55   3.9S  146.3E ML=4.7  EMSC   BISMARCK SEA                 

P: 19JUL2021 135420     3.0S  146.0E 4.0-5.4 AAAAA  New Ireland                

 

The M 5.7 in the New Britain area had been expected within about 50 km

in forecast 135419 to occur in mid-July.

 

O: 20JUL2021 04:22:47   5.5S  153.9E mb=4.8  EMSC   NEW IRELAND REGION, P.N.G.

O: 19JUL2021 23:02:08   5.0S  152.2E Mw=5.7  EMSC   NEW BRITAIN REGION, P.N.G.   

P: 15JUL2021 135419     5.0S  153.0E 4.0-5.5 BAAAA  New Britain                 

 

The strongest earthquake in the U.S. outside Alaska today was an M 4.0 in New Mexico near the Texas border. NEIC reported it was felt with intensity III in New Mexico at Carlsbad and Jai and in Mentone, Texas. This area has seen an upsurge in seismicity in recent months, possibly related to oil and gas extraction in the region. The last earthquake of M>=4 in the area was an M 4.4 on June 25, 2021 but four other such events have occurred in the region in the past five months. The activity began with an M 5.0 on March 26, 2020. There were no earthquakes of M>=4 in the area from 2010 to 2020.

Forecast 135508 had expected today's activity within about 100 km was likely

around July 18.

 

O: 20JUL2021 02:11:06  31.6N  104.6W ML=2.8  EMSC   WESTERN TEXAS                

O: 19JUL2021 11:23:25  32.1N  103.7W ML=3.9  EMSC   NEW MEXICO                   

O: 19JUL2021 11:23:25  32.1N  103.7W ML=4.0  ANSS   NEW MEXICO                   

P: 18JUL2021 135508    32.5N  104.6W 2.0-4.0 AAAAA  SW U.S.A                    

 

The strongest earthquake in Alaska today was an M 4.3 in the Kenai Peninsula. NEIC reported it was felt with intensity II-III in Alaska at Clam Gulch, Ninilchik, Kasilof, Anchor Point, Soldotna, Sterling, Homer, Kenai, Copper Landing and Moose Pass. The last earthquake in the Kenai Peninsula, Alaska region with larger magnitude was an M 4.7 on July 1, 2021. The only other such event in this region in the past year was an M 4.4 on January 26, 2021. Forecast 135590 had expected today's activity was likely within about 50 km around July 20.

 

O: 19JUL2021 10:52:19  60.2N  151.8W Mw=4.3  EMSC   KENAI PENINSULA, ALASKA      

P: 20JUL2021 135590    60.8N  151.7W 3.2-5.3 AAAAA  Central Alaska             

 

MODERATE QUAKE SHAKES SOUTHERN IRAN; UNUSUAL QUAKES IN SEVERAL AREAS

 

EARTHQUAKE SUMMARY FOR JULY 18, 2021

 

The strongest earthquake in the world today was an M 5.4 in Southern Iran.

NEIC reported this earthquake of M 5.4 in Southern Iran was felt with intensity II-III in the area(s) of Southern Iran with IV at Kazerun, Fars and Jabriya and in Berazan, Shiraz, Salmiya, el-Ahmadi and el-Wahah, Kuwait. It was followed by a series of moderate aftershocks. In the past year similar events hit the area on April 18, 20221 (M 5.8) and February 17, 2021 (M 5.4). Forecast 135473 had expected today’s event to the southeast was likely around July 17.

 

O: 18JUL2021 14:54:29  29.7N   51.1E mb=4.3  EMSC   SOUTHERN IRAN

O: 18JUL2021 15:08:42  29.7N   51.1E mb=4.4  EMSC   SOUTHERN IRAN

O: 18JUL2021 15:27:00  29.7N   51.1E ML=4.0  EMSC   SOUTHERN IRAN

O: 18JUL2021 17:32:33  29.7N   51.1E mb=4.4  EMSC   SOUTHERN IRAN

O: 18JUL2021 14:34:18  29.6N   51.2E Mw=5.4  EMSC   SOUTHERN IRAN                

P: 17JUL2021 135473    28.0N   52.0E 3.5-4.9 ABAAA  So. Iran/Persian Gulf      

 

A strong winter storm hit the area near Picton, New Zealand today. Thanks to a reader (Pam

) we have good data on this storm. An earthquake of M 4.2 in the Cook Strait accompanied the storm as noted in this summary:

 

"A strong Winter Storm hit the area near Picton, New Zealand over the weekend. It was accompanied by an M 4.2 near Picton which was probably triggered by stresses from this storm." (July 18-19, 2021)

 

This is the strongest earthquake in the Cook Strait area since an M 4.7 on March 12, 2021 - the strongest in the area in more than a year. NEIC reported this earthquake of M 4.2 in Cook Strait, New Zealand was felt with intensity II-III in the area(s) of Cook Strait, New Zealand in New Plymouth, Taranaki, New Zealand. Forecast 135638 had expected this activity within about 50 km was likely around July 20.

 

O: 18JUL2021 18:11:53  40.7S  173.8E mb=4.2  EMSC   COOK STRAIT, NEW ZEALAND     

P: 20JUL2021 135638    40.0S  174.0E 3.0-4.5 AAAAA  North Island, N.Z.         

 

An unusual earthquake of M 4.8 was also recorded north of New Zealand an west of the Kermadec Islands. It was not reported felt in this remote area. Only one other quake of M>=4.8 has occurred within about 300 km of this epicenter in the past 30 years - an M 4.8 on December 6, 2002. Unusual earthquakes northwest of New Zealand have occasionally occurred days before strong quakes, usually along the coast of South America. But the rarity of quakes in this region does not permit any such conclusions at this time. Still, it has been nearly two months since the last major earthquake in the world and a full moon will be arriving in the next week, so global activity is likely to be enhanced in coming days.

 

 

O: 19JUL2021 00:00:23  29.6S  174.7E ML=4.8  EMSC   NORTH OF NEW ZEALAND         

P: 16JUL2021 135636    33.0S  178.0E 4.0-5.6 BCCAA  So. Kermadec Islands       

 

GEONET also reported an earthquake in Te Anau, South Island was felt with weak intensity in the area southwest of Te Anau, South Island. 140 reports of felt intensity came from the area east and north of the epicenter. More than 140 people reported feeling this earthquake with 106 reporting weak shaking and 29 light intensity; 3 with moderate intensity and none with strong, 0 with  severe and 0 with extreme shaking.

O: 18JUL2021 08:36:26  45.0S  167.5E ML=3.9  EMSC   SOUTH ISLAND OF NEW ZEALAND  

O: 18JUL2021 08:36:26  45.0S  167.5E MS=4.4  GEONET Felt with weak intensity

P: 20JUL2021 135641    44.0S  168.0E 3.0-4.9 AAAAA  So. Island, N.Z.           

 

Unusual earthquakes also occurred today in the region off southern Cuba and

in the Pitcairn Island area of the South Pacific Ocean. This unusual activity further raises the specter of a major upcoming earthquake. The event in Cuba had been expected to the east in forecast 135462 around July 19.  NEIC reported this earthquake of M 4.2 in Cuba was felt with intensity II-III in the area(s) of Cuba at Guantanamo, and Santiago de Cuba.

 

O: 19JUL2021 01:33:27  19.8N   75.5W mb=4.2  EMSC   CUBA REGION                  

P: 18JUL2021 135462    20.0N   71.0W 3.0-4.7 AACAA  Bahamas/No. Caribbean      

 

An M 5.1 also occurred in the south Pacific in the Pitcairn Islands region It was not reported felt in this remote area. The only earthquake in the Pitcairn area in the past 30 years of M>=5.1 was an M 5.6 on September 23, 1995. Forecast 135624 had expected today's event within about 50 km was likely around July 14.

 

O: 18JUL2021 15:48:09  25.1S  129.6W mb=5.1  EMSC   PITCAIRN ISLANDS REGION      

P: 14JUL2021 135624    25.0S  130.0W 3.0-5.6 BAAAA  So. Pacific Ocean          

 

 

The strongest earthquake in the U.S/Canada or vicinity today was an M 4.1 in the northern Gulf of California. It was accompanied by at least nine quakes of M>=3.3. The mainshock occurred within about an hour of local solar noon and may have been enhanced by strong tidal stresses which maximize near this hour. This continues a series of events that began on July 9 and is the strongest in the current activity. This is a remote area and while some of these may have been lightly felt, this was not reported. Forecast 135465 had expected today's event within about 25 km was likely around July 18.

 

 

O: 18JUL2021 09:45:37  29.9N  114.1W ML=3.8  EMSC   GULF OF CALIFORNIA

O: 18JUL2021 18:40:50  29.9N  113.7W ML=4.1  EMSC   GULF OF CALIFORNIA

O: 18JUL2021 09:39:14  30.0N  114.1W ML=3.5  EMSC   GULF OF CALIFORNIA

O: 18JUL2021 20:18:46  30.0N  114.3W ML=3.6  EMSC   GULF OF CALIFORNIA

O: 18JUL2021 20:50:21  30.0N  114.1W ML=3.3  EMSC   GULF OF CALIFORNIA

O: 18JUL2021 21:02:33  30.1N  114.2W ML=3.6  EMSC   GULF OF CALIFORNIA

O: 18JUL2021 18:26:01  30.2N  114.3W ML=3.6  EMSC   GULF OF CALIFORNIA

O: 18JUL2021 18:35:08  30.2N  114.2W ML=3.5  EMSC   GULF OF CALIFORNIA

O: 18JUL2021 21:46:18  29.8N  114.5W ML=3.7  EMSC   BAJA CALIFORNIA, MEXICO      

P: 16JUL2021 135465    30.0N  114.0W 3.5-5.2 AAAAA  Gulf of California         

 

MODERATE QUAKE SHAKES COAST OF NORTHERN CALIFORNIA

 

EARTHQUAKE SUMMARY FOR JULY 17, 2021

 

An earthquake of M 5.1 occurred today off the coast of northern California today. NEIC reported it was felt with maximum intensity VI in California at Carlotta; IV in Petrolia, Myers Flat, Redcrest and II-III in Ferndale, Rio Dell, Fortuna, Scotia, Loleta, and Whitethorn. This event occurred within about an hour of local solar midnight and may have been enhanced by high tidal stresses which maximize near this hour. A second factor may have been the moderate geomagnetic storm of the past two days, the strongest such storm in the past month as noted in previous issues of this summary:

 

"The geomagnetic field saw disturbed conditions today. The AP level was 10.  High latitude geomagnetic field also saw disturbed conditions with AP 15. This is the strongest disturbance in the geomagnetic field in the past month - since June 16-18, 2021 and may enhance seismicity in the region of the geomagnetic equator and at high latitudes." (July 16-17, 2021)

 

Today's event is the largest in this area off the coast of Northern California in more than a year. Similar events have last occurred in the area as an M 5.2 on March 18, 2020, an M 5.8 on March 9, 2020 and an M 4.6 on June 23, 2019 after a four year lull following an M 5.7 on September 3, 2016. Forecast 135552 had expected today's event within about 25 km was likely in mid-July.

 

O: 18JUL2021 06:46:12  40.3N  124.4W Mw=5.1  EMSC   OFFSHORE NORTHERN CALIFORNIA 

P: 15JUL2021 135552    40.2N  124.2W 2.5-4.4 BAAAA  Off Coast of No. Calif     

 

As often occurs the significant earthquake off the coast of Northern California was preceded several hours earlier by a significant earthquake in the northeastern U.S. In this case an M 4.2 occurred in Lake Erie, Ohio and was lightly felt in the area. Two earthquakes of equal or larger magnitude have occurred in the Lake Erie area of Ohio in the past 30 years - an M 4.4 on January 26, 2001 and an M 4.5 on September 25, 1998. Forecast 135555 had expected today's event within about 100 km was likely around July 16. Like many recent unusual quakes in the northeastern U.S. in the past two months, this epicenter is at 103 degrees from the last major earthquake in the world - the M 7.4 of May 21, 2021 and was probably promoted by energy from that epicenter.

 

O: 17JUL2021 21:02:43  42.1N   81.4W ML=4.2  EMSC   LAKE ERIE, OHIO              

P: 16JUL2021 135555    41.0N   81.0W 2.0-4.3 ABAAA  Ohio/Lake Erie             

 

The strongest earthquake in the world today was an M 6.1 south of Panama. NEIC reported it was felt with maximum intensity IV in Panama at Cerro Sombrero; IV in San Andres and II-III in Puerto Armuelles, Guarumal, Pedregal, David, Quiterio, Tole, Petrerillos and Golfito, Panama. This is the strongest event in the area south of Panama within about 200 km since an M 6.6 on January 7, 2015. An M 6.2 also occurred about 200 km north of today's epicenter on June 26, 2019. Forecast 135406 had expected today's event within about 50 km was likely around July 19.

 

O: 18JUL2021 01:21:37   7.1N   82.7W mb=4.2  EMSC   SOUTH OF PANAMA

O: 17JUL2021 20:56:11   6.9N   82.6W Mw=6.1  EMSC   SOUTH OF PANAMA              

P: 19JUL2021 135406     7.0N   82.0W 3.5-5.2 AAAAA  Costa Rica                 

 

A moderate event of M 5.5 also occurred in the northern Mid-Atlantic Ridge today. It was not reported felt in this remote area. The last earthquake within about 250 km of today's epicenter with M>=5.5 was an M 5.7 on October 18, 2007 and prior to that an M 5.5-5.6 on November 26, 2003. Forecast 135468 had expected today's event within about 100 km was likely around July 14.

 

O: 17JUL2021 21:31:21  28.5N   43.8W Mw=5.5  EMSC   NORTHERN MID-ATLANTIC RIDGE  

P: 14JUL2021 135468    29.0N   43.0W 4.0-5.6 BAAAA  Mid-Atlantic Ridge         

 

The aftershock sequence in southwestern Puerto Rico showed enhancement today.

Earthquakes of M 4.4 and 4.3 occurred, the strongest aftershocks in the area since December 24, 2020 when an M 4.7 and 4.8 occurred.  NEIC reported today's earthquake of M 4.4 in southwestern Puerto Rico was felt with intensity IV in the area(s) of southwestern Puerto Rico  at Lajas, Cabo Rojo, San German, Mayaguez, Adjuntas and II-III in Ensenada, Hormigueros, Yauco, Las Marias and Anasco. Today's event of M 4.4 occurred within about 15 minutes of local solar midnight and was likely promoted by high tidal stresses which maximize near this hour. Forecast 135455 had expected this activity around July 17.

 

O: 18JUL2021 03:50:03  17.9N   67.1W ML=3.5  EMSC   PUERTO RICO REGION

O: 18JUL2021 04:42:58  17.9N   67.2W ML=3.5  EMSC   PUERTO RICO REGION

O: 18JUL2021 04:45:40  17.9N   67.1W mb=4.4  EMSC   PUERTO RICO REGION

O: 18JUL2021 03:52:22  17.8N   67.1W mb=4.3  EMSC   PUERTO RICO REGION           

P: 17JUL2021 135455    18.0N   68.0W 3.4-5.3 AAAAA  Puerto Rico                

 

TIDAL STRESSES HELP PROMOTE MODERATE QUAKE IN SOUTH SANDWICH ISLANDS

 

EARTHQUAKE SUMMARY FOR JULY 16, 2021

 

The strongest earthquake in the world today was an M 5.7 in the South Sandwich Islands. It was not reported felt in this region. It occurred within about an hour of local solar midnight, a time when tidal stresses are maximized. Only one earthquake of larger or equal magnitude has occurred in the South Sandwich Islands in the past year - an M 6.0 about 500 km southwest of today's epicenter on March 14, 2021. Forecast 135645 had expected today's event within about 25 km was likely around July 16.

 

O: 17JUL2021 00:53:25  56.1S   27.8W Mw=5.7  EMSC   SOUTH SANDWICH ISLANDS REGION

P: 16JUL2021 135645    56.0S   28.0W 4.0-5.8 AAAAA  So. Sandwich Islands       

 

A strong series of light earthquakes occurred today in the Yellowstone National Park, Wyoming today. The strongest of these was an M 3.6. NEIC reported it was felt with intensity III in Yellowstone and in Jackson, Wyoming. Three events of M>=3 occurred in this swarm. This included an event of M 3.6, the largest in the Yellowstone area since an M 4.6 to the west of July 18, 2017.Several small preliminary events in this swarm occurred and were reported in the previous issue of this summary as:

 

 

"Light earthquakes of M 2.0 and 2.5 occurred in the Yellowstone National Park, Wyoming area today. These events were not reported felt in the area. The M 2.5 is the strongest in eastern Yellowstone since an M 2.6 near this epicenter on December 2, 2020. Swarms of light earthquakes occurred in western Yellowstone in late June, 2021 with maximum magnitudes of M 3.0 and 3.1. An aftershock in this area of M 2.7 occurred on July 12, 2021. The M 2.5 today occurred within about 30 minutes of local solar midnight and may have been enhanced by high tidal stresses which maximize near this hour. A further swarm is likely in this area in the next several days. Forecast 135567 had expected this activity in Yellowstone was likely between July 14 and 19." (July 15-16, 2021)

 

Following is a listing of events in the area with M>2.6. A more complete listing of today's events in Yellowstone can be found under the "ROCKY MOUNTAIN" regional section of this summary.

 

O: 16JUL2021 12:30:39  44.4N  110.4W Md=2.5  EMSC   YELLOWSTONE NAT. PARK, WYOMING

O: 16JUL2021 13:00:53  44.4N  110.3W Ml=2.6  EMSC   YELLOWSTONE NAT. PARK, WYOMING

O: 16JUL2021 17:22:57  44.4N  110.4W ML=2.5  EMSC   YELLOWSTONE NAT. PARK, WYOMING

O: 16JUL2021 19:41:02  44.4N  110.3W Ml=2.5  EMSC   YELLOWSTONE NAT. PARK, WYOMING

O: 17JUL2021 05:27:41  44.4N  110.3W Ml=2.8  EMSC   YELLOWSTONE NAT. PARK, WYOMING

O: 17JUL2021 05:59:02  44.4N  110.3W ML=2.6  EMSC   YELLOWSTONE NAT. PARK, WYOMING

O: 16JUL2021 12:54:43  44.5N  110.4W ML=2.8  EMSC   YELLOWSTONE NAT. PARK, WYOMING

O: 16JUL2021 14:12:51  44.5N  110.4W ML=3.1  EMSC   YELLOWSTONE NAT. PARK, WYOMING

O: 16JUL2021 15:22:34  44.5N  110.3W ML=2.6  EMSC   YELLOWSTONE NAT. PARK, WYOMING

O: 16JUL2021 19:44:20  44.5N  110.4W Ml=3.2  EMSC   YELLOWSTONE NAT. PARK, WYOMING

O: 17JUL2021 00:45:36  44.5N  110.4W ML=3.3  EMSC   YELLOWSTONE NAT. PARK, WYOMING

O: 17JUL2021 00:45:35  44.5N  110.4W ML=3.6  ANSS   YELLOWSTONE NAT. PARK, WYOMING

O: 17JUL2021 01:05:37  44.5N  110.4W Ml=2.7  EMSC   YELLOWSTONE NAT. PARK, WYOMING

P: 14JUL2021 135567    44.6N  110.8W 2.0-3.9 AAAAA  Yellowstone/Wyoming        

 

An experimental explosion registering M 3.9 occurred today on a ship off the east coast of central Florida. NEIC reported it was felt with intensity IV in Florida at Ocala and II-III in Jacksonville, Merritt Island and in North Myrtle Beach, South Carolina. This is the second such experimental explosion in the area this summer. A similar A similar explosion of M 3.9 occurred on June 18, a month ago. It was followed by the collapse of a condominium in Surfside, Florida - a suburb of Miami on June 24.

 

O: 16JUL2021 17:48:33  30.1N   79.3W ML=3.9  EMSC   OFF EAST COAST OF UNITED STATE

 

The strongest earthquakes in the U.S. or Canada today were a pair of M 4.0 events in the Gulf of Alaska. They were not reported felt in this region.

This is the strongest earthquake in the Gulf of Alaska since events of M 4.2 on June 9 and M 4.4 on May 18. Forecast 135596 had expected today's activity within about 150 km was likely in the Gulf of Alaska around July 15.

 

O: 16JUL2021 20:01:34  56.5N  148.7W mb=4.0  EMSC   GULF OF ALASKA

O: 16JUL2021 20:44:06  56.6N  148.6W ML=3.1  EMSC   GULF OF ALASKA

O: 16JUL2021 19:10:38  56.3N  148.6W ML=4.0  EMSC   GULF OF ALASKA               

P: 15JUL2021 135596    55.0N  149.0W 3.0-4.6 ABAAA  Gulf of  Alaska            

 

MODERATE QUAKE SOUTH OF TOKYO, JAPAN

 

EARTHQUAKE SUMMARY FOR JULY 15, 2021

 

The strongest earthquake in the world today was an M 5.5 in the Izu Islands area of southern Japan. It was reported with intensity II in Yokohama, Kanagawa, Japan. The mainshock was followed by a series of moderate aftershocks including an M 4.2. The mainshock occurred within about an hour of local solar noon and may have been promoted by high tidal stresses which maximize near this hour. It also occurred in a region where tidal stresses were maximized with the last new moon as noted in previous issues of this summary:

 

"The new moon arrived on July 10, 2021 at 01:17 UT. Longitudes which were anti-solar at this time area near 20 West and those which are sub-solar (local solar noon) are near 160 East longitude. These include, in the west the areas of Iceland and western Europe and portions of the central mid-Atlantic near the equator and in the east areas of the Solomon and Vanuatu Islands, Kamchatka and Northern Japan and the Kurils among others. These include areas where strong tidal effects and help promote strong to major earthquakes and such an event may be expected in the next week." (July 7-14, 2021)

 

Today's M 5.5 is the strongest event in the Izu Islands since an M 5.8 on March 28, 2021. The only other such event in the past 1.5 years was an M 5.9 on October 3, 2020. Forecast 135504 expected today's activity to the east was likely around July 14.

 

O: 16JUL2021 05:51:30  33.2N  139.4E ML=3.8  EMSC   IZU ISLANDS, JAPAN REGION

O: 16JUL2021 06:01:30  33.2N  139.4E ML=3.8  EMSC   IZU ISLANDS, JAPAN REGION

O: 15JUL2021 14:04:30  33.3N  139.5E ML=3.9  EMSC   IZU ISLANDS, JAPAN REGION

O: 16JUL2021 04:19:57  33.3N  139.5E Mw=5.5  EMSC   IZU ISLANDS, JAPAN REGION

O: 16JUL2021 04:30:30  33.3N  139.4E ML=3.9  EMSC   IZU ISLANDS, JAPAN REGION

O: 16JUL2021 04:55:30  33.3N  139.6E ML=4.2  EMSC   IZU ISLANDS, JAPAN REGION

O: 16JUL2021 05:09:30  33.2N  139.5E ML=4.2  EMSC   IZU ISLANDS, JAPAN REGION    

P: 14JUL2021 135504    33.0N  142.0E 4.0-5.6 AABAA  Off East Coast Honshu      

 

Light earthquakes of M 2.0 and 2.5 occurred in the Yellowstone National Park, Wyoming area today. These events were not reported felt in the area. The M 2.5 is the strongest in eastern Yellowstone since an M 2.6 near this epicenter on December 2, 2020. Swarms of light earthquakes occurred in western Yellowstone in late June, 2021 with maximum magnitudes of M 3.0 and 3.1. An aftershock in this area of M 2.7 occurred on July 12, 2021. The M 2.5 today occurred within about 30 minutes of local solar midnight and may have been enhanced by high tidal stresses which maximize near this hour. A further swarm is likely in this area in the next several days. Forecast 135567 had expected this activity in Yellowstone was likely between July 14 and 19.

 

O: 16JUL2021 05:53:20  44.5N  110.4W Md=2.0  EMSC   YELLOWSTONE NAT. PARK, WYOMING

O: 16JUL2021 06:25:55  44.4N  110.4W Md=2.5  EMSC   YELLOWSTONE NAT. PARK, WYOMING

P: 14JUL2021 135567    44.6N  110.8W 2.0-3.9 AAAAA  Yellowstone/Wyoming        

P: 19JUL2021 135567    44.2N  110.3W 2.0-4.3 BAAAA  Yellowstone/Wyoming        

 

The strongest earthquake in the U.S. or Canada or vicinity today was an M 4.1 in the northern Gulf of California. This continues a swarm of lighter events in the which began July 9. It is the strongest event in this region in at least a year. Forecast 135465 had expected today's event within about 10 km  was likely around July 16.

 

O: 16JUL2021 00:30:00  30.0N  114.0W ML=4.1  EMSC   GULF OF CALIFORNIA            

P: 16JUL2021 135465    30.0N  114.0W 3.5-5.2 AAAAA  Gulf of California         

 

 

ODERATE QUAKE SHAKES GUAM

 

EARTHQUAKE SUMMARY FOR JULY 14, 2021

 

The strongest earthquake in the world today was an M 5.3 in the area of Guam. The only event of M>=5.3 in the past year was an M 5.4 on November 24, 2020.  Forecast 135457 had expected today's event within about 150 km was likely around July 17.

 

O: 14JUL2021 09:24:52  12.0N  143.8E Mw=5.3  EMSC   GUAM REGION                  

P: 17JUL2021 135457    13.0N  145.0E 4.0-5.7 BAAAA  So. Marianas/Guam          

 

An earthquake of M 2.8 shook regions of Virginia today. NEIC reported it was felt with intensity II-III in Virginia at Pearlsburg, Dublin, Pulaski, Bland, Redford, Penbroke, Newport, Max Meadows, Blacksburg and Christianburg.

An M 5.1 hit Virginia on August 9, 2020 within about 100 km of today's epicenter. More recent earthquakes of M 2.8 or grater have since occurred on August 11, 2020 (M 2.8) and October 25, 2020 (M 2.8). Forecast 135492 had expected today's event in this area was likely around July 20.

 

O: 15JUL2021 00:55:47  37.3N   80.8W mb=2.4  EMSC   VIRGINIA                     

P: 20JUL2021 135492    37.2N   81.9W 2.0-4.1 BAAAA  Kentucky/Tennessee/NC      

 

A similar M 2.8-3.2 also shook areas of New York State and Ontario, Canada today. NEIC reported it was felt with intensity II-III in Massena, Chase Mills, Norfolk, Norwood, Brasher Falls, Madrid and Morrisburg,  Chesterville, Cornwall, Ontario, Canada.  The last earthquake within about 100 km of this epicenter with M>=3.2 occurred as an M 3.4 on January 13, 2020 and prior to that as an M 3.3 on November 28, 2015. Forecasts 135291 and 135547 had expected today's event between July 7 and 15.

 

 

O: 14JUL2021 23:35:50  45.0N   75.0W mb=2.8  EMSC   NEW YORK                     

O: 14JUL2021 23:35:49  45.0N   75.0W MB=3.2  ECAN Morrisburg, ON                 

P:  7JUL2021 135291    45.0N   75.0W 2.0-4.4 CAAAA  New York State             

P: 15JUL2021 135547    47.0N   76.0W 2.0-4.2 ABAAA  New York State             

 

MODERATE QUAKE IN LOYALTY ISLANDS

 

EARTHQUAKE SUMMARY FOR JULY 13, 2021

 

The strongest earthquake in the world today was an M 5.4 in the Loyalty Islands.

This earthquake was not reported felt in this remote area. Earthquakes of M 5.4-5.5 have occurred most recent in the Loyalty Islands on June 23 and May 15 both with M 5.4-5.5. The last of larger magnitude was an M 5.9 on March 12, 2021.

Forecast 135621 had expected today's event was likely within about 50 around July 16.

 

O: 13JUL2021 11:26:51  23.3S  172.3E Mw=5.4  EMSC   SOUTHEAST OF LOYALTY ISLANDS 

P: 16JUL2021 135621    23.0S  172.0E 4.0-5.4 BAAAA  Loyalty Islands            

 

An M 5.4 also occurred in the Banda Sea, Indonesia today. Earthquakes during 2021 of equal or larger size in the Banda Sea occurred as an M 6.0 on April 3 and  an M 5.6 on June 24, 2021. Forecast 135164 had expected today's event within about 100 km was likely around July 10.

 

O: 13JUL2021 12:45:55   5.1S  130.9E mb=5.4  EMSC   BANDA SEA                    

P: 10JUL2021 135164     6.0S  131.0E 4.0-5.4 BAAAA  West Irian, PNG            

 

The strongest aftershocks in the series following the July 7 quake of M 6.0 in Central California today was an M 4.0 after several days of much reduced aftershock activity. It was reported by NEIC to have been felt with intensity II-III in Coleville, Long Barn, South Lake Tahoe, Arnold, Glenbrook, Groveland, Grizzly Flats, Murphys, Sonor and in Reno, Nevada. The M 4.0 was the strongest earthquake in the U.S. or Canada today. Forecast 135480 had expected this activity was likely within about 30 km around July 16. Following is a listing of aftershocks of M>2.5 today. A more complete listing is located in the "California" regional section of this summary.

 

O: 13JUL2021 12:02:17  38.5N  119.5W ml=2.7  EMSC   CENTRAL CALIFORNIA

O: 13JUL2021 17:51:38  38.5N  119.5W ML=2.6  EMSC   CENTRAL CALIFORNIA

O: 14JUL2021 03:46:14  38.6N  119.5W Mw=4.0  EMSC   CENTRAL CALIFORNIA

O: 14JUL2021 04:01:28  38.6N  119.5W Md=2.6  EMSC   CENTRAL CALIFORNIA

P: 16JUL2021 135480    38.8N  119.6W 2.5-4.4 BAAAA  California/Nevada area     

 

A strong swarm of moderate earthquakes occurred today in Taiwan. This series included an M 5.1 and at least eight other events of M>=4. It appears to be an extension of the M 5.3 and 5.2 which hit this epicenter on July 7, 2021. NEIC reported these earthquakes of M 4.7, 4.7 and 5.2 in Taiwan were felt with intensity II-III in the area(s) of Taiwan at Taichung, Changhua, Taipei.  CWB reported the largest of these events of M 5.1 was felt in Taiwan with intensity V in Hualien, III in nmantou, Taichung, Changhua; II in Yilan, Taoyuan, Hsinchu, Miali, Yunlin and I in Taipei, Kaohsiung and Tainan Counties, Taiwan. Forecasts 135209 and 135474 had expected this activity was likely between July 7 and 17 within about 50 km.

 

O: 13JUL2021 22:53:49  23.9N  121.6E ML=4.1  EMSC   TAIWAN

O: 13JUL2021 22:59:24  23.9N  121.7E mb=4.9  EMSC   TAIWAN

O: 13JUL2021 23:02:40  23.9N  121.6E ML=4.0  EMSC   TAIWAN

O: 13JUL2021 23:14:29  23.9N  121.7E mb=4.5  EMSC   TAIWAN

O: 13JUL2021 23:45:26  23.9N  121.7E mb=4.7  EMSC   TAIWAN

O: 14JUL2021 00:11:57  24.0N  121.6E ML=4.0  EMSC   TAIWAN

O: 14JUL2021 03:36:33  24.0N  121.6E ML=4.5  EMSC   TAIWAN

O: 13JUL2021 22:52:05  23.9N  121.6E Mw=5.1  EMSC   TAIWAN                        

O: 14JUL2021 17:00:44  23.9N  121.6E ML=4.7  TAI    Hualien, Taiwan              

O: 14JUL2021 12:55:33  23.9N  121.6E ML=4.1  TAI    Hualien, Taiwan              

P:  7JUL2021 135209    24.0N  122.0E 4.0-5.4 CAAAA  Taiwan                      

P: 17JUL2021 135474    23.0N  122.0E 4.0-5.4 BAAAA  Taiwan                     

 

MODERATE QUAKES SHAKE NORTHWEST PACIFIC; NICARAGUA

 

EARTHQUAKE SUMMARY FOR JULY 12, 2021

 

The strongest earthquakes in the world today were an M 5.8 in the Kuril Islands; an M 5.3 in Kamchatka and an M 5.2 in the area of Nicaragua. This is the strongest earthquake in Nicaragua since an M 5.5 on May 21, 2021, part of a swarm at that time.  NEIC reported today's earthquake of M 5.2 in Nicaragua was felt with intensity IV-V   in the area(s) of Nicaragua at El Crucero, San Marcos, Managua and II-III in Masayam and Tola. Forecast 135184 had expected today's event in Nicaragua was likely around July 8 within about 50 km of this epicenter.

 

O: 12JUL2021 23:26:35  11.7N   86.4W Mw=5.2  EMSC   NEAR COAST OF NICARAGUA      

P:  8JUL2021 135184    12.0N   86.0W 3.5-5.3 BAAAA  Nicaragua                  

 

An earthquake of M 5.8 occurred about 400 km southwest of today's Kuril Island epicenter on March 2. 2021, but there have been no such earthquakes within  about 200 km of today's epicenter since an M 7.0 on February 13, 2020 and an M 5.6 on December 5, 2019.  Forecast 135308 had expected seismic enhancement in this region in early July. This may have been promoted by high tidal stresses associated with the new moon of July 10 as it occurred near the longitude of maximum tidal stress within about an hour of local solar noon. The expected enhancement with the new moon had been noted in previous issues of this summary as:

 

"The new moon arrived on July 10, 2021 at 01:17 UT. Longitudes which were anti-solar at this time area near 20 West and those which are sub-solar (local solar noon) are near 160 East longitude. These include, in the west the areas of Iceland and western Europe and portions of the central mid-Atlantic near the equator and in the east areas of the Solomon and Vanuatu Islands, Kamchatka and Northern Japan and the Kurils among others. These include areas where strong tidal effects and help promote strong to major earthquakes and such an event may be expected in the next week." (July 8-13, 2021)

 

O: 13JUL2021 00:30:16  46.2N  151.6E Mw=5.6  EMSC   KURIL ISLANDS                

P:  4JUL2021 135308    47.0N  151.0E 3.5-5.4 CAAAA  So. Kurils                 

 

The event in the Kuril Islands was accompanied about two hours later by an M  5.3 in Kamchatka, also within about an hour of local solar noon. It too was probably promoted by high tidal stresses. The only earthquake in Kamchatka of M>5.3 in the past year was an M 6.6 about 300 km northeast of today's event on March 16, 2021. Forecasts 135323 and 135576 had expected today's activity in Kamchatka was likely between July 7 and 16.

 

O: 12JUL2021 23:06:10  52.7N  160.3E mb=4.7  EMSC   OFF EAST COAST OF KAMCHATKA

O: 13JUL2021 02:28:54  52.5N  160.4E Mw=5.3  EMSC   OFF EAST COAST OF KAMCHATKA  

P:  7JUL2021 135323    54.0N  161.0E 4.0-5.4 CBAAA  E. of Kamchatka            

P: 16JUL2021 135576    52.0N  160.0E 4.0-5.4 BAAAA  E. of Kamchatka            

 

The strongest earthquake in the U.S. or Canada today was an M 4.2 in New Mexico. NEIC reported it was felt with intensity V in New Mexico at Gallina, Lindrift, IV in Coyote, Tierra Amarilla, and II-III in Counselor, La Jara, Regina, Jemez Springs, El Rito, Abiquiu. NEIC reported an aftershock of M 3.7 in New Mexico was felt with intensity II-III in the area(s) of New Mexico at Lindrith, Jemez Springs, El Rito, Abquiu, Tierra Amarilla, Dulce, Los Alamos, Espanola, Broomfield, Santa Fe. A foreshock of M 3.0 in the region of New Mexico was reported felt with intensity II-III in Abiquiu and Los Alamos. The last earthquake in New Mexico within about 200 km of today's epicenter with M>=4.2 occurred on August 1, 2004 about 200 km to the northeast of today's epicenter with M 4.3.  Forecasts 135227 and 135489 had expected today's activity was likely between July 8 and 13 to the north of today's epicenter.

 

O: 12JUL2021 16:06:14  36.2N  106.8W ML=3.7  EMSC   NEW MEXICO

O: 12JUL2021 13:44:29  36.3N  106.8W ML=3.0  EMSC   NEW MEXICO

O: 13JUL2021 00:40:23  36.3N  106.8W ML=2.7  EMSC   NEW MEXICO

O: 12JUL2021 15:33:36  36.2N  106.7W Mw=4.2  EMSC   NEW MEXICO                   

P:  8JUL2021 135227    38.8N  107.4W 2.0-4.0 BCAAA  Colorado area              

P: 13JUL2021 135489    36.5N  106.0W 2.0-3.9 AAAAA  Colorado area              

 

The aftershock sequence near the California-Nevada border continued today with a series of minor shocks. The largest aftershock today was an M 2.6 and was lightly felt in the Markleeville area.

 

Following are event of M>2.5 in the area today. A more extensive listing can be found in the "California" regional forecast later in this summary. Forecast

135217 and 135218 had expected this activity was likely within about 25 km of these epicenters in early July.

 

O: 12JUL2021 15:43:06  38.6N  119.5W ML=2.6  EMSC   CENTRAL CALIFORNIA

P:  8JUL2021 135218    39.3N  120.0W 2.5-4.4 BAAAA  California/Nevada area     

P: 14JUL2021 135479    38.2N  118.8W 2.5-4.9 AAAAA  California/Nevada area     

P: 16JUL2021 135480    38.8N  119.6W 2.5-4.4 BAAAA  California/Nevada area     

 

An unusual earthquake of M 3.1 was recorded about 150 km southeast of Hawaii today. Only one other event of M>=3.1 has been recorded within about 100 km of today's epicenter in the past 30 years - an M 3.1 on March 29, 2021. An M 3.2  occurred about 100 km to the north of this on August 19, 2013. Forecast 135176 had expected activity south of Hawaii in early July.

 

O: 12JUL2021 23:42:03  18.0N  154.1W ML=3.1  EMSC   HAWAIIAN ISLANDS REGION      

P:  5JUL2021 135176    18.9N  155.1W 3.0-4.6 CAAAA  Hawaii                     

 

MODERATE QUAKE SHAKES ADAK, ANDREANOF ISLANDS, ALASKA

 

EARTHQUAKE SUMMARY FOR JULY 11, 2021

 

The largest earthquake in the U.S. or Canada today (or in the world) was an M 4.9 in the central Andreanof Islands, Alaska. NEIC reported it was felt with intensity IV at Adak, Alaska. This follows a smaller M 4.7 on July 9 and is the strongest event in the Andreanof Islands since an M 5.1 on May 22, 2021 about 200 km to the east of today's epicenter. The last event within about 200 km of today's epicenter and the only such event in the past year was an M 5.2 on October 1, 2020. Forecast 135318 had expected today's event within about 50 km was likely around July 7.

 

O: 11JUL2021 17:04:37  51.8N  176.0W Mw=4.9  EMSC   ANDREANOF ISLANDS, ALEUTIAN IS

P:  7JUL2021 135318    51.7N  175.3W 3.5-5.2 BAAAA  Andreanoff Isls, Aleutians 

 

 

 

Aftershocks also continued in the area of Central California near the Nevada border. The larger of these were lightly felt in the epicentral area. Following are event of M>2.5 in the area today. A more extensive listing can be found in the "California" regional forecast later in this summary. Forecast 135217 and 135218 had expected this activity was likely within about 25 km of these epicenters in early July.

 

 

O: 11JUL2021 09:39:04  38.5N  119.5W ML=2.6  EMSC   CENTRAL CALIFORNIA

O: 11JUL2021 12:35:42  38.5N  119.5W ML=3.1  EMSC   CENTRAL CALIFORNIA

O: 11JUL2021 18:56:29  38.5N  119.4W Md=2.6  EMSC   CENTRAL CALIFORNIA

O: 11JUL2021 18:56:29  38.5N  119.4W Md=2.6  EMSC   CENTRAL CALIFORNIA

O: 11JUL2021 19:06:53  38.5N  119.5W ml=2.9  EMSC   CENTRAL CALIFORNIA

O: 11JUL2021 21:52:21  38.5N  119.5W Md=2.8  EMSC   CENTRAL CALIFORNIA

O: 12JUL2021 04:36:33  38.5N  119.5W ML=2.7  EMSC   CENTRAL CALIFORNIA

O: 12JUL2021 02:04:36  38.6N  119.4W MD=3.0  EMSC   CENTRAL CALIFORNIA

O: 11JUL2021 07:37:05  38.5N  119.5W Md=2.6  EMSC   CENTRAL CALIFORNIA           

P:  8JUL2021 135218    39.3N  120.0W 2.5-4.4 BAAAA  California/Nevada area     

 

The strong swarm in northern Baja California, Mexico also continued today. The strongest of these events in the past two days has not exceeded M 4.0 and these events are not being reported felt in the area. Forecasts 135198 and 135251 had expected this activity was likely in early July within about 50 km.

 

O: 11JUL2021 19:24:32  31.0N  115.5W ML=3.3  EMSC   BAJA CALIFORNIA, MEXICO

O: 11JUL2021 20:08:35  31.0N  115.2W ML=3.4  EMSC   BAJA CALIFORNIA, MEXICO

O: 11JUL2021 07:41:02  31.2N  115.3W ML=3.0  EMSC   BAJA CALIFORNIA, MEXICO

O: 11JUL2021 14:13:53  31.4N  115.5W ML=3.1  EMSC   BAJA CALIFORNIA, MEXICO

O: 11JUL2021 14:13:53  31.4N  115.5W ML=3.1  EMSC   BAJA CALIFORNIA, MEXICO

O: 12JUL2021 05:31:20  31.4N  115.5W ML=3.1  EMSC   BAJA CALIFORNIA, MEXICO

O: 11JUL2021 14:10:57  31.0N  115.0W ML=3.3  EMSC   BAJA CALIFORNIA, MEXICO      

P:  5JUL2021 135198    30.0N  114.0W 3.5-5.3 CAAAA  Gulf of California         

P:  7JUL2021 135251    31.8N  115.6W 2.5-4.4 BAAAA  So. California             

 

An M 4.4 also occurred today in the Strait of Gibraltar. This area has been active in recent months but has produced no damage. The only event in the region in the past year, however, of M>=4.4 was an M 4.7 on June 19, 2021. Forecast

135234 had expected today's event to the north was likely around July 8.

 

O: 11JUL2021 11:40:00  35.2N    3.7W mb=4.4  EMSC   STRAIT OF GIBRALTAR          

P:  8JUL2021 135234    37.0N    3.0W 3.5-5.2 BAAAA  Morocco/Spain              

 

 

 

 

 

MODERATE QUAKE IN RAT ISLANDS TIDALLY TRIGGERED

 

EARTHQUAKE SUMMARY FOR JULY 10, 2021

 

The strongest earthquake in the world today was an M 5.5 in the Rat Islands in the western Aleutian Islands. It was not reported felt in this remote area.

It was preceded by an M 5.0 foreshock. This activity began within several minutes of local solar noon and was probably triggered by high tidal stresses with the new moon which maximized near this hour. The tidal seismicity forecast in this and previous summaries for this new moon reads:

 

"The new moon will arrive on July 10, 2021 at 01:17 UT. Longitudes which are anti-solar at this time area near 20 West and those which are sub-solar (local solar noon) are near 160 East longitude. These include, in the west the areas of Iceland and western Europe and portions of the central mid-Atlantic near the equator and in the east areas of the Solomon and Vanuatu Islands, Kamchatka and Northern Japan and the Kurils among others. These include areas where strong tidal effects and help promote strong to major earthquakes and such an event may be expected in the next week." (July 8-10, 2021)

 

Today’s event is the strongest within about 200 km of this epicenter since an M 6.4 on April 2, 2019 and prior to that an M 6.6 on October 8, 2017. Forecast 135331 had expected this activity was likely in early July within about 25 km of today's epicenters.

 

O: 11JUL2021 02:11:37  52.2N  177.4E Mw=5.4  EMSC   RAT ISLANDS, ALEUTIAN ISLANDS

O: 11JUL2021 00:08:01  52.3N  177.3E Mw=5.1  EMSC   RAT ISLANDS, ALEUTIAN ISLANDS

O: 10JUL2021 20:42:55  52.1N  177.2E mb=4.3  EMSC   RAT ISLANDS, ALEUTIAN ISLANDS

P:  5JUL2021 135331    52.0N  177.0E 4.0-5.8 BAAAA  Rat Islands                

 

Aftershocks also continued in the area of Central California near the Nevada border. The larger of these were lightly felt in the epicentral area. Following are event of M>2.5 in the area today. A more extensive listing can be found in the "California" regional forecast later in this summary. Forecast 135217 had expected this activity was likely within about 25 km of these epicenters in early July.

 

O: 10JUL2021 10:15:55  38.5N  119.5W Md=2.8  EMSC   CENTRAL CALIFORNIA

O: 10JUL2021 15:42:14  38.5N  119.5W ml=2.6  EMSC   CENTRAL CALIFORNIA

O: 10JUL2021 19:45:04  38.5N  119.5W Md=2.6  EMSC   CENTRAL CALIFORNIA

O: 10JUL2021 20:18:11  38.5N  119.6W Md=2.6  EMSC   NORTHERN CALIFORNIA

O: 10JUL2021 22:25:05  38.5N  119.6W Md=2.6  EMSC   CENTRAL CALIFORNIA

O: 10JUL2021 23:13:51  38.5N  119.5W Md=2.8  EMSC   CENTRAL CALIFORNIA

O: 11JUL2021 00:58:19  38.5N  119.5W Md=2.6  EMSC   CENTRAL CALIFORNIA

O: 11JUL2021 01:27:47  38.5N  119.5W ML=2.8  EMSC   CENTRAL CALIFORNIA

O: 11JUL2021 06:09:03  38.5N  119.5W ML=2.9  EMSC   CENTRAL CALIFORNIA

O: 11JUL2021 04:23:21  38.6N  119.5W ML=2.9  EMSC   CENTRAL CALIFORNIA

O: 11JUL2021 04:23:21  38.6N  119.5W ML=2.9  EMSC   CENTRAL CALIFORNIA           

P:  7JUL2021 135217    38.8N  119.6W 2.5-4.6 BAAAA  California/Nevada area     

 

 

ENHANCED GLOBAL SEISMICIT?Y CONTINUES

 

EARTHQUAKE SUMMARY FOR JULY 9, 2021

 

Seismicity around the world continued today for the second straight day. Large or moderately large quakes were recorded in Sulawesi (M 5.6), Molucca (M  6.3, 5.5) and Tajikistan (M 5.9).  These events follow 4-5 days after the X1.5 solar flare of July 3. Seismicity is often seen to increase at this time following major solar flares, probably due to the time taken to significantly increase telluric and ionospheric electrical currents following such events. This delay has been discussed in this summary on several previous occasions. The activity today was mostly confined to southern and southeastern Asia. Tropical Storms 07W and 08W have made landfall in this area in the past several days and may have helped trigger these events. The earthquake in Molucca is near 104 degrees from the M 6.0 in Nevada two days ago. This is a distance at which triggering from strong earthquakes is likely, and probably was involved in today's events in Indonesia. The new moon which arrived today was also probably promotional in enhancing the global seismicity today. The tidal forecast for this alignment is provided in this summary as:

 

"The new moon will arrive on July 10, 2021 at 01:17 UT. Longitudes which are anti-solar at this time area near 20 West and those which are sub-solar (local solar noon) are near 160 East longitude. These include, in the west the areas of Iceland and western Europe and portions of the central mid-Atlantic near the equator and in the east areas of the Solomon and Vanuatu Islands, Kamchatka and Northern Japan and the Kurils among others. These include areas where strong tidal effects and help promote strong to major earthquakes and such an event may be expected in the next week." (July 7-9, 2021)

 

The largest earthquake in the world today was an M 6.3 in the Molucca Sea south of the Talaud Islands, Indonesia. It was reported felt lightly in the epicentral area. The last earthquake of larger magnitude within about 200 km of this epicenter in the Molucca Sea was an M 7.1 on November 14, 2019. Forecast 135136 had expected today's activity within about 100 km was likely around July 7.

 

O: 10JUL2021 03:30:51   2.9N  126.7E mb=4.6  EMSC   MOLUCCA SEA

O: 10JUL2021 00:43:57   3.0N  126.6E Mw=6.3  EMSC   MOLUCCA SEA

O: 10JUL2021 00:51:09   3.0N  126.6E mb=5.5  EMSC   MOLUCCA SEA

O: 10JUL2021 01:10:36   3.0N  126.7E ML=4.0  EMSC   KEPULAUAN TALAUD, INDONESIA

O: 10JUL2021 02:20:22   3.0N  126.7E ML=4.4  EMSC   MOLUCCA SEA

O: 10JUL2021 02:30:57   3.0N  126.8E mb=4.6  EMSC   KEPULAUAN TALAUD, INDONESIA

O: 10JUL2021 01:18:07   3.1N  126.7E ML=4.1  EMSC   KEPULAUAN TALAUD, INDONESIA

O: 10JUL2021 00:58:13   2.9N  126.6E mb=5.0  EMSC   MOLUCCA SEA                  

P:  7JUL2021 135136     4.0N  127.0E 4.0-5.4 BBAAA  Halmahera                  

 

The strongest earthquake in the world today which was strongly felt was an M 5.8-5.9 in Tajikistan. NEIC reported it was felt with intensity VIII in Garm, Tajikistan and II in Dushanbe and in Tashkent, Uzbekistan. This is the strongest earthquake in Tajikistan since an M 6.1-6.3 on February 12, 2021 about 300 km southeast of today's epicenter. The last of stronger size within about 200 km was an M 6.0 on May 3, 2017 and prior to that an M 5.9 on May 12, 2012. Forecast 135230 had expected today's event within about 100 km was likely around July 11.

 

 

O: 10JUL2021 05:48:06  39.1N   70.6E mb=4.6  EMSC   TAJIKISTAN

O: 10JUL2021 06:07:00  39.1N   70.4E mb=4.3  EMSC   TAJIKISTAN

O: 10JUL2021 02:14:43  39.0N   70.7E mb=5.9  EMSC   TAJIKISTAN                   

P: 11JUL2021 135230    39.0N   72.0E 3.8-5.2 AAAAA  Hindu Kush/Pakistan        

 

An M 5.6 was also felt in Indonesia in the Sulawesi and Minahasa area. NEIC reported intensity II-III in Poso and Mobagu, Sulawesi and in Gorontalo, Indonesia. The last earthquake within about 200 km of this epicenter with M>=5.6 was an M 5.8 on February 22, 2021. Forecast 135137 had expected today's activity in this area was likely around July 10.

 

O:  9JUL2021 13:31:10   0.1N  123.7E Mw=5.6  EMSC   MINAHASA, SULAWESI, INDONESIA

P: 10JUL2021 135137     1.0N  125.0E 4.0-5.4 AABAA  Mindanao, Philippines      

 

Aftershocks of the M 6.0 in western Nevada of July 7 continued today. The largest of these in magnitudes 3.5-4.0 were felt with intensity V in Sonora, California and II-III in Markleevile, Twain Harte, Davis, Los Banos. Forecast 135217 had expected this activity within about 25 km of these epicenters was likely around July 7. This activity was likely triggered by motions of the North American Plate by Hurricane Elsa which made landfall in western Florida simulteneously with the M 6.0 in Nevada/California. The last earthquake within  this area of Nevada within about 100 km of the M 6.0 epicenter occurred on September 12, 1994 about 50 km to the northwest of the recent M 6.0 with M 6.1.  Aftershocks of M>=3 follow. A more complete listing can be found in the "California" regional section below.

 

O: 09JUL2021 09:16:17  38.5N  119.5W ML=3.2  EMSC   CENTRAL CALIFORNIA

O: 09JUL2021 09:38:16  38.5N  119.5W ML=3.4  EMSC   CENTRAL CALIFORNIA

O: 09JUL2021 09:45:17  38.5N  119.5W ML=3.6  EMSC   CENTRAL CALIFORNIA

O: 09JUL2021 20:18:38  38.5N  119.5W MD=3.0  EMSC   CENTRAL CALIFORNIA

O: 09JUL2021 22:59:49  38.5N  119.5W ML=3.0  EMSC   CENTRAL CALIFORNIA

O: 10JUL2021 01:21:00  38.5N  119.6W ML=3.3  EMSC   CENTRAL CALIFORNIA

O: 10JUL2021 02:48:44  38.5N  119.5W ML=3.2  EMSC   CENTRAL CALIFORNIA

O: 09JUL2021 09:13:49  38.6N  119.5W Mw=3.5  EMSC   CENTRAL CALIFORNIA

O: 09JUL2021 11:49:18  38.6N  119.5W ml=3.2  EMSC   CENTRAL CALIFORNIA

P:  7JUL2021 135217    38.8N  119.6W 2.5-4.6 AAAAA  California/Nevada area     

 

The strongest earthquake in the U.S. or Canada today was an M 4.7 in the central

Andreanof Islands, Alaska. It was not felt in this remote region. The only earthquake with equal or larger magnitude within about 150 km of this epicenter in the past year was an M 5.2 on October 1, 2020. Forecast 135318 had expected today's event within about 10 km was likely around July 7.

 

O:  9JUL2021 19:14:59  51.7N  175.3W mb=4.7  EMSC   ANDREANOF ISLANDS, ALEUTIAN IS

P:  7JUL2021 135318    51.7N  175.3W 3.5-5.2 AAAAA  Andreanoff Isls, Aleutians 

 

STRONG M 6.0 HITS WESTERN NEVADA; CENTRAL AND NORTHERN CALIFORNIA

 

EARTHQUAKE SUMMARY FOR JULY 8, 2021

 

Global seismicity took a leap upward today with moderate to large earthquakes

spread over much of the world including in Atacama, Chile (M 5.5); South Sandwich Islands (M 4.7); the Pacific-Antarctic Ridge (M 5.4); the Macquarie Islands (M 5.2); Bolivia (M 5.2); Tarapaca, Chile (M 5.2);  El Salvador (M 5.4).  The strongest earthquake of the day was an M 6.0 which widely felt in the area of western Nevada, and in Central and Northern California. NEIC reported the mainshock was felt with maximum intensity V in Nevada at Garnerville, Smith, Wellington and in California at Topaz, Coleville, Markleeville, and IV in South Alpine County, Pinecrest, Bridgeport, Long Barn, California and in general as far as Canada, Colorado, Montana, Washington, Arizona, Idaho, Oregon and Baja California. A series of aftershocks was also felt with light to moderate intensity.

 

In previous issues of this summary the possibility of a moderate to large earthquake in the region of California had been addressed as:

 

"Hurricane Elsa made landfall in western Florida today. Hurricanes in this area are often followed by moderate to strong earthquakes in the area of California. This summary has been a strong advocate for weather-related seismicity at a distance for many years, and before that when this was a private communication. This does not occur in each instance when a hurricane makes landfall on the U.S. East coast but occurs often enough to be notable. This may be due to stresses and movement applied through the North American Plate from motions imparted by landfall. This relation is strongest at the beginning of the hurricane season. So enhancement along the west coast of North America is likely in the next several days. This summary noted in regard to the possible effects on seismicity of Hurricane Elsa.

 

 

"Hurricane Elsa continued today over the Carolinas with winds up to 45 kts. It is expected to track to the north in the next days It has caused considerable damage in Florida and Georgia leading to at least 11 deaths. It is expected to track up the Atlantic Coast of the U.S. eventually dissipating over Newfoundland, Canada at the end of the week. Regional seismicity in the eastern U.S. is likely to be enhanced while this storm is in the area. It is also possible that landfall in this region could trigger a moderate earthquake in California at this time." (July 6-7, 2021)

 

Hurricane Enrique also hit the Gulf of California on July 4 and had been expected to enhance seismicity in the California region at this time as noted in that summary:

 

 

"A series of moderately large to large earthquake hit along the western coastline of North and South America today. These included an M 5.6-5.7 in Nayarit, Gulf of California; two events of M 5.8-6.0 in Atacama, Chile and a series of light, but widely felt quakes in southern and central California of M 3.4-3.6...

 

 

A moderately strong earthquake occurred today in western Mexico in the southern Gulf of California. This event of M 5.6 in Nayarit was reported by NEIC to have been felt with maximum intensity V in Mazatlan, Sinaloa, Mexico and IV in Mascota, Jalisco. Intensity II-III shaking occurred in Nayarit at La Penita de Jattemba. Bicerias. Sam Blas, Jala, Tepic; in Jalisco at Ixtapa, Puerto Vallarta, Mascota, and in Manzanillo, Colima, Mexico.  As noted in the previous issue of this summary Hurricane Enrique passed over this epicenter several days ago:

 

 

"Hurricane Enrique  continued near Michoacan, Mexico with winds up to 080 kts. It is expected to move west of Mexico and not to make landfall in that country for several more days. Seismic effects on regional seismicity are expected at this time in the regions of Michoacan, Baja and the Gulf of California." (June 30, 2021)

 

The area may see additional triggered seismicity from Enrique over the next several days possibly including moderate to large earthquake." (July 2-3, 2021) (July 7-8, 2021)

 

 

Several other indicators had suggested that a strong earthquake was imminent in

California at this time. For example when a light earthquake occurred in western

South Dakota on June 16, this summary noted:

 

"Seismic activity in South Dakota often is precursory to significant seismicity in the western region of the North American plate.  For example, the last earthquakes in South Dakota of M 3.7 and 3.1 on June 4 and preceded the M 5.3 in Southern California the next day." (June 16, 2021)

 

In this regard, it is interesting to note that an M 4.1 earthquake in eastern

Montana near the North/South Dakota/Montana border occurred yesterday, July 7 and may have been precursory to today's activity. This summary had noted this event in the previous issue as:

 

"The strongest earthquake in the U.S. or Canada today was an M 3.9-4.1 in Eastern Montana. NEIC reported it was felt with maximum intensity IV in Roundup, and East Helena, Montana with II-III shaking in Custer, Musselshell, Billings, Jordan, Helena, Plentywood and Kalispell. This is the strongest earthquake in Eastern Montana within about 100 km of this epicenter in at least 30 years. Earthquakes of M 4.0 and 4.1 hit about 150 km from this epicenter on August 22, 2209 and November 26, 2007." (July 7, 2021)

 

Likewise an earthquake in Maryland occurred on June 26, 2021 this summary noted the possibility of it being precursory to a strong upcoming quake in California as:

 

"An unusual earthquake of M 2.6 was reported widely felt in the region of northern Maryland today. NEIC reported maximum intensity IV in Maryland at Baltimore with II-III in Gwynn, Catonsville, Windsor, Pikesville. The last earthquake of M>=2.6 within about 100 km of this epicenter was an M 2.8 on September 15, 2019. The largest event in the region in the past 30 years occurred as an M 4.6 on January 16,  1994. This was followed hours later by the M 6.7 in Northridge, California of the same date. It may have been precursory to that event. At the time of the M 4.1 on November 30, 2017 this summary noted in this regard:

 

 

"The Delaware earthquake of M 4.1-4.5 was reported felt with maximum intensity V in Clayton, Delaware; Newport New Jersey, and IV in Delaware at Dover, Magnolia, Camden Wyoming, Marydel, in Maryland at Galena, Sudlersville, and in general within about 50 km of the epicenter. It was felt with intensity II-III throughout much of the central eastern coast of the U.S. including in New Jersey, Delaware, Pennsylvania, Virginia, New York, Washington D.C, Connecticut, West Virginia, Massachusetts, Rhode Island, North Carolina, Vermont, Ohio, Kentucky, South Carolina, Illinois, Florida, Mississippi, Missouri, and Maryland, The earthquake in Delaware is one of the strongest recorded in that State. Earthquake in this area are often followed within days by a strong quake in southern or central California, such as occurred in the Northridge quake of M 6.7 on January 17, 1994 (preceded by an M 4.6 in southern Pennsylvania on January 16, 1994) and the Morgan Hill quake of April 24, 1984 preceded by an M 4.4 in Pennsylvania on April 23, 1984.  The events in August 2011 were later found to occur at the time of one of the strongest cosmic ray events known, possibly associated with a gravity wave and other effects which may have triggered this series. A similar relation may be found with today's events, but these area usually not announced until extensive data anaylsis. As this list includes the largest events in the Delaware area in the past 50 years and some of the strongest earthquakes in Central and southern California in the same period, it may be significant. This correlation is strongest with moderate starting quakes in the region of Delaware. The area of southern California near Northridge is currently at the 23-year cycles of large quakes in the area. A moderate earthquake in the region west of Los Angeles and north to San Francisco is considered possible in the next four days. At the least, residents should check their earthquake preparedness kits to see if they are ready for a moderate quake at this time." (December 1, 2017) (June 27, 2021)

 

Forecast 135217 had expected today's activity within about 25 km was likely to occur around July 7. As noted in previous issues of this summary this activity is near 100-102 degrees from the M 7.5 in Qinghai of May 21, 2021, the last major earthquake in the world and was probably promoted by energy from that source.  Following is a listing of events in today's series of M>=4. A more complete listing can be found in the "California" section of this summary.

 

O: 08JUL2021 22:50:12  38.5N  119.5W mb=5.2  EMSC   CENTRAL CALIFORNIA

O: 08JUL2021 22:59:45  38.5N  119.5W ML=4.3  EMSC   CENTRAL CALIFORNIA

O: 08JUL2021 23:33:40  38.5N  119.6W Mw=4.6  EMSC   NORTHERN CALIFORNIA

O: 08JUL2021 23:58:53  38.5N  119.5W Mw=4.2  EMSC   CENTRAL CALIFORNIA

O: 09JUL2021 00:27:46  38.5N  119.5W mb=4.0  EMSC   CENTRAL CALIFORNIA

O: 09JUL2021 01:46:00  38.5N  119.5W mb=4.3  EMSC   CENTRAL CALIFORNIA

O: 09JUL2021 05:04:17  38.6N  119.5W Mw=4.0  EMSC   CENTRAL CALIFORNIA

O: 09JUL2021 05:10:35  38.6N  119.5W ML=4.5  EMSC   CENTRAL CALIFORNIA

O:  8JUL2021 22:49:49  38.5N  119.5W Mw=6.0  EMSC   CENTRAL CALIFORNIA           

P:  7JUL2021 135217    38.8N  119.6W 2.5-4.6 AAAAA  California/Nevada area     

 

Moderate earthquakes also occurred today with M 4.5 and 4.3 in Southeastern Alaska and in Northern Alaska. The events in southeastern Alaska preceded the M 6.0 in Nevada by about an hour. The earthquake of M 4.5 in Southeastern Alaska occurred within minutes of local solar noon and was probably promoted by high tidal stresses which maximize near this hour. Forecast 135334 had expected this activity within about 150 km was likely around July 8.

 

The earthquake of M 6.0 in California was preceded about an hour earlier by an M 4.4-4.5 in Southeastern Alaska. NEIC reported this earthquake was felt with intensity IV in Alaska at Haines, Skagway and II-III in Elfin Cove, Gustavus, Hoonah, Juneau, Douglas, and in Whitehorse, Yukon, Canada.

 

 

O: 08JUL2021 20:40:17  59.2N  136.2W Mw=4.5  EMSC   SOUTHEASTERN ALASKA

O: 08JUL2021 20:53:43  59.2N  136.3W ml=3.6  EMSC   SOUTHEASTERN ALASKA

O: 08JUL2021 21:31:31  59.2N  136.2W ML=3.3  EMSC   SOUTHEASTERN ALASKA

O:  8JUL2021 20:46:51  59.1N  136.1W ml=3.3  EMSC   SOUTHEASTERN ALASKA          

P:  8JUL2021 135334    59.0N  139.0W 3.0-4.6 AABAA  Southeast Alaska           

 

The M 4.2 in northern Alaska was not a classical aftershock of the events of August and May 2018 which included an M 6.3 on August 12, 2018 as they occurred about 200 km southwest of those epicenters.  This activity began at local solar midnight and was probably promoted by strong tidal stresses which maximize near this hour. This activity is at 102 degrees from the M 8.1 in the Kermadec Islands of March 4, 2021 and may have been promoted by energy from that source.

 

O: 08JUL2021 09:41:21  68.6N  148.6W ML=3.0  EMSC   NORTHERN ALASKA

O: 08JUL2021 09:50:53  68.6N  148.6W ML=3.2  EMSC   NORTHERN ALASKA

O: 08JUL2021 10:03:41  68.6N  148.5W ML=2.6  EMSC   NORTHERN ALASKA

O: 08JUL2021 15:19:57  68.7N  148.4W ml=3.4  EMSC   NORTHERN ALASKA

O:  8JUL2021 14:17:20  68.6N  148.5W mb=4.2  EMSC   NORTHERN ALASKA              

 

MODERATE EARTHQUAKES IN TAIWAN TRIGGERED BY TROPICAL STORM 07W

 

EARTHQUAKE SUMMARY FOR JULY 7, 2021

 

The series of moderate earthquakes in Taiwan associated with the passage of TS 07W over the past two days continued today. The largest of today's events were of M 5.3 and M 5.2 which was felt in Taiwan with intensity VI-VII in Hualien; IV in Taoyuan and Taichung and II-III in Taipei, Taiwan. CWB reported the largest of these events of M 5.4 each were felt in Taiwan with intensity V in Hualien, III in nmantou, Taichung, Changhua; II in Yilan, Taoyuan, Hsinchu, Miali, Yunlin and I in Taipei, Kaohsiung and Tainan Counties, Taiwan. As noted in the previous issue of this summary, this activity appears to be related to the passage of Tropical Storm 07W:

 

"A series of moderate earthquakes also occurred today in Taiwan. This continues a series of moderate sized events in Taiwan which began yesterday. This regional enhancement is likely related to the passage of Tropical Strom 07W through the area over the past two days as noted in previous issues of this summary:

 

"TD 07W continued today south of Taiwan with winds up to 30 kts. It is expected to track to the northeast over the next several days and could enhance seismicity in the region of Taiwan." (July 6, 2021)

 

Forecast 135209 expected today's activity within about 50 km of the epicenters was likely around July 7.

 

O:  7JUL2021 11:38:13  23.9N  121.6E ML=4.1  TAI    Hualien, Taiwan              

O:  7JUL2021 13:36:27  23.9N  121.6E ML=4.6  TAI    Hualien, Taiwan               

O:  7JUL2021 11:24:58  23.9N  121.6E ML=5.4  TAI    Hualien, Taiwan              

O:  7JUL2021 22:11:55  23.9N  121.6E ML=5.4  TAI    Hualien, Taiwan              

O:  7JUL2021 23:31:02  23.9N  121.6E ML=4.0  TAI    Hualien, Taiwan               

O: 07JUL2021 11:24:57  23.8N  121.7E mb=5.3  EMSC   TAIWAN

O: 07JUL2021 22:11:54  23.8N  121.7E Mw=5.2  EMSC   TAIWAN

O: 07JUL2021 13:38:27  23.9N  121.6E ML=4.6  EMSC   TAIWAN

O: 07JUL2021 23:31:02  23.9N  121.6E ML=4.0  EMSC   TAIWAN

P:  7JUL2021 135209    24.0N  122.0E 4.0-5.4 AAAAA  Taiwan                     

 

The strongest earthquake in the U.S. or Canada today was a regional aftershock of the M 5.2 two days ago north of the island of Hawaii. Today's epicenter was about 50 km south of that  and shaking was felt in Hawaii with intensity II-III in Kailua Kona, Waikoloa, Kula, Kapaau, Houaloa, Kamuela, Kihei, Makawao, Lahaima, and Waikuku. Forecast 135199 had expected today's event was likely within about 50 km  of this epicenter around July 5.

 

O:  7JUL2021 17:40:57  19.9N  156.7W ML=4.2  EMSC   HAWAII REGION, HAWAII        

P:  5JUL2021 135199    20.1N  156.1W 4.0-5.5 AAAAA  Hawaii area                

 

Hurricane Elsa made landfall in western Florida today. Hurricanes in this area are often followed by moderate to strong earthquakes in the area of California. This summary has been a strong advocate for weather-related seismicity at a distance for many years, and before that when this was a private communication. This does not occur in each instance when a hurricane makes landfall on the U.S. East coast but occurs often enough to be notable. This may be due to stresses and movement applied through the North American Plate from motions imparted by landfall. This relation is strongest at the beginning of the hurricane season. So enhancement along the west coast of North America is likely in the next several days. This summary noted in regard to the possible effects on seismicity of Hurricane Elsa.

 

 

"Hurricane Elsa continued today over the Carolinas with winds up to 45 kts. It is expected to track to the north in the next days. It has caused considerable damage in Florida and Georgia leading to at least 11 deaths. It is expected to track up the Atlantic Coast of the U.S. eventually dissipating over Newfoundland, Canada at the end of the week. Regional seismicity in the eastern U.S. is likely to be enhanced while this storm is in the area. It is also possible that landfall in this region could trigger a moderate earthquake in California at this time." (July 6-7, 2021)

 

Hurricane Enrique also hit the Gulf of California on July 4 and had been expected to enhance seismicity in the California region at this time as noted in that summary:

 

 

"A series of moderately large to large earthquake hit along the western coastline of North and South America today. These included an M 5.6-5.7 in Nayarit, Gulf of California; two events of M 5.8-6.0 in Atacama, Chile and a series of light, but widely felt quakes in southern and central California of M 3.4-3.6...

 

 

A moderately strong earthquake occurred today in western Mexico in the southern Gulf of California. This event of M 5.6 in Nayarit was reported by NEIC to have been felt with maximum intensity V in Mazatlan, Sinaloa, Mexico and IV in Mascota, Jalisco. Intensity II-III shaking occurred in Nayarit at La Penita de Jattemba. Bicerias. Sam Blas, Jala, Tepic; in Jalisco at Ixtapa, Puerto Vallarta, Mascota, and in Manzanillo, Colima, Mexico.  As noted in the previous issue of this summary Hurricane Enrique passed over this epicenter several days ago:

 

 

"Hurricane Enrique  continued near Michoacan, Mexico with winds up to 080 kts. It is expected to move west of Mexico and not to make landfall in that country for several more days. Seismic effects on regional seismicity are expected at this time in the regions of Michoacan, Baja and the Gulf of California." (June 30, 2021)

 

The area may see additional triggered seismicity from Enrique over the next several days possibly including moderate to large earthquake." (July 2-3, 2021)

 

MODERATE QUAKES CONTINUE IN FIJI

 

EARTHQUAKE SUMMARY FOR JULY 6, 2021

 

The strongest earthquake in the world today was an M 5.7 in the Fiji Islands. NEIC reported it was lightly felt with intensity I in Navua, Central Fiji. The last earthquake of M>=5.7 within about 150 km of this epicenter was an 5.9 more than a year ago ono June 10, 2020 and prior to that an M 6.1 on June 17, 2017;

An M 6.1 hit the region about 150 km north of this on July 2, 2021 at the start of the seismic enhancement related to the strong solar flares at that time. This was noted at the time as:

 

"This follows a particularly long period of global seismicity without any strong earthquakes. The last event in the world of M>=6.1 was an M 6.5 aftershock in the northern Kermadec Islands of June 20, 2021. The only other such event in the world in the past month was a similar M 6.1 on June 3, 2021. Today's activity may represent the beginning of more active period of enhanced global seismicity with tropical storms and geomagnetic storms on the increase." (July 3, 2021)

 

Today's event had been expected in forecast 135378 to occur around July 4 within

about 50 km of today's epicenter.

 

O:  7JUL2021 06:39:08  23.2S  179.6E Mw=5.7  EMSC   SOUTH OF FIJI ISLANDS        

P:  4JUL2021 135378    23.0S  179.0E 4.0-5.5 BAAAA  Tonga/Fiji                 

 

An M 5.3 in the area of Assam, India today was widely felt. NEIC reported maximum intensity VII in Assam in Bilasipara and Bongagaon and VI in Tura, Meghalaya. Intensity IV was felt in Assam at Dhubun, Alpurduan, Nongstoin, and North Guwahati with lesser shaking in Bangladesh in Rangur and Mamanaingh.

An earthquake of M 6.0 occurred about 300 km northeast of this epicenter on

April 28, 2021 and about 100 km to the north on September 12, 2018 with M 5.3. Forecast 134273 had expected activity in this region to the north around July 6, 2021.

 

O:  7JUL2021 03:15:24  26.0N   90.4E mb=5.3  EMSC   MEGHALAYA, INDIA REGION      

P:  6JUL2021 135273    30.0N   90.0E 3.8-5.4 ACAAA  Xizang                     

 

Two moderate earthquakes also occurred today in southern Iran with M 4.9 and 5.0. This is the strongest activity in this area since an M 5.1 on March 14, 2021. The only earthquake of larger magnitude in the area of southern Iran in the past year was an M 5.5 on January 15, 2021. Forecast 135208 had expected today's events within about 150 km was likely around July 5-6.

 

O:  6JUL2021 11:44:34  27.6N   53.3E mb=5.0  EMSC   SOUTHERN IRAN                

P:  5JUL2021 135208    29.0N   53.0E 3.5-4.9 ABAAA  So. Iran/Persian Gulf      

 

O:  6JUL2021 12:44:05  26.8N   59.5E mb=4.9  EMSC   SOUTHEASTERN IRAN            

P:  6JUL2021 135208    29.0N   58.0E 3.5-4.9 ACAAA  So. Iran/Persian Gulf      

 

A series of moderate earthquakes also occurred today in Taiwan. This continues a series of moderate sized events in Taiwan which began yesterday. This regional enhancement is likely related to the passage of Tropical Strom 07W through the area over the past two days as noted in previous issues of this summary:

 

"TD 07W continued today south of Taiwan with winds up to 30 kts. It is expected to track to the northeast over the next several days and could enhance eismicity in the region of Taiwan." (July 6, 2021)

 

Activity is expected to continue in the region of Taiwan for the next several days perhaps with some events of larger magnitude. Forecast 135209 had expected today's activity was likely within about 50 km around July 7.

 

CWB reported these earthquakes were felt with intensity IV in Hualien, II in Nantou and I in Taichung, Yilan, Yunlin and Changhua Counties, Taiwan.

 

O: 06JUL2021 19:21:45  23.9N  121.6E ML=4.2  EMSC   TAIWAN

O:  6JUL2021 10:26:35  23.9N  121.5E ML=4.5  EMSC   TAIWAN                       

O:  6JUL2021 10:26:35  23.9N  121.5E ML=4.5  TAI    Hualien, Taiwan              

O:  6JUL2021 19:21:45  23.9N  121.6E ML=4.2  TAI    Hualien, Taiwan              

P:  7JUL2021 135209    24.0N  122.0E 4.0-5.4 AAAAA  Taiwan                     

 

The strongest earthquake in the U.S. or Canada today was an M 3.9-4.1 in Eastern Montana. NEIC reported it was felt with maximum intensity IV in Roundup, and East Helena, Montana with II-III shaking in Custer, Musselshell, Billings, Jordan, Helena, Plentywood and Kalispell. This is the strongest earthquake in Eastern Montana within about 100 km of this epicenter in at least 30 years. Earthquakes of M 4.0 and 4.1 hit about 150 km from this epicenter on August 22, 2209 and November 26, 2007. Forecast 135314 had expected enhanced seismicity west of this in early July.

 

O:  6JUL2021 11:44:41  46.4N  107.8W Ml=3.9  EMSC   EASTERN MONTANA              

O:  6JUL2021 11:44:40  46.4N  107.7W Ml=4.1  ANSS   EASTERN MONTANA              

P:  3JUL2021 135314    46.4N  111.4W 2.0-4.3 BACAA  Yellowstone/Wyoming        

 

MODERATE QUAKE IN HAWAII PART OF GLOBAL VOLCANIC SURGE

 

EARTHQUAKE SUMMARY FOR JULY 5, 2021

 

The strongest earthquake in the U.S. or Canada today was an M 4.5-5.2 north of Hawaii. It was also the strongest earthquake in the world today. It was widely felt throughout much of Hawaii. NEIC reported maximum intensity V at Honokaa, Paauilo with IV in Kapaau, Hawi, Kamuela, Ookala, Laupahoehoe, Papaaloa, Hakalau and IIII in Waikoloa and as far as 400 km from the epicenter in Princeville and Kapaa, Hawaii. The earthquake in Hawaii follows a strong series of volcanic eruptions which accompanied the solar flares of July 2-3, which included an X1.5 on July 3, the largest observed in nearly four years. The current volcanic eruptions had spectacular lava eruptions in Taal, Indonesia, southern Iceland and Mt. Etna, Sicily and were probably promoted by SFE related to the solar flares. Videos of these e Mid-ocean ridges have also been active in the past several days with significant earthquakes in the Southern Indian Ocean (M 5.7);  the Central Mid-Atlantic (M 4.9); the Owen Fracture Zone (M 5.7); and the South Sandwich Islands (M 5.2) among others. These are sub-marine volcanic sites and often become active during global volcanic episodes. 

 

The last earthquake in the region of Hawaii of M>=5.2 occurred on April 14, 2019 more than two years ago with M 5.2-5.3. Similar earthquakes occurred with the eruption of the Spring and summer of 2018 which began with an M 6.9 about 100 km  southeast of today's epicenter on May 4, 2018.  Forecast 135199 had expected today's event within about 25 km was likely around July 5.

 

 

O:  5JUL2021 23:43:33  20.1N  155.8W Mw=4.6  EMSC   HAWAII REGION, HAWAII        

O:  5JUL2021 23:43:35  20.2N  155.6W Mw=5.2  ANSS   HAWAII REGION, HAWAII         

P:  5JUL2021 135199    20.1N  156.1W 4.0-5.5 AAAAA  Hawaii area                

 

 

The sudden surge in volcanic activity was accompanied by the spectacular eruption of a mud volcano on July 4 in the area of Azerbaijan, near the island of Dashlyg in the vicinity of oil and gas fields and plumes of fire reached 100 meters above sea level.  Videos of this eruption are available on social media. Stresses triggering mud volcano eruptions (eruption of mud instead of lava) are similar to those related to lava eruptions. In the current case, strong solar flares, such as the X1.5 on July 3, can heat the underlying rock and mud as telluric currents dissipate into heat (ohmic heating).

 

 

The strongest solar flare of the day occurred with maximum at 18:43 UT with C1.7 (#7350). The second strongest earthquake in the world occurred in conjunction with this flare - an M 4.9 on July 5, 2021. It was followed about 20 minutes later by an M 4.7 in the Ryukyu Islands, Japan which JMA reported was felt in Okinawa with intensity IV. The current activity felt in Okinawa is associated with the  eruption of Suwanose-jima in the Ryukyu Islands has been accompanied by a series of earthquakes large enough to be felt in Okinawa. The current eruption appears to have begun in mid-July 3, 2021 in coincidence with the X1.5 solar flare of that date. Forecast 135201 had expected today's activity in the area was likely around July 4.

 

NEIC reported this earthquake of M 4.7 in Okinawa, Ryukyu Islands, Japan was felt with intensity II-III in the area(s) of Okinawa, Ryukyu Islands, Japan.

 

O: 05JUL2021 19:06:08  28.1N  128.1E mb=4.7  EMSC   RYUKYU ISLANDS, JAPAN

O: 05JUL2021 22:30:30  28.1N  128.1E ML=4.4  EMSC   RYUKYU ISLANDS, JAPAN

O:  5JUL2021 06:58:43  27.8N  128.4E mb=4.5  EMSC   RYUKYU ISLANDS, JAPAN        

P:  4JUL2021 135201    27.0N  130.0E 4.0-5.6 AAAAA  Kyushu Japan               

 

O:  5JUL2021 18:47:23  24.1S  178.8E mb=4.9  EMSC   SOUTH OF FIJI ISLANDS        

P:  4JUL2021 135378    23.0S  179.0E 4.0-5.5 ABAAA  Tonga/Fiji                  

 

A major lava eruption also occurred at the Icelandic volcano Fagradalsfjall on July 4. It is the strongest eruption of this volcano since the current activity began shortly after the M 8.1 in the Kermadec Islands on March 19, 2021 - after 800 years of silence. Eruptions also occurred on July 4 in Iceland at Geldingadalir Volcano. Regional experts have suggested this may end the eruption which began in March, 2021.

 

The eruption of Taal Volcano in the Philippines also began around July 3. This eruption has the distinction of producing the highest ever recorded CO2 emission since monitoring began.

 

Other eruptions which may have been influenced by SFE included a strong eruption in Etna, Sicily, Italy. This peaked with a spectacular eruption near the time of the maximum solar flare activity. Eruptions also continued in Indonesia, Costa Rica, Guatemala and Chile.

 

AFTERSHOCKS CONTINUE IN ATACAMA, CHILE

 

EARTHQUAKE SUMMARY FOR JULY 4, 2021

 

The strongest seismicity in the world today occurred in the area off the coast of Atacama, Chile. The largest of today's activity was an M 5.0 but at least six other events of M 4-5 were also recorded.  GUC reported this earthquake was felt with intensity IV in  Atacama at Freirina, III in Huasco, Alto del Carmen and Vallenar, Chile. This activity had been expected around July 4 within about 50 km of these events to occur around July 4. It is aftershock activity of the two events of M 6.0 in the area as reported in the previous issue of this summary:

 

 

"Two strong earthquakes of M 5.9-6.0 struck the Atacama area of Central Chile today. They were felt with maximum intensity IX (local damage) at Vallenar; V in Vicuna and Ovalle, Coquimbo and IV in Coquimbo at Coquimbo, Copiapo, and IV in Valparaiso at Vina del Mar and Quilpue, Chile. GUC reported the M  4.4 was felt with intensity  III in  Atacama at Freirina, Huasco, Chile. GUC reported the M  5.8-6.0 events  were felt with intensity  V in  Atacama at Freirina, Huasco, Vallenar; IV in Alto del Carmen, Copiapo, Tierra Amarilla; in Coquimbo at Rio Hurtado; IV in Coquimbo, La Higuera, La Serena, Monte Patria, Ovalle, Paiguano, Vicuna; III in Andacollo, Tongoy and in Papudo, Valparaiso with IV, Chile. The last earthquake of M>=6 within about 200 km of today's activity was a series on September 1, 2020 including events of M 6.8, 6.5 and 6.3 and prior to that an M 6.9 on November 11, 2015. Forecasts 135367 and 135089  had expected today's activity was likely between June 29 and July 4, 2021." (July 4, 2021)

 

O: 04JUL2021 15:05:24  28.7S   71.8W mb=5.0  EMSC   OFFSHORE ATACAMA, CHILE

O: 04JUL2021 15:57:08  28.7S   71.7W mb=4.5  EMSC   OFFSHORE ATACAMA, CHILE

O: 04JUL2021 22:11:30  28.7S   71.6W mb=4.2  EMSC   OFFSHORE ATACAMA, CHILE

O: 04JUL2021 23:40:22  28.7S   71.7W Mw=4.3  EMSC   OFFSHORE ATACAMA, CHILE

O: 04JUL2021 19:39:24  28.8S   71.6W ML=4.0  EMSC   OFFSHORE ATACAMA, CHILE

O: 05JUL2021 06:06:35  28.8S   71.7W Mw=4.1  EMSC   OFFSHORE ATACAMA, CHILE

O:  4JUL2021 11:43:42  28.7S   71.8W mb=4.3  EMSC   OFFSHORE ATACAMA, CHILE      

O:  4JUL2021 23:40     28.7S   71.6W mb=4.4  GUC    Atacama at Freirina, III in Hu

P:  3JUL2021 135384    30.0S   71.0W 4.0-5.5 ABAAA  Coast Central Chile        

P:  8JUL2021 135367    29.0S   71.0W 4.0-5.5 BAAAA  Coast Central Chile        

P:  4JUL2021 135367    29.0S   72.0W 4.0-5.5 AAAAA  Coast Central Chile        

 

The strongest earthquake in the U.S. or Canada today was an M 4.1 in Wyoming. NEIC reported this earthquake of M 4.1 in Wyoming was felt with intensity II-III in the area(s) of Wyoming at Thermopolis and Riverton.  Similar earthquakes within about 200 km of this epicenter occurred in the past 30 years with M 4.1-4.2 on November 3, 2017 and October 19, 1996. Forecast 135270 had expected activity in this area was possible around July 4 to the southwest of today's epicenter.

 

O:  4JUL2021 21:17:42  43.7N  107.4W ML=4.1  EMSC   WYOMING                       

P:  4JUL2021 135278    41.8N  108.7W 2.0-4.0 ABAAA  Colorado area              

 

An earthquake of M 2.8 also occurred today in the region of Arizona. This is the strongest earthquake within about 200 km of this epicenter in Arizona since an M 3.3 on April 7, 2021 and prior to that an M 2.8 on November 17, 2020. Forecast 135248 had expected today's event within about 15 km was likely in early July, 2021.

 

O:  4JUL2021 22:35:01  34.6N  111.1W ML=2.8  EMSC   ARIZONA                      

P: 10JUL2021 135248    34.7N  111.0W 2.0-3.9 CAAAA  SW U.S.A                   

 

An M 3.2 earthquake occurred in the Southampton Island area, Nunavut, Canada today. It was not reported felt in this remote area. The solar eclipse a month ago passed over this epicenter and may have helped promote regional seismicity there. An M 4.2 was recorded to the west of this on March 10, 2012 after a series of light to moderate earthquake up to M 4.6 in early 2008, the last such events within about 200 km of today's epicenter. Forecast 135344 had expected today's event was likely around July 11 within about 50 km of this epicenter.

 

O:  4JUL2021 18:18:34  64.7N   86.6W ML=3.2  EMSC   SOUTHAMPTON ISL, NUNAVUT, CANA

O: 04JUL2021 18:18:34  64.7N   86.6W MB=3.2  ECAN Coral Harbour, NU   

P: 11JUL2021 135344    65.0N   86.0W 2.5-4.1 CAAAA  Nunavit/Hudson Bay, Canada 

 

 

WESTERN AMERICAN COASTLINE ACTIVATED BY X1.5 SOLAR FLARE

 

EARTHQUAKE SUMMARY FOR JULY 3, 2021

 

A series of moderately large to large earthquake hit along the western coastline of North and South America today. These included an M 5.6-5.7 in Nayarit, Gulf of  California; two events of M 5.8-6.0 in Atacama, Chile and a series of light, but widely felt quakes in southern and central California of M 3.4-3.6.  Much of this activity may be related to an X1.5 solar flare which occurred when the region of Atacama was sub-solar at 14:30 UT (#6940). This is the strongest solar flare reported since X9 and X8 flares on September 6 and 10, 2017, nearly four years ago. An M 8.3 earthquake in Chiapas, Mexico accompanied those flares on September 8. 2017. Today's flare was immediately followed by a pair of moderate events of M 5.4 and 5.6 in the Owen Fracture Zone which were closely associated with a strong C-class solar flare at 17:03 (#7310). This activity was being monitored as this issues goes to press. Such sudden solar flare activity can and often is followed by a major enhancement in global seismicity.

 

 

Two strong earthquakes of M 5.9-6.0 struck the Atacama area of Central Chile today. They were felt with maximum intensity IX (local damage) at Vallenar; V in Vicuna and Ovalle, Coquimbo and IV in Coquimbo at Coquimbo, Copiapo, and IV in Valparaiso at Vina del Mar and Quilpue, Chile. GUC reported the M  4.4 was felt with intensity  III in  Atacama at Freirina, Huasco, Chile. GUC reported the M  5.8-6.0 events  were felt with intensity  V in  Atacama at Freirina, Huasco, Vallenar; IV in Alto del Carmen, Copiapo, Tierra Amarilla; in Coquimbo at Rio Hurtado; IV in Coquimbo, La Higuera, La Serena, Monte Patria, Ovalle, Paiguano, Vicuna; III in Andacollo, Tongoy and in Papudo, Valparaiso with IV, Chile. The last earthquake of M>=6 within about 200 km of today's activity was a series on September 1, 2020 including events of M 6.8, 6.5 and 6.3 and prior to that an M 6.9 on November 11, 2015. Forecasts 135367 and 135089  had expected today's activity was likely between June 29 and July 4, 2021.

 

O: 04JUL2021 02:57:46  28.7S   71.8W mb=4.7  EMSC   OFFSHORE ATACAMA, CHILE

O: 04JUL2021 01:01:35  28.8S   71.5W Mw=6.0  EMSC   OFFSHORE ATACAMA, CHILE

O: 04JUL2021 01:34:42  28.8S   71.5W ML=4.0  EMSC   OFFSHORE ATACAMA, CHILE

O: 04JUL2021 03:07:41  28.8S   71.6W mb=4.3  EMSC   OFFSHORE ATACAMA, CHILE

O:  4JUL2021 01:29:13  28.7S   71.5W Mw=6.0  EMSC   OFFSHORE ATACAMA, CHILE      

O:  4JUL2021 04:03     28.8S   71.6W mb=4.4  GUC    Atacama at Freirina, Huasco, C

O:  4JUL2021 01:29     28.8S   71.6W mb=5.8  GUC    Atacama at Freirina, Huasco, V

O:  4JUL2021 01:01     28.8S   71.6W mb=5.9  GUC    Atacama at Freirina, Huasco, V

P:  4JUL2021 135367    29.0S   72.0W 4.0-5.5 AAAAA  Coast Central Chile        

P: 29JUN2021 135089    29.0S   70.0W 4.0-5.4 BAAAA  Coast Central Chile        

 

A moderately strong earthquake occurred today in western Mexico in the southern Gulf of California. This event of M 5.6 in Nayarit was reported by NEIC to have been felt with maximum intensity V in Mazatlan, Sinaloa, Mexico and IV in Mascota, Jalisco. Intensity II-III shaking occurred in Nayarit at La Penita de Jattemba. Bicerias. Sam Blas, Jala, Tepic; in Jalisco at Ixtapa, Puerto Vallarta, Mascota, and in Manzanillo, Colima, Mexico. As noted in the previous issue of this summary Hurricane Enrique passed over this epicenter several days ago:

 

 

"Hurricane Enrique  continued near Michoacan, Mexico with winds up to 080 kts. It is expected to move west of Mexico and not to make landfall in that country for several more days. Seismic effects on regional seismicity are expected at this time in the regions of Michoacan, Baja and the Gulf of California." (June 30, 2021)

 

The area may see additional triggered seismicity from Enrique over the next several days possibly including moderate to large earthquake." (July 2-3, 2021)

 

Seismicity in this area was also probably also promoted by strong tidal stresses associated with the past full moon as it occurred on the longitude of maximum stress with those tides as reported in previous issues of this summary:

 

"The full moon arrived on June 24, 2021 at 18:40 UT. Longitudes which were sub-solar at this time are near 100 West ( local solar noon) while those which are anti-solar (local solar midnight) at this time at near 80 East. In the west these included the west coast of South America, Central America, Mexico and central U.S. while in the east they included western Indonesia and central Asia. These areas are likely to see enhanced seismicity in the next week. A strong quake is possible during this full moon but is not considered highly likely as global seismicity has been low in recent weeks and other seismic triggers at this time are not powerful." (June 21-24, 2021)

 

In the past several decades earthquakes of M>=5.6 have occurred approximately every 10 years within about 200 km of today's epicenter These occurred as an M 5.6 on April 1, 1991; an M 6.1 on November 13, 2001; an M 5.6 on September 14, 2010 and today's event of M 5.6 on July 4, 2021. Forecasts 134871 and 135172 had expected today's event in this area between June 29 and July 4.

 

O:  4JUL2021 02:45:00  21.1N  106.1W Mw=5.6  EMSC   OFFSHORE NAYARIT, MEXICO     

P:  3JUL2021 135172    18.0N  106.0W 3.5-5.1 ACAAA  Coast of Jalisco, Mexico   

P:  4JUL2021 135172    19.0N  107.0W 3.5-5.2 ACAAA  Coast of Jalisco, Mexico   

P: 29JUN2021 134871    18.0N  106.0W 3.5-5.1 BCAAA  Coast of Jalisco, Mexico   

 

Coincident the M1.0 solar flare today at 17:03 UT (#7030) an M 5.7 hit in the Owen Fracture Zone of the Arabian Sea. This was followed by an M 5.1 eight minutes later. These events occurred near local solar midnight, a time when solar flare can help trigger local seismicity and were probably triggered by Solar Flare Effects (SFE). The last earthquake within about 300 km of today's activity with M>=5.7 occurred on August 13, 2002, the only such event in  the area in the past 30 years. Earthquakes of M 5.7, 6.4 and 6.5 hit about 350 km to the east of this in 1995, 1996 and on April 15, 2009. Forecasts 134866 and 135166 had expected today's activity within about 100 km was likely between June 29 and July 3.

 

O: 03JUL2021 17:12:27  14.4N   57.0E mb=5.1  EMSC   OWEN FRACTURE ZONE REGION

O:  3JUL2021 17:04:31  14.3N   56.8E Mw=5.7  EMSC   OWEN FRACTURE ZONE REGION    

P:  3JUL2021 135166    15.0N   56.0E 3.5-5.1 AAAAA  Arabian Sea                

P: 29JUN2021 134866    15.0N   57.0E 3.5-4.9 BAAAA  Arabian Sea                

 

An earthquake of M 5.7 also hit in the southeast Indian Ridge today. It was not reported felt in this remote area. The last earthquake within about 300 km of this epicenter with M>=5.7 was an M 6.3 on March 24, 2018 and an M 6.5 on November 10, 2010. Forecast 135392 had expected this activity was likely around July 3-7.

 

O:  3JUL2021 11:58:06  43.4S   92.0E Mw=5.7  EMSC   SOUTHEAST INDIAN RIDGE       

P:  3JUL2021 135392    46.0S   96.0E 4.0-5.8 ACCAA  So. Indian Ocean           

P:  7JUL2021 135392    42.0S   88.0E 4.0-5.8 BBCAA  So. Indian Ocean            

 

An M 3.7 was widely felt in Central California today. NEIC reported maximum intensity IV in Los Banos with II-III in Gustine, Dos Palos, Hilmar, Crows Landing, Newman, Merced, Turlock, Mendota and Patterson, California. An M 3.8 hit west of this on February 22, 2021 but this is the first such event within about 50 km of this since a questionable event of M 3.9  given a deep focus on October 2, 2013. Forecast 135219 had expected today's event in this area around July 5.

 

O:  3JUL2021 23:23:50  37.1N  120.8W Mw=3.7  EMSC   CENTRAL CALIFORNIA           

P:  5JUL2021 135219    36.6N  120.7W 2.5-4.6 AAAAA  Central California         

 

An event of M 3.4 was also widely felt today in eastern Los Angeles, California. NEIC reported maximum intensity IV in California at Fontana, Rancho, Cucamonga, and II-III in Rialto, and Bloomington among other cities. This earthquake occurred within minutes of local solar midnight and may have been promoted by high tidal stresses which maximize near this hour. A series of light earthquakes have occurred in eastern Los Angeles over the  past wee including an M 2.7 on June 25 but last of equal or larger magnitude was an M 3.4 on August 3, 2020. Forecast 135257 had expected today's activity within about 25 km was likely around July 4.

 

O:  3JUL2021 08:22:25  34.1N  117.5W ML=3.3  EMSC   GREATER LOS ANGELES AREA, CALI

O:  3JUL2021 08:22:25  34.1N  117.5W ML=3.4  ANSS   GREATER LOS ANGELES AREA, CALI

P:  4JUL2021 135257    34.3N  117.5W 2.5-5.1 AAAAA  So. California              

 

The largest earthquake in the U.S. or Canada today was an M 4.7 in the central

Fox Islands, Aleutians, Alaska. The last earthquake within about 100 km of this epicenter in the Fox Islands with equal or larger magnitude was an M 6.4 to the west of this on December 1, 2020. Forecast 135324 had expected today's event  was likely within about 50 km near July 5.

 

O:  3JUL2021 13:42:54  53.2N  167.0W mb=4.7  EMSC   FOX ISLANDS, ALEUTIAN ISLANDS

P:  5JUL2021 135324    53.5N  167.3W 3.5-4.9 AAAAA  Fox Islands, Aleutians     

 

STRONG EARTHQUAKE SHAKES FIJI

 

EARTHQUAKE SUMMARY FOR JULY 2, 2021

 

An earthquake of M 6.1 hit the region of the Fiji Islands today. It was not reported felt in this remote area. This is the strongest earthquake in the Fiji Islands within about 200 km of this epicenter since an M 6.5 on November 8, 2019. An M 6.4 occurred about 150 kn northeast of this epicenter on April 25, 2021.  

 

This follows a particularly long period of global seismicity without any strong earthquakes. The last event in the world of M>=6.1 was an M 6.5 aftershock in the northern Kermadec Islands of June 20, 2021. The only other such event in the world in the past month was a similar M 6.1 on June 3, 2021. Today's activity may represent the beginning of more active period of enhanced global seismicity with tropical storms and geomagnetic storms on the increase.

 

Forecasts 135099 and 135377 had expected today's activity between June 26 and July 4, 2021 within about 50 km of this epicenter.

 

O:  3JUL2021 01:14:26  20.5S  178.4W mb=4.2  EMSC   FIJI REGION                  

O:  2JUL2021 20:14:38  21.8S  179.4W Mw=6.1  EMSC   FIJI REGION                  

P:  4JUL2021 135377    21.0S  179.0W 4.0-5.7 AAAAA  Tonga Islands              

P: 26JUN2021 135099    21.0S  179.0W 4.0-5.8 CAAAA  Tonga Islands              

 

An earthquake of M 3.5 was widely felt north of Los Angeles, California today. NEIC reported maximum intensity IV in Rancho Cucamonga and II-III in Bodfish, Lake Isabella, Weldon, Caliente, Tehachapi, Woody, Bakersfield. This is the strongest earthquake in the Bakersfield, California area since an  M 3.5 on December 27, 2020. The last of larger magnitude in the area was an M 3.7 on May 27, 2020. The last of M>=4 occurred as an M 4.3 on April 19, 2014. Forecasts 134920 and 135261 had expected an event within about 50 km of this epicenter was likely between June 29 and July 4.

 

O:  3JUL2021 04:58:09  35.5N  118.4W Mw=3.5  EMSC   CENTRAL CALIFORNIA           

P:  4JUL2021 135261    35.3N  118.6W 2.5-4.6 AAAAA  So. California              

P: 29JUN2021 134920    36.1N  118.1W 2.5-4.7 BAAAA  California/Nevada area     

 

An unusual earthquake of M 3.8 occurred today in the region of Baja California south of the California border. This appears to be the largest reported quake within about 100 km of this epicenter since an M  4.4 on December 12, 2019

about 150 km to the northeast of this epicenter.  But today's event appears to be the first of this magnitude level within about 50 km of this epicenter in at least 30 years and could represent a significant regional event. This epicenter may have been activated by the passage of Hurricane Enrique through the region several days ago as noted in previous issues of this summary:

 

"Hurricane Enrique  continued near Michoacan, Mexico with winds up to 080 kts. It is expected to move west of Mexico and not to make landfall in that country for several more days. Seismic effects on regional seismicity are expected at this time in the regions of Michoacan, Baja and the Gulf of California." (June 30, 2021)

 

The area may see additional triggered seismicity from Enrique over the nex

several days possibly including moderate to large earthquake. Forecasts 134900 and 135198

had expected enhanced regional seismicity in this are in late June or early

July, 2021.

 

O:  2JUL2021 21:34:37  29.8N  115.2W ML=3.8  EMSC   BAJA CALIFORNIA, MEXICO      

P:  5JUL2021 135198    30.0N  114.0W 3.5-5.3 BAAAA  Gulf of California         

P: 28JUN2021 134900    28.0N  112.0W 3.5-5.2 BBCAA  Gulf of California         

 

UNUSUAL QUAKE SOUTH OF INDIA

 

EARTHQUAKE SUMMARY FOR JULY 1, 2021

 

The strongest earthquake in the world today occurred with M 5.2 in the South Indian Ocean south of India. It was not reported felt in this remote area. Earthquakes within about 400 km of today's epicenter with equal or larger reported magnitude occurred 20 and 30 years ago with an M 6.1a on September 2, 2001 and May 13, 1991.

 

O:  1JUL2021 15:06:34   0.8S   80.7E mb=5.2  EMSC   SOUTH INDIAN OCEAN           

 

An unusual earthquake of M 4.0 occurred in Switzerland today. The only other event in Switzerland in the past year of larger magnitude was an M 4.3 about 100 km east of this epicenter on October 25, 2020. Forecast 134989 had expected this activity in late June, 2021.

 

The strong swarm of moderate earthquakes continued in southern Sumatra, Indonesia today with four additional shakes of M>=4.0. This summary noted this swarm in the previous issue as:

 

 

"A strong series of moderate earthquakes shook the region of southern Sumatra today. These were reported lightly felt in the region. This activity followed an M 4.4 in Northern Colombia near the antipode. Forecast 134857 had expected this activity south of Sumatra at the end of June. The M 4.4 in Northern Colombia had been anticipated in forecast 134803 to occurred within about 10 km of that epicenter at the end of June." (July 1, 2021) 

 

O: 01JUL2021 18:59:56   5.3S  104.7E mb=4.5  EMSC   SOUTHERN SUMATRA, INDONESIA

O: 01JUL2021 13:40:17   5.5S  104.6E ML=4.2  EMSC   SOUTHERN SUMATRA, INDONESIA

O: 01JUL2021 12:27:31   5.6S  104.6E ML=4.7  EMSC   SOUTHERN SUMATRA, INDONESIA

O: 01JUL2021 13:41:17   5.6S  104.6E ML=4.1  EMSC   SOUTHERN SUMATRA, INDONESIA

O:  1JUL2021 18:59:56   5.3S  104.7E mb=4.5  EMSC   SOUTHERN SUMATRA, INDONESIA  

P: 27JUN2021 134857     6.0S  102.0E 4.0-5.6 BACAA  So. of Sumatera            

 

As with the event in Colombia yesterday, a second quake of this magnitude and region occurred today with parameters:

 

O:  1JUL2021 14:07:42   6.8N   73.1W mb=4.5  EMSC   NORTHERN COLOMBIA            

P: 27JUN2021 134830     7.0N   73.0W 4.0-5.5 BAAAA  Colombia                   

 

O:  1JUL2021 11:11:50  46.6N    8.4E ML=4.0  EMSC   SWITZERLAND                  

P: 25JUN2021 134989    45.0N   11.0E 3.0-5.5 CBBAA  Austria                     

 

The strongest earthquake in the U.S. or Canada today was an M 3.5 in the Alaska Peninsula. This may be a regional aftershock of an M 4.5 which struck the area on June 28. Forecast 135031 had expected regional enhancement of seismicity at the end of June or in early July was likely.

 

O:  2JUL2021 04:42:25  57.9N  155.9W ML=3.5  EMSC   ALASKA PENINSULA             

P: 29JUN2021 135031    54.7N  156.9W 3.5-5.0 BCAAA  Alaska Peninsula           

 

MODERATE QUAKE SHAKES OAXACA, MEXICO

 

EARTHQUAKE SUMMARY FOR JUNE 30, 2021

 

A moderate M 5.1 shook regions of Oaxaca, Mexico today. The strongest shaking reported by NEIC was VIII in Zacatepec, Oaxaca and V in Pijiapan, Chiapas and Nezahualcoytl. Lesser shaking was reported in Mexico at Puebla, Mexico City and Tlalnepantla. The last earthquake of equal or larger magnitude within about 150 km of this epicenter was n M 5.2 one year ago on July 2, 2020. An M 5.7 hit about 150 km southwest of this on March 20, 2021. Forecast 134888 expected today's event in this area was likely around June 29.

 

O: 01JUL2021 01:13:40  16.8N   97.9W Mw=5.1  EMSC   OAXACA, MEXICO

O: 30JUN2021 20:32:46  16.2N   97.5W ML=4.0  EMSC   OAXACA, MEXICO               

P: 29JUN2021 134888    15.0N   98.0W 3.5-5.4 ABAAA  Oaxaca, Mexico             

 

Enhanced seismicity also continued today in Ocean Ridge. The largest of these was an M 5.2 in the Easter Island region of the South Pacific. It was followed by an M 5.0 aftershock. This is the strongest quake within about 300 km of this epicenter since an M 5.3 on October 28, 2020 the last such event of a swarm in October, 2020 which included an M 5.9 and 5.7. Forecast 135094 had expected today's activity in this region at the end of June.

 

 

O: 30JUN2021 19:52:27  28.4S  113.3W mb=5.0  EMSC   EASTER ISLAND REGION

O: 30JUN2021 15:07:54  28.4S  113.1W mb=5.2  EMSC   EASTER ISLAND REGION         

P: 24JUN2021 135094    25.0S  112.0W 4.0-5.6 CCAAA  So. East Pacific Rise      

P: 26JUN2021 135094    27.0S  117.0W 4.0-6.0 BCCAA  So. East Pacific Rise      

 

A strong series of moderate earthquakes shook the region of southern Sumatra today. These were reported lightly felt in the region. This activity followed an M 4.4 in Northern Colombia near the antipode. Forecast 134857 had expected this activity south of Sumatra at the end of June. The M 4.4 in Northern Colombia had been anticipated in forecast 134803 to occurred within about 10 km of that epicenter at the end of June. 

 

O: 01JUL2021 03:43:34   5.4S  104.7E mb=4.5  EMSC   SOUTHERN SUMATRA, INDONESIA

O: 01JUL2021 01:50:11   5.5S  104.6E mb=4.7  EMSC   SOUTHERN SUMATRA, INDONESIA

O: 30JUN2021 22:11:15   5.6S  104.6E ML=4.2  EMSC   SOUTHERN SUMATRA, INDONESIA  

P: 27JUN2021 134857     6.0S  102.0E 4.0-5.6 BABAA  So. of Sumatera            

 

O: 30JUN2021 12:15:03   6.9N   73.1W mb=4.4  EMSC   NORTHERN COLOMBIA            

P: 27JUN2021 134830     7.0N   73.0W 4.0-5.5 BAAAA  Colombia                   

 

The strongest earthquake in the U.S. or Canada today was an M 4.7 in the Kenai Peninsula, Alaska. NEIC reported this earthquake of M 4.3-4.7 in Southern Alaska was felt with intensity II-III in the area(s) of Southern Alaska at Kasilof, Clam Gulch, Soldotna and Sterling. This is the largest event in the Kenai area since an M 4.7 on July 3, 2019 and an M 5.0 north of this on January 13, 2019. The last earthquake in the region of greater magnitude was an M 5.3 on May 30, 2017 more than four years ago. Forecast 135060 had expected today's event was likely within about 25 km of this epicenter around June 28. 

 

O:  1JUL2021 02:27:21  60.6N  151.8W mb=4.7  EMSC   KENAI PENINSULA, ALASKA      

P: 28JUN2021 135060    60.8N  151.7W 3.2-5.1 BAAAA  Central Alaska             

 

MODERATE QUAKE SHAKES HAVANA, CUBA

 

EARTHQUAKE SUMMARY FOR JUNE 29, 2021

 

An earthquake of M 4.6 occurred south of Cuba today.  NEIC reported this earthquake of M 4.7 in Cuba was felt with intensity II-III in the area(s) of Cuba with IV in Havana and V in Pinar del Rio.  The only earthquakes in the past 30 years within about 250 km of today's event were an M 2.7 on March 9, 2013 and an M 5.1 on January 9, 2014 about 200 km northeast of today's epicenter. Forecast 134867 had expected today's event in this region was likely to the south around June 30, 2021. This earthquake is located at 104 degrees from the M 8.1 in the Kermadec Islands of March 4 and was probably promoted be energy from that source..

 

O: 29JUN2021 15:00:12  22.8N   82.9W mb=4.7  EMSC   CUBA REGION                  

P: 30JUN2021 134867    19.0N   81.0W 3.5-5.3 ACBAA  Caribbean Sea              

 

The strongest earthquake in the U.S. or Canada today was an M 4.8 in the eastern

Andreanof Islands, Aleutians, Alaska. It was not reported felt in this remote are. An earthquake of M 5.0 last hit this region about 100 km to the west on May 4, 2021 but this section between 172 and 173 West longitude has not seen an earthquake of this size or larger since an M 4.9 on October 20, 2016 nearly five years ago. Forecast 135035 had expected today's event in this area was likely around June 29. 

 

O: 30JUN2021 02:57:31  51.9N  172.4W mb=4.8  EMSC   ANDREANOF ISLANDS, ALEUTIAN IS

P: 29JUN2021 135035    52.2N  171.5W 3.5-4.9 AAAAA  Andreanoff Isls, Aleutians 

 

An M 2.8 also occurred in Wyoming today.  NEIC reported this earthquake of M 2.8 in Wyoming was felt with intensity II-III in the area(s) of Wyoming at Freedom, Etna, and Thayne. The area has seen a number of similar earthquakes in the last several years, mostly about 75 km southwest of this epicenter. The last event within about 50 km of this epicenter with M>=2.8 was an M 3.1 on August 22, 2018. Forecast 135028 had expected today's event within about 10 km was likely at the end of June, 2021.

 

O: 30JUN2021 06:38:38  43.1N  111.0W ML=2.8  EMSC   WYOMING                      

P: 23JUN2021 135028    43.2N  111.0W 2.0-4.4 CAAAA  Yellowstone/Wyoming        

 

MODERATE QUAKE SHAKES SAN FRANCISCO, CALIFORNIA

 

EARTHQUAKE SUMMARY FOR JUNE 28, 2021

 

A moderate earthquake of M 3.9-4.0 shook large areas of the San Francisco Bay, California today. NEIC reported it was felt with maximum intensity V in San Lorenze and IV in Hayward, Castro Valley, Oakland among others. Three earthquakes of M>=3.9 have occurred in the area of San Francisco in the past five years - an M 4.5 on October 15, 2019 and an M 4.4 on January 4, 2018. An M 4.0 also hit the area on August 17, 2015 and August 26, 2014 the only other such events in the area in nearly 10 years. Forecast 134930 had expected today's activity within about 50 km was likely at the end of June. Today's event may be related to the M 2.6 of June 25 in Baltimore, Maryland as reported at the time in this summary as:

 

 

"An unusual earthquake of M 2.6 was reported widely felt in the region of northern Maryland today. NEIC reported maximum intensity IV in Maryland at Baltimore with II-III in Gwynn, Catonsville, Windsor, Pikesville. The last earthquake of M>=2.6 within about 100 km of this epicenter was an M 2.8 on September 15, 2019. The largest event in the region in the past 30 years occurred as an M 4.6 on January 16,  1994. This was followed hours later by the M 6.7 in Northridge, California of the same date. It may have been precursory to that event. At the time of the M 4.1 on November 30, 2017 this summary noted in this regard:

 

 

"The Delaware earthquake of M 4.1-4.5 was reported felt with maximum intensity V in Clayton, Delaware; Newport New Jersey, and IV in Delaware at Dover, Magnolia, Camden Wyoming, Marydel, in Maryland at Galena, Sudlersville, and in general within about 50 km of the epicenter. It was felt with intensity II-III throughout much of the central eastern coast of the U.S. including in New Jersey, Delaware, Pennsylvania, Virginia, New York, Washington D.C, Connecticut, West Virginia, Massachusetts, Rhode Island, North Carolina, Vermont, Ohio, Kentucky, South Carolina, Illinois, Florida, Mississippi, Missouri, and Maryland,  The earthquake in Delaware is one of the strongest recorded in that State.  Earthquake in this area are often followed within days by a strong quake in southern or central California, such as occurred in the Northridge quake of M 6.7 on January 17, 1994 (preceded by an M 4.6 in southern Pennsylvania on January 16, 1994) and the Morgan Hill quake of April 24, 1984 preceded by an M 4.4 in Pennsylvania on April 23, 1984.  The events in August 2011 were later found to occur at the time of one of the strongest cosmic ray events known, possibly associated with a gravity wave and other effects which may have triggered this series. A similar relation may be found with today's events, but these area usually not announced until extensive data analysis. As this list includes the largest events in the Delaware area in the past 50 years and some of the strongest earthquakes in Central and southern California in the same period, it may be significant. This correlation is strongest with moderate starting quakes in the region of Delaware. The area of southern California near Northridge is currently at the 23-year cycles of large quakes in the area. A moderate earthquake in the region west of Los Angeles and north to San Francisco is considered possible in the next four days. At the least, residents should check their earthquake preparedness kits to see if they are ready for a moderate quake at this time." (December 1, 2017, June 26, 2021)

 

O: 29JUN2021 01:29:47  37.7N  122.1W Mw=4.0  EMSC   SAN FRANCISCO BAY AREA, CALIF.

P: 26JUN2021 134930    37.8N  122.6W 2.5-4.4 BAAAA  Central California         

 

An M 4.6 in El Salvador today was felt with intensity III in Nueva San Salvador, Antiguo Cuscatlan, San Salvador and in Armenta Cortes, Honduras. It followed a strong eruption earlier in the day in Costa Rica. The eruption of Rincon de la Vieja volcano in northern Costa Rica occurred near local solar midnight and may have been promoted by strong tidal effects which maximize near this hour. It is the strongest eruption at this volcano in many years. The largest earthquake in the volcanic eruption in Costa Rica occurred less than two minutes after the M 4.6 in El Salvador and may have been triggered by p- or s-waves from that source. Forecasts 134867 and 134870 had expected this activity in Costa Rica and El Salvador was likely around June 28.

 

O: 29JUN2021 00:02:30  10.7N   86.2W ML=3.9  EMSC   OFF COAST OF COSTA RICA      

P: 28JUN2021 134867    10.0N   84.0W 3.5-5.3 AABAA  Caribbean Sea              

 

O: 29JUN2021 00:00:17  13.2N   89.4W mb=4.6  EMSC   OFFSHORE EL SALVADOR         

P: 28JUN2021 134870    13.0N   89.0W 3.5-5.4 AAAAA  Coast of Central America   

 

The off-and-on seismicity in Yellowstone National Park continued today. The strongest event in the area today was an M 3.0-3.1. There were no reports that this activity was felt in the area. While an M 3.1-3.2 hit in the Yellowstone National Park on January 6, 2021, the last event in the area of significantly larger magnitude was an M 3.9 on February 29, 2020. Forecast 135029 had expected today's activity was likely around June 29.

 

O: 28JUN2021 14:02:30  44.7N  110.9W ML=3.1  ANSS   YELLOWSTONE NAT. PARK, WYOMING

O: 28JUN2021 14:02:30  44.7N  110.9W ML=3.0  EMSC   YELLOWSTONE NAT. PARK, WYOMING

O: 28JUN2021 14:16:42  44.7N  110.9W Ml=2.3  EMSC   YELLOWSTONE NAT. PARK, WYOMING

O: 28JUN2021 15:29:41  44.8N  110.9W ML=2.2  EMSC   YELLOWSTONE NAT. PARK, WYOMING

O: 28JUN2021 18:18:11  44.8N  110.9W Ml=2.2  EMSC   YELLOWSTONE NAT. PARK, WYOMING

O: 29JUN2021 05:14:20  44.8N  110.9W Ml=2.2  EMSC   YELLOWSTONE NAT. PARK, WYOMING

O: 28JUN2021 13:42:11  44.7N  110.9W Ml=2.0  EMSC   YELLOWSTONE NAT. PARK, WYOMING

P: 29JUN2021 135029    44.2N  110.3W 2.0-4.2 AAAAA  Yellowstone/Wyoming        

 

The strongest earthquakes in the world today were an M 5.3 in Vanuatu and an M 5.3 in the Bonin Islands, Japan. It was not reported felt in this remote region. Forecast 135087 had expected this earthquake was likely within about 100 km at the end of June.

 

 

O: 28JUN2021 14:00:44  15.4S  167.5E Mw=4.8  EMSC   VANUATU

O: 29JUN2021 03:14:13  15.2S  167.5E Mw=5.3  EMSC   VANUATU                      

P: 22JUN2021 135087    16.0S  168.0E 4.0-5.6 CAAAA  Vanuatu Islands            

 

The M 5.3 in the Bonin Islands occurred as Tropical Storm Champi passed over

the epicenter. This was probably promoted by energy from that storm as noted in previous issues of this summary:

 

"TS Champi (06W) continued today near the Bonin Islands with winds up to 45 kts. It is expected to track to the north and not to directly impact Honshu. Some seismic enhancement is possible in the Volcano, Bonin and Izu Islands over the next four days." (June 26, 2021)

 

O: 28JUN2021 09:12:42  26.8N  143.0E mb=5.3  EMSC   BONIN ISLANDS, JAPAN REGION  

P: 29JUN2021 134897    29.0N  143.0E 4.0-5.5 ACAAA  Bonin Islands              

 

Moderate quakes of M 5.0 also occurred today in the southern Mid-Atlantic and Kyushu, Japan today. These were not reported felt in these areas. Forecast 134941 and 135188 had expected these earthquakes were likely in late June, 2021.

 

O: 29JUN2021 05:55:49  31.8N  131.6E mb=5.0  EMSC   KYUSHU, JAPAN                

P: 24JUN2021 134941    32.0N  132.0E 3.5-5.0 BAAAA  Kyushu, Japan area         

 

O: 28JUN2021 18:09:36  41.7S   16.3W mb=5.0  EMSC   SOUTHERN MID-ATLANTIC RIDGE  

P: 29JUN2021 135118    44.0S   16.0W 4.0-5.6 ACAAA  So. Mid-Atlantic Ridge     

 

 

 

 

 

 

 

MODERATE QUAKES IN OCEAN RIDGES

 

EARTHQUAKE SUMMARY FOR JUNE 27, 2021

 

A series of moderate earthquakes occurred on mid-Ocean Ridges today. The strongest of these was an M 5.3 in the Southern East Pacific Rise. Other moderate quakes occurred in the northern Mid-Atlantic Ridge with an M 4.9 aftershock of the M 5.7 in that region yesterday and an M 4.5 north of the Azores. The M 4.9 in the northern mid-Atlantic is an aftershock of a larger M 5.5-5.7 yesterday. This had been noted in this summary in the previous issue as:

 

"The strongest earthquake in the world today was an M 5.5-5.7 in the northern Mid-Atlantic Ridge. It was not reported felt in this remote area. The last earthquake within about 200 km of this epicenter occurred as an M 5.9 on October 30, 2020. An M 6.0 also hit this region in July, 2011." (June 27, 2021)

 

O: 28JUN2021 05:45:52  11.8N   44.1W mb=4.9  EMSC   NORTHERN MID-ATLANTIC RIDGE  

 

The earthquake in the southern East Pacific Rise of M 5.3 was the strongest within about 250 km of this epicenter since an M 6.7 on May 19, 2021 and is an aftershock of that event. Forecast 135094 had expected today's activity to the south around June 29.

 

O: 28JUN2021 04:21:05  33.3S  109.6W mb=5.3  EMSC   SOUTHERN EAST PACIFIC RISE   

P: 29JUN2021 135094    36.0S  110.0W 3.0-5.8 ACAAA  So. Pacific Ocean          

 

The earthquake of M 4.5 in the area north of the Azores today is the strongest within about 150 km of this epicenter in more than a year - since an M 4.7 and 4.5 on June 5, 2020. Forecast 135007 had expected today's event within about 25 km was likely around June 24.

 

O: 27JUN2021 16:24:30  45.2N   28.0W mb=4.5  EMSC   NORTHERN MID-ATLANTIC RIDGE  

P: 24JUN2021 135007    45.0N   28.0W 4.0-5.9 AAAAA  No. Mid-Atlantic Ridge     

 

The strongest earthquake in the world today was an M 5.4 in northern Mindanao, Philippines. NEIC reported this earthquake of M 5.4 in northern Mindanao, Philippines was felt with intensity II-III in the area(s) of northern Mindanao, Philippines at San Isidro (IV), Tandag, Basag, Butuan, Brasilisa, Hinundayan.  An earthquake of M 5.7 hit about 200 km south of this on June 14, 2021 but the last such event within about 200 km of today's epicenter was an 6.1 on November 15, 2020. Forecast 134833 had expected today's earthquake in this region was likely around June 30.

 

O: 27JUN2021 07:14:10   9.0N  126.3E mb=5.4  EMSC   MINDANAO, PHILIPPINES        

P: 30JUN2021 134833     9.0N  127.0E 4.0-5.4 BAAAA  Halmahera                  

 

The strongest earthquake in the U.S. or Canada today was an M 4.5 in the Alaska Peninsula. NEIC reported this earthquake of M 4.2-4.5  in the Alaska Peninsula was felt with intensity II-III in the area(s) of the Alaska Peninsula at Kodiak.  The last earthquake within about 150 km of this epicenter of M>=4.5 was an M 5.3 about 150 km to the south on February 13, 2021 and an M 4.7 on January 3, 2021. No such earthquakes occurred in 2020. Forecast 135058 had expected today's event was likely in this area around June 25.

 

O: 28JUN2021 01:17:14  58.2N  154.2W mb=4.5  EMSC   ALASKA PENINSULA             

P: 25JUN2021 135058    60.1N  153.4W 3.2-5.1 BBAAA  Central Alaska             

 

MODERATE QUAKES SHAKE WESTERN AUSTRALIA AND NAMIBIA

 

EARTHQUAKE SUMMARY FOR JUNE 26, 2021

 

Two unusual earthquakes were felt today. These events of M 4.5 and 4.6 occurred in Western Australia and in Namibia in southern Africa. Namibia has been seismically active in the past several months starting with an M 5.4 on April 4, 2021 and an aftershock of M 5.0 on May 24, 2021. The only earthquakes within about 300 km of today's epicenter reported in the past 30 years were a pair of events of M 4.7 in early 2011. The quakes in 2011 may have been mining-related events.

 

NEIC reported this earthquake of M 4.6 in Namibia was felt with intensity II-III in the area(s) of Namibia at Warmbad Karas; in Bokspits, South Botswana dnd in Upington, Northern Cape, South Africa.

 

O: 27JUN2021 03:55:46  27.7S   19.6E mb=4.6  EMSC   NAMIBIA                      

 

The last earthquake of M>=4.5 within about 300 km of today's epicenter in Western Australia occurred  as an M 5.8 on December 16, 2018. This summary noted at the time:

 

 

 

"A moderately strong M 5.9 earthquake shook regions of western Australia today. NEIC reported it was lightly felt with intensity II-III in Western Australia at Carnarvon, Geraldton, and Perth. No major damage was reported with this earthquake. While western Australia has been active in the past half year, the largest within about 300 km in the past 30 years was an M 5.3 on February 15, 2007, the only such event in this period. Larger quakes were reported on April 29, 1941 (M 6.8) and November 19, 1906 (M 7.8). Local news reported that hundreds of people felt their houses shake in the quake, the second largest felt in Australia in the past 20 years. Loud earthquake noises accompanied the quake which was offshore, a factor that mitigated damage from the Coral Bay quake." (December 17, 2018)

 

It may be of some interest that the earthquakes in April, 2011 in western Australia and Namibia occurred with days of each other and my have been related to similar external stresses.

 

O: 26JUN2021 22:12:15  23.0S  114.0E mb=4.5  EMSC   WESTERN AUSTRALIA            

 

The strongest earthquake in the world today was an M 5.5-5.7 in the northern Mid-Atlantic Ridge. It was not reported felt in this remote area. The last earthquake within about 200 km of this epicenter occurred as an M 5.9 on October 30, 2020. An M 6.0 also hit this region in July, 2011.

 

O: 26JUN2021 18:01:23  11.8N   44.2W mb=5.5  EMSC   NORTHERN MID-ATLANTIC RIDGE  

O: 26JUN2021 18:01:23  11.8N   44.2W mb=5.7  ANSS   NORTHERN MID-ATLANTIC RIDGE  

 

 

The strongest earthquake in the U.S. or Canada today was an M 4.0 south of the Near Islands in the Aleutians, Alaska. This is the strongest earthquake within about 200 km of this epicenter since an M 4.5 on May 5, 2021 and an M 4.3 on January 8, 2021. Forecast 135047 had expected this event in this area was likely around June 28.

 

O: 27JUN2021 05:10:58  51.0N  174.0E mb=4.0  EMSC   SOUTH OF ALEUTIAN ISLANDS    

P: 28JUN2021 135047    52.0N  177.0E 4.0-5.8 AABAA  Rat Islands                

 

 

An unusual earthquake of M 2.5 occurred in southern Colorado today in the area of Canon City. NEIC reported this earthquake of M 2.5 in Canon City, Colorado was felt with intensity II-III in the area(s) of Canon City, Colorado. The last earthquake in this region of Colorado with equal or greater magnitude was an M 2.5 on November 18, 2020. The largest quake in the area in the past 30 years was an M 3.6 on November 30, 2017. A series of light earthquakes also occurred in this area in the summer of 2008. Forecast 135937 had expected activity in this region of Colorado would been enhanced around June 27.

 

O: 26JUN2021 19:17:16  38.5N  105.5W ML=2.5  EMSC   COLORADO                     

P: 27JUN2021 134937    38.9N  107.5W 2.0-4.1 AABAA  Colorado area              

 

A light earthquake was felt in the eastern San Francisco, California area today. Activity in this region had been expected to see enhancement near this time.  Forecast 134930 had expected today's epicenter was likely around June 24-26. An earthquake on June 29, 1988 of M 5.7 hit the southern San Francisco area on June 27, 1988 and may have been a foreshock to the later Loma Prieta, California quake of October, 1989. It was described in this summary at the time as"

 

"Likely foreshock to the Loma Prieta earthquake in 1989. This event caused slight damage near Los Gatos. Cracks formed in plaster and houses. Minor damage was reported throughout Santa Clara County. Windows were shattered. Water flow was changed in some areas." (June 27, 1988)

 

O: 26JUN2021 23:18:08  37.3N  121.6W Md=2.1  EMSC   NORTHERN CALIFORNIA          

P: 24JUN2021 134930    36.9N  121.7W 2.5-4.5 AAAAA  Central California         

P: 26JUN2021 134930    37.8N  122.6W 2.5-4.4 AAAAA  Central California         

MODERATE QUAKES SHAKE EUROPE

 

EARTHQUAKE SUMMARY FOR JUNE 25, 2021

 

A series of moderate earthquakes occurred across Europe today. These included an M 5.4 in eastern Turkey, an M 4.1 on the French-German border, an M 4.3 in Montenegro, an M 4.1 in the Dodecanese Islands, Greece and an M 4.2 in the Ionian Sea of Greece.

 

The strongest earthquake in the world today was an M 5.4 in eastern Turkey. NEIC reported it was felt with intensity V in Yayladere, Bingol Turkey; IV in Pulumur, Tunceli and II-III in Blazig and Batman, Turkey. This is the strongest earthquake within about 150 km of this epicenter in Eastern Turkey in more than a year. An M 5.9 with aftershock of M 5.4 hit this area on June 14 and 15, 2020. Forecast 134873 had expected today's event with magnitude up to M 5.5 was likely within about 25 km of this epicenter around June 26.

.

O: 25JUN2021 18:28:41  39.2N   40.2E Mw=5.2  EMSC   EASTERN TURKEY               

O: 25JUN2021 18:28:41  39.2N   40.2E Mw=5.4  ANSS   EASTERN TURKEY               

P: 26JUN2021 134983    39.0N   40.0E 3.5-5.5 AAAAA  Turkey                     

 

O: 25JUN2021 11:02:32  38.0N   20.8E ML=4.2  EMSC   IONIAN SEA                   

P: 28JUN2021 134947    37.0N   20.0E 3.0-4.9 BAAAA  No. Greece                 

 

 

An earthquake of M 4.3-4.5 in Montenegro was also felt in Europe today. NEIC reported it was felt with maximum intensity IV Croatia in Cilipi, Cabtat, Dubrovnik, Mokosica, and in Montenegro at Niksic, and in Trebinje, Bosnia and Herzegovina and with III in Herzegovina and Montnegro and Serbia, and Croatia.

The M 4.5 in Montenegro today was the strongest within about 100 km of that epicenter since an M 4.6 on January 8, 2016. Moderate to strong earthquakes occurred about 200 km southeast of today's epicenter in Croatia beginning with an M 5.6 on September 21, 2019. The strongest in this sequence was an M 6.4 near Zagreb on November 26, 2019. The last event of greater magnitude in this aftershock sequence was an M 4.6 on December 6, 2020 but the last of significantly larger magnitude was an M 5.1 on January 28, 2020.    Forecast 134988 had expected this epicenter would be active within about 50 km around June 26.

 

An unusual M 4.1 quake shook the French-German border today. NEIC reported it was felt with maximum intensity in Herrisheim, Alsace, France and II-III in France at Bishitem, Gambsheim, Schitigheim, Strasbourg, Graffenstaden, Haguenau, Alsace, and in Germany in Baden-Wurtemberg. It was followed five minutes later by an M 2.3 aftershock. This is the strongest earthquake within about 150 km of this epicenter since an M 4.8 on December 5, 2004. An M 4.4 hit about 150 km south of this epicenter on November 12, 2005.  Forecast 135043 had expected enhanced regional seismicity in late June.

 

O: 26JUN2021 03:05:23  48.7N    7.8E ML=2.3  EMSC   FRANCE-GERMANY BORDER REGION

O: 26JUN2021 03:00:24  48.7N    7.8E ML=4.1  EMSC   FRANCE-GERMANY BORDER REGION 

P: 21JUN2021 135043    51.0N    6.0E 3.0-5.0 BCBAA  Netherlands/Belgium        

 

 

An earthquake of M 4.2 in the Dodecanese Islands was reported felt with intensity IV in Lithakia, Zakinthos, Greece. This is an aftershock of the M 6.6-6.7 which hit the area on June 21. It had been expected in forecast 134917 to occur at the end of June, 2021.

 

O: 25JUN2021 09:21:09  36.4N   27.0E ML=4.1  EMSC   DODECANESE IS.-TURKEY BORDER R

P: 29JUN2021 134917    37.0N   26.0E 3.0-4.4 BAAAA  Aegean Sea                 

 

The earthquake in the Ionian Sea is the strongest in that region since an M 4.4 on May 7, 2021. Other event this year in the Ionian Sea occurred with M 4.5-4.6 on February 28 and January 25. This is the farthest north of these Ionian Sea events in the past year. Forecast 134947 had expected this activity at the end of June within about 150 km of today's epicenter.

 

O: 25JUN2021 11:02:32  38.0N   20.8E ML=4.2  EMSC   IONIAN SEA                   

P: 28JUN2021 134947    37.0N   20.0E 3.0-4.9 BAAAA  No. Greece                 

 

An earthquake of M 3.9 in Southern Alaska today was felt in the Kenai Peninsula with intensity II-III in Alaska at Indian, Girdwood, Anchorage. The last earthquake of M>=4.1 in the Kenai Peninsula was an M 4.4 on January 26, 2021. The last in Kenai within about 100 km of larger magnitude than M 4.1 occurred a year ago on June 18, 2020 with M 4.3. Forecast 135060 had expected today's activity was likely within about 50 km around June 22.

 

O: 25JUN2021 23:02:13  60.9N  149.5W ML=4.1  EMSC   KENAI PENINSULA, ALASKA      

P: 22JUN2021 135060    61.1N  150.2W 3.2-5.1 BAAAA  Central Alaska             

 

An unusual earthquake of M 2.6 was reported widely felt in the region of northern Maryland today. NEIC reported maximum intensity IV in Maryland at Baltimore with II-III in Gwynn, Catonsville, Windsor, Pikesville. The last earthquake of M>=2.6 within about 100 km of this epicenter was an M 2.8 on September 15, 2019. The largest event in the region in the past 30 years occurred as an M 4.6 on January 16,  1994. This was followed hours later by the M 6.7 in Northridge, California of the same date. It may have been precursory to that event. At the time of the M 4.1 on November 30, 2017 this summary noted in this regard:

 

 

"The Delaware earthquake of M 4.1-4.5 was reported felt with maximum intensity V in Clayton, Delaware; Newport New Jersey, and IV in Delaware at Dover, Magnolia, Camden Wyoming, Marydel, in Maryland at Galena, Sudlersville, and in general within about 50 km of the epicenter. It was felt with intensity II-III throughout much of the central eastern coast of the U.S. including in New Jersey, Delaware, Pennsylvania, Virginia, New York, Washington D.C, Connecticut, West Virginia, Massachusetts, Rhode Island, North Carolina, Vermont, Ohio, Kentucky, South Carolina, Illinois, Florida, Mississippi, Missouri, and Maryland,  The earthquake in Delaware is one of the strongest recorded in that State. Earthquake in this area are often followed within days by a strong quake in southern or central California, such as occurred in the Northridge quake of M 6.7 on January 17, 1994 (preceded by an M 4.6 in southern Pennsylvania on January 16, 1994) and the Morgan Hill quake of April 24, 1984 preceded by an M 4.4 in Pennsylvania on April 23, 1984.  The events in August 2011 were later found to occur at the time of one of the strongest cosmic ray events known, possibly associated with a gravity wave and other effects which may have triggered this series. A similar relation may be found with today's events, but these areas usually not announced until extensive data analysis. As this list includes the largest events in the Delaware area in the past 50 years and some of the strongest earthquakes in Central and southern California in the same period, it may be significant. This correlation is strongest with moderate starting quakes in the region of Delaware. The area of southern California near Northridge is currently at the 23-year cycles of large quakes in the area. A moderate earthquake in the region west of Los Angeles and north to San Francisco is considered possible in the next four days. At the least, residents should check their earthquake preparedness kits to see if they are ready for a moderate quake at this time." (December 1, 2017)

 

Forecast 135005 had expected today's activity was likely around June 25. This epicenter is at 105 degrees from the Qinghai, China event of May 21 and may have been promoted by energy from that epicenter. Other activity at this distance from the Qinghai epicenter today occurred at Barstow, California, Tonga, Fiji, the Central and northern Kermadec Islands.

 

O: 25JUN2021 19:40:45  39.3N   76.7W mb=2.6  EMSC   MARYLAND                     

P: 25JUN2021 135005    40.0N   74.0W 2.0-4.5 AABAA  New York State             

 

FULL MOON PROMOTES SEISMICITY IN AFGHANISTAN, TAJIKISTAN AND XINJIANG, CHINA

 

EARTHQUAKE SUMMARY FOR JUNE 24, 2021

 

Moderate earthquakes occurred today in Central Asia today in the regions of Tajikistan, Afghanistan and southern Xinjiang, China. The largest of these was an M 5.1 in Central Afghanistan. This activity had been expected at this time due to its location at the time of the full moon as described in this and previous issues of this summary:

 

"The full moon arrived on June 24, 2021 at 18:40 UT. Longitudes which were sub-solar at this time are near 100 West ( local solar noon) while those which are anti-solar (local solar midnight) at this time at near 80 East. In the west these included the west coast of South America, Central America, Mexico and central U.S. while in the east they included western Indonesia and central Asia. These areas are likely to see enhanced seismicity in the next week. A strong quake is possible during this full moon but is not considered highly likely as global seismicity has been low in recent weeks and other seismic triggers at this time are not powerful." (June 21-24, 2021)

 

Forecasts 134957, 134939 and 134997 had expected each of these events within about 100 km were likely in late June.

 

NEIC reported the earthquake of M 5.1 in Central Afghanistan was felt with intensity II-III in the area(s) of Central Afghanistan at Mahmoud Raqui, Kabul (IV), Baghrani (V) and in Carikar, Afghanistan (V).

 

O: 24JUN2021 23:04:43  34.9N   69.1E Mw=5.1  EMSC   HINDU KUSH REGION, AFGHANISTAN

P: 30JUN2021 134957    34.0N   70.0E 3.8-5.2 CAAAA  Pakistan                   

 

NEIC reported the earthquake of M 4.2 in Kabul, Afghanistan was felt with intensity IV in the area(s) of Kabul, Afghanistan.

 

O: 25JUN2021 01:11:17  36.5N   71.1E mb=4.1  EMSC   HINDU KUSH REGION, AFGHANISTAN

O: 25JUN2021 03:56:34  37.2N   71.9E mb=4.2  EMSC   TAJIKISTAN                   

P: 26JUN2021 134939    37.0N   72.0E 3.8-5.4 AAAAA  Hindu Kush/Pakistan        

 

O: 25JUN2021 01:42:09  41.3N   83.7E mb=4.6  EMSC   SOUTHERN XINJIANG, CHINA

O: 25JUN2021 04:57:27  41.1N   83.6E mb=4.4  EMSC   SOUTHERN XINJIANG, CHINA     

P: 24JUN2021 134997    42.0N   82.0E 4.0-5.4 AAAAA  Kirgizstan/Xinjiang        

 

A series of light to moderate earthquakes also occurred in the region of Southern Puerto Rico today. The largest of these was an M 4.3. This series began with an M 3.6 and 3.8 within about 10 minutes of local solar noon and were probably promoted by strong tidal stresses associated with the full moon which maximize at this hour. Forecast 134890 had expected this activity was likely around June 26.

 

NEIC reported this earthquake of M 4.3 in Puerto Rico was felt with intensity IV-V in the area(s) of Puerto Rico  at Lajas, Ensenada, San German, Sabana Grande, Guayanilla, and III in Cabo Rojo, Mayaguez, Yauco, Las Marias.

 

O: 24JUN2021 16:30:28  18.0N   67.1W ML=3.8  EMSC   PUERTO RICO

O: 24JUN2021 16:28:21  17.9N   67.1W Ml=3.6  EMSC   PUERTO RICO REGION

O: 24JUN2021 20:10:55  17.9N   67.1W mb=4.3  EMSC   PUERTO RICO REGION

O: 24JUN2021 20:42:35  17.9N   67.1W ML=3.6  EMSC   PUERTO RICO REGION

O: 25JUN2021 01:08:54  17.9N   67.1W ML=3.8  EMSC   PUERTO RICO REGION

O: 25JUN2021 03:37:03  17.8N   67.1W ML=3.6  EMSC   PUERTO RICO REGION           

P: 26JUN2021 134890    18.0N   67.0W 3.4-5.3 AAAAA  Puerto Rico                

 

 

An earthquake of M 5.1 occurred today in the Pacific-Antarctic Ridge. It was not reported felt in this remote area. A similar M 5.1 occurred in the area within about 300 km of this epicenter on November 28, 2020 but the last of larger magnitude was an M 5.8 on August 31, 2020. Forecast 135121 had expected today's event in this region was likely around June 23. This earthquake occurred within minutes of local solar midnight and was likely promoted by tidal stresses which maximize near this hour.

 

O: 24JUN2021 09:07:21  55.0S  127.2W mb=5.1  EMSC   PACIFIC-ANTARCTIC RIDGE      

P: 23JUN2021 135121    56.0S  122.0W 4.0-5.8 AACAA  Pacific-Antarctic Ridge    

 

ULL MOON OVER MIAMI

 

EARTHQUAKE SUMMARY FOR JUNE 23, 2021

 

A codominium in Surfside, Florida, a suburb of Miami collapsed early on June 24. The collapse of the Champlain Towers south occurred at about 1:30 EDT. Four people were confirmed killed with at least 159 still missing. Low water tides for the area occurred at 2:19 EDT less than an hour from the time of the collapse while the full moon over Miami occurred at 2:40 pm with the nighttime full moon at 2:40 am. Solid earth tides would have maximized  14:40 UT and 02:40 UT. These times are suspiciously close to the time of the collapse of the condo.  Miami is located at 25N 80W and was near the point of maximum altitude of the sun on June 21 (summer solstice). These factors enhanced the tidal stresses at this time as noted in previous issues of this summary:

 

"The full moon will arrive on June 24, 2021 at 18:40 UT. Longitudes which are sub-solar at this time are near 100 West ( local solar noon) while those which are anti-solar (local solar midnight) at this time at near 80 East. In the west these included the west coast of South America, Central America, Mexico and central U.S. while in the east they included western Indonesia and central Asia. These areas are likely to see enhanced seismicity in the next week. A strong quake is possible during this full moon but is not considered highly likely as global seismicity has been low in recent weeks and other seismic triggers at this time are not powerful." (June 22-23, 2021)

 

Furthermore, a very strong experimental explosion on a ship off the coast of southern Florida on June 18, 2021 was felt throughout much of the area on June 18, 2021 as noted in this summary at the time:

 

"An experimental explosion of M 3.9 off the coast of eastern Florida today was felt in Florida with intensity IV in Clemont and II-III in Ormond Beach, Cocoa, Jacksonville, Saint Johns and Opala." (June 19, 2021)

 

O: 18JUN2021 19:48:39  29.7N   79.3W ML=3.9  EMSC   OFF EAST COAST OF UNITED STATE

 

It is possible that the air waves from this explosion weakened the structure of the Condominium which was weakened to failure by the full moon today as shown by the coincidental timing of these events.

 

An unusual earthquake of M 5.0 shook regions of Western Australia today. NEIC reported it was felt with intensity II-III in Broome, Port Hedland and Roebourne, Western Australia. The antipode of this event is located at 18N 60W in the Virgin Islands, Caribbean where a series of moderate earthquakes has been occurring over the past week. It was preceded by an M 4.2 in the Dominican Republic which was felt with intensity III in Isabela, Puerto Rico. This event occurred within minutes of local solar midnight and may have been promoted by high tidal stresses which maximize near this hour.  An M 3.7 was also felt with intensity II in Utuado, Puerto Rico.

 

Two earthquakes of M>=5.1 have hit this area of Australia in the past 20 years - of M 6.6 on July 14, 2019 and an M 5.1 on March 6, 2009. At the time of the earthquake in July 14, 2019, this summary noted:

 

"A strong M 6.6 earthquake was located off the coast of western Australia today.

NEIC reported it was felt with maximum intensity V in Broome, and IV in Port Hedland. Karratha and Darwin, Western Australia and within about 1500 km of the epicenter. This is an area where strong tropical cyclones often make landfall in Australia. This summary has previously linked these events to increased antipodal seismicity in the northern Caribbean. Today's event is antipodal to the Virgin Islands and Puerto Rico....

 

No earthquakes of M>=6.5 have been recorded within about 400 km of this epicenter in at least 30 years. The last moderate quake in the area was an M 4.9 on May 10, 2016 and prior to that an M 5.1 on March 6, 2009." (July 14, 2019)

 

 

O: 24JUN2021 06:57:03  18.2S  120.3E Mw=5.1  EMSC   WESTERN AUSTRALIA            

 

 

O: 24JUN2021 04:56:47  18.3N   68.5W mb=4.0  EMSC   MONA PASSAGE, DOMINICAN REPUBL

O: 24JUN2021 04:56:47  18.3N   68.5W mb=4.2  EMSC   MONA PASSAGE, DOMINICAN REPUBL

P: 24JUN2021 134891    19.0N   68.0W 3.4-5.2 AAAAA  Puerto Rico                

 

O: 24JUN2021 05:51:26  19.0N   68.4W ML=3.1  EMSC   DOMINICAN REPUBLIC REGION    

O: 24JUN2021 03:48:30  19.4N   67.5W Md=3.7  EMSC   PUERTO RICO REGION           

P: 24JUN2021 134891    19.0N   68.0W 3.4-5.2 AAAAA  Puerto Rico                

 

The strongest earthquake in the world today was an M 5.7 north of Western Australia in the region of the Banda Sea, Indonesia. NEIC reported it was felt lightly in Ambon, Maluku, Indonesia and IV ikn Darwin, Northern Territory, Australia. Forecast 134840 had expected today's event was likely between June 24 and 27.

 

O: 24JUN2021 02:24:56   6.0S  128.3E Mw=5.6  EMSC   BANDA SEA

O: 23JUN2021 23:12:15   7.1S  129.2E ML=4.2  EMSC   KEPULAUAN BABAR, INDONESIA

O: 23JUN2021 12:44:42   7.5S  128.6E ML=4.1  EMSC   KEPULAUAN BARAT DAYA, INDONESIA

O: 23JUN2021 22:21:29   7.7S  127.9E ML=4.5  EMSC   KEPULAUAN BARAT DAYA, INDONESI

P: 24JUN2021 134840     8.0S  129.0E 4.0-5.5 AAAAA  Banda Sea                  

P: 27JUN2021 134840     8.0S  128.0E 4.0-5.4 AAAAA  Banda Sea                  

 

An M 3.2 was widely felt in the region of Los Angeles, California today. NEIC reported intensity II-III in Los Angeles, Culver City, El Segundo, Marina del Rey, Playa del Rey, Inglewood, An M 3.7 east of Los Angeles was felt with intensity II-III in Yucca Valley, Joshua Tree, White Water, Desert Hot Springs, Palm Springs, Landers, Cathedral City, Rancho Mirage, Palm Desert and Banning. Four earthquakes of M>=3.2 have occurred near this epicenter in Los Angeles in the past year - the largest of which was an M 4.5 on September 19, 2020 and the last of which was an M 3.5 on May 9, 2021. Forecast 134967 had expected this earthquake was likely around June 24.

 

O: 24JUN2021 00:08:35  34.0N  118.4W ML=3.0  EMSC   GREATER LOS ANGELES AREA, CALI

O: 24JUN2021 00:08:35  34.0N  118.4W ML=3.2  ANSS   GREATER LOS ANGELES AREA, CALI

P: 24JUN2021 134967    34.4N  118.6W 2.5-4.9 AAAAA  So. California             

 

The M 3.7 near Lander, California is the strongest within about 50 km of this  epicenter since an M 3.7 on September 25, 2020. The last of larger magnitude in this region occurred nearly two years ago on July 22, 2019 with M 4.2 Forecast 134966 had expected this event was likely around June 23 within about 15 km of this epicenter.

 

O: 23JUN2021 20:06:07  34.2N  116.4W Ml=3.6  EMSC   SOUTHERN CALIFORNIA          

O: 23JUN2021 20:06:07  34.2N  116.4W Ml=3.7  ANSS   SOUTHERN CALIFORNIA          

P: 23JUN2021 134966    34.3N  116.5W 2.5-5.2 AAAAA  So. California             

 

The second largest earthquake in the world today was an M 5.3 in the Volcano/Volcano Islands region. It had been expected around June 26. This earthquake occurred as TS Champi passed over this epicenter. A similar earthquake of M 4.2 also occurred yesterday in the northern Mariana Islands as noted in the previous issue of this summary:

 

"An earthquake of M 4.2 occurred in the northern Mariana Islands today. Forecast 134621 had expected this event within about 50 km around June 18. It is likely that  today's event was triggered by stresses associated with the passage of Tropical Storm Champi near this epicenter about the time of the earthquake." (June 23, 2021)

 

"TS Champi (06W) continued today near the Volcano Islands with winds up to 65 kts. It is expected to track to the north and not to directly impact Honshu. Some seismic enhancement is possible in the Volcano, Bonin and Izu Islands over the next four days." (June 22, 2021)

 

O: 24JUN2021 04:03:53  21.7N  145.7E mb=5.3  EMSC   MARIANA ISLANDS REGION       

P: 26JUN2021 134916    22.0N  143.0E 4.0-5.4 AABAA  Volcano Islands            

 

MODERATE QUAKE SHAKES CENTRAL PERU

 

EARTHQUAKE SUMMARY FOR JUNE 22, 2021

 

A moderately strong earthquake of M 5.8 shook areas of central Peru today. It was reported by NEIC with intensity VII in Peru in Lima at Mala; VI in Chica, Micolas de Pereola, V in Nuevo Imperia, San Luis, Lima and IV in Santa Maria, Ricardo, Huancayo and Matucana. This earthquake occurred within about an hour of local solar midnight and was probably promoted by high tidal stresses which maximize near this hour. The area near the coast of western South America is expected to see higher than normal seismicity in the next week due to the timing of the upcoming full moon as noted in this summary:

 

"The full moon will arrive on June 24, 2021 at 18:40 UT. Longitudes which are sub-solar at this time are near 100 West ( local solar noon) while those which are anti-solar (local solar midnight) at this time at near 80 East. In the west these included the west coast of South America, Central America, Mexico and central U.S. while in the east they included western Indonesia and central Asia. These areas are likely to see enhanced seismicity in the next week. A strong quake is possible during this full moon but is not considered highly likely as global seismicity has been low in recent weeks and other seismic triggers at this time are not powerful." (June 22-23, 2021)

 

Today's event in Peru is the strongest within about 200  km of this epicenter since an M 6.1 on March 15, 2014. An M 6.9 on August 24, 2014 occurred about 350 km to the southeast on August 24, 2014. A great earthquake of M 8.0 hit this region on August 15, 2007. That quake was extremely damaging in the area as noted in this summary at the time:

 

 

"Associated Press reported that at least 135 were killed in the quake on  initial  count with more than 1300 others injured mostly in the region around Lima where residents were said to be terrified. Civil defense put the number of dead at 335 and that was expected to rise considerably. The shaking lasted for several minutes longer than any earthquake in memory in the area. At Ica 17 people were killed when a church collapsed in the city of Ica. Seventy more were said injured in that incident. Huge cracks appeared in pavement and  the Pan American highway was out of commission. A bridge north of Ica had also collapsed. Power and utilities were out throughout the region. Walls of homes and businesses had fallen in at Chincha and many were hurt by falling bricks and broken glass. Many hospitals were also damaged and had cracks and the injured were placed on the floor for treatment. At Lima, a city of 8 million the lampposts collapsed and windows shattered throughout the city. Workers were evacuated from office buildings and remained on the streets. Most schools and businesses will be closed today. Many older houses in Lima collapsed. Fires erupted in many areas but  did not spread. The towns of Pisco and Chincha and others along the southern coast region were said to be in ruins. A tsunami warning was issued and a tsunami of 20-30 cm was observed in the local area. It was difficult to observe the tsunami because a strong storm in the area was causing heavy seas. In Colombia the port cities of Tumaco, Buenaventura and Bahia Solano saw buildings evacuated. Similar evacuations took place in some ports in Peru." (August 16, 2007)

 

Forecast 135076 had expected today's event within about 50 km of this epicenter

with magnitude up to M 5.8 was likely around June 27. 

 

O: 23JUN2021 02:54:18  12.7S   76.7W Mw=5.8  EMSC   NEAR COAST OF CENTRAL PERU   

P: 27JUN2021 135076    13.0S   77.0W 4.0-5.8 BAAAA  Central Peru               

 

The M 5.8 in Peru was preceded by an M 5.3 in Central Chile in Coquimbo. NEIC reported maximum intensity V in Valparaiso at Vina del Mar and Quilpue; IV in Los Andes and Villa Alamana, Calera, Valparaiso and III in La Ligua, San Felipe, Lampa and Santiago. Forecast 135102 had expected today's event in Coquimbo Chile was likely around June 22 to the east of today's epicenter.

 

O: 22JUN2021 19:16:26  32.1S   71.1W Mw=5.3  EMSC   COQUIMBO, CHILE              

P: 22JUN2021 135102    33.0S   68.0W 4.0-5.8 AABAA  Central Chile              

 

An earthquake in the Drake Passage southeast of South America and Antarctica of M 5.4 also occurred today. An M 5.4-5.5 in the Drake Passage last occurred on February 7, 2020. This appears to be an extension of the strong quakes in the South Shetland Islands of early 2021. Forecast 135126 had expected activity in this region was likely around June 25.

 

O: 23JUN2021 00:47:05  58.2S   63.8W Mw=5.4  EMSC   DRAKE PASSAGE                

P: 25JUN2021 135126    62.0S   58.0W 4.0-5.5 ACCAA  Southern  Ocean            

 

An earthquake of M 5.5 also occurred today in the area southeast of the Loyalty Islands. This area was active beginning with an M 7.7 on February 10, 2021 and in March, 2021.  The only similar event in the Loyalty Islands of M>=5.5 was an M 5.5 on May 15, 2021. Forecast 135091 had expected today's event with magnitude up to M 5.6 was likely around June 26.

 

O: 23JUN2021 05:39:39  22.8S  171.7E mb=5.5  EMSC   SOUTHEAST OF LOYALTY ISLANDS 

P: 26JUN2021 135091    22.0S  172.0E 4.0-5.6 BAAAA  Loyalty Islands            

 

An earthquake of M 4.2 occurred in the northern Mariana Islands today. Forecast 134621 had expected this event within about 50 km around June 18. It is likely that today's event was triggered by stresses associated with the passage of Tropical Storm Champi near this epicenter about the time of the earthquake. This summary had expected this possibility at this time as:

 

"TS Champi (06W) continued today near Guam with winds up to 50 kts. It is expected to track to the north and not to directly impact Honshu. Some seismic enhancement is possible in the Volcano, Bonin and Izu Islands over the next four days." (June 22-23, 2021)

 

O: 23JUN2021 04:03:57  18.6N  145.6E mb=4.2  EMSC   PAGAN REG., N. MARIANA ISLANDS

P: 18JUN2021 134621    18.0N  145.0E 4.0-5.4 BAAAA  No. Marianas               

 

MODERATE QUAKE SHAKES DODECANESE ISLANDS, GREECE

 

EARTHQUAKE SUMMARY FOR JUNE 21, 2021

 

A moderately strong M 5.5-5.7 hit the region of the Dodecanese Islands, Greece today. NEIC reported maximum shaking with intensity V in Kefalos, and Drosia; IV in Kos, Rhodos, Greece; Datca, and Soke, Turkey and III in Koycega, Mugla, Turkey. An M 5.4 hit near this epicenter on April 13, 2021 but the last earthquake of stronger magnitude in the Dodecanese Islands was an M 7.0 on October 30, 2020. Forecasts 134646 and 134917 had expected today's activity within about 50 km of this epicenter was likely between June 15 and 23. Today's M 5.5-5.7 occurred within minutes of local solar midnight and was probably promoted by strong tidal stresses which maximize near this hour.

 

O: 21JUN2021 23:47:26  36.4N   27.1E ML=3.9  EMSC   DODECANESE IS.-TURKEY BORDER REG

O: 21JUN2021 22:14:14  36.4N   27.1E Mw=5.5  EMSC   DODECANESE IS.-TURKEY BORDER R

O: 21JUN2021 22:14:14  36.4N   27.1E Mw=5.7  ANSS   DODECANESE IS.-TURKEY BORDER R

P: 15JUN2021 134646    38.0N   26.0E 3.0-4.7 CBAAA  Aegean Sea                 

P: 23JUN2021 134917    36.0N   27.0E 3.0-5.4 AAAAA  Aegean Sea                 

 

The strongest earthquake in the world today was an M 6.0 aftershock in the Central Kermadec Islands, New Zealand. It was not reported felt in this remote area. This is an aftershock of the M 6.3 at this epicenter of June 20, 2021. It occurred within about 30 minutes of local solar midnight and was probably promoted by high tidal stresses which maximize near this hour. Forecasts 134813 and 135107 had expected this activity within about 50 km was likely around June 18-23.

 

O: 22JUN2021 02:04:07  30.4S  177.2W mb=4.9  EMSC   KERMADEC ISLANDS, NEW ZEALAND

O: 21JUN2021 11:14:12  30.4S  177.6W Mw=6.0  EMSC   KERMADEC ISLANDS, NEW ZEALAND

P: 18JUN2021 134813    31.0S  179.0W 4.0-5.6 BAAAA  So. Kermadec Islands       

P: 23JUN2021 135107    30.0S  177.0W 4.0-5.5 AAAAA  No. Kermadec Islands       

 

The strongest earthquake in the U.S. or Canada reported today was an M 3.8 off the coast of Eugene, Oregon. It was accompanied today by an M 3.2 south of this epicenter. An M 5.3 hit this area with aftershocks on April 29, 2021. Forecasts 134729 and 135013 had expected today's event within about 50 km was likely around June 18.

 

O: 19JUN2021 19:34:07  44.2N  128.7W MB=3.8  ECAN Eugene, Oregon, USA            

P: 18JUN2021 134729    44.4N  129.3W 3.0-4.6 AAAAA  Off Coast of Oregon        

 

 

NEIC reported the earthquake of M 3.2 off the coast of Oregon  was felt with intensity II-III in the area(s) of Oregon at Eugene and Lake Oswego.

 

O: 22JUN2021 00:25:19  43.2N  128.1W ML=3.2  EMSC   OFF COAST OF OREGON          

P: 22JUN2021 135013    44.4N  129.3W 3.0-4.6 ABAAA  Off Coast of Oregon        

P: 25JUN2021 135013    43.9N  128.4W 3.0-4.9 BAAAA  Off Coast of Oregon        

 

A swarm of minor earthquakes struck the region of Yellowstone National Park today. The last swarm of this type in Yellowstone occurred on September 10, 2020. Forecasts 134742 and 135029 had expected this activity was likely around

June 17-22.

 

O: 21JUN2021 14:33:48  44.6N  110.8W Md=2.5  EMSC   YELLOWSTONE NAT. PARK, WYOMING

O: 21JUN2021 16:55:12  44.6N  110.8W Ml=2.4  EMSC   YELLOWSTONE NAT. PARK, WYOMING

O: 21JUN2021 17:02:25  44.6N  110.8W Ml=2.0  EMSC   YELLOWSTONE NAT. PARK, WYOMING

O: 21JUN2021 17:11:51  44.6N  110.8W Ml=2.1  EMSC   YELLOWSTONE NAT. PARK, WYOMING

O: 21JUN2021 17:20:10  44.6N  110.8W Ml=2.5  EMSC   YELLOWSTONE NAT. PARK, WYOMING

O: 21JUN2021 17:27:51  44.6N  110.8W Ml=2.4  EMSC   YELLOWSTONE NAT. PARK, WYOMING

O: 21JUN2021 17:59:18  44.6N  110.8W Ml=2.1  EMSC   YELLOWSTONE NAT. PARK, WYOMING

O: 21JUN2021 18:06:12  44.6N  110.8W Ml=2.1  EMSC   YELLOWSTONE NAT. PARK, WYOMING

O: 21JUN2021 18:52:52  44.6N  110.8W Ml=2.2  EMSC   YELLOWSTONE NAT. PARK, WYOMING

O: 21JUN2021 17:08:29  44.5N  110.7W Ml=2.5  EMSC   YELLOWSTONE NAT. PARK, WYOMING

P: 17JUN2021 134742    44.2N  110.3W 2.0-4.3 BAAAA  Yellowstone/Wyoming        

P: 22JUN2021 135029    44.6N  110.8W 2.0-4.3 AAAAA  Yellowstone/Wyoming        

 

An unusual M 3.4 hit the Maui region of Hawaii today.  NEIC reported this earthquake of M 3.3 in Maui, Hawaii was felt with intensity II-III in the area(s) of Maui, Hawaii at Hawi, Waikoloa, Kamuela, Kailua Kona, Honokaa, Kula and Captain Cook. This is the strongest earthquake in Maui since a M 3.6-3.8 on September 5, 2020. Forecast 134901 had expected a moderate quake in this area was likely around June 23.

 

O: 21JUN2021 07:36:01  20.1N  156.0W ML=3.4  EMSC   MAUI REGION, HAWAII          

P: 23JUN2021 134901    20.3N  155.1W 4.0-5.9 AAAAA  Hawaii area                

 

STRONG QUAKES HIT IN KERMADEC ISLANDS, NEW ZEALAND

 

EARTHQUAKE SUMMARY FOR JUNE 20, 2021

 

The strongest seismicity in the world today occurred in the Kermadec Islands of New Zealand. Earthquakes of M 6.3 followed by an M 5.7 were not reported felt in this remote area. These epicenters are about 150 km south of the M 8.1 in the Kermadec Islands of March 4, 2021, and while not classical aftershocks were probably enhanced by stress redistribution in the area follow that March activity. The M 6.3 is the strongest earthquake within about 250 km of this epicenter since an M 6.5 on April 1, 2021 and the mainshocks of M 81 and M 7.4 on March 4, 2021. The last quakes south of 40 South Latitude in this area of M>=6.3 occurred in June , 2019 following an M 7.2 on June 15. The last such event in this area within about 100 km of today's epicenter occurred two years ago on June 19, 2019.  Forecasts 134809 and 134813 had expected enhanced seismicity in this area within about 50 km of these epicenters was likely in mid-June. This activity is at 103 degrees from the M 7.4 in Qinghai, China of May 21, 2021 and was probably promoted by concentrated surface energy from that source. Recent earthquakes at this distance from Qinghai have occurred in  South Island, New Zealand, Indiana, Ontario, Quebec, Canada, Lake Erie, Utah, Southern California, and South Dakota among others. They are also located at 103 degrees from the M 6.7 in the South Indian Ocean of May 12, 2021.

 

 

O: 20JUN2021 17:05:48  30.4S  177.8W Mw=6.3  EMSC   KERMADEC ISLANDS, NEW ZEALAND

O: 20JUN2021 17:24:33  30.2S  177.5W Mw=5.5  EMSC   KERMADEC ISLANDS, NEW ZEALAND

P: 15JUN2021 134809    30.0S  178.0W 4.0-5.4 BAAAA  No. Kermadec Islands       

P: 18JUN2021 134813    31.0S  179.0W 4.0-5.6 AAAAA  So. Kermadec Islands       

 

A possibly-related earthquake of M 4.3-4.6 occurred later near Te Anau, South

Island, New Zealand.  GEONET reported this earthquake was felt with weak intensity in the area southwest of Te Anau, South Island. 418 reports of felt intensity came from the area east and north of the epicenter. More than 416 people reported feeling this earthquake with 203 reporting weak shaking and 166 light intensity; 39 with moderate intensity and one with strong, 5 with  severe and 2 with extreme shaking. NEIC reported this earthquake of M 4.3 in  South Island, New Zealand was felt with intensity II-IV in the area(s) of  South Island, New Zealand  at Manapouri, Te Anau, Riverton. Forecast 134819 had expected today's activity in South Island was likely around June 17.  This activity is at 103 degrees from the M 7.4 in Qinghai, China of May 21, 2021 and was probably promoted by concentrated surface energy from that source.

 

O: 21JUN2021 05:16:59  45.6S  167.7E mb=4.3  EMSC   SOUTH ISLAND OF NEW ZEALAND  

O: 21JUN2021 05:16:59  45.6S  167.7E MS=4.6  GEONET Felt with weak intensity

P: 17JUN2021 134819    44.0S  168.0E 3.0-5.0 BAAAA  So. Island, N.Z.           

 

The strongest earthquake in the U.S. or Canada today was an M 3.5 in Baja California, Mexico. This is part of the activation of southern California of the past three weeks. Forecast 134680 had expected today's activity was likely in mid-June.

 

O: 20JUN2021 07:53:32  32.5N  115.2W Ml=2.2  EMSC   BAJA CALIFORNIA, MEXICO

O: 21JUN2021 06:32:34  31.7N  115.8W ML=3.5  EMSC   BAJA CALIFORNIA, MEXICO      

P: 16JUN2021 134680    31.7N  115.3W 2.5-4.4 BAAAA  So. California             

 

A strong series of earthquake occurred today in Michoacan, Mexico. No mainshock was included with the maximum sized event of M 3.6-4.0. Following is a listing of events of M>3.5 in the area today. These are occurring near the landfall of Tropical Storm Dolores which made landfall at this epicenter two days as detailed in previous issues of this summary:

 

"TS Dolores continued today south of Michoacan, Mexico with winds up to 45 kts. It is expected to track to the west and north over the next several day making landfall near Manzanillo around June 20. Seismicity in western Mexico is likely to be enhanced as this storm makes landfall with a moderate to large earthquake in Michoacan, Baja or Colima possible in the next week." (June 18-20, 2021)

 

It is likely that this activity is related to regional stresses associated with landfall of TS Dolores. Forecasts 134617 and 134618 had expected this activity in Michoacan in mid-June.

 

O: 20JUN2021 09:24:26  19.3N  102.2W ML=3.6  EMSC   MICHOACAN, MEXICO

O: 20JUN2021 16:07:09  19.3N  102.2W ML=3.6  EMSC   MICHOACAN, MEXICO

O: 20JUN2021 16:50:11  19.3N  102.2W ML=3.7  EMSC   MICHOACAN, MEXICO

O: 20JUN2021 18:23:06  19.3N  102.2W ML=3.7  EMSC   MICHOACAN, MEXICO

O: 21JUN2021 01:37:52  19.3N  102.2W ML=3.6  EMSC   MICHOACAN, MEXICO

O: 20JUN2021 16:03:58  19.4N  102.2W ML=3.6  EMSC   MICHOACAN, MEXICO

O: 20JUN2021 16:45:11  19.4N  102.2W ML=3.7  EMSC   MICHOACAN, MEXICO

O: 20JUN2021 17:07:38  19.5N  102.1W ML=3.7  EMSC   MICHOACAN, MEXICO

O: 20JUN2021 08:09:30  19.3N  102.1W ML=3.6  EMSC   MICHOACAN, MEXICO            

P: 14JUN2021 134618    19.0N  102.0W 3.5-5.6 CAAAA  Michoacan, Mexico          

P: 19JUN2021 134617    17.0N  102.0W 3.5-5.7 ACAAA  Michoacan, Mexico          

 

MODERATE QUAKE SHAKES CHIAPAS, MEXICO

 

EARTHQUAKE SUMMARY FOR JUNE 19, 2021

 

An earthquake of M 5.4 was felt in the region of the Chiapas-Guatemala border today. This earthquake occurred within about half an  hour of local solar noon and was probably promoted by high tidal stress which maximize near this hour.

The last earthquake within about 150 km of this epicenter with M>=5.4 was an

M 5.5 on August 12, 2019 about 150 km west of today's epicenter. The last event with greater magnitude in this area was an M 6.6 on February 1, 2019. Forecast 134609 had expected today's event was likely within about 100 km around June 19.

 

 

O: 19JUN2021 18:57:17  16.0N   92.3W Mw=5.4  EMSC   CHIAPAS, MEXICO              

P: 19JUN2021 134609    15.0N   92.0W 3.5-5.3 AAAAA  Guatemala                  

 

The strongest earthquake in the U.S. or Canada today was an M 4.4-4.7 aftershock in Central Alaska. NEIC reported it was felt with intensity IV at Anderson and II-III in Healy, Denali National Park, Cantwell, Fairbanks, Fort Wainwright, North Pole, Matanuska. NEIC reported an aftershock of M 3.3 in Central Alaska was felt with intensity II-III in the area(s) of Central Alaska at Fairbanks. Forecast 134768 had expected today's activity was likely within this aftershock zone around June 19.

 

O: 19JUN2021 21:43:04  64.0N  149.7W mb=4.7  EMSC   CENTRAL ALASKA               

P: 19JUN2021 134768    62.7N  149.3W 3.2-5.3 ABAAA  Central Alaska             

 

NEIC reported the earthquake of M 3.3 in Central Alaska was felt with intensity II-III in the area(s) of Central Alaska at Fairbanks.

 

O: 20JUN2021 03:11:06  63.1N  150.9W ML=3.3  EMSC   CENTRAL ALASKA               

P: 18JUN2021 134770    62.9N  150.2W 3.2-5.1 AAAAA  Central Alaska             

 

The strongest earthquake in the world today was an M 5.7 in the Fiji Islands.  This continues gradually increasing seismicity in this region after a lull period of a couple of weeks. This event was followed by an M 5.1 in Fiji about 350 km to the southeast. The M 5.7 occurred near local solar midnight and may have been promoted by high tidal stresses which maximize near this hour. The last earthquake of M>=5.7 within about 250 km of this epicenter was an 6.2 ten years ago on July 31, 2011. Forecast 134797 had expected seismic enhancement in this area in mid-June. 

 

O: 19JUN2021 11:59:05  16.3S  173.1E Mw=5.7  EMSC   FIJI REGION                  

O: 19JUN2021 11:59:05  16.4S  173.1E Mw=5.8  ANSS   FIJI REGION                  

P: 14JUN2021 134797    22.0S  171.0E 4.0-5.6 BCBAA  Loyalty Islands            

 

O: 19JUN2021 16:22:19  18.1S  178.2W mb=5.1  EMSC   FIJI REGION                  

P: 18JUN2021 134791    18.0S  178.0W 4.0-5.8 AAAAA  Tonga Islands              

 

ODERATE QUAKE IN ALASKA PENINSULA RELATED TO SOLAR ECLIPSE

 

EARTHQUAKE SUMMARY FOR JUNE 18, 2021

 

The strongest earthquake in the world today was an M 5.3 in the region south of

Alaska. It was not reported felt in this remote area. An earthquake of M 5.3 last occurred in this region within about 150 km of this epicenter on December 16, 2020. But the last events in this region of larger magnitude occurred on October 19-20, 2020 following the M 7.6 quake in the Alaska Peninsula of October 19, 2020. When an M 4.8 hit near this epicenter on June 14, 2021, this summary noted in this regard:

 

 

"The strongest earthquake in the U.S. or Canada today was an M 4.8 in the area of the Alaska Peninsula. The last earthquake of equal or larger magnitude within about 200 km of this epicenter occurred on December 16 and 19, 2020 with M 5.3 and 5.1. These are aftershocks of the M 6.5 in the Alaska Peninsula of October 19, 2020. Forecast 134744 had expected today's event in this area was likely around June 16. Today's event occurred within minutes of local solar midnight and was probably triggered by high tidal stresses which maximize at this hour. The event occurred at the maximum tidal longitude with the new moon as expected in this summary as" (June 15, 2021)

 

The epicenter of today's earthquake was probably promoted by energy associated with the eclipse and new moon of June 10 as it occurred a the longitude of maximum tidal stress with that eclipse as noted in previous issues of this summary:

 

"The new moon arrives on June 10 at 10:53 UT. Longitudes which are at local solar midnight at this hour include those near 160 West while those at local solar noon are near 20 East longitude. These include areas from the northern Kermadec/Tonga/Samoa arc, Hawaii and Alaska and the Aleutians in the west and Central Europe and Africa in the east. These areas are most likely to see tidal enhancement of seismicity with this new moon. Other areas could also see an increase in seismicity especially near local solar noon and midnight with a moderately strong to major quake possible in the next week. This is an annular solar eclipse. The maximum will be at 80N 66W and will be visible in northern and central Alaska and central and northern Canada. It will end north of Kamchatka, Russia and could trigger a large earthquake or volcanism in that area. In the U.S. it will be partially visible in Central Alaska, North and South Dakota through much of the eastern and northern U.S., Greenland and Canada beginning in the region of the Virgin Islands and Puerto Rico. A strong to major earthquake is likely within several days of this eclipse, most likely in eastern Asia or the Caribbean." (June 8-10, 2021)

 

O: 18JUN2021 10:02:41  53.3N  160.3W Mw=5.3  EMSC   SOUTH OF ALASKA              

P: 16JUN2021 134744    54.7N  158.9W 3.5-4.9 ABAAA  Alaska Peninsula           

 

An earthquake of M 3.9 also continued the enhancement of the aftershocks series in Southern Idaho today. The M 3.9 is the strongest aftershock in southern Idaho in the region of the March 31, 2020 event of M 6.5 since early January 2021.

The mainshock was followed  by several aftershocks of M>=3. NEIC reported this earthquake of M 3.9 in Southern Idaho was felt with intensity II-III in the area(s) of Southern Idaho at Emmett and Middleton.  The mainshock occurred within about an hour of local solar noon and was probably enhanced by tidal stresses which maximize near this hour.

 

O: 18JUN2021 21:01:37  44.5N  115.2W Ml=2.1  EMSC   SOUTHERN IDAHO

O: 18JUN2021 21:04:11  44.5N  115.3W ML=3.1  EMSC   SOUTHERN IDAHO

O: 18JUN2021 21:44:25  44.5N  115.2W Ml=3.2  EMSC   SOUTHERN IDAHO

O: 18JUN2021 20:49:36  44.5N  115.2W Ml=3.9  EMSC   SOUTHERN IDAHO               

P: 17JUN2021 134717    44.6N  115.0W 2.0-4.0 AAAAA  Montana/Idaho              

 

An M 4.7 earthquake shook the area of the Strait of Gibraltar in Morocco today. NEIC reported it was felt with intensity IV in Morocco at Al Hoceima and Imzourem. This activity is near the antipode of the major earthquakes in New Zealand and the Kermadec Islands of March 4, 2021 and had been expected as far-field  aftershocks from those events in this summary. A swarm of earthquakes in  the region of Gibraltar began shortly after the New Zealand quakes of March 4 and had been noted in this summary at the time as:

 

 

"The earlier speculation regarding far-field activity (FFA) from the southwest

Pacific in the area of western Africa and Europe is still appropriate but needs to be updated. In particular, a set of moderate earthquakes in the region of southern Spain has been ongoing since early February. The epicenter of these events is almost exactly at the antipode of the M 7.3 in the area of North Island, New Zealand. of March 4 with a number of events in this region and south in Morocco today, including at least one at exactly the antipode of the Kermadec event." (March 6-7, 2021)

 

The only earthquake in the Strait of Gibraltar of M>=4.7 in the past two years was an M 4.7 on July 25, 2020 and December 8, 2020. Forecast 134666 had expected today's event was likely within about 100 km of this epicenter in mid-June, 2021.

 

O: 19JUN2021 03:23:05  35.5N    3.6W mb=4.7  EMSC   STRAIT OF GIBRALTAR          

P: 12JUN2021 134666    36.0N    4.0W 3.5-4.9 CAAAA  Morocco/Spain              

P: 17JUN2021 134666    37.0N    4.0W 3.5-5.1 ABAAA  Morocco/Spain              

 

An experimental explosion of M 3.9 off the coast of eastern Florida today was felt in Florida with intensity IV in Clemont and II-III in Ormond Beach, Cocoa, Jacksonville, Saint Johns and Opala.

 

O: 18JUN2021 19:48:39  29.7N   79.3W ML=3.9  EMSC   OFF EAST COAST OF UNITED STATE

 

Current activity in the Virgin Islands and Anguilla of the Caribbean also continued today. This has been previous commented on in this summary and may have been initially promoted by the solar eclipse of June 10 as it was first visible in this area. The largest earthquake in this area today was an M 4.4 with an aftershock of M 4.0. Forecast 134629 had expected this activity within  about 50 km was likely around June 16.

 

O: 19JUN2021 00:57:29  19.1N   64.8W ML=3.6  EMSC   VIRGIN ISLANDS REGION

O: 18JUN2021 14:52:15  19.2N   64.5W ML=3.1  EMSC   VIRGIN ISLANDS REGION

O: 18JUN2021 12:30:06  19.3N   63.7W ML=3.4  EMSC   VIRGIN ISLANDS REGION

O: 18JUN2021 14:48:14  19.5N   63.6W ML=3.3  EMSC   VIRGIN ISLANDS REGION

O: 18JUN2021 17:51:26  19.6N   63.4W mb=4.4  EMSC   NORTH OF ANGUILLA, LEEWARD ISL.

O: 18JUN2021 20:00:09  19.7N   63.5W Md=4.0  EMSC   VIRGIN ISLANDS REGION        

P: 16JUN2021 134629    20.0N   63.0W 3.0-4.5 AAAAA  Bahamas/No. Caribbean      

 

The current swarm in Ecuador also continued today. This activity began shortly  after the solar eclipse of June 10 and may have been enhanced by stresses associated with that event. It is at the antipode of the Sumatra quake of  M 6.7 of May 14, 2021 and has included maximum magnitude events of M 4.9 and 4.9 on June 14 and 15. Forecast 134582 had expected this activity was likely within about 50 km in mid-June.

 

O: 18JUN2021 22:15:29   1.6S   80.8W ML=4.1  EMSC   NEAR COAST OF ECUADOR

O: 18JUN2021 12:00:07   1.4S   80.9W ML=4.0  EMSC   NEAR COAST OF ECUADOR        

P: 13JUN2021 134582     1.0S   81.0W 4.0-5.8 BAAAA  Ecuador                    

 

MODERATE QUAKES SHAKE HAWAII AND INDIANA

 

EARTHQUAKE SUMMARY FOR JUNE 17, 2021

 

The strongest earthquake in the U.S. or Canada today was an M 4.5 in Hawaii. It was followed by a strong series of minor aftershocks. The mainshock was reported by NEIC to have been felt throughout much of southern Hawaii Island with intensity III in Hawaii National Park, Pahala, Naalehu, Volcano, Captain Cook, Mountain View, Pahoa, Hilo, Kurtistown and Holualoa. The epicenter is near Mount Kilauea and may represent a reinvigoration of volcanism at this time. NEIC reported aftershocks of M 3.5 in Hawaii was felt with intensity II-III in the area(s) of Hawaii at Volcano, Naalehu, Captain Cook, Hilo, Kailua Kona, Kamuela and Wakoloa. Today's event is the strongest in Hawaii since an M 4.6 on July 27, 2020. Seismicity in Hawaii often is enhanced during summer months and some of this can be related to tropical storms in the north Pacific during this season. The first Tropical Cyclone in the North Pacific - TS  Carlos was active today and may have helped promote today's Hawaiian activity. Forecast 134611 had expected a moderate quake was possible in Hawaii around June 17.  These events followed an  M 4.5 on June 3, 2021. When that event occurred this summary noted it as:

 

"Hawaii is at the seventh node from the M 8.1 in the Kermadec Islands of March 4 and was probably promoted by energy from that source. And, like the event is Central Alaska of M 6.1 two days ago is near 104 degrees from the M 6.7 in Sumatra of May 14 and was probably also promoted from that epicenter. Qinghai China is at the fourth node from Hawaii (90 degrees)." (June 3, 2021)

 

The last earthquake in Hawaii of larger magnitude was an M 4.7 on January 1, 2021.

 

Forecast 134611 had expected enhanced seismicity in Hawaii was like around June 17.

 

O: 18JUN2021 02:32:04  19.4N  155.5W mb=4.4  EMSC   ISLAND OF HAWAII, HAWAII

O: 18JUN2021 03:00:51  19.3N  155.4W ML=3.7  EMSC   ISLAND OF HAWAII, HAWAII     

P: 17JUN2021 134611    18.8N  155.2W 3.0-4.4 AAAAA  Hawaii                      

 

A light to moderate earthquake of M 3.8 in the region of Indiana today continued the enhanced seismicity in the central and eastern U.S. observed over the past three days. Today's event was reported by NEIC with maximum intensity VI in Indiana at Hillsdale; V in Kingman; IV in Dana, Marshall, Rockville, Montezuma and III in Bloomingdale, Cayuga, and in Illinois at Rosedale and Clinton among others. It was reported lightly felt as far as Texas, Massachusetts, Florida, Maine, North Dakota, Minnesota, Ontario Canada along with most of the remaining states and provinces of eastern U.S. and Canada. The total eclipse of the sun of June 10, 2021 was visible in most of the region where today's event was felt and may have been a promoter of this seismicity as reported in earlier issues of this summary:

 

"The new moon arrives on June 10 at 10:53 UT. Longitudes which are at local solar midnight at this hour include those near 160 West while those at local solar noon are near 20 East longitude. These include areas from the northern Kermadec/Tonga/Samoa arc, Hawaii and Alaska and the Aleutians in the west and Central Europe and Africa in the east. These areas are most likely to see tidal enhancement of seismicity with this new moon. Other areas could also see an increase in seismicity especially near local solar noon and midnight with a moderately strong to major quake possible in the next week. This is an annular solar eclipse. The maximum will be at 80N 66W and will be visible in northern and central Alaska and central and northern Canada. It will end north of Kamchatka, Russia and could trigger a large earthquake or volcanism in that area. In the U.S. it will be partially visible in Central Alaska, North and South Dakota through much of the eastern and northern U.S., Greenland and Canada beginning in the region of the Virgin Islands and Puerto Rico. A strong to major earthquake is likely within several days of this eclipse, most likely in eastern Asia or the Caribbean." (June 8-10, 2021)

 

Today's event in Indiana is the strongest within about 150 km of this epicenter since an M 3.8 on December 30, 2010 and an M 3.8 on September 12, 2004. The only event in this region of larger magnitude occurred about 200 km northwest of today's epicenter on June 28, 2004. The day before this earthquake occurred this summary noted in this regard:

 

 

"Unusual earthquakes in the interior of the U.S. or Canada often precede strong earthquakes elsewhere along the western edge of North America. We have emphasized this in the past and it is always a possibility that a strong earthquake is possible when a moderate intraplate earthquake occurs. In the past several days we have been discussing the unusual activity in the region of the northwest U.S. and southwest Canada. This is probably the most likely region for such an event should it occur at this time." (June 27, 2004)

 

"The earthquake of Mb 4.1 (Mblg 4.5) that occurred in northern Illinois this morning several hours before the Alaska earthquake was felt lightly with light damage from falling objects and cracked plaster. This event was the strongest in the Chicago area since a moderate event which occurred nearly 70 years ago on Nov. 12, 1934." (June 29, 2004)

 

The day after this, an M 7.0 occurred in southeastern Alaska. Some light earthquakes in southeastern Alaska over the past two days are in the vicinity of the large quake on June, 30, 2004 and may continue for several more days. Forecasts 134730 and 134667 had expected today's activity within about 250 km of this epicenter in mid-June. This epicenter is at 100-103 degrees from the M 7.4 in the M 7.4 in Qinghai, China of May 21, 2021 and was probably promoted by energy from that source. Other earthquakes at this distance from the Kermadec

Islands today included the largest earthquake of the day - an M 5.3 in the Fiji Islands as well as moderate quakes in the Kermadec Islands and light earthquakes in California. An M 5.0 occurred 19 years ago in Indiana on June 18, 2002, one of the largest on record in that State.

 

O: 17JUN2021 19:18:01  39.8N   87.3W Mw=3.8  EMSC   INDIANA                      

P: 11JUN2021 134730    40.0N   84.0W 2.0-3.9 CABAA  Ohio/Lake Erie             

P: 18JUN2021 134667    38.0N   91.0W 2.0-4.4 ABBAA  New Madrid area            

 

An unusual earthquake of M 4.6 occurred today in Lake Tanganyika today. NEIC reported it was felt with maximum intensity V in Bondo Nyanza, Kenya and IV in Kreka and Jinja, Uganda, and in Homa Bay, Kenya. Lesser shaking occurred in Kenya at Migon, Slaya, and in Uganda at Kampala, Kajansi, Makono, Entebbe.

Forecast 134585 had expected today's event in mid-June.

 

O: 17JUN2021 17:49:07   0.9S   33.4E mb=4.6  EMSC   LAKE VICTORIA REGION, UGANDA 

P: 11JUN2021 134585     2.0S   29.0E 3.0-4.4 CCCAA  Lake Victoria area         

 

UNUSUAL QUAKE IN NORTHERN QINGHAI, CHINA

 

EARTHQUAKE SUMMARY FOR JUNE 16, 2021

 

The strongest earthquake in the world today was an M 5.4 in northern Qinghai, China. It was not reported felt in this region. It is not a classical aftershock of the M 7.5 in Qinghai of May 21 as it occurred about 600 km northwest of that epicenter. It was probably promoted by regional stress redistribution from the May 21 event, however. Today's event is the strongest earthquake within about 300 km of today's epicenter since an M 5.6 on November 4, 2009 about 300 km  to the southeast of the epicenter today. It is the strongest event within about 200 km of the epicenter in at least 30 years. Forecasts 134692 and 124703 had expected a moderately large earthquake in this region was possible in mid-June.

 

O: 16JUN2021 08:48:58  38.2N   93.8E Mw=5.4  EMSC   NORTHERN QINGHAI, CHINA      

P: 14JUN2021 134692    38.0N   97.0E 3.5-5.1 AACAA  So. China                  

P: 19JUN2021 134703    36.0N   93.0E 3.8-5.5 BCAAA  Xizang                      

 

A series of light earthquakes occurred today in the eastern U.S. and Canada.

These were located in Arkansas, Tennessee, Virginia, North Carolina, Ontario, and Quebec - all with M 2-3. This activity may have been enhanced by effects related to the recent solar eclipse which was visible in these areas on June 10; the current geomagnetic storm, the strongest in nearly a month and/or effects of Tropical Storm Bill which has passed east of the U.S. East Coast over the past several days as noted in previous issues of this report as:

 

 

"TS Bill formed today in the region east of Virginia with winds up to 45 kts. It is expected to track to the northeast over the next several days following the coastline of North America. Some regional seismic enhancement in eastern U.S. may accompany this storm" (June 14-16, 2021)

 

This summary has previously noted the current geomagnetic storm possible effects on seismicity as:

 

"The geomagnetic field saw active conditions today. The AP level was 17.  High latitude geomagnetic field also saw active conditions with AP 21. This is the strongest geomagnetic storm in nearly a month since AP reached 24 on May 20. This was followed the next day by the M 7.4 in Qinghai, China, the last major earthquake in the world. Geomagnetic storms of this size are often associated with enhanced global seismicity especially near the geomagnetic equator and at high latitudes and this is likely in the next several days." (June 16, 2021)

 

O: 16JUN2021 07:16:54  36.2N   91.6W Md=2.1  EMSC   ARKANSAS                     

P: 15JUN2021 134667    35.0N   92.0W 2.0-4.2 ABAAA  New Madrid area            

 

O: 16JUN2021 08:01:21  36.3N   89.5W Md=2.0  EMSC   TENNESSEE                    

P: 17JUN2021 134667    36.9N   89.2W 2.0-4.0 AAAAA  New Madrid area            

 

O: 16JUN2021 13:24:31  35.5N   84.9W Md=2.1  EMSC   EASTERN TENNESSEE            

P: 15JUN2021 134663    35.0N   84.0W 2.0-4.1 AAAAA  Kentucky/Tennessee/NC      

 

O: 16JUN2021 09:19:36  36.7N   81.1W Md=2.0  EMSC   VIRGINIA-N CAROLINA BORDER REG

O: 17JUN2021 02:43:10  36.7N   81.1W Md=2.3  EMSC   VIRGINIA-N CAROLINA BORDER REG

P: 16JUN2021 134663    37.2N   81.9W 2.0-3.9 AAAAA  Kentucky/Tennessee/NC      

 

O: 17JUN2021 03:08:23  50.1N   90.4W MB=2.7  ECAN Allanwater Bridge, ON           

 

O: 16JUN2021 08:58:48  49.1N   67.6W MB=1.6  ECAN Matane, QC                     

P:  8JUN2021 134443    47.0N   70.0W 2.0-3.9 CCBAA  Maine                      

 

O: 15JUN2021 10:29:19  44.8N   74.8W MB=2.6  ECAN Cornwall, ON                   

P: 15JUN2021 134723    45.7N   75.2W 2.0-4.3 AAAAA  New York State             

 

The increased seismicity in the Virgin Islands, Puerto Rico and the Dominican Republic continued today. Earthquakes of M 3.9 and 4.4 occurred in the Virgin Islands. Forecast 134613 had expected this activity within about 100 km around June 15. This regionally enhanced seismicity is likely for several more days.

 

NEIC reported this earthquake of M 4.2-4.4 in the Virgin Islands was felt with intensity II-III in the area(s) of the Virgin Islands at Saint Thomas.

 

O: 16JUN2021 13:00:19  19.6N   64.8W Md=3.9  EMSC   VIRGIN ISLANDS REGION

O: 16JUN2021 12:52:31  19.3N   64.9W mb=4.4  EMSC   VIRGIN ISLANDS REGION        

P: 15JUN2021 134613    19.0N   64.0W 3.0-5.1 AAAAA  Leeward Islands            

 

STRONG SERAM, INDONESIA STRIKES WITH NEW GEOMAGNETIC STORM

 

EARTHQUAKE SUMMARY FOR JUNE 15, 2021

 

An earthquake of M 5.8-6.1 shook regions of the Banda Sea, Indonesia today. NEIC reported it was felt with intensity VI in Amahai, Maluku, Indonesia.

BMG reported this event with M 6.1 was felt with intensity III in Tehoru, Masohi, Bula, Kairatu and Ambon, Indonesia. This event occurred as the strongest geomagnetic storm of the month occurred and reached its maximum intensity. As it is located near the geomagnetic equator and occurred near local solar noon, it is likely this was promoted by effects associated with this geomagnetic storm which are described in this summary as:

 

"The geomagnetic field saw active conditions today. The AP level was 17.  High latitude geomagnetic field also saw active conditions with AP 21. This is the strongest geomagnetic storm in nearly a month since AP reached 24 on May 20. This was followed the next day by the M 7.4 in Qinghai, China, the last major earthquake in the world. Geomagnetic storms of this size are often associated with enhanced global seismicity especially near the geomagnetic equator and at high latitudes and this is likely in the next several days." (June 16, 2021)

 

Two earthquake have occurred within about 250 km of this epicenter with M>=5.8 in the past year - an M 5.9 on April 3, 2021 and an M 5.9 on September 8, 2020. The last of magnitude larger than M 6.1 in this area was an M 6.5 on Septembere 25, 2019. Forecast 134581 had expected today's earthquake within about 100 km of this epicenter was likely around June 13.

 

O: 16JUN2021 04:43:08   3.5S  129.5E Mw=5.8  EMSC   SERAM, INDONESIA             

O: 16JUN2021 04:43:08   3.5S  129.5E Mw=6.1  BMG    SERAM, INDONESIA             

P: 13JUN2021 134581     4.0S  129.0E 4.0-5.4 BAAAA  Ceram area                 

 

An earthquake of M 5.5 also occurred in the south Indian Ocean area today. It was not reported felt in this remote area. Two moderately large quakes hit this region of the Indian Ocean last year - an M 6.1 on April 12, 2020 and an M 5.8 on September 19. 2020. These are the last events in this area of M>=5.5 since 2015. Forecast 134546 had expected today's activity was likely around June 9 within about 100 km of this epicenter.

 

O: 15JUN2021 23:50:04  37.5S   78.1E Mw=5.5  EMSC   MID-INDIAN RIDGE             

O: 15JUN2021 23:50:04  37.3S   78.1E mw=5.5  ANSS   Mid-Indian Ridge"

P:  9JUN2021 134546    37.0S   79.0E 4.0-5.7 CAAAA  So. Indian Ocean           

 

The M 5.5 in the Indian Ocean was followed about an hour later by an M 2.6 near the antipode in western South Dakota. Seismic activity in South Dakota often is precursory to significant seismicity in the western region of the North American plate.  For example, the last earthquakes in South Dakota of M 3.7 and 3.1 on June 4 and preceded the M 5.3 in Southern California the next day. North American plate. As today's event appears to have been triggered by energy from the M 5.5 in the Indian Ocean, that may not be the case this time. The solar eclipse of June 10 was visible in this region of South Dakota. This epicenter is at 101 degrees from the M 8.1 in the Kermadec Islands of March 4 and may have been  promoted by energy from that source.

 

O: 16JUN2021 00:11:28  44.1N  102.1W mb=2.6  ANSS   Quinn South Dakota

O: 16JUN2021 00:11:28  44.1N  102.1W mb=2.6  EMSC   SOUTH DAKOTA                 

 

MODERATE QUAKE SHAKES NORTHERN MINDANAO, PHILIPPINES

 

EARTHQUAKE SUMMARY FOR JUNE 14, 2021

 

The strongest earthquake in the world today was an M 5.7 in Northern Mindanao, Philippines. NEIC reported it was felt with intensity VII in Mindanao at Don Carlos, Osias, Bao, V in Maluko, Lumbia; IV in Kabacan, Liboran, Lumbia, Cagayan, and III in Lasang, Sumpong and Bac. It was followed by an M 5.4 aftershock. This activity was reported by PHIVOLCS to have been felt with intensity VI in Kadingilan, Bukidnon; V in Damulog and Don Carlos, Bukidnon; Wao, Lanao del Sur; IV in Kalilangan, Kitaotao, Panantucan, Kibawe, Maramag, Quezon, Libona and Talakag, Bukidnon; Cobato City, Marawi City; Marantao, Lanao del Sur, City of Iligan, Cagayan de Oro City, Banisilan and Pikit, Cotabato, Philippines. This event continues elevated seismicity in the region of Mindanao and Central Philippines which began shortly after Tropical Storm Choi-Wan made landfall near this epicenter in early June as identified in this summary at the time:

 

"TS Choi-Wan (04W) continued today east of the Philippine Islands with winds up to 40 kts. It is expected to track to the north and west over the next four days and could help promote seismicity in the Philippines while in the area." (June 1-5, 2021)

 

The last earthquake in northern Mindanao, Philippines of larger magnitude was an M 6.0 on February 7, 2021 and an M 6.0 on November 15, 2020. Forecast 134564 had expected today's event within about 150 km was likely around June 14.

 

O: 14JUN2021 14:59:43   7.7N  124.8E ML=4.7  EMSC   MINDANAO, PHILIPPINES

O: 14JUN2021 14:49:55   7.8N  125.0E Mw=5.3  EMSC   MINDANAO, PHILIPPINES

O: 14JUN2021 14:38:41   7.7N  125.0E Mw=5.7  EMSC   MINDANAO, PHILIPPINES        

P: 14JUN2021 134564     7.0N  126.0E 4.0-5.5 AAAAA  Central Philippines        

 

A moderate earthquake of M 5.0 occurred today midway between Puerto Rico and the Dominican Republic. NEIC reported it was felt with intensity IV in Higuey, Dominican Republic and II-III in the Dominican Republic at Boca de Yuma, Otra Banda La Altagracia, La Romana, San Pedro de Marcoris, Los Llanos,and in Puerto Rico at Aguada, Cabo Rojo, Mayaguez and Anasco. It was preceded by an M 4.1 foreshock felt with intensity IV in Otra Banda and II in Santo Domingo, Dominican Republic. NEIC reported aftershocks in Puerto Rico and the Dominican Republic were felt with intensity II-III in the area(s) of Puerto Rico at Mayaguez and Gurabo. The solar eclipse of June 10 was first visible in this area of the northern Caribbean as previously discussed in this summary. In the previous issue the increased seismicity in this region had been noted as:

 

"Enhanced seismicity in the Virgin Islands and in areas of northeastern Asia is expected to continue for several more days. After several days of enhanced regional activity today's was muted and seemed to be nearer the border of Puerto Rico and the Dominican Republic than in the Virgin Islands area." (June 13-14, 2021)

 

Today's event of M 5.0 is the strongest within about 100 km since an M 5.3 on

February 3, 2019. The only other such event in the region in the past 9 years was an M 5.8 on May 28, 2014. Forecast 134625 had expected today's activity was likely around June 15.

 

O: 14JUN2021 10:10:07  18.2N   68.5W mb=3.8  EMSC   MONA PASSAGE, DOMINICAN REPUBLIC

O: 14JUN2021 10:15:42  18.2N   68.5W Mw=5.0  EMSC   MONA PASSAGE, DOMINICAN REPUBLIC

O: 14JUN2021 11:56:29  18.3N   68.5W Md=3.2  EMSC   MONA PASSAGE, DOMINICAN REPUBLIC

O: 14JUN2021 19:51:57  18.5N   67.4W Md=3.0  EMSC   PUERTO RICO REGION

O: 15JUN2021 01:30:57  18.8N   68.4W Md=3.2  EMSC   DOMINICAN REPUBLIC REGION

O: 15JUN2021 06:39:53  19.1N   68.3W ML=3.0  EMSC   DOMINICAN REPUBLIC REGION

O: 14JUN2021 16:28:50  18.1N   68.5W ML=3.0  EMSC   DOMINICAN REPUBLIC REGION    

P: 15JUN2021 134625    19.0N   68.0W 3.4-5.1 AAAAA  Puerto Rico                

 

An M 2.8 earthquake in the Resolution Island area, Nunavit, Canada occurred today. NEIC has not reported an earthquake of this size within about 250 km of this epicenter in the past 30 years. The annular solar eclipse of June 10 was visible at this epicenter 10:04 UT and stresses associated with that event probably helped trigger today's earthquake. Forecast 134762 had expected this event was likely within this area around June 18.

 

O: 14JUN2021 07:29:21  61.7N   64.2W MB=2.8  ECAN Resolution Island, NU          

P: 18JUN2021 134762    61.0N   60.0W 2.5-4.2 BABAA  Baffin/Davis Strait Canada 

 

The strongest earthquake in the U.S. or Canada today was an M 4.8 in the area of the Alaska Peninsula. The last earthquake of equal or larger magnitude within about 200 km of this epicenter occurred on December 16 and 19, 2020 with M 5.3 and 5.1. These area aftershocks of the M 6.5 in the Alaska Peninsula of October 19, 2020. Forecast 134744 had expected today's event in this area was likely around June 16. Today's event occurred within minutes of local solar midnight and was probably triggered by high tidal stresses which maximize at this hour. The event occurred at the maximum tidal longitude with the new moon as expected in this summary as:

 

 

"The new moon arrives on June 10 at 10:53 UT. Longitudes which are at local solar midnight at this hour include those near 160 West while those at local solar noon are near 20 East longitude. These include areas from the northern Kermadec/Tonga/Samoa arc, Hawaii and Alaska and the Aleutians in the west and Central Europe and Africa in the east. These areas are most likely to see tidal enhancement of seismicity with this new moon. Other areas could also see an increase in seismicity especially near local solar noon and midnight with a moderately strong to major quake possible in the next week. This is an annular solar eclipse. The maximum will be at 80N 66W and will be visible in northern and central Alaska and central and northern Canada. It will end north of Kamchatka, Russia and could trigger a large earthquake or volcanism in that area. In the U.S. it will be partially visible in Central Alaska, North and South Dakota through much of the eastern and northern U.S., Greenland and Canada beginning in the region of the Virgin Islands and Puerto Rico. A strong to major earthquake is likely within several days of this eclipse, most likely in eastern Asia or the Caribbean." (June 8-10, 2021)

 

O: 14JUN2021 10:41:55  53.6N  159.7W mb=4.8  EMSC   SOUTH OF ALASKA              

P: 16JUN2021 134744    54.7N  158.9W 3.5-4.9 ABAAA  Alaska Peninsula           

 

SEISMIC ENHANCEMENT FROM ECLIPSE CONTINUES

 

EARTHQUAKE SUMMARY FOR JUNE 13, 2021

 

Earthquakes of M 4.4 and 4.5 in Sakhalin, Russia and of M 4.2-4.5 in Kamchatka as well as an M 2.4 in Virginia today were in the zone of the Partial Solar eclipse of June 10. The events in Kamchatka and Sakhalin were near the annular eclipse and were likely promoted by high tidal stresses associated with the eclipse and new moon. These areas were expected to see enhanced seismicity at this time as previously described in the tidal forecast in this summary:

 

"The new moon arrives on June 10 at 10:53 UT. Longitudes which are at local solar midnight at this hour include those near 160 West while those at local solar noon are near 20 East longitude. These include areas from the northern Kermadec/Tonga/Samoa arc, Hawaii and Alaska and the Aleutians in the west and Central Europe and Africa in the east. These areas are most likely to see tidal enhancement of seismicity with this new moon. Other areas could also see an increase in seismicity especially near local solar noon and midnight with a moderately strong to major quake possible in the next week. This is an annular solar eclipse. The maximum will be at 80N 66W and will be visible in northern and central Alaska and central and northern Canada. It will end north of Kamchatka, Russia and could trigger a large earthquake or volcanism in that area. In the U.S. it will be partially visible in Central Alaska, North and South Dakota through much of the eastern and northern U.S., Greenland and Canada beginning in the region of the Virgin Islands and Puerto Rico. A strong to major earthquake is likely within several days of this eclipse, most likely in eastern Asia or the Caribbean." (June 8-10, 2021)

 

The earthquakes in Sakhalin, Russia of M 4.4 and 4.5 are of particular note.

They are the strongest within about 250 km of these epicenters since an M 4.6 on November 8, 2020 - the only such event in the area in the past year and a half with the last earthquake in this area of significantly larger magnitude an M 5.2 on February 19, 2014. Earthquakes of M 4.5-4.7 also occurred in this region on September 1, 2018 and December 7, 2018. These events are located at the southwestern edge of the end of the eclipse and were likely, given their unusual position and timing, which was within about half an hour of local solar noon, enhanced by strong tidal effects associated with the eclipse. Forecast 134757 had expected this activity was likely within about 50 km around June 15.

 

O: 14JUN2021 01:57:18  53.8N  143.6E mb=4.4  EMSC   SAKHALIN, RUSSIA

O: 14JUN2021 00:26:58  53.9N  143.7E mb=4.5  EMSC   SAKHALIN, RUSSIA             

P: 15JUN2021 134757    54.0N  143.0E 4.0-5.8 AAAAA  Sakhalin                   

 

O: 13JUN2021 14:30:39  52.8N  159.7E mb=4.0  EMSC   OFF EAST COAST OF KAMCHATKA  

P: 18JUN2021 134749    53.0N  160.0E 4.0-5.4 BAAAA  E. of Kamchatka            

 

Earthquakes Canada released new data for the Ontario quake on June 13 with revised magnitude M 2.7. In the previous issue of this summary this event had been noted as:

 

"The eclipse was partial when it passed over the epicenter of the M 2.2 in southern Ontario on June 10 becoming an annual eclipse several minutes later in Quebec. It is the largest earthquake in southern Ontario since a similar M 2.2 on January 25, 2021 and was probably enhanced by tidal effects associated with the eclipse. The only earthquake within about 200 km of this epicenter in the past year with larger magnitude was an M 2.4 on August 10, 2020. Forecast 134723 had expected today's event was likely within about 50 km of today's epicenter around June 15." (June 12-13, 2021)

 

The last earthquake within about 100 km of this epicenter with M>=2.7 was an M 2.9 on July 19, 2018. An M 3.9 occurred about 150 km north of this on May 9, 2020. This epicenter is at 100 degrees from the M 7.4 quake in Qinghai, China of  May 21 and may have been promoted by energy from that source.

 

O: 13JUN2021 02:02:52  45.7N   76.2W MB=2.7  ECAN Wakefield, QC                  

P: 15JUN2021 134723    45.7N   75.2W 2.0-4.3 AAAAA  New York State             

 

An earthquake of M 2.4 in Virginia today was also at an epicenter where a partial solar eclipse was visible on June 10. The last earthquake within about 100 km of this epicenter with M>=2.4 occurred February 12, 2021 with M 2.6 and 2.8. Forecast 134663 had expected today's activity was likely around June 16 within about 50 km of today's epicenter.

 

O: 13JUN2021 09:23:23  37.0N   82.3W Md=2.4  EMSC   VIRGINIA                     

P: 16JUN2021 134663    37.2N   81.9W 2.0-3.9 BAAAA  Kentucky/Tennessee/NC      

 

Enhanced seismicity in the Virgin Islands and in areas of northeastern Asia is expected to continue for several more days. After several days of enhanced regional activity today's was muted and seemed to be nearer the border of Puerto Rico and the Dominican Republic than in the Virgin Islands area.

 

O: 14JUN2021 04:42:29  17.9N   67.0W Md=3.0  EMSC   PUERTO RICO REGION           

P: 16JUN2021 134625    18.0N   67.0W 3.4-5.2 AAAAA  Puerto Rico                

 

O: 13JUN2021 09:58:00  18.6N   69.0W ML=3.0  EMSC   DOMINICAN REPUBLIC           

P: 15JUN2021 134625    19.0N   68.0W 3.4-5.1 AAAAA  Puerto Rico                

 

O: 13JUN2021 19:43:10  19.4N   63.8W ML=3.2  EMSC   VIRGIN ISLANDS REGION        

P: 15JUN2021 134613    19.0N   64.0W 3.0-5.1 AAAAA  Leeward Islands            

 

The aftershock series in the Niland area of Southern California was in decline today. A new series about 150 km southwest of this, however began and some indications suggested a further migration to the west with these events  was occurring. This series included events of M 3.2, 3.3 and 3.2 and had been expected in forecast 134780 to occur within about 15 km of these epicenters around June 14. 

 

NEIC reported the earthquake of M 3.5 in Baja California  was felt with intensity II-III in the area(s) of  California in Chula Vista.

 

O: 13JUN2021 14:21:59  32.0N  116.2W Ml=2.5  EMSC   BAJA CALIFORNIA, MEXICO

O: 13JUN2021 14:35:05  32.0N  116.2W ML=3.2  EMSC   BAJA CALIFORNIA, MEXICO

O: 13JUN2021 15:08:10  32.0N  116.3W ML=3.3  EMSC   BAJA CALIFORNIA, MEXICO

O: 13JUN2021 15:08:10  32.0N  116.3W ML=3.5  ANSS   BAJA CALIFORNIA, MEXICO

O: 13JUN2021 17:55:44  31.6N  116.0W ML=3.2  EMSC   BAJA CALIFORNIA, MEXICO      

P: 14JUN2021 134680    31.9N  116.3W 2.5-4.4 AAAAA  So. California             

 

The strongest earthquakes in the world today occurred in oceanic regions  south of Iran and Yemen. The largest of these was an M 5.5 in the Gulf of Aden which was preceded by an M 4.5 foreshock. An M 5.1 also occurred in the Chagos Archipelago area southeast of this. The events in the Gulf of Aden are the strongest in that region within about 250 km since an M 5.7 on August 2, 2007.

Forecast 134610 had expected this region would see enhanced seismicity within  this area around June 18. This and the event in Chagos are near the seventh node (51 degrees) from the M 7.4 in Qinghai, China of May 21 and may have been promoted by energy from that source. Other activity today at this distance from Qinghai occurred in central and eastern New Guinea.

 

O: 13JUN2021 14:32:31  12.5N   48.5E mb=4.5  EMSC   GULF OF ADEN

O: 14JUN2021 02:44:58  12.7N   48.6E Mw=5.5  EMSC   GULF OF ADEN                 

P: 18JUN2021 134610    13.0N   51.0E 3.5-4.9 BACAA  Gulf of Aden               

 

The M 5.1 in the Chagos Archipelago region is the largest within about 250 km of that epicenter since an M 5.4 on April 9, 2020. An M 4.8 occurred about 250 km

north of this on May 21, 2021 and this may be a regional aftershock of that event. Forecast 134584 had expected enhanced seismicity in this area around June 19. This epicenter is near the antipode of Tropical Storm Carlos in the Pacific and may have been promoted by energy from that source.

 

O: 13JUN2021 09:28:02   4.9S   68.5E mb=5.1  EMSC   CHAGOS ARCHIPELAGO REGION    

P: 19JUN2021 134584     3.0S   68.0E 4.0-5.6 CBAAA  Indian Ocean               

 

MODERATE QUAKES SHAKE GUATEMALA

 

EARTHQUAKE SUMMARY FOR JUNE 12, 2021

 

The largest earthquake widely felt in the world today was an M 5.4 in Guatemala. NEIC reported it was felt with intensity VI in Guatemala at La Democracia, Cotzumalguapa Escuinta, Patulul, IV in Nueva Concepcion, San Juan la Laguna Solola, San Marcos, and III in La Gomvera, Rio Bravo, Patsun, Chimaltenago and Ciudad Vieja, Sacatepequez.  The only earthquakes in Guatemala in the past year of larger magnitude occurred as an M 5.8 on August 4, 2020 and an M 5.9 on January 15, 2021. Forecasts 134323 and 134609 had expected today's activity was likely between June 8 and 16.

 

O: 12JUN2021 22:50:30  13.5N   92.2W mb=4.1  EMSC   OFFSHORE GUATEMALA           

O: 13JUN2021 02:58:18  14.1N   91.3W Mw=5.4  EMSC   GUATEMALA                    

P:  8JUN2021 134323    14.0N   91.0W 3.5-5.3 BAAAA  Guatemala                  

P: 16JUN2021 134609    15.0N   91.0W 3.5-5.5 BAAAA  Guatemala                  

 

O: 12JUN2021 13:17:12  13.6N   90.4W mb=4.4  EMSC   OFFSHORE GUATEMALA           

P: 15JUN2021 134609    13.0N   90.0W 3.5-5.5 BAAAA  Guatemala                  

 

O: 13JUN2021 06:07:24  15.4N   93.6W ML=4.2  EMSC   OFFSHORE CHIAPAS, MEXICO

O: 12JUN2021 09:44:26  15.6N   94.9W ML=4.0  EMSC   OFFSHORE OAXACA, MEXICO

O: 12JUN2021 15:57:47  14.2N   93.1W mb=4.5  EMSC   OFF COAST OF CHIAPAS, MEXICO 

O: 13JUN2021 06:47:02  15.3N   94.0W ML=4.0  EMSC   OFFSHORE CHIAPAS, MEXICO     

P: 13JUN2021 134606    15.0N   94.0W 3.5-5.3 AAAAA  Chiapas, Mexico             

 

A moderate quake of M 4.0-4.1 shook the California Geysers area north of San Francisco today. NEIC reported maximum intensity VI in California at Windsor and IV in Kelseyville with lesser shaking in Geyserville, Cloverdale, Middletown, Healdsburg, Hidden Valley, Hopland, Calistoga and Lakeport among others.  This is the strongest earthquake in the area of the California Geysers in 1.5 years - since an M 4.2 on November 3, 2019. An M 4.1 also occurred on March 25, 2020.

The last earthquake significantly larger magnitude in the area was an M 5.0 on December 14, 2016. Forecast 134657 had expected today's event was likely around June 14.

 

O: 13JUN2021 06:54:46  38.8N  122.8W ML=3.2  EMSC   NORTHERN CALIFORNIA          

O: 13JUN2021 06:54:46  38.8N  122.8W ML=4.1  ANSS   NORTHERN CALIFORNIA          

O: 13JUN2021 06:54:46  38.8N  122.8W ML=4.0  EMSC   NORTHERN CALIFORNIA          

P: 14JUN2021 134657    38.7N  122.7W 2.5-4.4 AAAAA  Central California         

 

The most active region of the U.S. or Canada today occurred in the Kodiak Island area of Alaska. The last earthquake of M>=4.2 in the Kodiak area was an M 4.4 on March 4, 2021 and prior to that an M 4.4 on February 11. Forecast 134745 expected today's event was likely within about 200 km of this epicenter was likely around June 15.

 

O: 12JUN2021 20:47:57  56.3N  152.1W mb=4.2  EMSC   KODIAK ISLAND REGION, ALASKA

O: 12JUN2021 21:00:41  56.3N  152.1W ML=3.1  EMSC   KODIAK ISLAND REGION, ALASKA

O: 12JUN2021 20:39:21  56.5N  152.4W ML=3.1  EMSC   KODIAK ISLAND REGION, ALASKA

O: 12JUN2021 21:20:09  56.2N  152.2W ML=3.2  EMSC   KODIAK ISLAND REGION, ALASKA 

P: 15JUN2021 134745    54.7N  148.9W 3.5-4.9 BBBAA  Alaska Peninsula           

 

The enhanced seismicity related to the solar eclipse of June 10 continued today. Light to moderate earthquakes occurred today at the locations where the eclipse began over Southern Ontario (M 2.2) and at the end of eclipse in Sakha, Russia (M 4.0). Earthquakes of M>=4 in the Sakha region of Russia within about 500 km of this epicenter are not common. Events of M>4.2-4.3 last occurred in this area on January 11, 2021 and March 27, 2020, so today's event appears to have been enhanced by effects from the solar eclipse.

 

O: 13JUN2021 04:28:45  72.3N  124.9E mb=4.0  EMSC   NORTHWESTERN SAKHA, RUSSIA   

 

The eclipse was partial when it passed over the epicenter of the M 2.2 in southern Ontario on June 10 becoming an annual eclipse several minutes later in Quebec. It is the largest earthquake in southern Ontario since a similar M 2.2 on January 25, 2021 and was probably enhanced by tidal effects associated with the eclipse. The only earthquake within about 200 km of this epicenter in the past year with larger magnitude was an M 2.4 on August 10, 2020. Forecast 134723 had expected today's event was likely within about 50 km of today's epicenter around June 15.

 

O: 13JUN2021 02:02:52  45.7N   76.2W mb=2.2  EMSC   SOUTHERN ONTARIO, CANADA     

P: 15JUN2021 134723    45.7N   75.2W 2.0-4.3 AAAAA  New York State             

 

The solar eclipse began near the Virgin Islands and Anguilla region of the Leeward Islands. It was preceded and coincident with a series of moderate earthquakes in the area. This activity also continued today with lightly felt quakes of M 4.0 and 4.1. Forecast 134629 had expected this activity within about 100 km was likely around June 11.

 

O: 12JUN2021 11:29:34  19.3N   63.1W mb=4.1  EMSC   ANGUILLA REGION, LEEWARD ISLANDS

O: 12JUN2021 19:58:04  19.3N   63.6W ML=3.2  EMSC   VIRGIN ISLANDS REGION

O: 12JUN2021 08:41:44  19.3N   63.2W mb=4.0  EMSC   ANGUILLA REGION, LEEWARD ISLAN

P: 11JUN2021 134629    20.0N   64.0W 3.0-4.6 AAAAA  Bahamas/No. Caribbean      

 

SOUTHERN CALIFORNIA SERIES RE-ENERGIZED

 

EARTHQUAKE SUMMARY FOR JUNE 11, 2021

 

 

The series of earthquakes in the Niland and El Centro area of Southern California resumed today after several days of quiet in the aftershocks following an M 5.3 three days ago. Today's activity included an M 3.9 and 4.3 which were felt with intensity III-IV in Calipatria, Winterhaven, Thermal, Calexico, Imperial, Brawley and El Centro, California. Following is a listing of events of M>=3 in this area today. A listing of aftershocks of M>=2 can be found in the California section below. Forecast 134682 had expected today's enhanced activity was likely around June 13.

 

O: 12JUN2021 04:27:34  33.2N  115.7W Mw=3.9  EMSC   SOUTHERN CALIFORNIA

O: 12JUN2021 04:30:28  33.2N  115.7W Mw=3.7  EMSC   SOUTHERN CALIFORNIA

O: 12JUN2021 04:39:46  33.2N  115.7W Mw=4.3  EMSC   SOUTHERN CALIFORNIA

O: 12JUN2021 04:41:37  33.2N  115.7W Mw=3.9  EMSC   SOUTHERN CALIFORNIA

O: 12JUN2021 04:48:44  33.2N  115.7W ML=3.2  EMSC   SOUTHERN CALIFORNIA

O: 12JUN2021 05:55:20  33.2N  115.7W Mw=3.8  EMSC   SOUTHERN CALIFORNIA

P: 13JUN2021 134682    33.2N  115.7W 2.5-4.6 AAAAA  So. California             

 

 

The strongest earthquakes in the U.S. or Canada today were a pair of M 4.2-4.3 events in the Fort McPherson of Northwest Territories, Canada.  The partial annular eclipse was visible at this epicenter around 11:00 UT on June 10.

Earthquakes of M 4.2-4.3 occurred within about 200 km of this epicenter on

February 10, 2021 and December 21, 2020, but the last such event of significantly larger magnitude in this area was an M 5.0 on December 22, 2017. Forecast 134503 expected this area would see enhanced seismicity in early June.

Forecast 134774 and 134777 had expected this event was likely around June 11-15 within about 50 km of this epicenter.

 

O: 11JUN2021 07:05:15  66.7N  135.8W Mw=3.8  EMSC   NORTHERN YUKON TERRITORY, CANA

O: 11JUN2021 07:05:15  66.8N  135.9W MB=4.3  ECAN Fort McPherson, NT   

O: 11JUN2021 07:05:00  66.7N  135.9W MB=4.2  ECAN of Fort McPherson, NT  

O: 11JUN2021 07:05:15  66.7N  135.4W MB=4.2  ECAN OF FORT MCPHERSON, NT          

P: 11JUN2021 134774    66.9N  135.8W 3.0-4.9 AAAAA  Northern Alaska            

P: 15JUN2021 134777    67.0N  135.0W 2.5-4.3 BAAAA  Yukon Territory, Canada    

 

The strongest earthquake in the world today was an M 5.2 and M 5.3 in the

region of Taiwan. CWB reported this earthquake was felt with intensity IV in Taitung, III in Pingtung; II in Hualien, Kaohsiung, Chiayi, Tainan, Yunlin, Changhua, Nantou and Taichung Counties, Taiwan. NEIC reported this earthquake of M 4.9 in Taiwan was felt with intensity II-III in the area(s) of Taiwan in Taitung (IV) and Taichung. The M 5.2 was reported by NEIC as felt with intensity IV in Taiwan at Hualien, and Taoyuan and II-III in Taichung, Taipei, and Tainan. The last earthquake in the region of Taiwan of M>=5.3 occurred as an M 5.8  near today's epicenter on April 18. Forecasts 134644 and 134360 had expected today's activity within about 50 km was likely around June 10-13.

 

 

O: 11JUN2021 07:36:43  23.9N  121.5E ML=4.9  EMSC   TAIWAN

O: 11JUN2021 08:53:47  23.9N  121.6E ML=4.2  EMSC   TAIWAN

O: 11JUN2021 08:55:19  23.9N  121.6E ML=4.1  EMSC   TAIWAN

O: 11JUN2021 22:49:12  24.8N  122.6E mb=4.6  EMSC   TAIWAN REGION

O: 11JUN2021 21:58:56  22.6N  121.1E ML=5.3  TAI    Hualien, Taiwan              

O: 11JUN2021 21:58:57  22.6N  121.3E Mw=4.9  EMSC   TAIWAN REGION                

O: 11JUN2021 07:33:26  23.9N  121.6E Mw=5.2  EMSC   TAIWAN                       

P: 13JUN2021 134644    24.0N  121.0E 4.0-5.4 AAAAA  Taiwan                     

P: 10JUN2021 134360    21.0N  120.0E 4.0-5.4 ABAAA  Taiwan                     

 

TRIGGERED ECLIPSE SEISMICITY EXPANDS

 

EARTHQUAKE SUMMARY FOR JUNE 10, 2021

 

In the previous issue of this summary, it was noted that the M 4.8-5.0 in the Ungava, Quebec area of Canada occurred a bit more than an hour after the center of the solar eclipse of  June 10 passed over this exact epicenter and was the strongest earthquake in Quebec within about 500 km of this epicenter in at least 30 years. This was not the only earthquake located in Canada since the eclipse which occurred at an epicenter where the eclipse was fully visible. An M 2.6 near Resolution Island to the west of the M 4.8-5.0 occurred several hours before the eclipse and an M 2.3 in the Baffin Bay area of Nunavit, Canada occurred early on June 11. The full eclipse was also visible at this epicenter. The Resolution Island event had been expected in early June within about 150 km of this epicenter in forecast 134491. The M 2.3 in Baffin Bay had been expected within about 100 km of this epicenter around June 9.

 

O: 10JUN2021 05:36:16  61.0N   61.2W MB=2.6  ECAN Resolution Island, NU          

P:  4JUN2021 134491    61.0N   58.0W 2.5-4.1 CABAA  Baffin/Davis Strait Canada 

 

The annular eclipse was fully visible at this epicenter at 10:06 UT on June 10.

 

O: 11JUN2021 03:20:44  72.0N   75.1W MB=2.3  ECAN Pond Inlet, NU                 

P:  9JUN2021 134508    71.0N   75.0W 2.5-4.1 AAAAA  Baffin/Davis Strait Canada 

 

The annular eclipse was fully visible at this epicenter at 10:26 UT on June 10.

 

A group of other minor earthquakes occurred within the area where the eclipse was partially visible. These occurred in the Lake Erie area of Ohio,  and in the Fort McPherson area of Northwest Territories, Canada with two events of M 4.2 reported by Earthquakes Canada. This event had been expected in early June in this general area.

 

O: 11JUN2021 07:05:15  66.7N  135.4W MB=4.2  ECAN OF FORT MCPHERSON, NT          

O: 11JUN2021 07:05:00  66.7N  135.9W MB=4.2  ECAN of Fort McPherson, NT          

O: 11JUN2021 07:05:15  66.7N  135.8W mb=4.1  EMSC   NORTHERN YUKON TERRITORY, CANA

P:  6JUN2021 134503    64.0N  138.0W 3.0-4.7 BCAAA  Northern Alaska            

 

The partial annular eclipse was visible at this epicenter around 11:00 UT on June 10.

 

The earthquake in Lake Erie had been expected within about 150 km of this epicenter in forecast 134459 to occur around June 10.

 

O: 10JUN2021 12:52:34  42.3N   81.1W MB=2.1  ECAN Lake Erie                      

P: 10JUN2021 134459    41.0N   81.0W 2.0-3.9 ABAAA  Ohio/Lake Erie             

 

O: 10JUN2021 15:36:20  63.3N  165.5W ML=3.0  EMSC   BERING STRAIT                

 

The partial annular eclipse was visible at this epicenter around 10:40 UT on June 10.

 

 

The mainquake triggered by tidal stresses associated with the eclipse occurred

in the Ungava area of Quebec and was reported in the previous issue of this summary as:

 

"The annular solar eclipse occurred today. At least one significant earthquake appears to have been directly triggered by this tidal alignment. According to the NASA solar eclipse page the Annular eclipse passed over an area of Quebec, Canada at 60N 74W at 10:04 UT. A bit more than hour later an earthquake of M 4.6 hit at 60N 74W in the Ungava Peninsula, Quebec Canada. Earthquakes Canada gives this event at M 4.9 in the region east of Povungnituk south of Baffin Bay, Canada. This is not an insignificant regional event. It is the largest within about 500 km of this epicenter in at least 30 years. The only larger earthquake in the past 30 years within about 1000 km of this epicenter occurred on October 13, 1992 (M 4.8). No events of M>=4.9 had hit this area in at least 30 years. An earthquake of M 6.5 hit within about 500 km of today's epicenter on December 25, 1989, part of a series with foreshocks of M 5.6 on March 16, 1989 and M 5.1 on December 25, 1989. The earthquake which began this activity in March, 1989  also followed a solar eclipse which was visible at this epicenter a week earlier on March 16, 1989. Other earthquakes of M>4.9 occurred in the area on March 5, 1955 and January 30, 1959. This is a remarkable occurrence and is direct proof of the triggering capacity of strong tidal stresses associated with eclipses on seismicity, the clearest example in many years. The coincidence of the solar eclipse at this epicenter at the time of this earthquake clearly indicates a direct triggering relationship with the earthquake.

 

"The new moon arrives on June 10 at 10:53 UT. Longitudes which are at local solar midnight at this hour include those near 160 West while those at local solar noon are near 20 East longitude. These include areas from the northern Kermadec/Tonga/Samoa arc, Hawaii and Alaska and the Aleutians in the west and Central Europe and Africa in the east. These areas are most likely to see tidal enhancement of seismicity with this new moon. Other areas could also see an increase in seismicity especially near local solar noon and midnight with a moderately strong to major quake possible in the next week. This is an annular solar eclipse. The maximum will be at 80N 66W and will be visible in northern and central Alaska and central and northern Canada. It will end north of Kamchatka, Russia and could trigger a large earthquake or volcanism in that area. In the U.S. it will be partially visible in Central Alaska, North and South Dakota through much of the eastern and northern U.S., Greenland and Canada beginning in the region of the Virgin Islands and Puerto Rico. A strong to major earthquake is likely within several days of this eclipse, most likely in eastern Asia or the Caribbean." (June 7-9, 2021)

 

This was further noted in the previous issue of this summary as:

 

 

"The path of this eclipse does not cover many major seismic zones. As noted above it begins near the Virgin Islands where a series of unusual moderate earthquakes has been occurring over the past two days in the Anguilla area. This continued today with an M 3.6, 3.8 and 4.0. Other areas of interest on this eclipse path include the Baffin Bay area of Canada and the North Geomagnetic Pole which will see a total eclipse. Unusual seismicity in these areas is a possibility at this time. An M 2.1 did occur on the eclipse path today in the Baffin Bay and it will be interesting to see what effect this alignment has on the geomagnetic field as it passes over. Central and Northern Alaska saw an unusual M 6.1 near Fairbanks last week and aftershocks and perhaps a separate mainshock are likely in this area in the next several days." (June 9-10, 2021)

 

 

O: 10JUN2021 11:20:14  60.1N   73.9W mb=4.6  EMSC   UNGAVA PENINSULA, QUEBEC, CANA

O: 10JUN2021 11:20:13  60.2N   74.3W MB=4.8  ECAN OF POVUNGNITUK, QC             

P:  9JUN2021 134485    59.0N   76.0W 2.0-3.9 ABAAA  Quebec, Canada             

P: 10JUN2021 134491    60.0N   79.0W 2.5-4.2 AABAA  Baffin/Davis Strait Canada 

 

The strongest earthquakes in the U.S. or Canada today were a pair of M 4.2 events in the Fort McPherson of Northwest Territories, Canada.  The partial annular eclipse was visible at this epicenter around 11:00 UT on June 10. Earthquakes of M 4.2-4.3 occurred within about 200 km of this epicenter on  February 10, 2021 and December 21, 2020, but the last such event of significantly larger magnitude in this area was an M 5.0 on December 22, 2017. Forecast 134503 expected this area would see enhanced seismicity in early June.

 

O: 11JUN2021 07:05:15  66.7N  135.4W MB=4.2  ECAN OF FORT MCPHERSON, NT          

O: 11JUN2021 07:05:00  66.7N  135.9W MB=4.2  ECAN of Fort McPherson, NT          

P:  6JUN2021 134503    64.0N  138.0W 3.0-4.7 BCAAA  Northern Alaska            

 

 

The strongest earthquake in the world today was an M 5.7 in Costa Rica. NEIC reported it was felt in Costa Rica with maximum intensity VI at Chacanita, Puntarenas,V in Esparta and IV in Jaco and Atenas. Lesser shaking occurred in Samara, AGuanacasts, Papuera, Santa Cruz, Miramar, Juntas, and Santiago, Alajuela. The last earthquake of equal or larger magnitude in Costa Rica was an M 6.0 on August 24, 2020. Forecast 134282 had expected today's event was likely within about 50 km around June 9.

 

O: 10JUN2021 23:27:00   9.0N   85.3W Mw=5.7  EMSC   OFF COAST OF COSTA RICA      

P:  9JUN2021 134282     9.0N   86.0W 3.5-5.0 AAAAA  Costa Rica                 

 

 

LAR ECLIPSE TRIGGERS UNPRECEDENTED QUAKE IN UNGAVA, QUEBEC, CANADA

 

EARTHQUAKE SUMMARY FOR JUNE 9, 2021

 

The annular solar eclipse occurred today. At least one significant earthquake appears to have been directly triggered by this tidal alignment. According to the NASA solar eclipse page the Annular eclipse passed over an area of Quebec, Canada at 60N 74W at 10:04 UT. A bit more than hour later an earthquake of M 4.6 hit at 60N 74W in the Ungava Peninsula, Quebec Canada. Earthquakes Canada gives this event at M 4.9 in the region east of Povungnituk south of Baffin Bay, Canada. This is not an insignificant regional event. It is the largest within about 500 km of this epicenter in at least 30 years. The only larger earthquake in the past 30 years within about 1000 km of this epicenter occurred on October 13, 1992 (M 4.8). No events of M>=4.9 had hit this area in at least 30 years. An earthquake of M 6.5 hit within about 500 km of today's epicenter on December 25, 1989, part of a series with foreshocks of M 5.6 on March 16, 1989 and M 5.1 on December 25, 1989. The earthquake which began this activity in March, 1989 also followed a solar eclipse which was visible at this epicenter a week earlier on March 16, 1989. Other earthquakes of M>4.9 occurred in the area on March 5, 1955 and January 30, 1959. This is a remarkable occurrence and is direct proof of the triggering capacity of strong tidal stresses associated with eclipses on seismicity, the clearest example in many years. The coincidence of the solar eclipse at this epicenter at the time of this earthquake clearly indicates a direct triggering relationship with the earthquake.

 

"The new moon arrives on June 10 at 10:53 UT. Longitudes which are at local solar midnight at this hour include those near 160 West while those at local solar noon are near 20 East longitude. These include areas from the northern Kermadec/Tonga/Samoa arc, Hawaii and Alaska and the Aleutians in the west and Central Europe and Africa in the east. These areas are most likely to see tidal enhancement of seismicity with this new moon. Other areas could also see an increase in seismicity especially near local solar noon and midnight with a moderately strong to major quake possible in the next week. This is an annular solar eclipse. The maximum will be at 80N 66W and will be visible in northern and central Alaska and central and northern Canada. It will end north of Kamchatka, Russia and could trigger a large earthquake or volcanism in that area. In the U.S. it will be partially visible in Central Alaska, North and South Dakota through much of the eastern and northern U.S., Greenland and Canada beginning in the region of the Virgin Islands and Puerto Rico. A strong to major earthquake is likely within several days of this eclipse, most likely in eastern Asia or the Caribbean." (June 7-9, 2021)

 

This was further noted in the previous issue of this summary as:

 

 

"The path of this eclipse does not cover many major seismic zones. As noted above it begins near the Virgin Islands where a series of unusual moderate earthquakes has been occurring over the past two days in the Anguilla area. This continued today with an M 3.6, 3.8 and 4.0. Other areas of interest on this eclipse path include the Baffin Bay area of Canada and the North Geomagnetic Pole which will see a total eclipse. Unusual seismicity in these areas is a possibility  at this time. An M 2.1 did occur on the eclipse path today in the Baffin Bay and it will be interesting to see what effect this alignment has on the geomagnetic field as it passes over. Central and Northern Alaska saw an unusual M 6.1 near Fairbanks last week and aftershocks and perhaps a separate mainshock are likely in this area in the next several days." (June 9, 2021)

 

Forecasts 134485 and 134491 had expected today's activity within about 150-250 km of today's epicenter in Quebec or the Baffin Bay area of Canada was likely around June 9-10. This activity may also have been promoted by energy from  the M 8.1 in the Kermadec Islands of March 4, 2021 and the M 6.6 in Sumatra of May 14, 2021 as it is at the third node (120 degrees) from those epicenters. Current enhanced seismicity in the Virgin Islands is also at this distance from the Kermadec Islands.

 

O: 10JUN2021 11:20:14  60.1N   73.9W mb=4.6  EMSC   UNGAVA PENINSULA, QUEBEC, CANA

O: 10JUN2021 11:20:13  60.2N   74.3W MB=4.9  ECAN OF POVUNGNITUK, QC             

P:  9JUN2021 134485    59.0N   76.0W 2.0-3.9 ABAAA  Quebec, Canada             

P: 10JUN2021 134491    60.0N   79.0W 2.5-4.2 AABAA  Baffin/Davis Strait Canada 

 

An earthquake of M 2.4 also occurred today in New Jersey. It was not reported felt in this area. It was also likely promoted by high tidal stresses associated with the new moon. The only other event of M>=2.4 in New Jersey in the past year was an M 3.1 on September 9, 2020. An M 4.1 also occurred in New Jersey on November 30, 2017.

 

O:  9JUN2021 11:52:35  39.6N   74.3W mb=2.4  EMSC   NEW JERSEY                   

 

Earthquakes of M 4.4, 3.8 and M 4.0 were also felt in the Virgin Islands and Anguilla today. The solar eclipse was first observed in this area. Today's events follows similar activity in the area over the past several days and was reported by NEIC to have been felt with intensity II in San Juan, Puerto Rico. This activity was reviewed in the previous issue of this report as:

 

"A series of moderate earthquakes also hit in the northeastern Caribbean near the Virgin Islands  and Anguilla region of the Leeward Islands with M 4.6, 4.5, 4.1 ... This is the area in which the coming solar eclipse will first be seen. It is likely that this series was enhanced by tidal effects associated with the coming new moon. The last earthquake of M>=4.6 in this region was an M 4.9 on August 31, 2019 and prior to that an M 4.6 on June 25, 2014. Forecast 134343 had expected today's activity within about 50 km was likely around June 10. This activity is at the third node (120 degrees) from the M 8.1 in the Kermadec Islands of March 4 and may have been promoted by energy from that source." (June 7, 2021)

 

O: 10JUN2021 08:58:33  19.6N   63.7W Md=3.9  EMSC   VIRGIN ISLANDS REGION

O: 10JUN2021 00:29:34  19.7N   63.5W Md=4.1  EMSC   NORTH OF ANGUILLA, LEEWARD ISL.

O:  9JUN2021 08:09:31  19.3N   63.3W mb=4.4  EMSC   ANGUILLA REGION, LEEWARD ISLAN

P: 10JUN2021 134343    20.0N   64.0W 3.0-4.6 AAAAA  Bahamas/No. Caribbean      

 

An M 5.0 earthquake was widely felt in the area of Lake Tanganyika, Congo today. NEIC reported maximum intensity V in the Congo (DR) at Bukavu, Kabare; IV in KLalima and III in Uvira. This follows volcanic eruptions in the area of Mount Nyirangongo in the region of the DR Congo of May 23-27, 2021 which is about 150 km north of Lake Tanganyika and occurred with the last full moon. The last earthquake in the Lake Tanganyika area of M>=5.0 was an M 5.3 on October 30, 2019. Forecast 134299 had expected enhanced seismicity in this area was likely in early June.

 

O: 10JUN2021 08:54:17   3.1S   28.3E Mw=5.0  EMSC   LAKE TANGANYIKA REGION, CONGO

P:  5JUN2021 134299     2.0S   29.0E 3.0-4.5 BBAAA  Lake Victoria area          

 

An earthquake of M 4.0 was widely felt in Utah today. It was followed by a smaller aftershock. NEIC reported this activity was felt in Utah at Heber City, Mountain Home, Tabiona, Provo, Lindon, Spanish Fork, Lehi, Saratoga Springs, South Jordan and Salt Lake City. It occurred near local solar noon and was probably triggered by strong tidal stresses associated with today's new moon and eclipse which maximize near this hour.  This is not an aftershock of the M 5.7 of March 18, 2020 as it occurred about 150 km southeast of that epicenter. The only events in the area within about 100 km of today's epicenter with M>=4 occurred as an M 4.0 on May 25, 2016. Forecast 134433 had expected today's activity was likely around June 8. This epicenter is at 101 degrees from the M 7.4 in Qinghai, China of May 21  and was probably promoted by energy from that source.

 

O: 09JUN2021 19:55:21  40.3N  111.1W ML=2.5  EMSC   UTAH

O:  9JUN2021 19:52:50  40.3N  111.0W mb=4.0  EMSC   UTAH                         

P:  8JUN2021 134433    40.6N  106.6W 2.0-4.1 AACAA  Colorado area              

 

IMMEDIATE MAJOR SEISMIC EFFECTS FROM SOLAR ECLIPSE UNLIKELY 

 

EARTHQUAKE SUMMARY FOR JUNE 8, 2021

 

The annular solar eclipse will occur early on June 10. This summary expects

some enhanced seismicity with this event as reported in previous issues as:

 

"The new moon arrives on June 10 at 10:53 UT. Longitudes which are at local solar midnight at this hour include those near 160 West while those at local solar noon are near 20 East longitude. These include areas from the northern Kermadec/Tonga/Samoa arc, Hawaii and Alaska and the Aleutians in the west and Central Europe and Africa in the east. These areas are most likely to see tidal enhancement of seismicity with this new moon. Other areas could also see an increase in seismicity especially near local solar noon and midnight with a moderately strong to major quake possible in the next week. This is an annular solar eclipse. The maximum will be at 80N 66W and will be visible in northern and central Alaska and central and northern Canada. It will end north of Kamchatka, Russia and could trigger a large earthquake or volcanism in that area. In the U.S. it will be partially visible in Central Alaska, North and South Dakota through much of the eastern and northern U.S., Greenland and Canada beginning in the region of the Virgin Islands and Puerto Rico. A strong to major earthquake is likely within several days of this eclipse, most likely in eastern Asia or the Caribbean." (June 7-9, 2021)

 

The path of this eclipse does not cover many major seismic zones. As noted above it begins near the Virgin Islands where a series of unusual moderate earthquakes has been occurring over the past two days in the Anguilla area. This continued today with an M 3.6, 3.8 and 4.0. Other areas of interest on this eclipse path include the Baffin Bay area of Canada and the North Geomagnetic Pole which will see a total eclipse. Unusual seismicity in these areas is a possibility  at this time. An M 2.1 did occur on the eclipse path today in the Baffin Bay and it will be interesting to see what effect this alignment has on the geomagnetic field as it passes over. Central and Northern Alaska saw an unusual M 6.1 near Fairbanks last week and aftershocks and perhaps a separate mainshock are likely in this area in the next several days.

 

Forecast 134508 had expected the M 2.1 in Baffin Bay in Nunavit, Canada today was likely within about 100 km of this epicenter around June 9.

 

O:  7JUN2021 20:34:41  72.0N   75.2W MB=2.1  ECAN Pond Inlet, NU                 

P:  9JUN2021 134508    71.0N   75.0W 2.5-4.1 AAAAA  Baffin/Davis Strait Canada 

 

The activity in the Virgin Islands was noted in the previous issue of this

summary as:

 

"A series of moderate earthquakes also hit in the northeastern Caribbean near the Virgin Islands  and Anguilla region of the Leeward Islands with M 4.6, 4.5, 4.1 ... This is the area in which the coming solar eclipse will first be seen. It is likely that this series was enhanced by tidal effects associated with the coming new moon. The last earthquake of M>=4.6 in this region was an M 4.9 on August 31, 2019 and prior to that an M 4.6 on June 25, 2014. Forecast 134343 had expected today's activity within about 50 km was likely around June 10. This activity is at the third node (120 degrees) from the M 8.1 in the Kermadec Islands of March 4 and may have been promoted by energy from that source." (June 7, 2021)

 

 

O: 09JUN2021 01:47:03  19.3N   63.3W mb=4.0  EMSC   ANGUILLA REGION, LEEWARD ISLANDS

O: 08JUN2021 07:37:22  19.4N   64.1W Md=3.8  EMSC   VIRGIN ISLANDS REGION

O:  8JUN2021 09:09:18  19.2N   63.6W ML=3.6  EMSC   VIRGIN ISLANDS REGION        

P: 10JUN2021 134343    20.0N   64.0W 3.0-4.6 AAAAA  Bahamas/No. Caribbean      

 

The largest earthquake in the world today was an M 5.7 in New Britain. NEIC reported it was felt in New Britain at Kimbe and Kokopo. The last earthquake in New Britain of near-equal or greater magnitude occurred with the new moon on May 11, 2021 with M 5.4. The last of greater magnitude occurred as an M 6.1 on August 25, 2020 and  events of M 6.0-6.1 on February 9 and January 7, 2020. Forecast 134303 had expected today's event within about 200 km of this epicenter was likely around June 9.

 

O:  8JUN2021 10:56:37   5.2S  151.3E Mw=5.7  EMSC   NEW BRITAIN REGION, P.N.G.   

P:  9JUN2021 134303     7.0S  151.0E 4.0-5.4 ABAAA  New Ireland                

 

A moderate earthquake of M 5.3 also occurred off the east coast of Honshu, Japan today. NEIC reported this earthquake of M 5.3 off eastern Honshu, Japan  was felt with intensity II-III in the area(s) of eastern Honshu Japan in Fukushima and Tokyo. It may have been promoted by high tidal stresses as it occurred near local solar midnight, a time when such stresses are maximized. Forecast 134297  had expected activity within about 100 km of this epicenter was likely around June 8.

 

O:  8JUN2021 15:29:01  36.5N  143.0E Mw=5.3  EMSC   OFF EAST COAST OF HONSHU, JAPA

P:  8JUN2021 134397    37.0N  142.0E 4.0-5.4 AAAAA  Off East Coast Honshu      

 

The aftershocks in the area of southern California largely died out today without a second mainshock. There is a general tendency for the larger events in this aftershock sequence to migrate towards the northwest closer to 103 degrees from the Qinghai China M 7.4 of May 21. The largest event in the general region today was an M 3.0 south of the aftershock zone. An M 3.9 in the Gulf of California continued a series of recent events in that region. The M 3.9 may have been related to strong tidal stresses as it occurred near local solar noon when such stresses are maximized.

 

O:  8JUN2021 20:45:44  30.6N  114.3W ML=3.9  EMSC   GULF OF CALIFORNIA           

P:  4JUN2021 134348    28.0N  112.0W 3.5-4.9 BCBAA  Gulf of California         

 

O:  8JUN2021 17:35:05  31.1N  115.4W ML=3.0  EMSC   BAJA CALIFORNIA, MEXICO      

O:  8JUN2021 17:06:24  33.1N  116.0W Ml=2.6  EMSC   SOUTHERN CALIFORNIA          

O:  8JUN2021 12:37:10  33.5N  116.9W Ml=2.6  EMSC   SOUTHERN CALIFORNIA          

O: 08JUN2021 17:09:17  33.1N  115.6W ML=2.0  EMSC   SOUTHERN CALIFORNIA

O: 09JUN2021 00:39:35  33.2N  115.6W Ml=2.0  EMSC   SOUTHERN CALIFORNIA

O: 09JUN2021 05:35:34  33.2N  115.6W Ml=2.0  EMSC   SOUTHERN CALIFORNIA

P:  7JUN2021 134406    33.9N  116.6W 2.5-4.6 AAAAA  So. California             

 

OCEAN RIDGES ACTIVE

 

EARTHQUAKE SUMMARY FOR JUNE 7, 2021

 

The strongest earthquakes in the world today occurred in several ocean ridge

areas including the Southern mid-Atlantic (M 4.7); the South Sandwich Islands (M 5.0) and the Gulf of Aden (M 4.5) and central Atlantic (M 4.9). These remote events were not reported felt in these areas. Forecast 134535, 134324, 134555 and 134559 had expected this activity in general within about 200 of of these events, with the best forecasts for the Gulf of Aden for an event within about 50 km of that epicenter around June 9 and in the Southern Mid-Atlantic Ridge for an event around June 9 within about 50 km of that epicenter. While most of these appear to have been slightly promoted by high tidal stresses associated with the upcoming new moon, the relation is not yet well defined. This summary had expected associated seismicity with the new moon and eclipse of June 10 as:

 

"The new moon arrives on June 10 at 10:53 UT. Longitudes which are at local solar midnight at this hour include those near 160 West while those at local solar noon are near 20 East longitude. These include areas from the northern Kermadec/Tonga/Samoa arc, Hawaii and Alaska and the Aleutians in the west and Central Europe and Africa in the east. These areas are most likely to see tidal enhancement of seismicity with this new moon. Other areas could also see an increase in seismicity especially near local solar noon and midnight with a moderately strong to major quake possible in the next week. This is an annular solar eclipse. The maximum will be at 80N 66W and will be visible in northern and central Alaska and central and northern Canada. It will end north of Kamchatka, Russia and could trigger a large earthquake or volcanism in that area. In the U.S. it will be partially visible in Central Alaska, North and South Dakota through much of the eastern and northern U.S., Greenland and Canada beginning in the region of the Virgin Islands and Puerto Rico. A strong to major earthquake is likely within several days of this eclipse, most likely in eastern Asia or the Caribbean." (June 6-8, 2021)

 

O:  8JUN2021 04:39:59  17.9S   12.9W mb=4.9  EMSC   SOUTHERN MID-ATLANTIC RIDGE  

P:  5JUN2021 134535    20.0S   12.0W 4.0-5.5 BBAAA  So. Mid-Atlantic Ridge     

 

O:  7JUN2021 07:39:34  13.2N   50.7E mb=4.5  EMSC   GULF OF ADEN                 

P:  9JUN2021 134324    13.0N   51.0E 3.5-4.9 AAAAA  Gulf of Aden               

 

O:  7JUN2021 14:17:23  44.3S   16.2W mb=5.0  EMSC   SOUTHERN MID-ATLANTIC RIDGE  

P:  9JUN2021 134555    44.0S   16.0W 4.0-5.5 AAAAA  So. Mid-Atlantic Ridge     

 

O:  7JUN2021 06:55:18  59.6S   25.4W mb=4.7  EMSC   SOUTH SANDWICH ISLANDS REGION

P:  6JUN2021 134559    60.0S   29.0W 4.0-5.6 AABAA  So. Sandwich Islands       

 

A series of moderate earthquakes also hit in the northeastern Caribbean near the Virgin Islands  and Anguilla region of the Leeward Islands with M 4.6, 4.5, 4.1 ... This is the area in which the coming solar eclipse will first be seen. It is likely that this series was enhanced by tidal effects associated with the coming new moon. The last earthquake of M>=4.6 in this region was an M 4.9 on August 31, 2019 and prior to that an M 4.6 on June 25, 2014. Forecast 134343 had expected today's activity within about 50 km was likely around June 10. This activity is at the third node (120 degrees) from the M 8.1 in the Kermadec Islands of March 4 and may have been promoted by energy from that source.

 

O: 08JUN2021 02:44:14  19.2N   63.8W Md=3.9  EMSC   VIRGIN ISLANDS REGION

O: 07JUN2021 12:08:56  19.3N   63.6W mb=4.5  EMSC   VIRGIN ISLANDS REGION

O: 08JUN2021 05:57:17  19.4N   63.6W mb=4.1  EMSC   VIRGIN ISLANDS REGION

O: 07JUN2021 11:24:54  19.6N   64.0W Md=3.8  EMSC   VIRGIN ISLANDS REGION

O: 08JUN2021 05:11:18  19.6N   63.6W Md=4.0  EMSC   VIRGIN ISLANDS REGION

O:  7JUN2021 20:15:39  19.1N   63.3W mb=4.6  EMSC   ANGUILLA REGION, LEEWARD ISLAN

P: 10JUN2021 134343    20.0N   64.0W 3.0-4.6 BAAAA  Bahamas/No. Caribbean      

 

An unusual earthquake of M 4.5 also occurred near the antipode of these events in the Virgin Islands today. This was located in Western Australia. Antipodal effects between these two regions are unlikely to have been great enough to trigger them, but is is quite possible that tidal effects from the upcoming new moon and eclipse may have affected each area. 

 

O:  7JUN2021 08:03:18  22.5S  120.1E mb=4.5  EMSC   WESTERN AUSTRALIA            

 

The largest earthquake in the aftershock zone in southern California today was an M 3.9-4.1. NEIC reported maximum intensity IV in Calipatria and Brawley and II-III in Imperial, El Centro, Rancho Mirage, Palm Sprints, Jamul, Escondido, and San Diego. Most of today's strongest activity occurred near local solar noon and was probably promoted by strong tidal stresses associated with the coming new moon and eclipse of June 10. Forecast 134406 had expected today's activity  in Southern California was likely around June 7.

 

O: 07JUN2021 14:45:22  33.2N  115.7W ML=3.0  EMSC   SOUTHERN CALIFORNIA

O: 07JUN2021 21:08:27  33.2N  115.7W ML=3.9  EMSC   SOUTHERN CALIFORNIA

O: 07JUN2021 21:08:27  33.2N  115.7W ML=4.1  ANSS   SOUTHERN CALIFORNIA

O: 07JUN2021 21:24:51  33.2N  115.7W ML=3.3  EMSC   SOUTHERN CALIFORNIA

O: 07JUN2021 18:05:02  31.2N  116.4W Ml=3.3  EMSC   OFFSHORE BAJA CALIFORNIA, MEXICO

O:  7JUN2021 18:49:34  31.1N  116.4W ML=3.4  EMSC   OFFSHORE BAJA CALIFORNIA, MEXI

P:  7JUN2021 134406    33.9N  116.6W 2.5-4.6 AAAAA  So. California             

 

 

The seismic activity at Mount Hood, Oregon ceased today as quickly as it began yesterday. In the previous issue of this summary it had been noted as:

 

"An unusually large M 3.9-4.0 earthquake shook the Mount Hood area of Oregon today. NEIC reported intensity IV in Oregon at Government Camp, Rhododendron, and Cascake Locks, Oregon with III in Mount Hood, Parkdale, Welches, Brightwood, Hood River,  Sandy, Mosier and Estacada.  It was followed by aftershocks of M 2.1 and 2.4 and may represent subterranean volcanism in the area. The only earthquake in the past 30 years in the Mount Hood area of Oregon with M>=4 was an M 4.5 on June 29, 2002. Forecast 134461 had expected today's event within about 10 km of this epicenter was likely around June 4. This activity is at the fourth node (90 degrees) from the M 8.1 in the Kermadec Islands of March 4 and was probably promoted by energy from that source." (June 6, 2021)

 

This activity may have been triggered by effects of a strong Gamma Ray Burst (GRB) (#210606A) which occurred simultaneously with the mainshocks and may be a one-off event related to that GRB. NASA Swift catalog reported this GRB with the following parameters:

 

 

"The last major Gamma Ray Burst (GRB) according to the online NASA Swift GRB Catalog was observed on June 6, 2021 at 03:56 UT with BAT Fluence n/a 10-7 erg/cm2 (MAGNITUDE: n/a), Associated earthquakes: Mt Hood, Oregon M 4.0)" (June 7, 2021)

 

A second GRB  (#210605B) was closely associated with the energetic M 5.3 in southern California on June 5 as:

 

"The last major Gamma Ray Burst (GRB) according to the online NASA Swift GRB Catalog was observed on June 5, 2021 at 14:55 UT with BAT Fluence n/a 10-7 erg/cm2 (MAGNITUDE: n/a), Associated earthquakes: Southern California M 5.3)" (June 7, 2021)

 

O: 06JUN2021 04:14:23  45.3N  121.7W Ml=2.1  EMSC   MOUNT HOOD AREA, OREGON

O: 06JUN2021 03:51:37  45.4N  121.7W MD=4.0  EMSC   MOUNT HOOD AREA, OREGON

O: 06JUN2021 03:51:37  45.4N  121.7W MD=3.9  EMSC   MOUNT HOOD AREA, OREGON

O:  6JUN2021 03:55:36  45.3N  121.7W ML=2.4  EMSC   MOUNT HOOD AREA, OREGON      

P:  4JUN2021 134461    45.3N  121.7W 2.0-4.0 AAAAA  Oregon state, U.S.         

 

 

NEW MOON, SOLAR ECLIPSE, MAY BRING ENHANCED SEISMICITY

 

EARTHQUAKE SUMMARY FOR JUNE 6, 2021

 

The strongest earthquakes in the world today occurred at the northern Kermadec-Fiji region. An M 5.7 in the Kermadec Islands and an M 5.6 in Fiji were not reported in this remote area today. The M 5.7 in the Kermadec Islands is the strongest in that aftershock zone (of the M 8.1 of March 4, 2021) since an M 5.9 on April 28, 2021. This may be related to tidal stresses which maximize near this longitude with the coming new moon as noted in this and previous summaries:

 

"The new moon arrives on June 10 at 10:53 UT. Longitudes which are at local solar midnight at this hour include those near 160 West while those at local solar noon are near 20 East longitude. These include areas from the northern Kermadec/Tonga/Samoa arc, Hawaii and Alaska and the Aleutians in the west and Central Europe and Africa in the east. These areas are most likely to see tidal enhancement of seismicity with this new moon. Other areas could also see an increase in seismicity especially near local solar noon and midnight with a moderately strong to major quake possible in the next week. This is an annular solar eclipse. The maximum will be at 80N 66W and will be visible in northern and central Alaska and central and northern Canada. It will end north of Kamchatka, Russia and could trigger a large earthquake or volcanism in that area. In the U.S. it will be partially visible in Central Alaska, North and South Dakota through much of the eastern and northern U.S., Greenland and Canada beginning in the region of the Virgin Islands and Puerto Rico. A strong to major earthquake is likely within several days of this eclipse, most likely in eastern Asia or the Caribbean." (June 6-7. 2021)

 

Forecast 134530 had expected today's event was likely in the Kermadec Islands within about 50 km and two days of today's epicenter. This earthquake is at 102-103 degrees from the M 7.4 in Qinghai, China of May 21, 2021 and was probably promoted by energy from that source. Other activity at this distance from Qinghai today occurred in southern California and  Oklahoma.

 

O:  6JUN2021 23:16:39  27.7S  176.3W Mw=5.7  EMSC   KERMADEC ISLANDS REGION      

P:  4JUN2021 134530    28.0S  177.0W 4.0-5.5 AAAAA  No. Kermadec Islands        

 

The M 5.6 in the Fiji Islands may be a regional aftershock of the M 6.5  of

May 21, 2021. Forecast 134521 had expected today's event was likely around June 5.

 

O:  6JUN2021 18:24:29  15.9S  177.4W Mw=5.6  EMSC   FIJI REGION                  

P:  5JUN2021 134521    16.0S  176.0W 4.0-5.7 AABAA  Tonga Islands              

 

The strong aftershock series in Southern California following the M 5.3 there of June 6 continued at a reduced rate today. The strongest aftershock in the area today was an M 3.8 with intensity V in Brawley and II-III in Calipatria, San Diego, Riverside, and Norco, California. A later M 3.6 was felt in the same area. Forecast 134406 had expected today's activity within about 50 km was likely around June 7. Following is a listing of events in the aftershock area today of M>=3. A more complete listing can be found in the "CALIFORNIA" section of this summary.

 

O: 07JUN2021 05:44:35  33.2N  115.6W ML=3.3  EMSC   SOUTHERN CALIFORNIA

O: 06JUN2021 10:30:36  33.3N  116.0W ML=3.2  EMSC   SOUTHERN CALIFORNIA

O: 07JUN2021 05:44:35  33.2N  115.6W ML=3.6  ANSS   SOUTHERN CALIFORNIA

O: 06JUN2021 08:05:36  33.2N  115.6W ML=3.8  ANSS   SOUTHERN CALIFORNIA

P:  7JUN2021 134406    33.9N  116.6W 2.5-4.6 AAAAA  So. California             

 

The strongest earthquake in the U.S. or Canada today was an M 4.3 in the area south of Alaska near the Alaska Peninsula. This is an unusual event, the first of M>=4.3 south of 54 North latitude in the region since an M 4.7 about 50 km south of today's epicenter nearly 15 years ago on September 2, 2006. Forecast 134472 had expected today's event in this area was likely around June 9. This earthquake occurred near local solar noon at a longitude where tidal stresses are expected to maximize with the next new moon as noted in this and previous summaries. (see above)

 

 

O:  6JUN2021 21:34:01  53.3N  156.8W ml=4.3  EMSC   SOUTH OF ALASKA              

P:  9JUN2021 134472    54.7N  156.9W 3.5-4.9 BBAAA  Alaska Peninsula           

 

MODERATE M 5.3 SHAKES SOUTHERN CALIFORNIA

 

EARTHQUAKE SUMMARY FOR JUNE 5, 2021

 

A moderate earthquake of M 5.3 shook large portions of Southern California southeast of Los Angeles today. This event was accompanied by a strong swarm of foreshocks and aftershocks also felt lightly in the area. NEIC reported the mainshock was felt with maximum intensity V in southern California at Westmorland, Calipatria, IV in Brawley, Imperia, El Centro, Neber and III in Niland, Thermal, Holtville and Calexico, California. Lesser shaking was reported as far as Las Vegas, Nevada and Los Angeles, California.

 

Today's activity in Southern California continues a series of enhanced earthquakes in the area which followed the M 7.4 in the area of Qinghai, China of May 21. These have been followed by this summary as the area is at or near 103 degrees from the Qinghai epicenter. This is a distance at which seismic energy is strongly concentrated from large surface disturbances due to reflection and refraction of the energy from internal earth boundaries back to the surface. Seismicity is often seen to increase substantially at this distance following major earthquakes. Several swarms have occurred in Baja and Southern California since May 21, the date of the Qinghai quake. Among these were a series about 150 km to the southeast in the area of northern Gulf of California. At the time this summary noted:

 

"A series of light earthquakes of M 3.4, 3.6 and 3.8 occurred near the border of Southern California in the Gulf of California today. These were not reported felt in this epicentral area. The M 3.8 is the strongest event within about 100 km of this epicenter since an M 4.4 on December 28, 2020, the only such event in the past year. An M 5.5 hit near this epicenter on March 7, 2020. ... These earthquakes as well as an M 3.2 near Bakersfield and events in eastern Los Angeles are located near 103 degrees from the Qinghai epicenter of M 7.4 which occurred on May 21 and were probably promoted by energy from that source." (May 27-30, 2021)

 

In the previous issue of this summary it was noted that an M 3.7 on the South Dakota - Nebraska border may have been precursory to a significant earthquake in western North America ina the next several days. That summary had noted in this regard:

 

"An unusual earthquake of M 3.1 occurred south of Mitchell, South Dakota on the Nebraska-South Dakota border today. NEIC reported maximum intensity with this quake was V in Fairfax and Herrick and Saint Charles, South Dakota with III-IV in South Dakota at Lake Andes, Bonesteel, Burke, Platte, and in Nebraska at Bristol, Butte, Oneill, Atkinson, Lincoln, Spencer. It was followed by an M 3.1 aftershock felt in much the same area. This is the strongest earthquake within about 200 km of this epicenter in South Dakota and Nebraska since an M 4.3 on November 3, 2002 about 30 km south of today's epicenter.  Earthquakes in western and central South Dakota often occur shortly before or in conjunction with strong earthquakes along the western rim of the North American Tectonic plate. As today's activity occurred hours after the two earthquakes off the coast of Oregon of M 5.9, they may have been more directly associated with that activity and less or a precursor to another strong earthquake off western North America  ..." (June 5, 2021)

 

An M 7.9 followed the Nebraska earthquake in the Denali National Park area of Alaska about 1.5 hours after the event in South Dakota described above.

 

The epicenter in South Dakota was at 101-102 degrees from the Qinghai, China of M 7.4 on May 21, 2021 and from the M 8.1 in the Kermadec Islands of March 4, 2021 and was probably promoted by energy from those epicenters.

 

Earthquakes in this area often occur in several day swarms and several mainshocks often occur, so a second mainshock of M>=5 is possible in this swarm. The last earthquake within about 150 km of today's epicenter with M>=5.3 was an M 5.5 on August 26, 2012. An M 7.2 hit about 150 km southeast of this epicenter on Easter Sunday April 4, 2010. Today's event, the strongest in the region in nearly nine years is a significant regional earthquake.  Forecasts 134118 and 134406 had expected today's activity was likely at the end of May or in early June within about 50-100 km of today's swarm.

 

Today's activity is located at 104-105 degrees from the M 7.4 in Qinghai of May 21 and was probably promoted by energy from that source. Other moderate earthquakes in the world today at 103-105 degrees from Qinghai occurred in the Ascension Islands, south of New Zealand, North and South Island, New Zealand, and the Kermadec Islands. Following is a listing of earthquakes of M>=3 in the area of Calipatria, California which occurred today. A more extensive listing of events of M>=2 can be found below in the "CALIFORNIA" regional section of this summary.

 

O: 05JUN2021 17:40:51  33.1N  115.6W Mw=3.6  EMSC   SOUTHERN CALIFORNIA

O: 05JUN2021 17:42:10  33.1N  115.7W ML=3.1  EMSC   SOUTHERN CALIFORNIA

O: 05JUN2021 17:45:16  33.1N  115.7W Mw=4.0  EMSC   SOUTHERN CALIFORNIA

O: 05JUN2021 17:46:39  33.1N  115.7W Mw=3.8  EMSC   SOUTHERN CALIFORNIA

O: 05JUN2021 17:47:50  33.1N  115.6W ML=3.4  EMSC   SOUTHERN CALIFORNIA

O: 05JUN2021 17:48:58  33.1N  115.6W Ml=3.2  EMSC   SOUTHERN CALIFORNIA

O: 05JUN2021 17:50:37  33.1N  115.6W ML=3.2  EMSC   SOUTHERN CALIFORNIA

O: 05JUN2021 17:57:21  33.1N  115.6W ML=4.0  EMSC   SOUTHERN CALIFORNIA

O: 05JUN2021 17:58:42  33.1N  115.6W ML=3.4  EMSC   SOUTHERN CALIFORNIA

O: 05JUN2021 18:16:51  33.1N  115.6W ML=3.1  EMSC   SOUTHERN CALIFORNIA

O: 05JUN2021 18:21:48  33.1N  115.6W Mw=4.2  EMSC   SOUTHERN CALIFORNIA

O: 05JUN2021 21:49:39  33.1N  115.6W ML=3.1  EMSC   SOUTHERN CALIFORNIA

O: 05JUN2021 18:00:48  33.2N  115.7W ML=3.0  EMSC   SOUTHERN CALIFORNIA

O: 05JUN2021 18:03:39  33.2N  115.6W ML=3.5  EMSC   SOUTHERN CALIFORNIA

O: 05JUN2021 19:05:31  33.2N  115.6W ML=3.2  EMSC   SOUTHERN CALIFORNIA

O: 06JUN2021 05:01:30  33.2N  115.6W ML=3.2  EMSC   SOUTHERN CALIFORNIA

O: 05JUN2021 17:56:02  33.2N  116.3W Mw=5.3  EMSC   SOUTHERN CALIFORNIA

P:  7JUN2021 134406    33.9N  116.6W 2.5-4.6 AAAAA  So. California             

P: 29MAY2021 134118    33.4N  116.7W 2.5-4.4 CAAAA  So. California             

 

 

An earthquake of M 5.3 was also felt strongly on the Iran-Iraq border today. NEIC reported maximum intensity shaking of VIII in Ilam and V in Mendali, Iran for this event. Forecast 134414 had expected today's event was likely within about 50 km of this epicenter around June 7.

 

O:  6JUN2021 04:54:22  33.4N   46.3E mb=5.2  EMSC   IRAN-IRAQ BORDER REGION      

P:  7JUN2021 134414    33.0N   46.0E 3.8-5.3 AAAAA  So. Iran                   

 

An unusually large M 3.9-4.0 earthquake shook the Mount Hood area of Oregon today. NEIC reported intensity IV in Oregon at Government Camp, Rhododendron, and Cascake Locks, Oregon with III in Mount Hood, Parkdale, Welches, Brightwood, Hood River,  Sandy, Mosier and Estacada. It was followed by aftershocks of M 2.1 and 2.4 and may represent subterranean volcanism in the area. The only earthquake in the past 30 years in the Mount Hood area of Oregon with M>=4 was an M 4.5 on June 29, 2002. Forecast 134461 had expected today's event within about 10 km of this epicenter was likely around June 4. This activity is at the fourth node (90 degrees) from the M 8.1 in the Kermadec Islands of March 4 and was probably promoted by energy from that source.

 

O: 06JUN2021 04:14:23  45.3N  121.7W Ml=2.1  EMSC   MOUNT HOOD AREA, OREGON

O: 06JUN2021 03:51:37  45.4N  121.7W MD=4.0  EMSC   MOUNT HOOD AREA, OREGON

O: 06JUN2021 03:51:37  45.4N  121.7W MD=3.9  EMSC   MOUNT HOOD AREA, OREGON

O:  6JUN2021 03:55:36  45.3N  121.7W ML=2.4  EMSC   MOUNT HOOD AREA, OREGON      

P:  4JUN2021 134461    45.3N  121.7W 2.0-4.0 AAAAA  Oregon state, U.S.         

 

An M 4.8 earthquake occurred in the West Chile Rise today. This region was expected to see enhanced seismicity at this time as it is located near the antipode of the M 7.4 in Qinghai, China of May 21. Following large earthquakes seismic energy is focused at the opposite point on the near-spherical earth (the antipode) and can help enhance seismicity in that area. Forecast 134548 had expected today's event about 150 km to the southeast was likely around June 6.

 

O:  5JUN2021 13:47:19  41.7S   84.3W mb=4.8  EMSC   WEST CHILE RISE              

P:  6JUN2021 134548    43.0S   83.0W 4.0-5.5 ABAAA  Chile Rise                 

 

As Tropical Storm Choi-Wan moved north through the Ryukyu Islands today, it appears to have triggered another earthquake under the eye in the Ryukyu Islands. NEIC reported this earthquake of M 4.8 in the Ryukyu Islands, Japan was felt with intensity II-III in the area(s) of the Ryukyu Islands, Japan in Okinawa at Gushikawa, Ginowan, Okinawa, Tomigusuku and Yomitan.  This follows two moderate earthquake triggered in Taiwan by this storm yesterday. Forecast 134357 had expected today's event was likely in the Ryukyu Islands around June 4. Following is the expectations associated with Choi-Wan published in the previous issue  summary:

 

 

"TS Choi-Wan (04W) continued today near the Ryukyu Islands, Japan  with winds up to 45 kts. It is expected to track to the north and west over the next four days and could help promote seismicity in the region of Taiwan, the Ryukyu Islands and southern Japan while in the area." (June 5, 2021)

 

O:  5JUN2021 10:49:57  25.9N  128.5E mb=4.8  EMSC   RYUKYU ISLANDS, JAPAN        

P:  4JUN2021 134357    28.0N  127.0E 4.0-5.4 ABBAA  Ryukyu Islands             

 

STRONG QUAKES SHAKE COAST OF OREGON

 

EARTHQUAKE SUMMARY FOR JUNE 4, 2021

 

The strongest earthquakes in the world today were a pair of events of M 5.9 off the coast of Oregon. These were felt lightly on the Oregon coastline at Gold Beach (V), Coos Bay, Grants Pass, Mapleton, Brookings, Rogue Rive, Eugene, Salem, Oregon City and in Northern California at Crescent City, McKinleyville, Arcata.

 

These earthquake had been expected at this time due to their distance of 103  degrees from the M 6.1 which occurred yesterday in the Molucca Sea, Indonesia. At the time this summary reported on this possibility as:

 

"Areas off the coast of Oregon are at 103 degrees from the Molucca Sea event and may see triggered seismicity in the next several days. An example of this interaction occurred on December 1, 2013 when an M 6.4 in the Banda Sea was followed about two hours later by an M 5.5 off the coast of Oregon and Northern California as noted at the time in this summary:

 

"(this event  off the coast of northern California) also lies at 105 degrees from the earthquake in the Banda Sea which preceded it by several hours. As seismic energy from the Banda Sea quake was concentrated in this area of Northern California it seems likely that this event was triggered by those effects." (December 1, 2013)

 

A similar situation occurred when an M 7.0 in the Molucca Sea area of Indonesia on July 22, 1996 was followed by an M 6.2 off the coast of northern California less than two days later. Other sets of this type occurred with an M 6.6 in Indonesia on August 2, 1991 with M 6.6 followed on August 4, 1992 by an M 5.7 off the coast of Oregon on August 4, 1992 and in late December, 1992 with an Indonesian M 7.3 followed several days later by an M 5.5 off Oregon among others in 1990 and 1991." (June 4, 2021)

 

Today's activity of M 5.9 occurred within about half an hour of local solar midnight with a strong aftershock near local solar noon of M 4.7. Tidal stresses maximize near these hours and these were probably enhanced by those stresses. The last earthquake of M>=5.9 within about 200 km of today's epicenters occurred on September 5, 2019 with M 5.9 following an M 6.4 on August 29, 2019. These events were about 200 km northwest of today's activity. The last such event within about 150 km of today's epicenter were an M 7.1 on June 15, 2005 and an M 6.2 on July 24, 1996. When the M 6.4 occurred on August 29, 2019 this summary noted in this regard:

 

"This is the strongest earthquake off the coast of Oregon within about 250 km of this epicenter in more than 10 years - since an M 6.3 on January 10, 2008 and prior to that an M 6.3 on January 16, 2003. The only event in the region with greater magnitude in the past 30 years was an M 6.9 on July 13, 1991."  (September 5, 2019)

 

Forecast 134457 had expected today's activity was likely within about 50 km  of the epicenters off the coast of Oregon around June 4. These events are located at 103 degrees from the M 6.1 in the Molucca Sea, Indonesia reported in the previous issue of this summary and were probably promoted by energy from that source.

 

O: 04JUN2021 08:37:48  42.2N  126.2W mb=4.2  EMSC   OFF COAST OF OREGON

O: 04JUN2021 07:52:43  42.3N  126.3W Mw=5.9  EMSC   OFF COAST OF OREGON

O: 04JUN2021 08:13:32  42.3N  126.4W mb=3.9  EMSC   OFF COAST OF OREGON

O: 04JUN2021 08:17:01  42.3N  126.2W Mw=5.9  EMSC   OFF COAST OF OREGON

O: 04JUN2021 09:20:01  42.3N  126.4W ML=3.2  EMSC   OFF COAST OF OREGON

O: 04JUN2021 19:19:51  42.3N  126.4W ML=3.0  EMSC   OFF COAST OF OREGON

O: 04JUN2021 19:28:11  42.3N  126.3W Mw=4.7  EMSC   OFF COAST OF OREGON

O: 05JUN2021 01:05:44  42.4N  126.3W ML=3.1  EMSC   OFF COAST OF OREGON

O:  4JUN2021 08:37:48  42.2N  126.2W mb=4.2  EMSC   OFF COAST OF OREGON          

P:  4JUN2021 134457    42.5N  126.8W 3.0-4.4 AAAAA  Off Coast of Oregon        

 

The strongest earthquake California today was an M 3.0 off the coast of

Northern California. It was probably part of the activity off the coast of Oregon. Both occurred at 103 degrees from yesterday's event in the Molucca Sea, Indonesia. Forecast 134457 had expected today's event off northern California within about 15 km was likely around June 6.

 

O:  5JUN2021 05:28:53  40.4N  125.9W ML=3.0  EMSC   OFF COAST OF NORTHERN CALIFORN

P:  6JUN2021 134457    40.5N  125.8W 2.5-4.6 AAAAA  Off Coast of No. Calif     

 

An unusual earthquake of M 3.1 occurred south of Mitchell, South Dakota on the Nebraska-South Dakota border today. NEIC reported maximum intensity with this quake was V in Fairfax and Herrick and Saint Charles, South Dakota with III-IV in South Dakota at Lake Andes, Bonesteel, Burke, Platte, and in Nebraska at Bristol, Butte, Oneill, Atkinson, Lincoln, Spencer. It was followed by an M 3.1 aftershock felt in much the same area. This is the strongest earthquake within about 200 km of this epicenter in South Dakota and Nebraska since an M 4.3 on November 3, 2002 about 30 km south of today's epicenter.  Earthquakes in western and central South Dakota often occur shortly before or in conjunction with strong earthquakes along the western rim of the North American Tectonic plate. As today's activity occurred hours after the two earthquakes off the coast of Oregon of M 5.9, they may have been more directly associated with that activity and less or a precursor to another strong earthquake off western North America, however. When the earthquake in South Dakota occurred on November 3, 2002, it was followed 1-2 hours later by an M 8.0 in Denali National Park, Alaska. This summary noted the relation between North America quakes and those in this region of Nebraska and South Dakota at the time as:

 

 

"A great (Mw>=7.9) earthquake hit south-central Alaska, today, cracking highways and roads (a 3-foot crack was reported in the Parks Highway between Fairbanks and Anchorage) and knocking over fuel tanks and shaking rural homes. ...

 

This is the largest earthquake within the North American Continent north of Central America since the Great Good Friday earthquake in Alaska on March  28, 1964 (Mw 9.6), the largest earthquake in North America in the 20th Century.

 

The Alaskan earthquake today was preceded by a Ml 4.3 event about an hour and a half prior in eastern Nebraska. Two earthquakes occurred in Kansas on November 1 (Ml 3.0, 2.8). Such earthquakes often precede great earthquakes in Alaska and other areas on the borders of North America.  The resemblance of this great plains foreshock series to that which preceded the great Alaska earthquake of March, 1964 is uncanny, if there is no causative relation. In 1964 an Ml 4.3 earthquake was felt along the South Dakota/ Nebraska border about 30 minutes before the Great quake in Alaska, one of the largest ever recorded in this region. This had been preceded by smaller earthquake in the same region on March 24 and 27. Today's Nebraska earthquake occurred 1.5 hours before the great Alaska event and had been preceded by the Kansas earthquakes by two days.  Since all of these are unusual events, their coincidence in time (in more than one occasion) may be significant." (November 3, 2002)

 

Today's epicenter is at 101-102 degrees from the Qinghai, China of M 7.4 on May 21, 2021 and from the M 8.1 in the Kermadec Islands of March 4, 2021 and was probably promoted by energy from those epicenters.

 

O: 04JUN2021 15:25:00  43.0N   98.7W Mw=3.7  EMSC   SOUTH DAKOTA

O:  4JUN2021 22:50:40  43.0N   98.7W mb=3.1  EMSC   SOUTH DAKOTA                 

 

A moderate earthquake of M 5.4 was preceded by moderate foreshocks of M 4.6 and 4.7 in the Reykjanes Ridge of the northern Mid-Atlantic south of Iceland today. An M 4.6 hit about 100 km south of this epicenter on November 3, 2020 but the last event within about 200 km of this epicenter with M>=5.4 occurred on March 10, 2019 with M 5.9 and 5.5.  Forecast 134483 had expected today's event was likely within about 50 km of this epicenter around June 7, 2021. Today's event may have been promoted by high tidal stresses as it occurred within about 30 minutes of local solar midnight, a time when tidal stresses maximize. A similar series occurred on September 5, 2019 with the last strong quake off the Oregon coast. Those earthquakes  were located to the south of today's events in the Reykjanes Ridge. When an M 5.4 and 6.0 occurred in the Macquarie Islands on May 5 and 7, 2021 this summary noted the antipodal relation with the Reykjanes Islands as:

 

"The antipode of this event (in the Macquarie Island region) is at 57N 33W in the Reykjanes Ridge in the north Atlantic Ridge south of Iceland. Some seismic enhancement in this region is possible following today's event in the Macquarie Island area." May 6, 2021)

 

A similar pair occurred on March 20, 2021 as noted at the time in this summary:

 

"A strong near-antipodal pair also occurred today in the Macquarie Islands south of Australia and in the northern mid-Atlantic Ridge with M 6.1 and 5.7 respectively." (March 20, 2021)

 

Note that today's Reykjanes activity is within about 100 km of the antipode of that in the Macquarie Islands and was probably enhanced by energy from that antipode. Today's activity is also at 143 degrees from the M 8.1 in the Kermadec Islands of March 4, 2021 and was probably promoted by energy from that source.

 

O: 05JUN2021 01:31:46  58.4N   32.1W Mw=5.4  EMSC   REYKJANES RIDGE

O: 04JUN2021 21:02:56  58.8N   31.8W mb=4.6  EMSC   REYKJANES RIDGE

O:  4JUN2021 21:07:11  58.3N   32.0W mb=4.7  EMSC   REYKJANES RIDGE              

P:  7JUN2021 134483    58.0N   32.0W 4.0-5.6 BAAAA  North Mid-Atlantic Ridge   

 

The only tropical storm currently active is Tropical Storm Choi-Wan. It passed near Taiwan today and was accompanied by a pair of moderate quakes of M 4.6 and 4.3 beneath eye as it passed over. They were probably triggered by stresses related to TS Choi-Wan. This summary noted this in previous issues as:

 

"TS Choi-Wan (04W) continued today near the Ryukyu Islands, Japan  with winds up to 45 kts. It is expected to track to the north and west over the next four days and could help promote seismicity in the region of Taiwan, the Ryukyu Islands and southern Japan while in the area." (June 5-6, 2021)

 

Forecast 134357 had expected today's activity Taiwan was likely within about 50 km of these epicenters around June 5.

 

O: 05JUN2021 00:01:01  24.9N  122.6E mb=4.6  EMSC   TAIWAN REGION

O:  4JUN2021 16:19:28  24.9N  122.5E mb=4.3  EMSC   TAIWAN REGION                

P:  5JUN2021 134357    25.0N  123.0E 4.0-5.4 AAAAA  Ryukyu Islands             

 

An M 5.4 also occurred in central Chile today off the coast of Maule.  NEIC reported this earthquake of M 5.4 in Santiago, Chile was felt with intensity II-III in the area(s) of Santiago, Chile. GUC reported this earthquake was felt with intensity  IV in  Maule at Constitucion; III in Cauquenes, San Javier and II in Pelluhue and Pencahue and in Nuble with III in Trehuaco and II in Cobquecura, Chile. Forecast 134540 had expected this activity was likely within about 100 km of the epicenter around June 7. This epicenter is near the antipode of the M 7.4 in Qinghai, China of May 21 and may have been promoted by energy from that source.

 

O:  5JUN2021 03:05:11  34.9S   73.9W Mw=5.4  EMSC   OFF COAST OF O'HIGGINS, CHILE

O:  5JUN2021 03:05     35.0S   73.9W mb=5.3  GUC    Maule at Constitucion; III in

P:  7JUN2021 134540    36.0S   73.0W 4.0-5.5 AAAAA  Central Chile              

 

STRONG QUAKE IN MOLUCCA SEA MAY ENHANCE SEISMICITY OFF CALIFORNIA AND OREGON

 

EARTHQUAKE SUMMARY FOR JUNE 3, 2021

 

The strongest earthquake in the world today was an M 6.1 in the Molucca Sea, Indonesia. NEIC reported this event was felt with intensity II in Manado, Sulawesi. BMG reported it was felt with intensity III in Ternate and II-III in Labuha and Manado, Indonesia. It was followed by a series of moderate aftershocks which were reported felt with intensity II-III in Ternate. An earthquake of M 7.1 occurred about 150 km north of this on November 14, 2019. The last earthquake M>=6.1 within about 250 km of today's epicenter occurred as an M 7.1 about 150 km north of this on November 14, 2019 and an M 6.9 on July 7, 2019. Forecast 134286 had expected today's activity within about 150 km of these epicenters was likely around June 2. This activity is at the sixth node (60 degrees) from the M 8.1 in the Kermadec Islands of March 4 and from the M 6.7 in the Indian Ocean of May 12, 2021 and was probably promoted by energy from those sources.

 

O: 04JUN2021 03:31:09   0.2N  126.5E ML=4.2  EMSC   MOLUCCA SEA

O: 03JUN2021 10:28:19   0.3N  126.3E mb=4.8  EMSC   MOLUCCA SEA

O: 03JUN2021 11:14:15   0.3N  126.4E mb=4.5  EMSC   MOLUCCA SEA

O: 03JUN2021 11:19:03   0.3N  126.5E mb=4.9  EMSC   MOLUCCA SEA

O: 03JUN2021 12:03:03   0.3N  126.5E mb=4.5  EMSC   MOLUCCA SEA

O: 03JUN2021 13:53:54   0.3N  126.5E mb=4.7  EMSC   MOLUCCA SEA

O: 03JUN2021 15:27:18   0.3N  126.5E ML=4.1  EMSC   MOLUCCA SEA

O: 03JUN2021 10:21:36   0.4N  126.4E ML=4.5  EMSC   MOLUCCA SEA

O: 03JUN2021 10:23:26   0.4N  126.4E mb=5.1  EMSC   MOLUCCA SEA

O: 03JUN2021 13:01:09   0.4N  126.5E ML=4.1  EMSC   MOLUCCA SEA

O: 03JUN2021 10:17:13   0.5N  126.5E ML=4.5  EMSC   MOLUCCA SEA

O: 03JUN2021 23:07:15   0.8N  126.1E ML=4.0  EMSC   MOLUCCA SEA

O:  3JUN2021 10:09:55   0.3N  126.2E Mw=6.1  EMSC   MOLUCCA SEA                  

P:  2JUN2021 134286     2.0N  125.0E 4.0-5.6 ABBAA  Mindanao, Philippines      

 

 

An M 3.4-3.6 earthquake occurred today in Central California near San Jose. It was reported by NEIC to have been felt with intensity IV in San Jose and II in Milpitas and others of California near San Francisco and San Jose. The last earthquake within about 50 km of this epicenter near San Jose was an M 3.6 on April 25, 2021 and an M 3.8 on February 22, 2021. The last earthquake in the area of M>=4.5 occurred as an M 4.5 on October 15, 2019. This epicenter is near 106 degrees from the M 6.1 in the Molucca Sea earlier in the day and may have been promoted by energy from that source. Areas off the coast of Oregon are at 103 degrees from the Molucca Sea event and may see triggered seismicity in the next several days. An example of this interaction occurred on December 1, 2013 when an M 6.4 in the Banda Sea was followed about two hours later by an M 5.5 off the coast of Oregon and Northern California as noted at the time in this summary:

 

"(this event  off the coast of northern California) also lies at 105 degrees from the earthquake in the Banda Sea which preceded it by several hours. As seismic energy from the Banda Sea quake was concentrated in this area of Northern California it seems likely that this event was triggered by those effects." (December 1, 2013)

 

A similar situation occurred when an M 7.0 in the Molucca Sea area of Indonesia on July 22, 1996 was followed by an M 6.2 off the coast of northern California less than two days later. Other sets of this type occurred with an M 6.6 in Indonesia on August 2, 2991 with M 6.6 followed on August 4, 1992 by an M 5.7 off the coast of Oregon on August 4, 1992 and in late December, 1992 with an Indonesian M 7.3 followed several days later by an M 5.5 off Oregon among others in 1990 and 1991.

 

Forecast 134376 had expected today's activity within about 20 km was likely in early June. This activity is also located at the fifth node (72 degrees) from recent strong earthquakes off eastern Honshu, Japan and may have been promoted from that source.

 

O: 03JUN2021 13:58:28  37.4N  121.7W Md=2.1  EMSC   SAN FRANCISCO BAY AREA, CALIF.

O:  3JUN2021 12:15:32  37.4N  121.7W ML=3.4  EMSC   NORTHERN CALIFORNIA          

O:  3JUN2021 12:15:32  37.4N  121.7W ML=3.6  ANSS   NORTHERN CALIFORNIA          

P:  3JUN2021 134376    37.8N  122.6W 2.5-4.4 AAAAA  Central California         

P:  8JUN2021 134376    37.3N  121.6W 2.5-4.4 BAAAA  Central California         

 

 

An M 2.8 did occur today in northern California at 103 degrees from the M 6.1 in the Molucca Sea and was probably promoted by energy from that source.  Forecast 134456 had expected this activity around June 4.

 

O:  3JUN2021 19:34:02  41.0N  123.8W Md=2.8  EMSC   NORTHERN CALIFORNIA          

P:  4JUN2021 134456    40.6N  124.9W 2.5-4.6 AAAAA  Off Coast of No. Calif     

 

The strongest earthquake in the U.S. or Canada today was an M 4.0 in Central Alaska. NEIC reported this earthquake of M 3.9-4.0 in Central Alaska was felt with intensity II-III in the area(s) of Central Alaska with intensity V in Fairbanks and II-III in Talkeetna, Chugiak, Wasilla, Eagle River, Anchorage.  This is an aftershock of the M 6.1 which hit the area on May 31 - the strongest since then. Forecast 134497 had expected today's event was likely within about  50 km around June 4.

 

O:  3JUN2021 18:11:14  62.4N  148.3W ML=4.0  EMSC   CENTRAL ALASKA                

O:  3JUN2021 18:11:14  62.4N  148.3W ML=3.9  ANSS   CENTRAL ALASKA               

P:  4JUN2021 134497    62.7N  148.1W 3.2-5.0 AAAAA  Central Alaska             

 

MODERATE QUAKE SHAKES HAWAII

 

EARTHQUAKE SUMMARY FOR JUNE 2, 2021

 

The strongest earthquake felt in the U.S. or Canada today was an M 4.0-4.5 in Hawaii. This event which occurred south of Hawaii was reported by NEIC to have been felt with intensity V in Hawaii at Naalehu and II in Kealakekuam Waikoloa and Honokaa. This epicenter is in the neighborhood of Lo'ihi Seamount South of the big Island of Hawaii. This is a budding seamount and a possible extension of the continuing seismicity and volcanism of the Hawaiian Islands and may be over the Hawaiian Hotspot. Today's event of M 4.5 is the strongest south of Hawaii in the Lo'ihi area since an M 4.7 on July 27, 2020 and prior to that an M 4.6 on May 5, 2018 and an M 4.5 on June 21, 2017. Forecasts 134325 and 134033 had expected this activity within about 10 km of this epicenter was likely between May 30 and June 5. Hawaii is at the seventh node from the M 8.1 in the Kermadec Islands of March 4 and was probably promoted by energy from that source. And, like the event is Central Alaska of M 6.1 two days ago is near 104 degrees from the M 6.7 in Sumatra of May 14 and was probably also promoted from that epicenter. Qinghai China is at the fourth node from Hawaii (90 degrees).

 

O:  3JUN2021 04:44:32  18.9N  155.3W mb=4.5  EMSC   HAWAII REGION, HAWAII        

P:  5JUN2021 134325    18.8N  155.2W 3.0-4.4 AAAAA  Hawaii                     

P: 30MAY2021 134033    18.8N  155.2W 3.0-4.4 BAAAA  Hawaii                     

 

A light earthquake of M 3.6 was also widely felt in Central California today. NEIC reported this earthquake was felt with intensity IV in Central California at Paicines, Soledad, King City, and II-III in Gonzales, Hollister, Salinas, Greenfield, Carmel Valley and Aromas. The last earthquake within about 50 km of this epicenter in Central California occurred on January 17 and January 2, 2021 with M 4.2-4.3.  Forecast 134375 had expected today's event in this region was likely around June 5. This activity is at 102 degrees from the Qinghai, China M 7.4 of May 21 and was probably promoted by energy from that source.

 

O:  3JUN2021 04:34:42  36.6N  121.1W Mw=3.6  EMSC   CENTRAL CALIFORNIA           

P:  5JUN2021 134375    36.2N  121.8W 2.5-4.4 AAAAA  Central California         

 

A moderate earthquake was widely felt in the Rotorua area of North Island, New Zealand today. GEONET reported this earthquake was felt with moderate intensity northeast of Taupo and in northwestern North Island. Light to moderate intensity was reported throughout much of northern  North Island. More than 1613 people reported feeling this earthquake with 651 reports of weak intensity; 646 of light intensity; 262 with moderate intensity; 38 with strong intensity; and 2 of severe intensity and 4 of extreme shaking. NEIC reported this earthquake of M 4.2 in North Island, New Zealand was felt with intensity II-III in the area(s) of North Island, New Zealand at Taupo and Turangi, Waikato (IV) and Rotorua and Wanganui. The last earthquake of M>=4.8 in the region of Rotorua, New Zealand was the strongest in that area since an M 5.1 on September 4, 2019 and an M 5.1 on December 14, 2019. Forecast 134545 had expected today's event in this area was likely around June 2. This activity is at 102 degrees from the Qinghai, China M 7.4 of May 21 and was probably promoted by energy from that source. Several moderate earthquakes in the Kermadec Islands, southern California, and Nevada also shared this distance from Qinghai today.

 

O:  3JUN2021 00:23:41  38.9S  176.0E mb=4.2  EMSC   NORTH ISLAND OF NEW ZEALAND  

O: 03JUN2021 00:23:40  38.9S  176.0E ML=4.8  GEONET Felt with moderate intensity

P:  2JUN2021 134545    39.0S  175.0E 3.0-4.4 AAAAA  North Island, N.Z.         

 

The strongest earthquake in the world today was an M 5.4 in the Qinghai, China aftershock zone. This is the strongest aftershock to date of the M 7.4 quake of May 21, 2021. It was probably felt lightly in this remote area although this was not immediately reported. Forecast 13441 had expected continuing aftershocks in this area in early June.

 

O:  3JUN2021 05:55:18  34.7N   97.9E mb=5.4  EMSC   SOUTHERN QINGHAI, CHINA      

P:  6JUN2021 134411    34.0N   99.0E 3.5-5.1 BAAAA  So. China                  

 

 

 

 

 

 

 

MODERATE QUAKE SOUTH OF PANAMA

 

EARTHQUAKE SUMMARY FOR JUNE 1, 2021

 

A moderate sized earthquake of M 5.5 hit the area south of Panama today. NEIC reported this earthquake of M 5.5 in Panama was felt with intensity II-IV in the area(s) of Panama at Cerro Sombrero and Boquite, Chiriqui. This epicenter is near the antipode of the M 6.7 in Sumatra of May 14, 2021. The last earthquake within about 200 km of this epicenter south of Panama with M>=5.5 occurred as an M 5.8 on March 9, 2015, an aftershock of M 6.6 on January 7, 2015. Forecast 133985 had expected today's event was likely within about 100 km of this epicenter at the end of May.

 

O:  1JUN2021 11:20:57   5.1N   82.7W Mw=5.5  EMSC   SOUTH OF PANAMA              

P: 26MAY2021 133985     4.0N   83.0W 4.0-5.8 BAAAA  Ecuador                    

 

The strongest earthquake felt in the U.S. or Canada today was an M 3.4 in Southern Idaho. This continues the aftershock sequence in this area but was about 30 km to the east of the major aftershock area. Similar quakes of M 3.4-3.5 hit the area on April 25, March 15, February 27 and January 1 but the last of M>=4 east of 115 West longitude was an M 4.9 on April 13, 2014 followed by an M 4.4 on April 14, 2014. It occurred near local solar noon and was probably promoted by tidal stresses which maximize near this hour. Forecast 134446 had expected today's event in this area was likely around June 4.

 

 

O: 01JUN2021 21:16:52  44.3N  114.8W ML=2.3  EMSC   SOUTHERN IDAHO

O: 02JUN2021 04:58:42  44.3N  114.8W ML=2.6  EMSC   SOUTHERN IDAHO

O:  1JUN2021 20:15:13  44.3N  114.8W Ml=3.4  EMSC   SOUTHERN IDAHO               

P:  4JUN2021 134446    44.6N  115.0W 2.0-4.0 BAAAA  Montana/Idaho              

 

An earthquake of M 2.7 also occurred today in the region of eastern Yellowstone

National Park, Wyoming. The last earthquake of significantly larger magnitude in eastern Yellowstone was and M 3.3 on March 4, 2019. Forecast 134470 had expected enhanced seismicity in this area around June 4.

 

O:  2JUN2021 04:21:03  44.7N  110.0W ML=2.7  EMSC   YELLOWSTONE NAT. PARK, WYOMING

P:  4JUN2021 134470    44.6N  110.8W 2.0-4.4 AAAAA  Yellowstone/Wyoming        

 

MODERATE QUAKE SHAKES SOUTHEASTERN HONSHU, JAPAN

 

EARTHQUAKE SUMMARY FOR  MAY 31, 2021

 

The strongest earthquake in the world today was an M 5.3 off the southeast coast of Honshu, Japan. This is the strongest earthquake within about 200 km of this epicenter south of Tokyo, Japan since an M 5.4 on June 29, 2020. Forecast 134109 had expected this event was likely around May 28.

 

O: 31MAY2021 22:04:42  33.2N  142.6E Mw=5.3  EMSC   OFF EAST COAST OF HONSHU, JAPA

P: 28MAY2021 134109    33.0N  141.0E 4.0-5.5 BAAAA  Off East Coast Honshu      

 

An unusual earthquake of M 2.6 was felt in South Carolina today. NEIC reported intensity II-III in South Carolina at Leesville, Gilbert, Batesburg, Lexington, Ridge Spring, Pelion, Wagener, West Columbia and Chapin. The last earthquake in South Carolina with M>=2.6 occurred as an M 2.6 on September 13, 2018 with the last of larger magnitude an M 3.2 on June 20, 2017 and of M 3.0 on March 19, 2014. Forecast 134133 had expected today's event in South Carolina was likely  at the end of May. This earthquake was at 145 degrees from the M 6.7 in Sumatra of May 14 and may have been promoted by energy from that source.

 

O: 31MAY2021 22:53:25  33.9N   81.4W mb=2.5  EMSC   SOUTH CAROLINA               

O: 31MAY2021 22:53:25  33.9N   81.4W mb=2.6  ANSS   SOUTH CAROLINA               

P: 25MAY2021 134133    33.0N   80.0W 2.0-3.9 CAAAA  Southeast U.S.             

 

The strongest earthquake in the U.S. or Canada today occurred as an aftershock of the M 6.1 in Central Alaska yesterday. Today's event of M 4.6 was felt with maximum intensity V in Talkeetna and IV in Anchorage, Alaska according to NEIC.

Intensity II-III was also reported felt in Alaska at Palmer, Glennallen, Cantwell, Chugiak, Wasilla, Willow, Eagle River and Fort Richardson. NEIC reported the earthquake of M 3.4 in Central Alaska was felt with intensity II-III in the area(s) of Central Alaska at Chugiak and Eagle River. Forecast 134213 had expected today's activity was likely at the end of May.

 

O: 31MAY2021 07:08:31  62.5N  148.3W ml=3.1  EMSC   CENTRAL ALASKA

O: 31MAY2021 07:23:40  62.5N  148.3W ML=3.3  EMSC   CENTRAL ALASKA

O: 31MAY2021 08:29:36  62.5N  148.3W ML=3.2  EMSC   CENTRAL ALASKA

O: 31MAY2021 08:35:10  62.5N  148.2W ml=3.0  EMSC   CENTRAL ALASKA

O: 31MAY2021 08:43:53  62.5N  148.3W ml=3.2  EMSC   CENTRAL ALASKA

O: 31MAY2021 12:14:43  62.5N  148.2W mb=4.5  EMSC   CENTRAL ALASKA

O:  1JUN2021 00:16:12  62.5N  148.3W ML=3.4  EMSC   CENTRAL ALASKA               

P: 27MAY2021 134213    63.3N  151.0W 3.2-5.0 BABAA  Central Alaska             

 

A series of moderate earthquakes occurred in the northern mid-Atlantic Ridge today with M 4.6, 4.7 and 4.8. Like the events off southern California these events occurred near 16 degrees from the Qinghai, China M 7.4 of May 21 and may have been promoted from that source. Forecast 134063 had expected today's activity in the Mid-Atlantic was likely at the end of May. Other earthquakes at this distance from Qinghai today included an M 4.0 in North Island, New Zealand; an M 4.2 in the Christchurch region of South Island, New Zealand and a series of light events in southern and central California.

 

O: 31MAY2021 15:19:27  28.6N   43.6W mb=4.7  EMSC   NORTHERN MID-ATLANTIC RIDGE

O: 31MAY2021 14:38:56  28.7N   43.7W mb=4.6  EMSC   NORTHERN MID-ATLANTIC RIDGE

O: 31MAY2021 14:44:40  28.6N   43.6W mb=4.8  EMSC   NORTHERN MID-ATLANTIC RIDGE  

P: 23MAY2021 134063    27.0N   45.0W 4.0-5.6 CBAAA  Mid-Atlantic Ridge         

 

STRONG M 6.1 QUAKE SHAKES CENTRAL ALASKA

 

EARTHQUAKE SUMMARY FOR  MAY 30, 2021

 

The strongest earthquake in the world today was an M 6.1 in the region of central Alaska. NEIC reported it was felt with maximum intensity V in Alaska at Glennallen, Eagle River, and Talkeetna and IV in Maranuska-Sustina border, Palmer, Cantwell, Chugiak, Wasilla, Willow, and Fort Richardson. An M 3.2 regional foreshock occurred about an hour earlier and was reported felt with intensity IV in Anchorage and II-III in Valdez, Seward, Fairbanks and Port Wainwright. An earlier foreshock of M 3.4 was also felt with intensity II in Talkeetna and Chugiak, Alaska. No major damage was reported from these earthquakes. The last earthquake in Central Alaska within about 200 km of today's epicenter with M>=6.1 occurred on November 30, 2018 near Anchorage, Alaska with M 7.0 about 150 km southwest of today's epicenter. The largest earthquake in the area in the past 30 years was an M 7.9 in the Denali National Park on November 3, 2002 about 150 km northeast of today's epicenter. Other earthquakes of M>=6.1 in the past 30 years occurred on September 25, 2014 (M 6.2); October 23, 2002 (M 6.7) and May 1, 1991 (M 6.3). Forecast 134213 had expected today's event within about 100 km was likely around May 27.

 

Today's event may have been promoted by the past full moon as it occurred in

a region where high tidal stresses were expected with that alignment as noted

in this and previous issues of this summary:

 

 

"The full moon  arrived at 11:14 UT on May 26, 2021. Longitudes which were sub-solar (local solar noon) at this time are near 10 East longitude while those at local solar midnight are near 170 West longitude. In the east these include areas of western Europe and the Atlantic while the west areas of the Tonga-Fiji-Kermadec- New Zealand area and the central Aleutians of Alaska are near 170W longitude. These are the most likely areas to see tidally induced or enhanced seismicity at this time. Other regions may also see enhanced seismicity with this full moon. Enhanced seismicity is most like near local solar noon or local solar midnight." (May 24-30, 2021)

 

Today's event is located at 101-102 degrees from the M 6.6 in Sumatra of May 14, 2021 and  near the fifth node (72 degrees) from the Qinghai, China quake of May 21 and was probably promoted by energy from those sources.

 

O: 31MAY2021 01:17:31  62.1N  149.4W ML=3.5  EMSC   CENTRAL ALASKA

O: 31MAY2021 06:59:54  62.5N  148.2W Mw=6.1  EMSC   CENTRAL ALASKA               

P: 27MAY2021 134213    63.3N  151.0W 3.2-5.0 BABAA  Central Alaska             

 

A moderate earthquake of M 4.2 also occurred in Southern Puerto Rico today. NEIC reported it was felt with intensity V in Puerto Rico at Penuelas, Guayanilla, IV in Ponce, and Cabo Rojo with  lesser shaking in Adjuntas, Juana Diaz, Arecibo, Barranquitas and Coroza.  This is the strongest aftershock in southwestern Puerto Rico since an M 4.7 on December 24, 2020. These are aftershocks of the strong earthquakes in January 2020 (including an M 6.5 on January 7, 2020)  and December, 2019 (which started the sequence with an M 5.0 on December 29, 2019).  Forecast 134049 had expected today's event was likely around May 29.

 

O: 31MAY2021 06:42:25  18.0N   67.0W Md=3.1  EMSC   PUERTO RICO

O: 31MAY2021 05:18:39  18.0N   66.7W Mb=4.2  EMSC   PUERTO RICO                  

P: 29MAY2021 134049    19.0N   67.0W 3.4-5.2 AAAAA  Puerto Rico                

 

A pair of earthquakes were widely in felt in South Island, New Zealand today. An earthquake of M 5.0 occurred near Te Anau, South Island, New Zealand today. NEIC reported it was felt with intensity IV in Te Anau and Christchurch with II-III in Riverton,k Queenstown, Winton, Arrowtown, and Wanaka, Otago. GEONET reported this earthquake was felt with weak intensity in the area southwest of Haast, South Island. 544 reports of felt intensity came from the area east and north of the epicenter. More than 544 people reported feeling this earthquake with 369 reporting weak shaking and 161 light intensity; 12 with moderate intensity and one each with strong, severe and none with extreme shaking. The last earthquake reported with M>=5.5 in the Te Anau region of South Island was an M 5.5 on June 24, 2020 and prior to that an M 5.6 on May 5, 2015. Forecast 134268 had expected today's event was likely around May 26.

 

O: 31MAY2021 04:08:59  45.2S  166.7E Mw=5.0  EMSC   OFF W. COAST OF S. ISLAND, N.Z

O: 31MAY2021 04:09:01  45.3S  166.8E MS=5.5  GEONET Felt with weak intensity

P: 26MAY2021 134268    46.0S  167.0E 3.0-4.9 BAAAA  Southern S. Isl. N.Z.      

 

GEONET also reported also an M 4.2 was felt with moderate intensity in the area of Christchurch, South Island, New Zealand. 7990 felt reports were published including 3506 of weak and 3833 of light shaking; 601 moderate; 36 strong; 2 severe and 12 extreme shaking in northern South Island. It was preceded by a light foreshock of M 3.0 earlier in the day. This is the first event of M>=4.2 in the Christchurch area of South Island since an M 3.8 on March 8, 2017 more than four years ago. Forecast 134267 had expected today's event was likely around May 31. These two earthquake in South Island are located at 103 degrees from the M 7.4 in Qinghai, China of May 21 and was probably promoted by energy from that source.

 

O: 30MAY2021 14:18:05  43.9S  172.2E ML=3.0  EMSC   SOUTH ISLAND OF NEW ZEALAND  

O: 31MAY2021 09:47:24  43.4S  172.9E MS=4.2  GEONET Felt with moderate intensity

P: 31MAY2021 134267    42.0S  173.0E 3.0-4.9 ABAAA  So. Island, N.Z.           

 

The swarm of light to moderate earthquakes in the Baja California region continued today with at least 10 events of M>=3.3. The largest of these was an M 4.0 which occurred within minutes of local solar midnight and was probably promoted by high tidal stresses. This summary has previously noted this swarm as:

 

 

"The strongest seismicity in the U.S. or Canada or vicinity today occurred in the northern Gulf of California and Baja California. The strongest of these events was an M 3.8 but five other events with M>=3 occurred in the area today.  NEIC reported these earthquakes in Mexico were felt with intensity II-III in the area(s) of  Somerton, Arizona.  One of the strongest earthquake in the past in this region of Baja, California occurred as an M 6.0 on May 31, 1961, exactly 60 years ago today. Today's activity continues a swarm in the area which began several days ago and was discussed in previous issues of this summary as:

 

 

"A series of light earthquakes of M 3.4, 3.6 and 3.8 occurred near the border of Southern California in the Gulf of California today. These were not reported felt in this epicentral area. The M 3.8 is the strongest event within about 100 km of this epicenter since an M 4.4 on December 28, 2020, the only such event in the past year. An M 5.5 hit near this epicenter on March 7, 2020. Forecast 134117 had expected today's earthquake to the northwest around May 25. These earthquakes as well as an M 3.2 near Bakersfield and events in eastern Los Angeles are located near 103 degrees from the Qinghai epicenter of M 7.4 which occurred on May 21 and were probably promoted by energy from that source." (May 27-30, 2021)

 

An M 3.6 south of Los Angeles in the Baja region also continued the activity near 103 degrees from Qinghai, China today.  These earthquakes in Southern California and Baja are located at 103 degrees from the M 7.4 in Qinghai, China of May 21 and was probably promoted by energy from that source.

 

O: 30MAY2021 18:13:47  31.8N  117.2W ML=3.6  EMSC   OFFSHORE BAJA CALIFORNIA, MEXI

P: 31MAY2021 134120    34.1N  117.4W 2.5-4.9 CAAAA  So. California             

 

 

O: 30MAY2021 08:03:27  30.8N  116.0W ML=4.0  EMSC   BAJA CALIFORNIA, MEXICO

O: 30MAY2021 08:28:25  30.8N  115.9W ML=3.3  EMSC   BAJA CALIFORNIA, MEXICO

O: 30MAY2021 11:09:18  30.8N  116.0W ML=3.4  EMSC   BAJA CALIFORNIA, MEXICO

O: 30MAY2021 11:11:28  30.8N  116.0W ML=3.5  EMSC   BAJA CALIFORNIA, MEXICO

O: 30MAY2021 17:05:41  30.8N  116.0W ML=3.5  EMSC   BAJA CALIFORNIA, MEXICO

O: 30MAY2021 17:05:41  30.8N  116.0W ML=3.5  EMSC   BAJA CALIFORNIA, MEXICO

O: 30MAY2021 20:09:18  31.2N  116.6W ML=3.4  EMSC   FFSHORE BAJA CALIFORNIA, MEXICO

O: 30MAY2021 20:47:24  30.5N  114.4W ML=3.5  EMSC   GULF OF CALIFORNIA           

O: 30MAY2021 20:58:35  31.2N  115.5W ML=3.4  EMSC   BAJA CALIFORNIA, MEXICO      

P: 25MAY2021 134117    32.4N  115.7W 2.5-4.4 BAAAA  So. California             

 

MODERATE AFTERSHOCKS CONTINUE IN QINGHAI, CHINA

 

EARTHQUAKE SUMMARY FOR  MAY 29, 2021

 

Moderate aftershocks continued in the region of southern Qinghai, China today. These follow the M 7.4 in that region of May 21 which was damaging. The only

comparable aftershock to date was an M 5.2 on May 27.  While today's events were not reported felt they probably were felt with light intensity in this remote region. Forecast 134128 had expected this activity within the aftershock zone was likely at the end of May.

 

O: 30MAY2021 06:55:15  34.6N   98.5E mb=5.2  EMSC   SOUTHERN QINGHAI, CHINA

O: 30MAY2021 04:50:10  34.6N   98.4E mb=5.1  EMSC   SOUTHERN QINGHAI, CHINA      

P: 27MAY2021 134128    35.0N   99.0E 3.5-4.9 BAAAA  So. China                  

 

The strongest seismicity in the U.S. or Canada or vicinity today occurred in

the northern Gulf of California and Baja California. The strongest of these events was an M 3.8 but five other events with M>=3 occurred in the area today.  NEIC reported these earthquakes in Mexico were felt with intensity II-III in the area(s) of  Somerton, Arizona.  These are occurring near 104 degrees from the M 7.4 in Qinghai China of May 21 and may have been promoted by energy from that source. Other events today at this distance from Qinghai included an M 5.3 in Tonga, an M 4.4 and in North Island, New Zealand. This continues a swarm in the area which began several days ago and was discussed in previous issues of this summary as:

 

 

"A series of light earthquakes of M 3.4, 3.6 and 3.8 occurred near the border of Southern California in the Gulf of California today. These were not reported felt in this epicentral area. The M 3.8 is the strongest event within about 100 km of this epicenter since an M 4.4 on December 28, 2020, the only such event in the past year. An M 5.5 hit near this epicenter on March 7, 2020. Forecast 134117 had expected today's earthquake o the northwest around May 25. These earthquakes as well as an M 3.2 near Bakersfield and events in eastern Los Angeles are located near 103 degrees from the Qinghai epicenter of M 7.4 which occurred on May 21 and were probably promoted by energy from that source." (May 27-29, 2021)

 

O: 29MAY2021 17:07:06  31.8N  115.0W ML=3.4  EMSC   BAJA CALIFORNIA, MEXICO

O: 29MAY2021 18:26:38  32.1N  115.0W ML=3.0  EMSC   SONORA, MEXICO

O: 29MAY2021 09:03:04  31.1N  115.2W ML=3.1  EMSC   BAJA CALIFORNIA, MEXICO

O: 29MAY2021 10:25:28  31.5N  115.6W ML=3.5  EMSC   BAJA CALIFORNIA, MEXICO

O: 29MAY2021 12:27:47  30.5N  114.1W ML=3.8  EMSC   GULF OF CALIFORNIA           

O: 29MAY2021 10:22:24  30.9N  115.0W ML=3.5  EMSC   BAJA CALIFORNIA, MEXICO      

O: 29MAY2021 23:23:58  32.7N  115.8W Ml=2.2  EMSC   SOUTHERN CALIFORNIA          

P: 25MAY2021 134117    32.4N  115.7W 2.5-4.4 BAAAA  So. California              

 

A moderate earthquake of M 4.2 was felt today in North Island, New Zealand.

GEONET reported it was felt with moderate intensity in southeastern North Island. More than 1803 people reported feeling this earthquake. Light to moderate intensity was reported throughout much of southern and eastern North Island and northern South Island. 1045 reports of weak intensity; 667 of light intensity; 83 with moderate; 6 with strong shaking and 1 with severe and 1 with extreme intensity. While earthquakes of M 4.4 hit within about 100 km of this epicenter on February 24 2021 and July 16, 2020, the last earthquake of larger magnitude in this area was an M 4.6 on June 22, 2018 nearly three years ago. Forecast 134265 had expected today's event was likely at the end of May within about 100 km of this epicenter. Like the swarm in Baja California, this epicenter is at 103 degrees from the M 7.4 in Qinghai, China of May 21 and was probably promoted by energy from that source.

  

O: 30MAY2021 05:55:40  40.0S  176.7E MS=4.4  GEONET Felt with moderate intensity

O: 30MAY2021 05:55:40  40.0S  176.7E ML=4.2  EMSC   NORTH ISLAND OF NEW ZEALAND  

P: 26MAY2021 134265    40.0S  175.0E 3.0-4.5 BABAA  North Island, N.Z.         

 

MODERATE QUAKES CONTINUE OFF EASTERN HONSHU,  JAPAN

 

EARTHQUAKE SUMMARY FOR  MAY 28, 2021

 

The strongest earthquake in the world today was an M 5.5 off the east coast of Honshu, Japan. NEIC reported it was felt with intensity II-III in Fukushima, Chiba, Tochigi, Tokyo and Miyagi, Japan.  Foreshocks of M 5.3 and 4.9 were felt with intensity II-III in Chiba, Kanagawa and Ibaraki Prefectures. A series of large earthquakes have occurred off the northern coast of Honshu in the past three months, but today's activity is the strongest south of 37.5 North latitude - in the area - since a similar M 5.5 on November 22, 2020. The last of larger magnitude in this area was an M 5.9 on June 24, 2020. Forecast 134111 had expected today's activity was likely around May 28 within about 50 km of these epicenters.

 

O: 29MAY2021 00:04:49  36.4N  141.9E mb=4.9  EMSC   NEAR EAST COAST OF HONSHU, JAPAN

O: 29MAY2021 01:02:42  36.4N  141.8E Mw=5.5  EMSC   NEAR EAST COAST OF HONSHU, JAPAN

O: 29MAY2021 00:42:46  35.9N  142.7E mb=4.7  EMSC   OFF EAST COAST OF HONSHU, JAPA

O: 28MAY2021 23:21:04  36.4N  142.0E mb=5.3  EMSC   NEAR EAST COAST OF HONSHU, JAP

P: 28MAY2021 134111    37.0N  142.0E 4.0-5.5 AAAAA  Off East Coast Honshu      

 

The strongest earthquake in the U.S. or Canada today was an M 4.2 near Lake Tahoe, California. NEIC reported it was felt with maximum intensity IV in California at Tahoma, Carnelian Bay, Kings Beach, Tahoe City and III in Tahoe Vista, Glenbrook, Homewood and in Carson City, Nevada. A number of light aftershocks were felt in the Tahoe area. An M 4.7 hit about 50 km northwest of today's epicenter on May 7, 2021 and an M 4.5 hit east of this on March 21, 2020, the first such regional activity at this magnitude level since 2015. The last event within about 50 km of today's epicenter with M>=4.2 was an M 4.8 on June 26, 2005. Forecast 134081 had expected today's event within about 25 km was likely around May 25. This activity is at the fifth node (72 degrees) from the recent strong earthquakes off the east coast of Honshu, Japan and may have been promoted by energy from this region. Another series of moderate earthquakes at this distance from Japan occurred today in Iran with M 4.8, 4.9 among others as well as in Southern Idaho with M 3.3.

 

O: 28MAY2021 15:25:20  39.1N  120.0W Mw=4.1  EMSC   NORTHERN CALIFORNIA

O: 28MAY2021 15:25:20  39.1N  120.0W Mw=4.2  ANSS   NORTHERN CALIFORNIA

O: 28MAY2021 15:29:06  39.1N  120.0W Md=2.0  EMSC   NORTHERN CALIFORNIA

O: 28MAY2021 15:33:19  39.1N  120.0W Md=2.1  EMSC   NORTHERN CALIFORNIA

O: 28MAY2021 15:40:23  39.1N  120.0W Md=2.4  EMSC   NORTHERN CALIFORNIA

O: 28MAY2021 15:42:08  39.1N  120.0W Md=2.3  EMSC   NORTHERN CALIFORNIA

O: 28MAY2021 15:46:36  39.1N  120.0W MD=2.6  EMSC   NORTHERN CALIFORNIA

O: 28MAY2021 15:46:36  39.1N  120.0W MD=2.6  EMSC   NORTHERN CALIFORNIA

O: 28MAY2021 16:04:53  39.1N  120.0W ML=3.0  EMSC   NORTHERN CALIFORNIA

O: 28MAY2021 16:22:58  39.1N  120.0W MD=2.7  EMSC   NORTHERN CALIFORNIA

O: 28MAY2021 16:27:46  39.1N  120.0W MD=2.4  EMSC   NORTHERN CALIFORNIA

O: 28MAY2021 16:36:47  39.1N  120.0W Md=2.3  EMSC   NORTHERN CALIFORNIA

O: 28MAY2021 17:05:33  39.1N  120.1W ML=2.4  EMSC   NORTHERN CALIFORNIA

O: 28MAY2021 21:10:49  39.1N  120.0W Md=2.4  EMSC   NORTHERN CALIFORNIA

O: 28MAY2021 21:39:39  39.1N  120.0W Md=2.3  EMSC   NORTHERN CALIFORNIA

O: 28MAY2021 11:59:10  39.1N  120.0W ML=2.9  EMSC   NORTHERN CALIFORNIA          

P: 25MAY2021 134081    39.3N  120.0W 2.5-4.6 BAAAA  California/Nevada area     

 

The strong sequence in the northern Gulf of California also continued today with events of M 3.3, 3.5, 3.7 and two of 3.8. This activity began yesterday and was described in this summary in the previous issue as:

 

 

"A series of light earthquakes of M 3.4, 3.6 and 3.8 occurred near the border of Southern California in the Gulf of California today. These were not reported felt in this epicentral area. The M 3.8 is the strongest event within about 100 km of this epicenter since an M 4.4 on December 28, 2020, the only such event in the past year. An M 5.5 hit near this epicenter on March 7, 2020. Forecast 134117 had expected today's earthquake o the northwest around May 25. These earthquakes as well as an M 3.2 near Bakersfield and events in eastern Los Angeles are located near 103 degrees from the Qinghai epicenter of M 7.4 which occurred on May 21 and were probably promoted by energy from that source." (May 27-28, 2021)

 

O: 28MAY2021 07:11:13  31.5N  114.4W ML=3.5  EMSC   GULF OF CALIFORNIA

O: 28MAY2021 09:40:52  31.5N  114.5W ML=3.7  EMSC   GULF OF CALIFORNIA

O: 28MAY2021 09:43:13  31.5N  114.6W ML=3.8  EMSC   GULF OF CALIFORNIA

O: 28MAY2021 09:46:38  31.5N  114.5W ML=3.8  EMSC   GULF OF CALIFORNIA

O: 28MAY2021 09:54:58  31.2N  115.3W ML=3.3  EMSC   BAJA CALIFORNIA, MEXICO      

P: 25MAY2021 134117    32.4N  115.7W 2.5-4.4 BAAAA  So. California             

 

A pair of unusual earthquakes also occurred today in Southern Texas with M 2.8 and 3.1. NEIC reported these earthquakes of M 3.1 and 2.8 in Southern Texas was felt with intensity II-III in the area(s) of Southern Texas at Hobson and Falls City. Earthquakes of M>=3 have most recently occurred in this area as an M 3.4 on April 10 and February 7, 2021 (M 3.3), the only such events in the region in the past year. Forecast 133791 had expected today's event was likely in this area in late May, 2021.

 

O: 28MAY2021 11:58:48  29.1N   98.0W mb=2.8  EMSC   SOUTHERN TEXAS

O: 28MAY2021 12:34:33  28.9N   98.0W mb=3.0  EMSC   SOUTHERN TEXAS               

P: 19MAY2021 133791    28.0N   97.0W 3.0-4.7 CAAAA  Northern Mexico             

 

QU

MODERATE AFTERSHOCK IN QINGHAI, CHINA LARGEST TO DATE

 

EARTHQUAKE SUMMARY FOR  MAY 27, 2021

 

The strongest earthquake in the world today was an aftershock in southern Qinghai, China of M 5.2. This is the strongest aftershock to date of the M 7.4 of May 21 in Qinghai. It was probably felt in the epicentral area but this was not reported. Forecast 134128 had expected this earthquake was likely around May 27 within about 50 km of this epicenter in Qinghai.

 

O: 27MAY2021 13:06:07  34.5N   99.2E mb=5.2  EMSC   SOUTHERN QINGHAI, CHINA      

P: 27MAY2021 134128    35.0N   99.0E 3.5-4.9 AAAAA  So. China                  

 

A series of light earthquakes of M 3.4, 3.6 and 3.8 occurred near the border of Southern California in the Gulf of California today. These were not reported felt in this epicentral area. The M 3.8 is the strongest event within about 100 km of this epicenter since an M 4.4 on December 28, 2020, the only such event in the past year. An M 5.5 hit near this epicenter on March 7, 2020. Forecast 134117 had expected today's earthquake o the northwest around May 25. These earthquakes as well as an M 3.2 near Bakersfield and events in eastern Los Angeles are located near 103 degrees from the Qinghai epicenter of M 7.4 which occurred on May 21 and were probably promoted by energy from that source.

 

O: 27MAY2021 09:31:45  31.5N  114.6W ML=3.6  EMSC   GULF OF CALIFORNIA

O: 27MAY2021 14:51:06  31.5N  114.4W ML=3.8  EMSC   GULF OF CALIFORNIA

O: 27MAY2021 08:46:06  31.3N  114.4W ML=3.4  EMSC   GULF OF CALIFORNIA            

P: 25MAY2021 134117    32.4N  115.7W 2.5-4.4 ABAAA  So. California             

 

An earthquake of M 2.4-3.2 also occurred today in New York State. It was not reported felt in this area. This is the strongest earthquake in the region of New York State in at least a year. An M 3.1 occurred northeast of this on March 11, 2020. Forecast 134167 had expected today's event was likely within about  50 km of this epicenter in New York around May 23. This epicenter is at 100-101 degrees from the Qinghai M 7.4 of May 21 and was probably promoted by energy from this source.

 

O: 28MAY2021 00:41:27  42.7N   77.8W mb=2.4  EMSC   NEW YORK                     

O: 28MAY2021 00:41:28  42.7N   77.8W MB=3.2  ECAN  New York                      

P: 23MAY2021 134167    43.0N   78.0W 2.0-3.9 BAAAA  New York State             

 

IET CONDITIONS CONTINUE

 

EARTHQUAKE SUMMARY FOR  MAY 26, 2021

 

Global seismicity remained at low levels today. There was only one event recorded with M>=5.0 - an M 5.1 in Northern Vanuatu. It followed a foreshock of M 4.8 9 hours earlier. These events were not reported felt in this remote area. The last event with M>=5.1 in northern Vanuatu within about 100 km of today's activity occurred as an M 5.4 on March 1, 2021. Similar events of M 5.1 have hit the area this year on February 16 and January 19, 2021. The last strong earthquake in the area was an M 6.1 on March 28, 2020. Forecast 134238 had expected today's activity in this region was likely around May 26.

 

 

O: 26MAY2021 18:56:52  13.1S  166.5E mb=4.8  EMSC   VANUATU

O: 27MAY2021 03:58:15  13.3S  166.8E Mw=5.1  EMSC   VANUATU                      

P: 26MAY2021 134238    12.0S  166.0E 4.0-5.7 BAAAA  Vanuatu Islands            

 

An M 3.4 near Santa Catalina Island in southern California was widely felt in that region today.  NEIC reported this earthquake of M 3.4 in Southern California was felt with intensity II-III in the area(s) of Southern California in Summerland (IV), Santa Barbara, Carpinteria, Ventura and Ojai.  The last earthquake within about 100 km of this epicenter with M>=3.4 was an M 3.6-3.8 on September 6, 2020. An M 3.4 also occurred in the Santa Barbara Channel on April 19, 2020. Forecast 134119 had expected today's event within about 50 km of this epicenter was likely around May 25. This earthquake and an M 2.1 in eastern Los Angeles, California today are located at 102-103 degrees from the M 7.4 in Qinghai, China of May 21 and was probably promoted by energy from that source.

 

 

O: 26MAY2021 21:12:12  34.3N  119.7W Ml=3.4  EMSC   SANTA BARBARA CHANNEL, CALIF.

P: 25MAY2021 134119    33.8N  119.7W 2.5-5.1 AAAAA  So. California             

 

The strongest earthquake in the U.S. or Canada today was an M 3.9 in the central

Andreanof Islands, Aleutians, Alaska. It was not reported felt in this remote area. The last earthquake within about 100 km of this epicenter with M>=3.9 was an M 4.1 on May 24. A series of moderate earthquakes including an M 5.0 and 5.1 occurred east of this on May 22 in the Andreanof Islands. Forecast 134190 had expected today's activity within about 50 km was likely around May 28. This earthquake is located at the sixth node (60 degrees) from the M 7.4 in Qinghai, China of May 21 and was probably promoted by energy from that source.

 

O: 27MAY2021 00:41:04  51.3N  177.1W ml=3.9  EMSC   ANDREANOF ISLANDS, ALEUTIAN IS

P: 28MAY2021 134190    51.7N  176.4W 3.5-5.1 AAAAA  Andreanoff Isls, Aleutians 

 

Moderate earthquakes also continued today with the volcanic eruption of Mount Nyiragongo, a major volcano in the eastern DR Congo. Lava flows were slow today but continued. A new eruption at Mt. Etna, Sicily, Italy also produced lava flows today. Forecast 134005 had expected today's activity was likely within about 50 km around May 26.

 

NEIC reported these earthquakes of M 4.2 and 4.5 in Rwanda were felt with intensity II-III in the area(s) of Rwanda at Kigali and in Goma, Congo and Kisoro, Uganda.

 

O: 26MAY2021 23:19:32   1.8S   29.3E mb=4.5  EMSC   RWANDA

O: 26MAY2021 07:01:18   1.8S   29.5E mb=4.2  EMSC   RWANDA                       

P: 26MAY2021 134005     2.0S   29.0E 3.0-4.7 AAAAA  Lake Victoria area         

 

MODERATE QUAKE SHAKES WESTERN OKLAHOMA AND TEXAS

 

EARTHQUAKE SUMMARY FOR  MAY 25, 2021

 

A moderate earthquake of M 4.1 was widely felt today in western Oklahoma and the Texas Panhandle. NEIC reported maximum intensity V in Oklahoma at Gage with IV in Shattuck, Polett, Amett, Woodward and in Texas at Higgins. Lesser shaking occurred in Oklahoma at Fargo, Laverne, Sharon and in Booker, Texas.  This is the strongest earthquake within about 200 km of this epicenter since an M 4.3 on April 14, 2021, the only other such event in the area in the past 30 years. At the time this summary noted in this regard:

 

"Two unusual earthquakes occurred today in the region of northern Texas. This activity is at 100-104 degrees from the major and great earthquakes in the Loyalty Islands, Kermadec Islands and North Island, New Zealand of February and March , 2021 and was likely promoted by energy from that source. The largest of these, and the strongest in the U.S. or Canada was an M 4.3 which hit the Texas Panhandle today. NEIC reported it was felt with intensity IV in Miami, Texas and II-III in Borger, Skellytown, Pampa, Perryton, Groom, Amarillo, and possibly as far as Axtell, Nebraska. This is the strongest earthquake within about 200 km of this epicenter in at least 30 years. The only earthquake in this area of larger magnitude in the past 50 years was an M 4.5-4.6 on February 15, 1974. The strongest quake in this area on record is an M 5.0 on July 30, 1925." (April 15, 2021)

 

Today's event is not an aftershock of the April 14 M 4.3 as it occurred about 150 km to the east of that epicenter. Forecast 134116 had expected this region was likely to see enhanced seismicity at the end of May. This epicenter is located at 107 degrees from the M  7.4 in Qinghai, China of May 21 and may have been promoted by energy from that epicenter. Other earthquakes near 103 degrees from Qinghai occurred in Utah (M 3.8) and in Central and southern California today.

 

O: 25MAY2021 18:24:52  36.3N  100.0W Mw=4.1  EMSC   OKLAHOMA                     

P: 31MAY2021 134116    35.4N  101.8W 2.0-3.9 CABAA  SW U.S.A                   

 

An unusual earthquake of M 4.5 also occurred today north of Puerto Rico in the North Atlantic Ocean. This is the strongest earthquake north of the Puerto Rico Trench and 21N latitude since an M 4.6 on September 24, 2011 and an M 4.7 on September 19, 2005. This may be an outer Rise earthquake indicating a strong event is likely in the near future in the region of the Puerto Rico Trench. Such events can trigger tsunamis and can be very dangerous to local populations. The last such event in the region was an M 8.1 in 1946. Forecast 134055 had expected enhanced seismicity in this region was likely to the south around May 25.

 

O: 25MAY2021 16:19:24  22.7N   67.9W mb=4.5  EMSC   NORTH ATLANTIC OCEAN         

P: 25MAY2021 134055    20.0N   68.0W 3.0-4.6 ACAAA  Bahamas/No. Caribbean      

 

The strongest earthquakes in the world today were an M 5.2 in the area southeast of Easter Island and an M 5.4 in Tonga. They were not reported felt in these remotes. This event south of Easter Islands is in the antipodal region of the M 7.4 of May 21 in Qinghai, China and may have been promoted by energy from that source. An M 5.4 hit about 200 km west of today's epicenter on May 15, 2021 and an M 5.7 occurred about 100 km to the west on November 25, 2020. The last such event in the region nearer to today's epicenter was an M 5.5 on December 18, 2019. Forecast 134264 had expected today's event was likely within about 100 km of this epicenter was likely around May 27. 

 

O: 25MAY2021 23:20:51  41.4S   89.5W Mw=5.2  EMSC   SOUTHEAST OF EASTER ISLAND   

P: 27MAY2021 134264    41.0S   91.0W 4.0-5.4 AAAAA  Chile Rise                 

 

O: 25MAY2021 21:36:45  17.6S  174.8W Mw=5.4  EMSC   TONGA                         

P: 25MAY2021 134236    18.0S  177.0W 4.0-5.7 AABAA  Tonga Islands              

 

The most active seismicity in the world today continued in Rwanda in association with the eruption of Mount Nyiragongo, a major volcano in the eastern DR Congo. Lava flows were slow today but continued. A new eruption at Mt. Etna, Sicily, Italy also produced lava flows today. Forecast 134005 had expected today's activity was likely within about 50 km around May 26.

 

NEIC reported these earthquakes of M 4.7, 4.4, 4.6 and M 4.3 in Rwanda were felt with intensity II-III in the area(s) of Rwanda at Gisenyi (V), Kigali Ville de Kigali and Cyangigu (IV), VII in Gisenyi III in Ruhengeri and IV in Bujumbura, Burundi. 

 

O: 25MAY2021 20:38:12   1.6S   29.4E mb=4.3  EMSC   RWANDA

O: 26MAY2021 03:46:31   1.7S   29.3E mb=4.6  EMSC   RWANDA

O: 25MAY2021 09:41:16   1.8S   29.3E mb=4.4  EMSC   RWANDA

O: 25MAY2021 09:03:00   1.6S   29.3E mb=4.7  EMSC   RWANDA                       

P: 26MAY2021 134005     2.0S   29.0E 3.0-4.7 AAAAA  Lake Victoria area         

 

MODERATE QUAKES IN NAMIBIA AND DAVIS STRAIT, CANADA

 

EARTHQUAKE SUMMARY FOR  MAY 24, 2021

 

The strongest earthquake in the world today, and the only event today of M>=5.0

was an M 5.0 in Namibia, Southern Africa.  NEIC reported this earthquake of M 4.9-5.0 in Namibia was felt with intensity II-III in the area(s) of Namibia at Henties Bay Erongo. This epicenter is near 100 degrees from the Qinghai quake of May 21 (M 7.4) and was probably promoted by energy from that event. Similar events near 103 degrees from the Chinese epicenter occurred in Fiji, Tonga and the Kermadec Islands today. Today’s event appears to be the strongest aftershock to date of the M 5.4 in Namibia of April 4. When the mainshock occurred this summary noted in this regard:

 

"An unusual earthquake of M 5.4 hit the region of northern Namibia today. NEIC reported it was felt with maximum intensity VI in Namibia in Okahandja, IV in Khorixas and Outjo; III in Swakopmuna and I in Otjiwarongo. This is the largest earthquake in northern Namibia within about 500 km of this epicenter in at least the past 30 years. The largest earthquakes in Northern Namibia previously were an M 5.0 in southern Namibia on December, 1992 and an M 5.0-5.1 north of Namibia on June 5, 1989. An M 4.6 hit within about 25 km of today's event on November 21, 2019." (April 4, 2021)

 

O: 24MAY2021 08:27:42  19.8S   14.8E mb=5.0  EMSC   NAMIBIA                      

 

The strongest earthquake in the U.S. or Canada today occurred as an M 4.2-4.4 in the Davis Strait near Resolution Island, Nunavit, Canada. It was not reported felt in this remote area. The last earthquake within about 250 km of this epicenter with M>=4.2 occurred as an M 4.4 about 250 km southeast of this epicenter on September 30, 2006 and prior to that an M 4.6 on July 24, 2005. Forecast 134208 had expected today's event was likely around May 26 within about 25-50 km of this epicenter. This earthquake occurred within about 30 minutes of local solar noon and was probably enhanced by high tidal and geomagnetic stresses which maximize near this hour.

 

O: 24MAY2021 16:12:15  61.2N   58.2W MB=4.4  ECAN Resolution Island, NU   

O: 24MAY2021 16:12:10  60.7N   58.6W mb=4.2  EMSC   DAVIS STRAIT                 

P: 26MAY2021 134208    61.0N   58.0W 2.5-4.2 AAAAA  Baffin/Davis Strait Canada 

 

 

 

 

 

 

 

MO

MODERATE QUAKE SHAKES HAWAII

 

EARTHQUAKE SUMMARY FOR  MAY 23, 2021

 

The strongest earthquake in the U.S. or Canada today was an M 4.2-4.3 in the island of Hawaii. NEIC reported it was felt with intensity IV in Hawaii at Volcano, Pahala, Papaikou, and II-III in Hawaii National Park, Pahoa, Mountain View, Kurtistown, Hilo, Keaau and Naalehu. Foreshocks of M 3.5 and M 3.6-3.9 were felt with intensity II-III in Hawaii at Volcano, Pahoa, Keaau, Papaiku and Ninole. The last earthquake in Hawaii of M>4.3 was an M 4.4 on December 21, 2020 five months ago. Forecast 134033 had expected today's activity was likely within  about 10 km around May 24. This event of M 4.3 occurred within about 30 minutes of local solar noon and was probably promoted by tidal stresses which maximize near this hour. This activity is at the fourth node (90 degrees) from the Qinghai, China epicenter and was probably promoted by energy from that source.

 

O: 23MAY2021 19:38:23  19.3N  155.2W ML=3.5  EMSC   ISLAND OF HAWAII, HAWAII

O: 23MAY2021 21:40:44  19.3N  155.2W ML=4.3  EMSC   ISLAND OF HAWAII, HAWAII

O: 23MAY2021 18:36:56  19.3N  155.2W ML=3.9  EMSC   ISLAND OF HAWAII, HAWAII     

P: 24MAY2021 134033    19.2N  155.3W 3.0-4.6 AAAAA  Hawaii                     

 

The strongest earthquake in the world today was an M 5.3 in the South Sandwich Islands. It was not reported felt in this region. While an M 5.3 hit about 300 km northwest of this epicenter on April 26, 2021, the last earthquake within about 300 km of today's epicenter with larger magnitude was an M 6.0 west of this on March 14, 2021. Forecast 134273 expected today's event within about 150 km of this epicenter around May 27.

.

O: 23MAY2021 08:58:32  58.8S   25.3W Mw=5.3  EMSC   SOUTH SANDWICH ISLANDS REGION

P: 27MAY2021 134273    60.0S   26.0W 4.0-5.8 BBAAA  So. Sandwich Islands       

 

A light earthquake was widely felt in the region of Christchurch, South Island, New Zealand today. GEONET reported this earthquake was felt with moderate intensity in the area of Christchurch, South Island, New Zealand. 3755 felt reports were published including 1587 of weak and 1916 of light shaking; 233 moderate; 13 strong; 1 severe and 5 extreme shaking in northern South Island. NEIC reported this earthquake of M 3.0 in Christchurch, New Zealand was felt with intensity II-III in the area(s) of Christchurch, New Zealand at Lyttelton, (IV), Christchurch and Te Puru Thornton Bay, Waikato.  The last earthquake which was widely felt in Christchurch occurred as an M 3.9 on November 5, 2020, the only such event in the past year. Forecast 134267 had expected today's event was likely around March 24. It may have been promoted by tidal effects as it occurred within about 30 minutes of local solar noon. This epicenter is at 103 degrees from the M 7.4 in Qinghai and was also probably promoted by energy from that epicenter.

 

O: 23MAY2021 23:49:05  43.6S  172.7E ML=3.0  EMSC   SOUTH ISLAND OF NEW ZEALAND  

O: 23MAY2021 23:49:05  43.5S  172.7E MS=3.4  GEONET Felt with moderate intensity

P: 24MAY2021 134267    41.0S  174.0E 3.0-4.9 ACAAA  So. Island, N.Z.           

 

The eruption in the DR Congo and Rwanda of Mount Nyiragongo, a major volcano in the eastern DR Congo continued today. Lava flows Moderate earthquakes continued in Rwanda.  NEIC reported these earthquakes of M 4.5 and M 4.3 in Rwanda were felt with intensity II-III in the area(s) of Rwanda at Kigali and Nyanza. The largest of these events occurred within about 30 minutes of local solar midnight and probably was promoted by tidal stresses which maximize near this hour. Forecasts 133735 and 134005 had expected this activity between May 21 and 23 within about 50 km of these epicenters.

 

O: 23MAY2021 20:38:56   1.7S   29.3E mb=4.5  EMSC   RWANDA

O: 23MAY2021 16:52:25   1.8S   29.4E mb=4.3  EMSC   RWANDA

O: 23MAY2021 22:52:56   1.6S   29.4E mb=4.2  EMSC   RWANDA                       

P: 21MAY2021 133735     2.0S   29.0E 3.0-4.7 AAAAA  Lake Victoria area         

P: 23MAY2021 134005     1.0S   28.0E 3.0-4.7 AAAAA  Lake Victoria area         

 

 

UNT NYIRAGONGO ERUPTS IN DR CONGO

 

EARTHQUAKE SUMMARY FOR  MAY 22, 2021

 

Mount Nyiragongo, a major volcano in the eastern DR Congo erupted today. Lava flows nearly missed spilling into Goma as they came to a halt on the outskirts of that city. Residents fled in panic. The last major eruption of Nyiragongo  occurred on January 17, 2002. That eruption spread lava through much of Goma and killed more than 100 people. Today's eruption has destroyed a number of houses and may reach the airport on the shores of Lake Kivu. At least five were killed in accidents during the evacuation. The initial eruption was accompanied by a series of mild earth tremors.  It is likely that this was  promoted by the strong geomagnetic storm two days ago. This summary had noted in that regard:

 

 

"The geomagnetic field saw minor storm conditions today. The AP level was 24.  High latitude geomagnetic field  saw minor storm conditions with AP 33. Enhanced seismicity is likely at equatorial and polar latitudes in the next several days with this storm." (April 20-21, 2021)

 

The eruption maximized near local solar midnight a time when geomagnetic and tidal stresses maximize. It is also likely it was promoted by the M 7.4 in Qinghai, China yesterday.  This epicenter is at the fifth node (72 degrees) from the Qinghai epicenter, a distance where energy maximizes on the surface following strong earthquakes.

 

A strong series of solar flares occurred today with the eruption in the Congo.

This included flares of M1.1 and M1.4. The M1.4 is the second strongest flare reported by SWPC this year - an M3.9 was observed May 7 and an M4.4 on November 29. Today's M1.4 occurred within minutes of local solar midnight at the volcanic eruption site and may have helped enhance that event.  Forecast 133735 had expected today's activity in Rwanda was likely around May 21.

 

O: 23MAY2021 22:52:56   1.6S   29.4E mb=4.2  EMSC   RWANDA                       

P: 21MAY2021 133735     2.0S   29.0E 3.0-4.7 AAAAA  Lake Victoria area         

 

The strongest earthquake in the world today - an M 5.5 in the Talaud Islands, Indonesia - also occurred near the equator. It was felt lightly in southern Philippines. NEIC reported this earthquake of M 5.5 in the Talaud Islands was felt with intensity II-III in the area(s) of Mindanao, Philippines in Buayan and Davao. It is likely it was promoted by the recent geomagnetic storm and solar flares (see discussion above). Forecasts 13390 and 133987 had expected this event was likely within about 100 km around May 23-26. 

 

O: 23MAY2021 02:02:11   4.9N  127.5E Mw=5.5  EMSC   KEPULAUAN TALAUD, INDONESIA  

P: 23MAY2021 133990     4.0N  126.0E 4.0-5.4 AAAAA  Mindanao, Philippines      

P: 26MAY2021 133987     4.0N  127.0E 4.0-5.4 BAAAA  Halmahera                  

 

The strongest earthquake in the U.S. or Canada today was an M 5.0 in the eastern Andreanof Islands, Alaska. It was not reported felt in this remote area. This epicenter is near the sixth node (60 degrees) of the Qinghai epicenter of M 7.4, a distance at which energy on the surface maximizes following large earthquakes and can help enhance seismicity at this distance from the large earthquakes.  The last earthquake of larger magnitude than M 5.1 within about 150 km of this epicenter was an M 5.5 on October 1, 2020 about 150 km to the west of this epicenter and prior to that an M 5.2 on July 9, 2018. Forecast 134189 had expected today's event within about 100 km was likely around May 23.

 

O: 22MAY2021 13:57:14  51.6N  173.2W mb=3.9  EMSC   ANDREANOF ISLANDS, ALEUTIAN IS.

O: 22MAY2021 09:04:43  51.7N  173.3W mb=5.1  EMSC   ANDREANOF ISLANDS, ALEUTIAN IS.

O: 22MAY2021 08:56:12  51.9N  173.4W ML=4.0  EMSC   ANDREANOF ISLANDS, ALEUTIAN IS

P: 23MAY2021 134189    52.3N  174.6W 3.5-5.2 AAAAA  Andreanoff Isls, Aleutians 

 

 

STRONG QUAKES DAMAGING, DEADLY IN WESTERN CHINA

 

EARTHQUAKE SUMMARY FOR  MAY 21, 2021

 

Global seismicity took a quantum leap upward today following the strong geomagnetic storm of May 20, 2021. In addition to the largest earthquake in the world since March 4, 2021 - an M 7.4 in Qinghai, China - strong earthquakes also were felt in the Fiji Islands (M 6.5); Yunnan, China (M 6.1-6.2 while moderately strong quakes were recorded in Nicaragua (M 5.5); the Carlsberg Ridge (M 5.8) and Java (M 5.7). These events were generally near the geomagnetic equator and their timing suggests a combination of geomagnetic and tidal stresses helped lead to today's  dramatic change in global seismicity after a week of low level seismicity. In the previous issue of this summary the effects of the geomagnetic storm had been anticipated as:

 

"The geomagnetic field saw minor storm conditions today. The AP level was 24.  High latitude geomagnetic field  saw minor storm conditions with AP 33. Enhanced seismicity is likely at equatorial and polar latitudes in the next several days with this storm." (April 20-21, 2021)

 

The strongest earthquake in the world today was an M 7.3-7.4 in southern Qinghai, China. NEIC reported maximum intensity VII in Qinghai, China at Xining with II-III shaking in China at Lanzhou, Gansu, Chengdu, Sichean, Kian, Shaanxi, Anshun, Guizhou, Changsham Hunan and in India at Pasighat Arunachal Pradesh and Dhlia Gaon, Assam. It was followed by a series of moderate aftershocks. The M 7.3 followed an M 6.2 in Yunnan, China earlier in the day. Chinese media reported at least three people were kill and 33 injured. The event in Yunnan occurred near teh city of Dali, a popular tourist destination according to CENC (Chinese Earthquake Networks Centre). All of the deaths occurred with the Yunnan quake as well as 28 of the 33 reported injuries. At least 192 building collapsed in this earthquake. Two bridges also collapsed and several sections of highways were destroyed. The larger quake in Qinghai was less damaging as it occurred in a sparsely populated area. At least 20,000 people were relocated following today's earthquakes in China.

 

NEIC reported the M 6.1-6.2 in Yunnan, China was felt with intensity VIII in Yunnan at Dali and III in Kunning and Leshan. It was also felt in Vietnam and India.

 

The remnants of Tropical Cyclone Tauktae were located over the Qinghai Chinese epicenter when the earthquakes occurred today. The combined effects of string tidal stresses with the loading effects of TC Tauktae had previously been  hypothesized as a potential enhancer of regional seismicity in Central Asia at this time as:

 

 

"Tropical Cyclone Tauktae made landfall in western India in the area of Gujarat over the past two days. It is currently headed inland and is located near 30N 71E in the region of Afghanistan and Pakistan. This was a very deadly storm and was according to news sources, the strongest storm ever to hit the west coast of India in modern times. As it made landfall with winds up to 205 kph in the region of Gujarat it killed up to 26 people and did great damage to property. A number of barges in the Arabian Sea were capsized during this storm but most people were rescued. When Tauktae made landfall this summary reported a moderate earthquake in Gujarat and the forecast for regional seismicity induced by stresses from this storm as published in earlier issues of this summary read:

 ...

 

"The new moon arrived on May 11, 2021 at 19:00 UT. Longitudes which were at local solar noon at this hour are near 105 West and those at local solar midnight near 75 East longitude. In the west these include areas of central and Western U.S. and Canada and western Mexico as well as portions of the East Pacific Rise. In the east area near 75E include Afghanistan, India, Hindu Kush, Iran and eastern Indonesia and portions of the mid-Indian ridges. These regions are expected to see enhanced seismicity during the coming week. Other tidally promoted seismicity may occur elsewhere and is most likely near local solar midnight and noon when tidal stresses are generally maximized." (May 11-13, 2021)

 

Another likely promoter of today's event is the very strong Tropical Cyclone Tauktae as noted in previous issues of this summary:

 

"Tropical Cyclone Tauktae (01A) continued in the area west of India today with winds up to 185 kts. It is expected to track to the north and may impact regional seismicity in Gujarat, western India and the area of Pakistan and Afghanistan in the next several days. Land fall is expected south of Karachi, Pakistan around May 18. The antipode is at 19S 108W over the East Pacific Rise where some seismicity may be promoted at this time." (May 14-18, 2021)

 

Tropical Cyclone Tauktae made landfall at the same time as this earthquake occurred within about 50 km of this epicenter.

 

Following landfall of Tauktae, a strong earthquake occurred at the antipode of this storm in the South East Pacific Rise with M 6.6. This event was an expected consequence of TC Tauktae as discussed above. The only earthquake of larger magnitude in this region of the Southeast Pacific Rise in the past 30 years was an M 7.2 on October 9, 2014." (May 20, 2021)

 

The M 6.6 in the East Pacific Rise is not far from the antipode of M 7.4 in Qinghai and may have helped promote the earthquakes in western China today. Today's M 7.4 in Qinghai occurred within minutes of local solar midnight and was likely promoted by high tidal stresses which maximize near this time. Both this and the Yunnan quake earlier in the day were also likely promoted by high tidal stresses at this longitude associated with the recent new moon as previously (and above) expected in this summary. The M 7.4 was followed about an hour later by a C4.8 solar flare - the strongest flare since an M3.9 on May 7, 2021. The flare could not have triggered the event in Qinghai but is consistent with an interplanetary phenomenon such as a GRB or gravity wave helping to trigger both.

 

Major earthquakes within about 300 km of today's epicenter occurred in 1927, 1937 and 1947 with M 7.6, 7.7 and 8.0. The last of these was an M 7.7 on March 17, 1947 about 150 km south of today's event. The last within about 150 km was an M 7.6 on January 7, 1937. That event was reported in our history section on January 7, 2021:

 

" 1  7 13 20 41 1937  35.500   97.600   0 7.6   So. China

 

Destructive in Tsinghai Province."

 

It is interesting to note that the earthquake in 1927 of M 8.3 northeast of today's epicenter also occurred on May 22, 1927 and killed 200,000 with extreme damage in Qinghai Province, China.

 

Forecast 133541 had expected today's regional seismic enhancement within  about 200 km of these events was likely in early to mid-May, 2021. This activity is located at 103 degrees from the M 8.1 in the Kermadec Islands of March 4, 2021 and had been expected as far-field activity from that source at the time in central Asia and Myanmar.      It is also at the sixth node (60 degrees) from the M 6.7 in the South Indian Ocean of May 12, 2021 and was probably promoted from that source.

 

Far-field activation from Qinghai, China is most likely in the East Pacific Rise (180 degrees) Ecuador, Colombia and the South Shetland and Georgia Islands (144 degrees); western Mexico (120 degrees); Fiji, Tonga, Central and southern California, New Zealand, Kermadec Islands, (103 degrees); Southern Alaska (90 degrees).

 

O: 22MAY2021 02:38:45  34.5N   99.0E mb=5.1  EMSC   SOUTHERN QINGHAI, CHINA

O: 21MAY2021 18:04:14  34.6N   98.4E Mw=7.4  EMSC   SOUTHERN QINGHAI, CHINA

O: 21MAY2021 20:04:30  34.6N   98.6E mb=4.5  EMSC   SOUTHERN QINGHAI, CHINA

O: 21MAY2021 21:59:36  34.6N   98.3E mb=4.6  EMSC   SOUTHERN QINGHAI, CHINA

O: 21MAY2021 19:09:17  34.7N   97.9E mb=4.8  EMSC   SOUTHERN QINGHAI, CHINA

O: 21MAY2021 19:49:14  34.7N   97.8E mb=4.8  EMSC   SOUTHERN QINGHAI, CHINA

O: 22MAY2021 02:29:36  34.8N   97.4E mb=5.1  EMSC   SOUTHERN QINGHAI, CHINA

O: 22MAY2021 03:21:18  34.8N   98.1E mb=5.2  EMSC   SOUTHERN QINGHAI, CHINA

O: 21MAY2021 18:04:13  34.6N   98.3E mw=7.3  ANSS   Southern Qinghai China       

O: 22MAY2021 03:30:46  34.2N  101.0E mb=4.7  EMSC   GANSU-QINGHAI BORDER REG, CHIN

O: 21MAY2021 19:03:08  34.5N   99.1E mb=4.9  EMSC   SOUTHERN QINGHAI, CHINA      

O: 22MAY2021 04:03:46  36.5N   98.9E mb=4.4  EMSC   NORTHERN QINGHAI, CHINA      

P:  6MAY2021 133541    36.0N  100.0E 3.5-4.9 DBBAA  So. China                   

P:  6MAY2021 133541    33.0N   96.0E 3.5-5.1 DBBAA  So. China                  

 

The earthquake of M 6.1 in Yunnan, China was the strongest within about 200 km of this epicenter since an M 6.6 about 200 km north of today's event on February 3, 1996, the only such event of M>=6.1 in the past 30 years. An M 5.3 foreshock occurred about 27 minutes before the mainshock with an M 4.6 about an hour earlier. Forecast 133789 had expected today's event within about 100 km was likely in mid-May.

 

O: 21MAY2021 13:21:27  25.7N  100.1E Mw=5.3  EMSC   YUNNAN, CHINA

O: 21MAY2021 13:48:37  25.7N  100.1E Mw=6.1  EMSC   YUNNAN, CHINA

O: 21MAY2021 14:31:11  25.7N  100.1E mb=5.1  EMSC   YUNNAN, CHINA

O: 21MAY2021 15:23:37  25.7N  100.2E mb=4.5  EMSC   YUNNAN, CHINA

O: 21MAY2021 17:36:07  25.7N  100.1E mb=4.3  EMSC   YUNNAN, CHINA

O: 21MAY2021 17:50:18  25.7N  100.3E mb=4.2  EMSC   YUNNAN, CHINA

O: 22MAY2021 01:48:04  25.7N   99.9E mb=4.4  EMSC   YUNNAN, CHINA

O: 21MAY2021 12:56:04  25.7N  100.0E mb=4.6  EMSC   YUNNAN, CHINA                 

P: 14MAY2021 133789    26.0N  101.0E 4.0-5.4 AAAAA  Myanmar                    

 

An M 6.5 also occurred in the Fiji Islands today. It was reported felt with intensity III in The Fiji Islands at Labasa and Seaqaqe. The last earthquake in Fiji of M>=6.5 was an M 6.1 on May 7, 2021. It occurred near local solar noon and may have been promoted by the C4.4 solar flare discussed above. The event on May 7 occurred under very similar conditions. Comparison of the discussion in this summary on May 7-8 shows this similarity:

 

"The largest earthquake in the world today was an M 6.1 near the geomagnetic equator in Fiji. This event followed the strongest solar flare observed by SWPC since an M4.4 on November 29, 2020 and was measured by SWPC at M3.9.  The parameters for this flare given by SWPC are:

 

Flare #    START  MAX       END    CLASS     DATE    Flux (Jm-2)

#-------------------------------------------------------------------------------

 640       1843   1904      1919   M3.9      (May 7, 2021)   4.5E-02  

 

Today's flare:

 

2250       1915   1928      1932   C4.8      (May 21, 2021)   1.6E-03  

 

The earthquake of M 6.1 in Fiji occurred within minutes of local solar noon a time when solar and tidal effects are maximized and was probably triggered by the M3.9 flare.

 

That earthquake occurred at:

 

O:  7MAY2021 23:35:15   18.9S   177.6W Mw=6.1  EMSC   FIJI REGION " (May 7-8, 2021)

 

Today's event in Fiji  had been expected in mid-May within about 50 km of the epicenter in forecast 133940 and 133941. Like the event of May 7 it occurred near local solar noon and may have been promoted by tidal and/or geomagnetic effects.

 

O: 21MAY2021 22:13:18  16.6S  177.3W Mw=6.5  EMSC   FIJI REGION                  

P: 14MAY2021 133940    17.0S  177.0W 4.0-5.7 CAAAA  Tonga Islands              

P: 18MAY2021 133941    17.0S  179.0W 4.0-5.5 BABAA  Tonga Islands              

 

 

An earthquake of M 5.7 was also felt widely in Java, Indonesia today. It was reported by NEIC with intensity V in Java at Probolinggo and IV in Kanigoro, Malang, Batu and Trenggalek with lesser shaking in Tulungagung, Kertosono, Gedangan, Surbaya and Jember. An M 6.0 hit this area on April 10, 2021 within about 25 km of today's event and this may be an aftershock of that mainshock. Forecast 133743 had expected today's event was likely within about 100 km around May 18.

 

O: 21MAY2021 12:09:23   8.4S  112.4E Mw=5.7  EMSC   JAVA, INDONESIA              

P: 18MAY2021 133743     9.0S  113.0E 4.0-5.4 BAAAA  So. of Bali                

 

An M 5.8 in the Carlsberg Ridge today was the strongest in that region since an M 7.6 on July 15, 2003, the only event within about 300 km of today's epicenter with equal or stronger magnitude in the past 30 years. It was not reported felt in this remote area. Forecast 133734 had expected today's event in this region within about 150 km was likely between May 13 and 19.

 

O: 21MAY2021 16:19:11   2.8S   67.8E mb=4.8  EMSC   CARLSBERG RIDGE

O: 21MAY2021 16:02:36   2.7S   68.1E Mw=5.8  EMSC   CARLSBERG RIDGE              

P: 13MAY2021 133734     2.0S   69.0E 4.0-5.5 CAAAA  Indian Ocean               

P: 19MAY2021 133734     1.0S   67.0E 4.0-5.4 ABAAA  Indian Ocean               

 

The strongest earthquake in the western Hemisphere today was an M 5.5 in Nicaragua. This is the strongest earthquake in Nicaragua since an M 5.5 on January 3, 2020. Forecast 133770 had expected today's event was likely in mid-May within about 100 km of today's epicenter. This may have been promoted by a tropical weather system north of Nicaragua noted in the previous issue of this summary as:

 

 

"A strong weather system is also forming in the region north of Yucatan, Mexico.  NHC gives this 20% chance of becoming a tropical cyclone in the next 2 days." (May 20-21, 2021)

 

NEIC reported this earthquake of M 5.5 in Nicaragua was felt with intensity II-III in the area(s) of Nicaragua, Chinandega with V  and III in Leon, Ciudad Sandino, El Chicero, Managua, Ticuantepe, and in Tegucigalpa, Honduras and Antguo Cuscatlan, El Salvador. A foreshock of M 4.4 was felt with intensity IV in Managua, Nicaragua. The largest historical earthquake in the western Hemisphere - of M>=9 in Central Chile occurred on this date on May 22, 1960 (see history below) in this summary.

 

O: 22MAY2021 04:22:07  12.5N   87.9W ML=4.1  EMSC   NEAR COAST OF NICARAGUA

O: 22MAY2021 04:13:44  12.8N   87.3W mb=4.2  EMSC   NEAR COAST OF NICARAGUA

O: 21MAY2021 22:19:51  12.5N   87.6W Mw=5.5  EMSC   NEAR COAST OF NICARAGUA      

P: 15MAY2021 133770    12.0N   87.0W 3.5-5.3 CAAAA  Nicaragua                   

 

The strongest earthquake in the U.S. or Canada today was an M 4.2 in the eastern Andreanof Islands. These are not unusual events for the area. A foreshock of M 3.5 occurred within 30 minutes of local solar noon, and may have been promoted by high tidal stresses which maximize at this hour. Forecast 133899 had expected this activity in mid-May.

 

O: 22MAY2021 00:14:21  51.8N  174.0W ml=3.5  EMSC   ANDREANOF ISLANDS, ALEUTIAN IS.

O: 22MAY2021 05:50:10  51.5N  173.2W mb=4.2  EMSC   ANDREANOF ISLANDS, ALEUTIAN IS

P: 17MAY2021 133899    52.5N  169.2W 3.5-5.1 BACAA  Fox Islands, Aleutians     

 

UNUSUAL EARTHQUAKE IN LABRADOR SEA, CANADA

 

EARTHQUAKE SUMMARY FOR  MAY 20, 2021

 

The strongest and most unusual earthquake in the U.S. or Canada today was an M 4.5-4.7 in the Labrador Sea of Canada. It may have been lightly felt in Labrador according to data from Earthquakes Canada. Only two earthquakes of  M>=4.5 have hit within about 300 km of this epicenter in the past 30 years. These were an M 4.6 to the southeast of this on July 30, 2020 and an M 4.9 about 50 km to the west on January 21, 1998. Forecast 133912 had expected today's event was likely in this region aroun May 21. This event which occurred near local solar noon may have been enhanced by high tidal stresses which maximize near this hour. This epicenter is at the third node (120 degrees) from the M 6.6 in the South Indian Ocean of May 12. Similar events at this distance from the Indian Ocean were recorded today in northern Nunavit, Canada, Antofagasta, Chile, and the Andreanof Islands, Alaska.

 

O: 20MAY2021 16:59:28  59.2N   53.7W MB=4.7  ECAN Nutak, NL    

O: 20MAY2021 16:59:26  59.2N   54.1W mb=4.5  EMSC   LABRADOR SEA                 

P: 21MAY2021 133912    61.0N   58.0W 2.5-4.1 ABBAA  Baffin/Davis Strait Canada 

 

An unusual earthquake of M 2.2-2.5 also occurred in southern Ohio today. NEIC reported this earthquake of M 2.5 in Ohio was felt with intensity II-III in the area(s) of Ohio at South Point and Pedro. This is the strongest event within about 100 km of this epicenter since an M 2.9 on April 25, 2020. Forecast 133880 had expected this event in Ohio was likely around May 20. This epicenter is located at 142-145 degrees from the mainshocks in the South Indian Ocean (M 6.7, May 12, 2021) and the M 6.6 in Sumatra of May 14 and was probably enhanced by energy from these sources. Other events at this distance from these mainshocks occurred today in Oklahoma, the Gulf of California, Missouri, Texas, Haiti and Hawaii.

 

O: 21MAY2021 04:53:10  38.6N   82.4W mb=2.2  EMSC   OHIO                         

O: 21MAY2021 04:53:11  38.6N   82.4W mb=2.5  ANSS   OHIO                         

P: 20MAY2021 133880    40.0N   84.0W 2.0-4.4 ABAAA  Ohio/Lake Erie             

 

The strongest earthquake in the world today was an M 5.7 in the South Indian Ocean near the Crozet Islands. The last earthquake of greater or equal magnitude within about 300 km of this epicenter was an M 6.3 on August 6, 2020 and prior to that as an M 5.8 on June 12, 2020. Forecast 133968 had expected today’s event was likely within about 100 km in mid-May.

 

O: 20MAY2021 17:05:19  41.1S   44.2E Mw=5.7  EMSC   CROZET ISLANDS REGION        

P: 14MAY2021 133968    41.0S   43.0E 4.0-5.8 CAAAA  So. Indian Ocean           

 

A moderate earthquake of M 5.4 was felt strongly today in the Solomon Islands. NEIC reported this event with intensity IX in Honiara, Guadalcanal, Solomon Islands. The mainshock was preceded by an M 4.8 regional foreshock which NEIC reported was felt with intensity VII in Honiara, Guadalcanal and in KrakiraMakura and Ulawa, Solomon Islands. The last earthquake within about 200 km of this epicenter with M>=5.4 was an M 5.6 on October 30, 2020 and before that an M 5.8 on July 18, 2020. Forecast 133746 had expected this activity was likely in mid-May in the southeastern Solomon Islands. This activity is located at the seventh node (51.4 degrees) from recent earthquakes off the east coast of Honshu, Japan.

 

O: 21MAY2021 01:37:36   9.8S  160.4E Mw=5.4  EMSC   SOLOMON ISLANDS              

O: 20MAY2021 18:19:00   9.9S  161.3E mb=4.8  EMSC   SOLOMON ISLANDS

P: 14MAY2021 133746     9.0S  157.0E 4.0-5.5 CACAA  Solomon Islands            

 

MODERATE QUAKES HIT OCEAN RIDGES

 

EARTHQUAKE SUMMARY FOR  MAY 19, 2021

 

The strongest earthquakes in the world today occurred in the southern Ocean Ridges. The largest of these was an M 5.5 in the Southeast Indian Ridge but an M 5.1 was also registered in the Southern East Pacific Rise. The earthquake of M 5.5 near Crozet Island in the southeast Indian Ridge is he strongest within about 300 km of this epicenter last on May 9, 1999. An M 5.9 occurred about 350 km southeast of this on October 14, 2018 with a similar event of M 5.6 on May 24, 2009. The antipode of this event is at 41N 95W in western and Central Nebraska and north of Kansas and Oklahoma. Some enhancement of seismicity may occur in the next several days in these regions. Forecast 133968 had expected today’s earthquake within about 100 km was likely in mid-May.

 

O: 19MAY2021 16:08:26  41.3S   85.7E Mw=5.5  EMSC   SOUTHEAST INDIAN RIDGE       

P: 12MAY2021 133968    42.0S   85.0E 4.0-5.4 CAAAA  So. Indian Ocean           

 

The M 5.1 in the southern East Pacific Rise today was not a classical aftershock of the M 6.6 of May 19 which occurred about 500 km northeast of today's epicenter but may have been impacted by stress redistribution following that event. The last event within about 300 km of this epicenter with equal or greater magnitude was an M 5.4 on November 20, 2017. Forecasts 133952 and 133952 had expected enhanced activity in this area around May 20 to the north of today's event.

 

O: 19MAY2021 17:54:35  36.7S  110.4W mb=5.1  EMSC   SOUTHERN EAST PACIFIC RISE   

P: 20MAY2021 133952    27.0S  107.0W 4.0-5.8 ACCAA  So. East Pacific Rise      

P: 20MAY2021 133952    24.0S  112.0W 4.0-5.5 ADBAA  So. East Pacific Rise      

 

An M 4.6 was felt widely in Afghanistan. NEIC reported it was felt with maximum intensity V in Afghanistan and Mahmoud Raqui; IV in Kabul and II in Poke Alam Lawgar. This epicenter is exactly antipode to the event of M 6.6 in the East Pacific Rise earlier in the day and was probably promoted by energy from that source. Forecast 133818 had expected today's event in Hindu Kush was likely within about 200 km around May 17.

 

O: 19MAY2021 09:19:13  34.7N   69.6E mb=4.6  EMSC   HINDU KUSH REGION, AFGHANISTAN

P: 17MAY2021 133818    37.0N   69.0E 3.8-5.3 ACAAA  Hindu Kush/Pakistan         

 

 

EFFECTS OF NEW MOON, TROPICAL CYCLONE TAUKTAE SPREAD

 

EARTHQUAKE SUMMARY FOR  MAY 18, 2021

 

Tropical Cyclone Tauktae made landfall in western India in the area of Gujarat over the past two days. It is currently headed inland and is located near 30N 71E in the region of Afghanistan and Pakistan. This was a very deadly storm and was according to news sources, the strongest storm ever to hit the west coast of India in modern times. As it made landfall with winds up to 205 kph in the region of Gujarat it killed up to 26 people and did great damage to property. A number of barges in the Arabian Sea were capsized during this storm but most people were rescued. When Tauktae made landfall this summary reported a moderate earthquake in Gujarat and the forecast for regional seismicity induced by stresses from this storm as published in earlier issues of this summary read:

 

 

"An unusually large quake of M 3.8-3.9 occurred in the region of Gujarat, India today. MIS (India National Center for Seismicity) reported it was lightly felt in the region of Gujarat. This is the strongest earthquake in the Gujarat area of India since an M 4.1 on July 15, 2020. It may have been promoted by strong tidal stresses associated with the past new moon as noted in previous summaries:

 

"The new moon arrived on May 11, 2021 at 19:00 UT. Longitudes which were at local solar noon at this hour are near 105 West and those at local solar midnight near 75 East longitude. In the west these include areas of central and Western U.S. and Canada and western Mexico as well as portions of the East Pacific Rise. In the east area near 75E include Afghanistan, India, Hindu Kush, Iran and eastern Indonesia and portions of the mid-Indian ridges. These regions are expected to see enhanced seismicity during the coming week. Other tidally promoted seismicity may occur elsewhere and is most likely near local solar midnight and noon when tidal stresses are generally maximized." (May 11-13, 2021)

 

Another likely promoter of today's event is the very strong Tropical Cyclone Tauktae as noted in previous issues of this summary:

 

"Tropical Cyclone Tauktae (01A) continued in the area west of India today with winds up to 185 kts. It is expected to track to the north and may impact regional seismicity in Gujarat, western India and the area of Pakistan and Afghanistan in the next several days. Land fall is expected south of Karachi, Pakistan around May 18. The antipode is at 19S 108W over the East Pacific Rise where some seismicity may be promoted at this time." (May 14-18, 2021)

 

Tropical Cyclone Tauktae made landfall at the same time as this earthquake occurred within about 50 km of this epicenter.

 

Following landfall of Tauktae, a strong earthquake occurred at the antipode of this storm in the South East Pacific Rise with M 6.6. This event was an expected consequence of TC Tauktae as discussed above. The only earthquake of larger magnitude in this region of the Southeast Pacific Rise in the past 30 years was an M 7.2 on October 9, 2014. At the time of this earthquake in October, 2014, this summary noted:

 

"A major earthquake of M 7.0-7.1 hit the Southeast Pacific Rise near Easter Island today. This is an area and tectonic system in which an event of this size will not generate a sizable tsunami. The epicenter was near the triple junction of the East Pacific Rise. The mainshock was followed by an M 6.0-6.5 aftershock 17 minutes later.  An ScS phase returning to the epicenter after reflecting off the core-mantle boundary could have triggered the strong aftershock as it arrived 1-2 minutes prior to this event. This is the strongest earthquake ever recorded within 400 km of this epicenter. The previous largest event was an M 7.0 on March 20, 1920, the only event of M>6.9 previously recorded in the region. An M 6.6 hit the region on October 28, 1981 and an M 6.8 occurred in July, 1949 and again in July, 1950. This suggests about a 31-32 year incubation period for strong earthquakes in this area (1920, 1950, 1981, 2014). In addition to tidal stresses from the full moon today, this event may have been promoted by a pair of M-class solar flares which occurred about 15 minutes before the quake initiated. At this point M-class flares are relatively rare. In the past month there have been only six M1.3 -class flares or larger recorded. The last of these was an M7.3 on October 2. The antipode of this event is in the Pakistan-Afghanistan border region at 32N 69E." (October 9-10, 2014)

 

Forecast 133952 had expected today's event of M 6.6 in the southern East Pacific was likely to the north of today's event was likely around May 20.

 

O: 19MAY2021 00:39:01  32.8S  108.5W mb=4.6  EMSC   SOUTHERN EAST PACIFIC RISE

O: 19MAY2021 00:42:20  33.2S  109.4W Mw=6.6  EMSC   SOUTHERN EAST PACIFIC RISE   

P: 20MAY2021 133952    27.0S  107.0W 4.0-5.8 ACBAA  So. East Pacific Rise      

P: 20MAY2021 133952    24.0S  112.0W 4.0-5.5 ACBAA  So. East Pacific Rise      

 

Seismicity  also picked up in the area north of TC Tauktae. An M 4.6 was felt widely in Afghanistan. NEIC reported it was felt with maximum intensity V in Afghanistan at Mahmoud Raqui; IV in Kabul and II in Poke Alam Lawgar. This epicenter is exactly antipode to the event of M 6.6 in the East Pacific Rise earlier in  the day and was probably promoted by energy from that source.  Forecast 133818 had expected today's event in Hindu Kush was likely within  about 200 km around May 17.

 

O: 19MAY2021 09:19:13  34.7N   69.6E mb=4.6  EMSC   HINDU KUSH REGION, AFGHANISTAN

P: 17MAY2021 133818    37.0N   69.0E 3.8-5.3 ACAAA  Hindu Kush/Pakistan        

 

A series of earthquakes also occurred in the region of Nepal today. This included an M 5.3 which was felt in Nepal  in Pokhara, Bharantpur, Kurtipur, and II-III in Waing, Baguiri, Bulawi, Kathmandu, Latipur, and Tribuvannagar and Bhaktapur. Forecast 133790 had expected today's activity was likely in Nepal around May 21.

 

O: 19MAY2021 02:31:30  28.3N   84.3E ML=4.0  EMSC   NEPAL

O: 19MAY2021 02:32:30  28.3N   84.4E ML=4.1  EMSC   NEPAL

O: 19MAY2021 02:41:38  28.3N   84.3E mb=4.8  EMSC   NEPAL

O: 18MAY2021 23:57:58  28.3N   84.5E mb=5.3  EMSC   NEPAL                        

P: 21MAY2021 133790    27.0N   88.0E 3.5-5.6 BBCAA  Nepal                      

 

MODERATE QUAKE IN RAT ISLANDS, ALASKA

 

EARTHQUAKE SUMMARY FOR  MAY 17, 2021

 

The strongest earthquake in the U.S. or Canada today and the largest in the world was an M 5.4 in the Rat Islands, Aleutians, Alaska. NEIC reported it may have been felt as far as Unalaska and Anchorage, Alaska. This is the largest earthquake in the Rat Islands since an M 6.4 on April 2, 2019. An M 6.1 hit the Andreanof Islands east of this epicenter on January 3, 2021, the last of significantly larger magnitude within about 200 km of today's epicenter.  Forecast 133906 had expected this earthquake was likely within the Rat Islands around May 18.

 

O: 17MAY2021 20:25:07  51.3N  179.3E Mw=5.4  EMSC   RAT ISLANDS, ALEUTIAN ISLANDS

O: 18MAY2021 05:39:58  51.1N  179.4E mb=5.0  EMSC   RAT ISLANDS, ALEUTIAN ISLANDS

P: 18MAY2021 133906    51.0N  177.0E 4.0-5.8 AABAA  Rat Islands                

 

The strongest earthquake felt in the U.S. or Canada outside Alaska today was an M 3.3-3.9 in Quebec, Canada. NEIC reported this earthquake of M 3.3 in Quebec, Canada was felt with intensity II-III in the area(s) of Quebec, Canada with IV at Saint-Roch-de-l'Achigan, Crabtree, Contrecoeur, and II-III in L'Epiphane, Vercheres, Lac-Lapierre, Lavatine, Laurentides, Saint-Anne-des-Plaines and Sainte-Julienne. Earthquakes Canada reported with M 3.9 it was felt lightly in the epicentral area. This is the strongest earthquake within about 200 km of this epicenter since an M 4.2 on November 6, 2012 an aftershock of an M 4.5 on October 10, 2012. The strongest earthquake in the area in the past 300 years was an M 5.2 on April 20, 2002. Forecast 133874 had expected this activity within about 100 km of this epicenter was likely around May 19. This epicenter is at the third node (120 degrees) from the M 8.1 in the Kermadec Islands of March 4, 2021 and was probably promoted by energy from that source.

 

O: 17MAY2021 11:03:22  45.8N   73.5W MB=3.9  ECAN L'Epiphanie, QC. Felt          

O: 17MAY2021 11:03:22  45.8N   73.5W mb=3.3  EMSC   ST. LAWRENCE VALLEY REG., CANA

P: 19MAY2021 133874    46.0N   72.0W 2.0-3.9 AAAAA  New England                

 

MODERATE EARTHQUAKES IN NORTHEASTERN IRAN

 

EARTHQUAKE SUMMARY FOR  MAY 16, 2021

 

The strongest earthquakes in the world today were a pair of M 5.3-5.4 events in northeastern Iran. NEIC reported these were felt with maximum intensity VI in Minudasht, Iran, V in Bicnord, Khoarasan and III in Turkmenistan at Baherdan and Asgabat. This is an area where strong and major earthquake have historically done  much damage, but recently has been been relatively quiet. The last event within about 200 km of today's epicenter with equal of greater magnitude was an M 5.6 on May 13, 2017 and prior to that an M 5.9 on August 22, 2000. A major earthquake shook the area about 300 km northwest of today's epicenter on December 6, 2000.  Forecast 133829 had expected today's event in this area within about 200 km of these epicenter was likely in mid-May.

 

O: 17MAY2021 01:03:40  37.2N   56.6E ML=3.6  EMSC   NORTHEASTERN IRAN

O: 17MAY2021 02:57:41  37.2N   56.5E ML=3.7  EMSC   NORTHEASTERN IRAN

O: 17MAY2021 02:47:00  37.3N   56.7E mb=4.4  EMSC   NORTHEASTERN IRAN

O: 16MAY2021 23:04:56  37.4N   56.8E Mw=5.3  EMSC   NORTHEASTERN IRAN

O: 17MAY2021 00:54:01  37.4N   56.8E mb=5.3  EMSC   NORTHEASTERN IRAN            

O: 17MAY2021 00:54:01  37.3N   56.7E mb=5.4  EMSC   NORTHEASTERN IRAN             

P: 13MAY2021 133829    37.0N   59.0E 3.8-5.3 BABAA  No. Iran                   

 

An earthquake of M 4.4 was widely felt in the Dominican Republic today. NEIC reported maximum intensity V in Cotui and II-III in Piedra Blanca, Cenovi Duarte, Jarabacca, La Vega, San Franciso de Marcoris, San Cristobal, El Carril, Monte Plata and Tenares, Dominican Republic. Ir was preceded by an M 3.8 felt in the same area. It was preceded by an M 3.8 foreshock. The last earthquake in the Dominican Republic of larger magnitude occurred as an M 4.6 on November 30, 2020. Forecast 133775 had expected today's event within about 50 km was likely around May 17.

 

O: 16MAY2021 12:14:50  18.8N   70.4W mb=4.4  EMSC   DOMINICAN REPUBLIC           

O: 16MAY2021 10:07:13  18.9N   68.3W ML=3.6  EMSC   DOMINICAN REPUBLIC REGION

P: 17MAY2021 133775    19.0N   71.0W 3.4-5.1 AAAAA  Puerto Rico                

 

An unusually large quake of M 3.8-3.9 occurred in the region of Gujarat, India today. MIS (India National Center for Seismicity) reported it was lightly felt in the region of Gujarat. This is the strongest earthquake in the Gujarat area of India since an M 4.1 on July 15, 2020. It may have been promoted by strong tidal stresses  associated with the past new moon as noted in previous summaries:

 

"The new moon arrived on May 11, 2021 at 19:00 UT. Longitudes which were at local solar noon at this hour are near 105 West and those at local solar midnight near 75 East longitude. In the west these include areas of central and Western U.S. and Canada and western Mexico as well as portions of the East Pacific Rise. In the east area near 75E include Afghanistan, India, Hindu Kush, Iran and eastern Indonesia and portions of the mid-Indian ridges. These regions are expected to see enhanced seismicity during the coming week. Other tidally promoted seismicity may occur elsewhere and is most likely near local solar midnight and noon when tidal stresses are generally maximized." (May 11-13, 2021)

 

Another likely promoter of today's event is the very strong Tropical Cyclone Tauktae as reported in previous issues of this summary:

 

"Tropical Cyclone Tauktae (01A) continued in the area west of India today with winds up to 125 kts. It is expected to track to the north and may impact regional seismicity in Gujarat, western India and the area of Pakistan and Afghanistan in the next several days. Land fall is expected south of Karachi, Pakistan around May 18. The antipode is at 19S 108W over the East Pacific Rise where some seismicity may be promoted at this time." (May 14-17, 2021)

 

Tropical Cyclone Tauktae made landfall at the same time as this earthquake occurred within about 50 km of this epicenter. Forecast 133785 had expected this area would see enhanced seismicity around May 17.

 

O: 16MAY2021 22:07:18  20.7N   71.0E ML=3.8  EMSC   NEAR THE COAST OF GUJARAT, IND

O: 16MAY2021 22:07:18  20.7N   71.0E ML=3.8  MIS    NEAR THE COAST OF GUJARAT, IND

P: 17MAY2021 133785    24.0N   71.0E 3.5-5.2 ACAAA  India                      

 

An unusual earthquake of M 4.2 also hit the border between Mozambique and Zimbabwe today. This is the strongest earthquake within about 150 km of this epicenter since an M 4.3 on February 1, 2021 and prior to that an M 4.8 on April 26, 2020. Forecast 133953 had expected today's event within about 100 km was likely in mid-May.

 

O: 16MAY2021 09:11:50  22.1S   33.1E mb=4.2  EMSC   MOZAMBIQUE                   

P: 12MAY2021 133953    21.0S   33.0E 4.0-5.8 BBAAA  So. Indian Ocean           

 

The strongest earthquake in the western Hemisphere today was an M 4.9 in Antofagasta, Northern Chile.  GUC reported this earthquake was felt with intensity  IV in  Tarapaca at Huara, La Tirana, Mamina, Pozo Almnte and III in Alto Hospicio, Iquique, Pica and with IV in Antofagasta at Quillagua; III in Calama and II in Maria Eleana and Tocopilla, Chile. NEIC reported this earthquake of M 4.9 in Northern Chile was felt with intensity II-III in the area(s) of Northern Chile in Calama, Antofagasta and Iquique, Tarapaca. This event occurred about 25 minutes after a strong Gamma Ray Burst reported by

Swift at 05:28 UT with the following paramaters:

 

The last major Gamma Ray Burst (GRB) according to the online NASA Swift GRB Catalog was observed on May 17, 2021 at 05:28 UT with BAT Fluence n/a 10-7 erg/cm2 (MAGNITUDE: n/a), Associated earthquakes: Northern Chile M 4.9 05:43 UT)

 

Forecast 133949 had expected today's event was likely around May 19. This event occurred near local solar midnight.

 

O: 17MAY2021 05:43:42  21.4S   68.8W Mw=4.9  EMSC   ANTOFAGASTA, CHILE           

O: 17MAY2021 05:43     21.3S   68.8W mb=4.9  GUC    Tarapaca at Huara, La Tirana,

P: 17MAY2021 133945    22.0S   68.0W 4.0-5.6 AAAAA  Argentina                  

P: 19MAY2021 133949    22.0S   69.0W 4.0-5.4 AAAAA  Coast No. Chile             

 

GRBs are often reported just prior to moderate or unusual earthquakes and may have helped promote today's event in Chile. SWIFT also reported today the parameters of a very strong GRB which occurred on May 14 with the following parameters:

 

The last major Gamma Ray Burst (GRB) according to the online NASA Swift GRB Catalog was observed on May 14, 2021 at 18:23 UT with BAT Fluence 74 10-7 erg/cm2 (MAGNITUDE: >18.8), Associated earthquakes: Para, Brazil, 18:42 UT M 4.3)

 

This GRB was followed minutes later by an unprecedented earthquake in eastern

Brazil of M 5.1 on the equator. It is likely to have helped promote that event. At the time this summary noted in regard to this earthquake:

 

 

"An unusual earthquake of M 5.1 occurred today in the region near Para, Brazil. EMSC reported it was felt with intensity up to V in the epicentral area. This epicenter, near the equator may have been promoted by geomagnetic effects associated with the strong geomagnetic storm of May 12, 2021 ...

 

The only earthquake within about 500 km of this epicenter in the past 30 years with M>=4 was an M 4.8 about 500 km northeast of today's epicenter on  October 31, 2007. This event joins a series in Guyana which began on January 31, 2021 with an M 5.6 and continued through April 28, 2021 with an M 4.7 about 300 km south of this activity in Guyana on April 28, 2021. This event occurred in the Amazon area" (May 14-15, 2021)

 

The strongest earthquake felt in the U.S. or Canada today was an M 3.9 in Quebec, Canada. Earthquakes Canada reported it was felt lightly in the epicentral area. This is the strongest earthquake within about 200 km of this epicenter since an M 4.2 on November 6, 2012 an aftershock of an M 4.5 on October 10, 2012. The strongest earthquake in the area in the past 300 years was an M 5.2 on April 20, 2002. Forecast 133874 had expected this activity within about 100 km of this epicenter was likely around May 19.

 

O: 17MAY2021 11:03:22  45.8N   73.5W MB=3.9  ECAN L'Epiphanie, QC. Felt          

P: 19MAY2021 133874    46.0N   72.0W 2.0-3.9 AABAA  New England                

 

An earthquake of M 4.1 also continued the enhanced seismicity off the coast of Oregon today. This epicenter was southeast of the previous events in recent days which included an M 5.4 on April 29. Forecast 133879 had expected today's activity in mid-May.

 

NEIC reported this earthquake of M 4.1 Off the coast of Oregon  was felt with intensity II-III in the area(s) of Oregon in Gold Beach (IV) and Eugene. 

 

O: 16MAY2021 14:57:04  43.1N  126.4W mb=4.1  EMSC   OFF COAST OF OREGON          

P: 12MAY2021 133879    41.8N  126.9W 2.5-4.6 BBAAA  Off Coast of No. Calif     

P: 14MAY2021 133879    44.1N  128.8W 3.0-4.9 AABAA  Off Coast of Oregon        

 

STRONG EARTHQUAKE SHAKES HOKKAIDO, JAPAN

 

EARTHQUAKE SUMMARY FOR  MAY 15, 2021

 

A moderately strong quake of M 5.9-6.1 occurred in Hokkaido, Japan today. NEIC reported it was felt in Hokkaido with maximum intensity IV in Obihiro and II-III in Otofuke, Nakashibetsu and Sentai, Miyagi. The only earthquake of M>=5.9 in the region of Hokkaido, Japan in the past 1.5 years was an  M 6.0 on January 12, 2021. The last earthquake of M>=6.1 within about 300 km of this epicenter occurred as an M 6.3 in Northern Honshu on December 20, 2020 and in Hokkaido as an 6.1 on August 28, 2019. The last of larger magnitude in Hokkaido was an M 6.6 on September 5, 2018.  JMA reported this earthquake was felt with intensity II-IV in southern Hokkaido and northern Honshu, Japan. Forecasts 133864 abd 133863 had expected today's earthquake within about 100 km was likely in mid-May. This epicenter is located at 60 degrees from the M 6.6-7.2 in Nias, Indonesia of May 14, 2021 and may have been promoted by energy from that source.

 

O: 16MAY2021 03:23:53  42.1N  144.5E Mw=5.9  EMSC   HOKKAIDO, JAPAN REGION       

O: 16MAY2021 03:23:53  42.1N  144.5E Mw=6.1  JMA    HOKKAIDO, JAPAN REGION       

O: 16MAY2021 05:07:12  41.9N  144.5E mb=4.4  EMSC   HOKKAIDO, JAPAN REGION

O: 16MAY2021 05:18:01  41.9N  144.2E mb=4.1  EMSC   HOKKAIDO, JAPAN REGION

P: 12MAY2021 133864    43.0N  145.0E 3.5-5.5 BAAAA  Hokkaido, Japan            

P: 14MAY2021 133863    41.0N  143.0E 3.5-5.4 ABAAA  Hokkaido, Japan            

 

NUSUAL, MODERATE QUAKE SHAKES EASTERN BRAZIL

 

EARTHQUAKE SUMMARY FOR  MAY 14, 2021

 

An unusual earthquake of M 5.1 occurred today in the region near Para, Brazil. EMSC reported it was felt with intensity up to V in the epicentral area. This epicenter, near the equator may have been promoted by geomagnetic effects associated with the strong geomagnetic storm of May 12, 2021, the strongest in more than a year as noted in previous issues of this summary:

 

"The geomagnetic field saw stormy conditions today. The AP level was 41.  High latitude geomagnetic field also saw strong storm conditions with AP 47. Strong, sudden commencement storms such as this can enhance seismicity especially near the geomagnetic equator or near the polar auroral regions. This is the strongest geomagnetic storm since AP reached 45 on September 1, 2019 more than 1.5 years ago.." (May 12-13, 2021)

 

The only earthquake within about 500 km of this epicenter in the past 30 years with M>=4 was an M 4.8 about 500 km northeast of today's epicenter on  October 31, 2007. This event joins a series in Guyana which began on January 31, 2021 with an M 5.6 and continued through April 28, 2021 with an M 4.7 about 300 km south of this activity in Guyana on April 28, 2021. This event occurred in the Amazon area and was reported at the time in this summary as:

 

"An unusual earthquake of M 4.7 occurred in the Amazon region of Brazil today. NEIC reported it was felt in Brazil at Manaus, Amazonas. This event occurred within about 30 minutes of local solar midnight and was probably promoted by strong tidal stresses associated with today's full moon. This summary had forecast tidal effects on seismicity with this full moon in previous issues ...

 

The last earthquake located within about 300 km of this epicenter in Brazil with M>=4 was an M 4.4 about 300 km to the southwest on February 8, 2005 and an M 4.2 about 250 km northwest of this epicenter on March 15, 1999. No events of M>=4.7 have been recorded in this area in at least 30 years until today." (April 28, 2021)

 

Note that this event occurred with the last full moon as today's event was closely associated with the new moon. This epicenter is at 147 degrees from the M 6.6-7.2 in Sumatra and at 142 degrees from Honshu, Japan yesterday and may have been promoted by  energy from those sources.

 

O: 14MAY2021 18:42:28   1.4S   50.6W ML=5.1  EMSC   PARA, BRAZIL                 

 

The strongest earthquake in the world today was an M 5.5 in the area southeast of the Loyalty Islands. It was not reported felt in this remote area. This is the strongest aftershock in the Loyalty Islands of the M 7.7 of February 10, 2021 since an M 5.9 on March 12, 2021 more than two months ago. Today's event occurred within about one hour of local solar noon and may have been promoted by high tidal stresses associated with the recent new moon. Forecast 133950 had expected today's event was likely within about 100 km around May 17.

 

O: 15MAY2021 01:58:47  21.8S  170.3E Mw=5.5  EMSC   SOUTHEAST OF LOYALTY ISLANDS 

P: 17MAY2021 133950    23.0S  170.0E 4.0-5.4 ABAAA  Loyalty Islands            

 

The strongest seismicity in the world today occurred at ocean ridges. These included an M 5.4 in the West Chile Rise, an M 5.0 near South Georgia Island, an M 4.4 in the Greenland Sea and an M 4.0 in the South Shetland Islands. The last earthquake within about 300 km of the epicenter southeast of Easter Island in the South Pacific with M>=5.4 was an M  5.7 on November 25, 2020. The last of significantly larger magnitude was an M 5.8 on April 10, 2010.  Forecast 133966 had expected today's event within about 75 km of this epicenter was likely around May 12.

 

 

O: 15MAY2021 01:53:18  41.5S   91.5W Mw=5.4  EMSC   SOUTHEAST OF EASTER ISLAND   

P: 12MAY2021 133966    41.0S   91.0W 4.0-5.5 BAAAA  Chile Rise                 

 

The earthquake of M 5.0 in the South Georgia Island area today was the strongest in that region since an M 5.0 on June 2, 2020 and also on February 17, 2019. The last with larger magnitude in this area occurred with M 5.4 on December 12, 2018. Forecast 133975 had expected today's activity was likely within abotu 250 km of this epicenter around May 18.

 

O: 15MAY2021 06:59:51  55.1S   32.1W mb=5.0  EMSC   SOUTH GEORGIA ISLAND REGION  

P: 18MAY2021 133975    56.0S   29.0W 4.0-6.1 BABAA  So. Sandwich Islands       

 

The event of M 4.4 in the Greenland Sea was also not felt today. The last event in this region within about 250 km of today's event was recorded on May 10, 2021 with M 4.5. These appear to be aftershocks of the M 5.4 which hit the area on March 23, 2021.  Forecast 133926 had expected today's activity was like around May 12 within about 100 km of the epicenter.

 

O: 15MAY2021 02:31:23  79.3N    2.1E mb=4.4  EMSC   GREENLAND SEA                

P: 12MAY2021 133926    79.0N    7.0E 4.0-5.4 BAAAA  Arctic Ocean Region        

 

The strongest earthquake in the U.S. or Canada today was an M 4.5 in the Near Islands, Aleutians, Alaska. It was not reported felt in this area. The only earthquake of larger magnitude in the Near Islands in the past half year was an M 5.3 on April 15, 2021. An M 4.4-4.5 occurred about 200 km to the east of today's epicenter on May 5. Forecast 133901 had expected today's event in this area was likely around May 14.

 

 

O: 14MAY2021 23:26:16  53.1N  170.2E mb=4.5  EMSC   NEAR ISLANDS, ALEUTIAN ISLANDS

P: 14MAY2021 133901    55.0N  169.0E 4.0-5.8 BAAAA  Near Islands               

 

STRONG EARTHQUAKES SHAKE SOUTHERN SUMATRA, PANAMA AND HONSHU, JAPAN

 

EARTHQUAKE SUMMARY FOR  MAY 13, 2021

 

The strongest earthquake in the world today was an M 6.6 in Southern Sumatra in the Nias region of Indonesia. NEIC reported it was felt with intensity VI in Sunung, IV in Kuala Lumpur, Malaysia and II-III in Sumatra at Sibolga, Padang, and in Malaysia at Georgetown and Singapore. The regional network, BMG gave this event M 7.2 and reported it was felt with intensity III-IV in Gunung Sitoli, Kabupaten Nias, Nias Barat, Nias Selatan, and III in Banda Aceh; II in Aceh Tengah and II in AekGodang, Indonesia. This earthquake occurred near local solar noon and near the longitude of maximum tidal stress with the current new moon as described in the previous issues of this summary:

 

"The new moon arrived on May 11, 2021 at 19:00 UT. Longitudes which were at local solar noon at this hour are near 105 West and those at local solar midnight near 75 East longitude. In the west these include areas of central and Western U.S. and Canada and western Mexico as well as portions of the East Pacific Rise. In the east area near 75E include Afghanistan, India, Hindu Kush, Iran and eastern Indonesia and portions of the mid-Indian ridges. These regions are expected to see enhanced seismicity during the coming week. Other tidally promoted seismicity may occur elsewhere and is most likely near local solar midnight and noon when tidal stresses are generally maximized." (May 11-13, 2021)

 

This event was also probably enhanced by geomagnetic stresses associated with the geomagnetic storm of May 12-13, the strongest in more than a year. This had also been noted in the previous issues of this summary:

 

"A third factor which probably enhanced global seismicity today was a strong geomagnetic storm which began about the time of M 6.7 in the Mauritius-Reunion area (about 14:00 UT). Most of the strong activity today occurred near the geomagnetic equator or at high latitude as expected with strong geomagnetic triggering. As described in this summary, this storm is the strongest recorded since September 1, 2019:

 

"The geomagnetic field saw stormy conditions today. The AP level was 41.  High latitude geomagnetic field also saw strong storm conditions with AP 47. Strong, sudden commencement storms such as this can enhance seismicity especially near the geomagnetic equator or near the polar auroral regions. This is the strongest geomagnetic storm since AP reached 45 on September 1, 2019 more than 1.5 years ago." (May 12-13, 2021)

 

Today's earthquake in the Nias area of Indonesia is the strongest in more than 30 years. An M 6.8 was recorded about 300 km to the southwest of today's epicenter on October 15, 1990. The only earthquake of M>=5.6 in the area since 1990 was an M 5.9 on June 12, 2018. The antipode to today's event is in Ecuador at 0N 83W, and may see enhanced antipodal seismicity in the next several days. Forecast 133726 had expected today's earthquake was likely in southern Sumatra around May 14 within about 100 km of today's epicenter.

 

O: 14MAY2021 06:33:08   0.2N   96.7E Mw=7.2  BMG    NIAS REGION, INDONESIA       

O: 14MAY2021 07:01:41   0.0N   96.7E ML=4.4  EMSC   NIAS REGION, INDONESIA

O: 14MAY2021 06:43:17   0.1S   96.7E mb=5.0  EMSC   SOUTHWEST OF SUMATRA, INDONESIA

O: 14MAY2021 06:33:08   0.2N   96.7E Mw=6.6  EMSC   NIAS REGION, INDONESIA

P: 14MAY2021 133726     0.0N   98.0E 4.0-5.6 AAAAA  So. Sumatera               

 

 

When an M 5.7 hit the Mentawai region of Southern Sumatra on May 5, 2021 this summary noted:

 

"The antipode of this epicenter is in southern Colombia and Ecuador at 2N 80W - an area which is currently active and could see triggered antipodal seismicity with strong events in this area of Indonesia." (May 5, 2021)

 

An M 6.0 also occurred south of Panama and west of Colombia today. NEIC reported this earthquake was felt with intensity II-III in Panama in Chiriqui at Los Lomas and Boquete and in Santa Fe, Veraguas, Panama. When an M 5.7 near the antipode of this epicenter occurred on May 5, 2021. This is the strongest earthquake within about 200 km of this epicenter since an M 6.2 about 200 km to the north on June 26, 2019 and an M 6.6 about 150 km to the south on January 7, 2015. Forecast 133721 had expected seismic enhancement in this region was likely around May 11.

 

O: 13MAY2021 14:57:09   6.8N   82.4W mb=4.6  EMSC   SOUTH OF PANAMA

O: 13MAY2021 09:42:12   6.7N   82.3W Mw=6.0  EMSC   SOUTH OF PANAMA              

P: 16MAY2021 133721     5.0N   83.0W 3.5-5.4 BBAAA  Costa Rica                 

 

 

An earthquake of M 6.0 also shook regions of eastern Honshu, Japan today. This earthquake was reported by NEIC to have been felt with intensity V in Miyagi, Yamagata, and IV in Fukushima, and III throughout most of northern and eastern Honshu.  JMA reported IV in Fukushima and Miyagi with lesser shaking throughout most of northern and eastern Honshu.  An aftershock of M 4.4 was reported with intensity II in Miyagi, Saitama and Chiba, Honshu, Japan. This is apparently the strongest aftershock of the M 7.1 which occurred on February 13, 2021. Like today's event that quake in February occurred two days after the new moon and was associated with a strong geomagnetic storm This area is very sensitive to geomagnetic effects on seismicity. Forecast 133833 had expected today's event within about 100 km was likely around May 14.

 

O: 14MAY2021 00:23:23  38.0N  141.3E mb=4.4  EMSC   NEAR EAST COAST OF HONSHU, JAPAN

O: 13MAY2021 23:58:16  37.8N  141.7E Mw=6.0  EMSC   NEAR EAST COAST OF HONSHU, JAP

P: 14MAY2021 133833    37.0N  141.0E 4.0-5.5 AAAAA  Off East Coast Honshu      

 

An M 5.8 also occurred in the Fiji Islands south of Samoa today. Larger earthquakes of M 6.0 and 6.1 occurred about 200 km northeast of this on February 18, 2021 and December 6, 2019. This event occurred within about an hour of local solar midnight near the geomagnetic equator and was probably promoted by the major geomagnetic storm on May 12-13, 2021. Forecast 133940 had expected today's activity was likely within about 100 km around May 14.

 

O: 13MAY2021 13:31:33  15.9S  177.4W Mw=5.8  EMSC   FIJI REGION                  

P: 14MAY2021 133940    17.0S  177.0W 4.0-5.7 ABAAA  Tonga Islands              

 

UNPRECEDENTED M 6.7 IN MAURITIUS-REUNION AREA TRIGGERED BY ANTIPODAL EFFECTS

 

EARTHQUAKE SUMMARY FOR  MAY 12, 2021

 

The strongest earthquake in the world today was an M 6.7 in the Mauritius-Reunion area in the South Indian Ocean. NEIC reported it was as far as 1000 km from the epicenter in Mauritius at Laimatie Flaco, Bois des Amourettes, Grand Port, Curepipe Plaines Wilheim, Quatre Bornes Paines Wilheim and in Antananarivo, Madagascar and at Male, Maldives. The last earthquake in the world of larger magnitude was an M 7.0 on March 20, 2021 off the coast of eastern Honshu. A smaller event off Honshu of M 6.7-6.8 occurred more recently on May 1, 2021. The only earthquake ever recorded of M>=6.7 within about 300 km of this epicenter was an M 6.6 on July 26, 2012. Today's earthquake is at the exact antipode of the eye of Tropical Storm Andres which is south of western Mexico at this time. The possibility of such an event at this time had been suggested in this summary in the previous summary as:

 

"Tropical storm Andres continued in the area south of Jalisco, Mexico with winds up to 85 kts.  The M 5.1 in Michoacan today was probably promoted by stresses from this storm. The antipode of this storm is at 17S 67E in the South Indian Ridge. A moderate to strong earthquake in this area is possible at this time. This longitude is also near the maximum tidal stress with the current new moon as noted in previous issues of this summary:

 

"The new moon will arrive on May 11, 2021 at 19:00 UT. Longitudes which are at local solar noon at this hour are near 105 West and those at local solar midnight near 75 East longitude. In the west these include areas of central and Western U.S. and Canada and western Mexico as well as portions of the East Pacific Rise. In the east area near 75E include Afghanistan, India, Hindu Kush, Iran and eastern Indonesia and portions of the mid-Indian ridges. These regions are expected to see enhanced seismicity during the coming week. Other tidally promoted seismicity may occur elsewhere and is most likely near local solar midnight and noon when tidal stresses are generally maximized." (May 9-12, 2021)

 

A third factor which probably enhanced global seismicity today was a strong geomagnetic storm which began about the time of M 6.7 in the Mauritius-Reunion area (about 14:00 UT). Most of the strong activity today occurred near the geomagnetic equator or at high latitude as expected with strong geomagnetic triggering. As described in this summary, this storm is the strongest recorded since September 1, 2019:

 

"The geomagnetic field saw stormy conditions today. The AP level was 41.  High latitude geomagnetic field also saw strong storm conditions with AP 47. Strong, sudden commencement storms such as this can enhance seismicity especially near the geomagnetic equator or near the polar auroral regions. This is the strongest geomagnetic storm since AP reached 45 on September 1, 2019 more than 1.5 years ago.." (May 12-13, 2021)

 

An M 6.7 in Fiji accompanied the strong geomagnetic storm on September 1, 2019. Moderately strong earthquakes in Panama, Peru and Halmahera today followed with this storm and lie near the geomagnetic equator. They were probably promoted by geomagnetic effects associated with today's storm.

 

The M 6.6-6.7 on July 26, 2012 was also apparently triggered by a similar storm south of Mexico as noted in this summary at the time as:

 

"A strong M 6.7 earthquake occurred today off the Indian Ocean islands of Mauritius, The epicenter was about 400 km north of the island of Rodrigues. There were no immediate reports of damage or injury. No tsunami warning was issued. Mauritius is a popular tourist area and a tsunami would do major damage. This earthquake is located on the mid-Indian ridge near the volcanic centers at Reunion and could be associated with a volcanic epicenter. Earthquakes on mid-Ocean ridges, no matter how large, seldom produce appreciable tsunamis.  This epicenter is antipodal to the region of western Mexico where Socorro and Revilla Gigedo Islands are located. A series of hurricanes has been passing over this area in the past two weeks. Microseismics from these could have helped promote the antipodal activity in the Indian Ocean as we suggested at the time. It is also possible that the earthquake near Mauritius will trigger renewed activity in the region of western Mexico near its antipode. We discussed this possibility in our summary of July 8 where we stated in this regard on the occurrence of the M 5.0 foreshock to today's earthquake in Mauritius:

 

"A moderate earthquake hit the region of Mauritius and Reunion in the South Indian Ocean today with M 5.0. This is at the antipode of the current location of Hurricane Daniel which is a major hurricane south of Mexico. Microseisms from this hurricane will focus at this location in the south Indian Ocean and could help promote seismicity in the area. This has been seen in the case of major hurricanes on a number of occasions in the past and appears to be another way to promote regional seismicity. A more detailed study of this is probably called for." (July 8, 2012)  - note since that time three other hurricanes have taken the same path, an unprecedented series in this region.

 

This event is the strongest in this region of the South Indian Ocean ever recorded. The last of M>=6 was an M 6.3 on August 16, 2010 and the last of M>=6.5 was an M 6.5 on September 17, 1995 and November 5, 1991. These last two were the largest previously recorded in the area." (July 26, 2012)

 

Forecast 133641 had expected this event within about 300 km was likely in the South Indian Ocean around May 9.

 

O: 12MAY2021 14:05:16  17.3S   66.5E Mw=6.7  EMSC   MAURITIUS - REUNION REGION   

P:  9MAY2021 133641    14.0S   66.0E 4.0-5.4 BCAAA  So. Indian Ocean           

 

 

A strong earthquake of M 5.9 also occurred near El Salvador today. NEIC reported

this event was felt with maximum intensity V in San Salvador at La Libertad; IV in Antiguo Cuscatlan, El Salvador and II-III in Armenia, Nueva San Salvador, Nuevo Cuscatlan, Opico, San Marcos, San Salvador and Ilopango and in Guatemala at Masagua Escuintla. This event followed a smaller M 5.7 foreshock reported in the previous summary as:

 

 

"A moderately strong earthquake occurred near El Salvador today with M 5.6. NEIC reported it was felt with maximum intensity VIII in El Salvador at Acajuatla; IV in Nuevo Cuscatlan, Antiguo Cuscatlan, and II-III in Opico, and in Guatemala at Masagua, Mixco, Guatemala City, Antigua Guatemala, Santa Catarina Pinula. This earthquake occurred within minutes of local solar midnight and was probably promoted by high tidal stresses which maximize near this hour. It is also near the maximum tidal longitude for the current new moon. It also occurred near the origination point of Tropical Storm Andres which is now south of Jalisco, Mexico and may have helped trigger the M 5.1 in Michoacan yesterday as well as the activity in El Salvador today." (May 12, 2021)

 

 

Forecasts 133447 and 133760 had expected this activity was likely between May 5 and 13 within about 100 km of this epicenter. No major damage was reported with this earthquake and no tsunami was expected nor observed. This epicenter is at 103 degrees from the M 7.7 in the Loyalty Islands of February 10, 2021 and was probably promoted by energy from that source. Today's event of M 5.9 is the strongest within about 200 km of this epicenter since an M 5.9 on December 19, 2019 and an M 5.9 on July 31, 2019. A strong M 6.6 hit the area about 100 km to the east on May 30, 2019.  Forecasts 133760 and 133758 had expected today's event within about 100 km was likely around May 13-14.

 

O: 12MAY2021 08:45:48  13.3N   90.2W Mw=5.9  EMSC   OFFSHORE EL SALVADOR         

P: 13MAY2021 133760    13.0N   91.0W 3.5-5.6 AAAAA  Guatemala                  

P: 14MAY2021 133758    13.0N   89.0W 3.5-5.2 AAAAA  Coast of Central America   

 

An M 6.0 also occurred south of Panama and west of Colombia today. NEIC reported this earthquake was felt with intensity II-III in Panama in Chiriqui at Los Lomas and Boquete and in Santa Fe, Veraguas, Panama. When an M 5.7 near the antipode of this epicenter occurred on May 5, 2021 this summary noted this relation could bring about a strong earthquake at this time in the area of Colombia or Ecuador at this time as:

 

"The antipode of this epicenter is in southern Colombia and Ecuador at 2N 80W - an area which is currently active and could see triggered antipodal seismicity with strong events in this area of Indonesia." (May 5, 2021)

 

This is the strongest earthquake within about 200 km of this epicenter since

an M 6.2 about 200 km to the north on June 26, 2019 and an M 6.6 about 150 km to the south on  January 7, 2015. Forecast 133721 had expected seismic enhancement in this region was likely around May 11.

 

O: 13MAY2021 09:42:10   6.7N   82.4W Mw=6.0  EMSC   SOUTH OF PANAMA               

P: 11MAY2021 133721     8.0N   83.0W 3.5-5.4 ABAAA  Costa Rica                 

 

 

An earthquake of M 5.5-5.6 shook the area of Central Peru today. NEIC reported it was felt with intensity V in Ica, Peru at Ica and Santiago; IV in Arequipa and II-III in the Lima area at Nuevo Imperial, Mala, San Luis, Santa Maria and Lima. This epicenter is located on the geomagnetic equator and was probably promoted by today's geomagnetic storm. The last earthquake within about 200 km of this epicenter with M>=5.6 occurred on October 28, 2020 with M 5.6 and prior to that on May 8, 2019. A strong M 7.1 hit about 150 km southeast of this on January 14, 2018. Forecast 133932 had expected today's event was likely within about 100 km around May 17. This earthquake occurred within about an hour of local solar noon, a time when tidal and geomagnetic stresses are maximized.

 

O: 12MAY2021 15:56:57  14.1S   75.6W mb=5.6  EMSC   NEAR COAST OF CENTRAL PERU   

P: 17MAY2021 133932    15.0S   76.0W 4.0-5.7 BAAAA  Central Peru                

 

The M 5.6 followed an M 5.3 which occurred earlier in the day in southern

Peru. NEIC reported this earthquake was felt with maximum intensity VII in Tarata, Tacna, Peru and in La Paz, Bolivia. Forecast 133937 had expected today's event was likely within about 200 km around May 15.

 

O: 12MAY2021 07:53:23  17.2S   70.0W mb=5.3  EMSC   SOUTHERN PERU                

P: 15MAY2021 133937    17.0S   72.0W 4.0-5.5 BABAA  So. Peru/Bolivia           

 

An earthquake of M 5.5 also occurred today north of Halmahera, Indonesia. It was felt lightly in the epicentral region. It was preceded by an M 5.3 about three hours earlier. This event occurred within about 15 minutes of local solar midnight, a time when tidal and geomagnetic stresses are maximized and was probably promoted by them. Forecast 133406 had expected this event within about 100 km was likely around May 10.

 

 

O: 12MAY2021 15:45:31   4.0N  128.7E mb=5.3  EMSC   NORTH OF HALMAHERA, INDONESIA

O: 12MAY2021 18:20:28   4.0N  128.7E Mw=5.5  EMSC   NORTH OF HALMAHERA, INDONESIA

P: 10MAY2021 133406     4.0N  128.0E 4.0-5.4 AAAAA  Halmahera                  

 

The strongest earthquake in the U.S. or Canada today was an M 5.1 in the Rat Islands, Aleutians. It followed an M 4.8 foreshock but neither of these events were reported felt in this remote area. These occurred near local solar midnight and noon about 12 hour apart. The M 5.1 is the strongest in the Rat Islands

since an M 5.3 on February 4, 2020 and April 14, 2019. It was probably promoted by the major geomagnetic storm today.  Forecast 133906 had expected today's events within about 100 km of these epicenters were likely mid-May.

 

O: 12MAY2021 22:00:34  51.8N  176.3E mb=5.1  EMSC   RAT ISLANDS, ALEUTIAN ISLANDS

O: 12MAY2021 09:32:35  51.3N  176.7E mb=4.8  EMSC   RAT ISLANDS, ALEUTIAN ISLANDS

P: 17MAY2021 133906    52.0N  175.0E 4.0-5.6 BAAAA  Rat Islands                

 

MODERATE QUAKES WITH NEW MOON IN MICHOACAN, MEXICO; KERMADEC ISLANDS

 

EARTHQUAKE SUMMARY FOR  MAY 10, 2021

 

The generally quiet conditions in the world seismicity continued today. The largest earthquakes of the day were and M 5.3 in the Kermadec Islands aftershock zone and an M 5.1 in Michoacan, Mexico.

 

The event in Michoacan occurred in conjunction with the passage of the first Tropical Storm (Andres) to the south of this epicenter and was likely promoted by stresses from this storm as noted in previous issues of this summary:

 

"Tropical storm Andres continued in the area south of Michoacan, Mexico with winds up to 85 kts.  Little impact on regional seismicity is expected with this storm but an M 5.1 in Michoacan today was probably promoted by stresses from this storm.

 

This is the strongest earthquake in the Mexican State of Michoacan in at least

a year. The last such event of M>=5.1 occurred more than three years ago as an M 5.8 on February 9, 2018 and before that as an M 5.5 on September 30, 2015.

Tidal stresses with the new moon today had been expected to maximize near 105 West longitude in western Mexico (see below) and probably helped promote today's event. Forecast 133454 had expected today's activity in Michoacan was likely around May 7.

 

"The new moon will arrive on May 11, 2021 at 19:00 UT. Longitudes which are at local solar noon at this hour are near 105 West and those at local solar midnight near 75 East longitude. In the west these include areas of central and Western U.S. and Canada and western Mexico as well as portions of the East Pacific Rise. In the east area near 75E include Afghanistan, India, Hindu Kush, Iran and eastern Indonesia and portions of the mid-Indian ridges. These regions are expected to see enhanced seismicity during the coming week. Other tidally promoted seismicity may occur elsewhere and is most likely near local solar midnight and noon when tidal stresses are generally maximized." (May 9-11, 2021)

 

NEIC reported this earthquake of M 5.1 in Michoacan, Mexico was felt with intensity II-III in the area(s) of  Michoacan at Aguilla (VII), Uruapan (IV) and in Artega, Pihuamo, Paizcuaro, Zamora, Zapotitic, Jalisco.  This epicenter is near 100 degrees from the recent strong quakes in Honshu, Japan and may have been promoted from that source as well. An unusual M 4.5 in the Madeira Islands off Portugal today shared this distance from Japan.

 

O: 11MAY2021 04:37:12  18.9N  102.6W Mw=5.1  EMSC   MICHOACAN, MEXICO            

P:  7MAY2021 133454    19.0N  101.0W 3.5-5.8 BAAAA  Michoacan, Mexico          

 

An unusual M 4.1 also occurred north of Michoacan, Mexico today in the state of Coahuila, Mexico. It was not reported felt in this area. It, too, was probably promoted by tidal stresses with the new moon. The last earthquake within  about 200 km of this epicenter with M>=4.1 occurred as an M 4.7 on December 5, 1993, the only such event in this region in the past 30 years. An M 5.7 about 300 km northwest of this occurred on April 14, 1995.

 

 

O: 10MAY2021 16:40:59  27.5N  102.4W ML=4.1  EMSC   COAHUILA, MEXICO             

 

Another unusual earthquake at this longitude (120W) also occurred today in the region of the Texas Panhandle. NEIC reported an earthquake of M 3.2 in Texas Panhandle was felt with intensity II-III in the area(s) of Texas Panhandle in Hartley.  The last earthquake within about 100 km of this epicenter in the Texas Panhandle with M>=3.2 occurred on  January 6, 2014 with an M 3.5. An M 4.3 hit the area about 150 km northeast of this on April 14 with the new moon. At the time this summary noted in this regard:

 

"Two unusual earthquakes occurred today in the region of northern Texas.

This activity is at 100-104 degrees from the major and great eartquakes

in the Loyalty Islands, Kermadec Islands and North Island, New Zealand of

February and March , 2021 and was likely promoted by energy from that source.

The largest of these, and the strongest in the U.S. or Canada was an M 4.3 which hit the Texas Panhandle today. NEIC reported it was felt with intensity IV in Miami, Texas and II-III in Borger, Skellytown, Pampa, Perryton, Groom, Amarillo, and possibly as far as Axtell, Nebraska. This is the strongest earthquake within about 200 km of this epicenter in at least 30 years. The only earthquake in this area of larger magnitude in the past 50 years was an M 4.5-4.6 on February 15, 1974. The strongest quake in this area on record is an M 5.0 on July 30, 1925." (April 14-15, 2021)

 

Forecast 133506 had expected enhanced activity in this area was likely around May 8. This activity is at 101-103 degrees from recent large events in the Loyalty Islands and New Zealand and was probably promoted by energy from those sources.

 

O: 10MAY2021 11:46:31  35.7N  102.5W ml=3.2  ANSS   W of Channing Texas           

P:  8MAY2021 133506    37.0N  105.2W 2.0-4.2 AAAAA  Colorado area              

 

The aftershock of M 5.3 in the Kermadec Islands was the largest event located in the world today. This is the strongest aftershock of the M 8.1 of March 4, 2021 in this area since an M 5.9 on April 29, 2021 which occurred near the full moon with a series of moderate to strong  earthquakes from April 27-29. Today's event occurred near local solar midnight and was also probably promoted by tidal stresses. Forecast 133663 had expected this activity was likely around May 7. More such activity is expected in the next several days as tidal effects linger.

 

O: 10MAY2021 14:10:20  29.2S  176.1W mb=5.3  EMSC   KERMADEC ISLANDS REGION      

P:  7MAY2021 133663    29.0S  178.0W 4.0-5.4 BABAA  No. Kermadec Islands       

 

Seismicity was also up in the region of central Asia today in the areas of Hindu Kush, Afghanistan, Kyrgyzstan and Kazakshstan where moderate earthquakes occurred. This is consistent with tidal triggering in these areas as expected in the tidal forecast for the upcoming new moon of May 11 as noted in  previous issues of this summary (see above).

 

Forecasts 133563 and 133509 had expected today's activity in early May. This activity is at the third node (120 degrees) from the quakes in New Zealand of March 4 and was probably promoted by energy from those sources.

 

O: 10MAY2021 08:04:24  36.5N   71.2E mb=4.3  EMSC   HINDU KUSH REGION, AFGHANISTAN

P:  7MAY2021 133509    37.0N   72.0E 3.8-5.4 BAAAA  Hindu Kush/Pakistan        

 

O: 10MAY2021 10:00:54  42.3N   76.3E mb=3.9  EMSC   KYRGYZSTAN                   

P:  9MAY2021 133563    40.0N   75.0E 4.0-5.5 ACAAA  Kirgizstan/Xinjiang        

 

O: 10MAY2021 16:51:42  47.1N   83.1E mb=4.3  EMSC   KAZAKHSTAN-XINJIANG BORDER REG

P:  5MAY2021 133563    42.0N   83.0E 4.0-5.4 BCAAA  Kirgizstan/Xinjiang        

 

 

MODERATE QUAKES IN KURIL ISLANDS

 

EARTHQUAKE SUMMARY FOR  MAY 9, 2021

 

It was a quiet day in global seismicity. The largest earthquakes of the day were located with M 5.0 in the Kuril Islands and Tonga. The events in the Kuril Islands were the most active in the world today with four other additional moderate quakes in the area. These were not reported felt. The M 5.0 in the Kuril Islands is the strongest in the Kurils since an M 5.1 on March 20, 2021. Forecasts 133585, 133559 and 133570 expected this activity was likely in early May.

 

O: 09MAY2021 16:05:00  47.4N  151.6E mb=4.4  EMSC   KURIL ISLANDS

O:  9MAY2021 23:33:37  46.6N  152.1E mb=5.0  EMSC   KURIL ISLANDS                

P:  4MAY2021 133585    48.0N  154.0E 3.5-5.8 BABAA  So. Kurils                  

 

O: 10MAY2021 00:39:51  43.9N  146.7E mb=4.5  EMSC   KURIL ISLANDS                

P:  8MAY2021 133559    44.0N  145.0E 3.5-5.6 AAAAA  Hokkaido, Japan            

 

O:  9MAY2021 16:23:45  49.4N  155.8E mb=4.8  EMSC   KURIL ISLANDS                

P:  7MAY2021 133570    49.0N  155.0E 3.5-5.8 AAAAA  NE Pacific                 

 

The M 5.0 in the Tonga Islands was reported felt in that area. NEIC reported this earthquake of M 5.0 in Tonga was felt with intensity II-III in the area(s) of Tonga in Neiafu, Vavau. This area has been active in the past week and has included events of M 6.1 and 5.5 in the past week. Today's M 5.0 is not a classical aftershock of the M 6.1 on May 7 as it occurred about 400 km northeast of that event. Forecast 133647 expected the M 5.0 in Tonga today was likely around May 8. 

 

O: 10MAY2021 01:59:17  17.8S  173.6W mb=5.0  EMSC   TONGA                        

P:  8MAY2021 133647    18.0S  178.0W 4.0-5.7 AACAA  Tonga Islands              

 

Two light earthquakes were felt today in the Los Angeles, California area. These occurred within about half an hour of each other. These began with an M 3.2  near local solar midnight and was followed half an hour later by an M 2.5 in the Santa Monica Bay area of California. The may signal a more active period in  the Los Angeles area and resembles some of the precursory activity in the area prior to the Northridge quake of January, 1994. Forecasts 133536 and 133531 expected this activity in early May in this area.

 

NEIC reported the earthquake of M 2.5 in Santa Monica Bay, California was felt with intensity II-III in the area(s) of Santa Monica Bay, California at Hermosa Beach, Manhattan Beach, Redondo Beach, El Segundo, Torrance, Lawndale, Hawthorne and Palos Verdes.  NEIC reported the earthquake of M 3.2 in eastern Los Angeles, California was felt with intensity II-III in the area(s) of eastern Los Angeles, California at Loma Linda, Grand Terrace, Colton, Redlands, San Bernardino, Moreno Valley, Highland.

 

O:  9MAY2021 09:37:57  33.9N  118.5W Ml=2.5  EMSC   SANTA MONICA BAY, CALIFORNIA 

O:  9MAY2021 09:09:33  34.0N  117.2W ML=3.2  EMSC   GREATER LOS ANGELES AREA, CALI

P:  5MAY2021 133535    34.1N  117.4W 2.5-4.8 BAAAA  So. California             

P:  7MAY2021 133531    33.8N  117.7W 2.5-4.7 AAAAA  So. California             

 

 

MODERATE QUAKE SHAKES YUKON TERRITORY, CANADA

 

EARTHQUAKE SUMMARY FOR  MAY 8, 2021

 

The strongest earthquake in the U.S. or Canada today was an M 4.6-4.9 in the Yukon Territory, Canada. This is the strongest earthquake within about 250 km of this epicenter since an M 5.3 about 250 km northwest of today's epicenter occurred on February 13. 2017. An M 6.0 hit about 100 km south of this on July 17, 2014. Forecast 133621 had expected elevated seismicity in this region was likely around May 6. This earthquake was located at the seventh node (51.4 degrees) from the M 7.1, 7.2 and 6.8 in Honshu Japan in March and April and was probably promoted by energy from those sources.  It is also located at 104 degrees from the M 7.3 off North Island, New Zealand of March 4 and was probably promoted by energy from that source.

 

O:  9MAY2021 02:03:44  61.4N  141.0W MB=4.6  ECAN  BEAVER CREEK, YT            

O:  9MAY2021 02:03:46  61.5N  140.6W mb=4.9  EMSC   SOUTHERN YUKON TERRITORY, CANA

O:  9MAY2021 02:03:46  61.5N  140.5W mb=4.9  ANSS   SOUTHERN YUKON TERRITORY, CANA

P:  6MAY2021 133621    62.8N  143.8W 3.2-5.3 BBBAA  Central Alaska             

 

The strongest earthquake in the U.S. or Canada today outside Alaska was and M 4.4 in western Nevada. NEIC reported it was felt with intensity II-III in Nevada at Glenbrook and Fallon and in Carson City. A similar M 4.4 occurred about 25 km west of this on March 30, 2021 but the last event in the area of larger magnitude was an M 4.7 on December 14, 2020. Forecast 133495 expected enhanced activity in this area was likely around May 4 to May 7, 2021. This event is located at the fourth node (90 degrees) from the M 7.7 in the Loyalty Islands of February 10 and at the fifth node (72 degrees) recent major events off eastern Honshu, Japan and was probably promoted by energy from those sources.

 

O: 08MAY2021 13:07:02  38.2N  117.9W ml=2.3  EMSC   NEVADA

O: 08MAY2021 13:07:02  38.2N  117.9W ml=2.3  EMSC   NEVADA

O: 08MAY2021 15:31:26  38.2N  117.9W ml=2.0  EMSC   NEVADA

O:  8MAY2021 08:13:52  38.2N  117.9W Mw=4.1  EMSC   NEVADA                       

O:  8MAY2021 08:13:52  38.2N  117.9W Mw=4.4  ANSS   NEVADA                       

P:  4MAY2021 133495    38.0N  118.8W 2.5-4.6 BAAAA  California/Nevada area     

P:  7MAY2021 133495    37.5N  118.6W 2.5-4.6 AAAAA  California/Nevada area     

 

An M 3.8 also occurred today off the coast of Oregon. It may have been felt lightly on the coast of Oregon at Hillsboro. This continues the enhanced seismicity in this area which began with an M 4.1 on April 26, 2021 with an M 5.4, 5.3 and 5.2 on April 29. Forecast 133578 expected this event was likely around 133578 around May 9.

 

O:  8MAY2021 08:37:00  44.2N  129.2W mb=3.8  EMSC   OFF COAST OF OREGON          

P:  9MAY2021 133578    44.5N  129.8W 3.0-4.5 AAAAA  Off Coast of Oregon        

 

The strongest earthquake in the world today was an M 5.1 in the South Sandwich Islands. It was not reported felt in this remote region. While earthquakes of M 5.0 and M 5.3 occurred about 200 km southeast of this on May 7 and April 26, 2021, the last event of M>=5.1 within this distance of today's epicenter occurred on February 23, 2021 with M 5.2. The last of significantly large magnitude in this area was an M 5.4 on May 8, 2020 exactly one year ago. Forecast 133712 had expected today's event within about 50 km in early May.

 

O:  8MAY2021 18:17:38  55.6S   29.2W mb=5.1  EMSC   SOUTH SANDWICH ISLANDS REGION

P:  3MAY2021 133712    55.0S   29.0W 4.0-6.0 BAAAA  So. Sandwich Islands       

P:  9MAY2021 133712    57.0S   27.0W 4.0-6.0 ABBAA  So. Sandwich Islands       

 

An earthquake of M 4.5 continued the aftershocks in Gabon, West Africa today.

NEIC reported this earthquake of M 4.5 in Lambarene, Gabon was felt with intensity II-III in the area(s) of Lambarene, Gabon. The mainshocks in this area were an 5.2 on March 6 and an M 5.4 on March 9, 2021. Aftershocks of M 5.4 and 4.7 occurred on April 27. At the time this summary noted in this regard:

 

"A pair of moderate aftershocks occurred in the region of Gabon, West Africa today. These are aftershocks of the M 5.2 and 5.4 in the area of March 6 and 9, 2021 and are the largest since those events occurred. They occurred near local solar midnight and may have been promoted by high tidal stresses with the full moon. The activity in Gabon is near 144 degrees from the M 8.1 in the Kermadec  Islands of March 5 and is probably promoted by energy from that source." (April 26, 2021)

 

 

O:  9MAY2021 01:30:07   1.2S   10.1E mb=4.5  EMSC   GABON                        

 

 

 

 

 

STRONG FIJI QUAKE PROMOTED BY LARGEST FLARE IN HALF A YEAR

 

EARTHQUAKE SUMMARY FOR  MAY 7, 2021

 

The largest earthquake in the world today was an M 6.1 near the geomagnetic equator in Fiji. This event followed the strongest solar flare observed by SWPC since an M4.4 on November 29, 2020 and was measured by SWPC at M3.9.  The parameters for this flare given by SWPC are:

 

Flare #    START  MAX       END    CLASS     DATE    Flux (Jm-2)

#-------------------------------------------------------------------------------

 640       1843   1904      1919   M3.9      (May 7, 2021)   4.5E-02  

 

The earthquake of M 6.1 in Fiji occurred within minutes of local solar noon a time when solar and tidal effects are maximized and was probably triggered by the M3.9 flare. Forecast 133647 expected today's event in Fiji was likely within about 100 km around May 8. An M 6.5 occurred within about 150 km of this epicenter on April 24, 2021 (also near local solar noon) with the previous such quake of M 6.1 on November 11, 2019. When the M 6.5 occurred in late April, this summary noted in this regard:

 

"The strongest earthquake in the world today was an M 6.5  in Central Tonga. NEIC reported it was felt with intensity VI in Tofoa-Koloua, Tonga  and II in Neiafu, Vavau, Tonga. The last earthquake with M>=6.5 in the world was an M 6.6 on April 3, 2021 in the South Atlantic. The only other event of this magnitude or greater in the world in the past month was an M 6.5 aftershock in the Kermadec Islands aon April 1, 2021. This earthquake occurred near local solar noon in an area near the regional geomagnetic equator. It was preceded about an hour earlier by an M 5.3 about 150 km to the south, an earthquake which occurred within about 30 minutes of local solar noon. It was probably promoted effects from the strong geomagnetic storm and solar flares of the past several days which maximize near this hour. The M 6.5 is the strongest earthquake within about 250 km of this epicenter since an M 6.6 on November 4, 2019." (April 24, 2021)

 

O:  7MAY2021 23:35:15  18.9S  177.6W Mw=6.1  EMSC   FIJI REGION                  

P:  8MAY2021 133647    18.0S  178.0W 4.0-5.7 AAAAA  Tonga Islands              

 

The series of moderate earthquakes of the past several days in California continued today. Moderate earthquakes in the northern Gulf of California and Baja California continued with a series of events of M 3.5-4.2 today. This summary reported in the previous issue on this series as:

 

 

"A pair of moderate earthquakes of M 4.1 and 4.2 also occurred in the Gulf of California today. Earthquakes of M>=4.2 have most recently occurred within about 100 km of these epicenters on April 1, 2021 (M 4.7) and February 13, 2020 (M 4.3). Forecast 133527 had expected this activity within about 25 km was likely to occur in early May." (May 6-7, 2021)

 

Moderate activity in this region can precede enhanced regional seismicity in Southern California within days as stresses migrate to the northwest.

 

O: 07MAY2021 08:53:20  30.1N  113.9W ML=4.0  EMSC   GULF OF CALIFORNIA

O: 07MAY2021 08:58:35  30.1N  113.8W ML=3.8  EMSC   GULF OF CALIFORNIA

O: 07MAY2021 09:00:14  30.1N  113.7W ML=3.9  EMSC   GULF OF CALIFORNIA

O: 07MAY2021 09:27:03  30.1N  113.9W ML=3.8  EMSC   GULF OF CALIFORNIA

O:  7MAY2021 08:49:02  30.0N  114.0W ML=4.1  EMSC   GULF OF CALIFORNIA           

P:  1MAY2021 133527    30.2N  114.1W 2.0-4.1 BAAAA  SW U.S.A                   

 

An earthquake of M 6.0 in the Macquarie Islands today followed an M 5.4 to the southeast of this on May 5. This summary noted that event at the time as:

 

An "M 5.4 in the area west of the Macquarie Island area and an M 5.1 in the

Southwest Indian Ridge. An M 6.1 hit the area west of Macquarie Island on March 20, 2021 about 400 km southeast of today's epicenter but the last of similar or larger magnitude within about 200 km of today's epicenter occurred as an M 5.7 on November 8, 2016 and prior to that as an M 5.5 on December 24, 2014. The antipode of this event is at 57N 33W in the Reykjanes Ridge in the north Atlantic Ridge  south of Iceland. Some seismic enhancement in this region is possible following today's event in the Macquarie Island area." (May 6, 2021)

 

O:  7MAY2021 15:21:14  54.5S  144.1E Mw=6.0  EMSC   WEST OF MACQUARIE ISLAND     

 

A moderate sized earthquake in the Northern Mid-Atlantic today of M 5.5 did occur along with today's M 6.0 in the Macquarie Islands. It was located east of The Leeward Islands in the eastern Caribbean. This is among the largest earthquakes in this area of the North Atlantic (within about 200 km) in the past 30 years. A set of three moderate to large  quakes last hit the area in November,  2018 which included the largest event in this area in the past 30 years and were the last events of M>=5.5 in the area. Forecast 133455 had expected activity in this area of the North Atlantic Ridge was likely around May 8.

 

O:  7MAY2021 11:45:25  14.1N   48.3W Mw=5.5  EMSC   NORTH ATLANTIC OCEAN         

P:  8MAY2021 133455    15.0N   46.0W 4.0-5.5 AABAA  Mid-Atlantic Ridge         

 

MODERATE QUAKE SHAKES TAHOE, CALIFORNIA AREA

 

EARTHQUAKE SUMMARY FOR  MAY 6, 2021

 

A moderate earthquake of M 4.7 was widely felt in the area of Tahoe on the northern border of California and Nevada today. This was the strongest earthquake in the U.S. or Canada today. It was accompanied by several felt foreshocks and aftershocks. NEIC reported it was felt with maximum intensity IV in California at Sierraville, Truckee, Soda Springs, Norden, Loyalton, Kings Beach and with lesser intensity in Tahoe National Park, Calpine, and Carnelian Bay among other localities. An M 2.5 regional foreshock occurred and was felt with intensity II in Incline Village, Nevada. This is the strongest earthquake in the Tahoe region within about 150 km of this epicenter since an M 4.8 on August 4, 2016 about 75 km northeast of today's epicenter. An M 5.0 hit about 150 km west of this on January 30, 2016. A moderately larger M 5.7 occurred about 100 km northwest of today's epicenter on May 24, 2013 - that was the  strongest in the area in the past 30 years at least.

 

When an M 3.7 hit the area about 50 km south of this epicenter near Reno, Nevada and Tahoe, California on April 25, 2021 this summary noted:

 

"A moderate earthquake of M 3.7 was widely felt in the area of Reno, Nevada near the California-Nevada border. NEIC reported it was felt with intensity IV in Tahoe City, Olympic Valley, Homewood, Kings Beach and III in Tahoe Vista, Tahoma, Carnelian Bay and in Nevada with II-III in Carson City, Glenbrook. 

This is the strongest earthquake in this region within about 100 km since an M 4.5 in Nevada about 50 km to the east of today's epicenter. An M 3.7-3.8 also  occurred about 100 km east of this on December 12, 2020. Forecast 133197 had expected today's quake within about 25 km was likely around April 24. This epicenter is at the fourth node (90 degrees) from the M 7.7 in the Loyalty Islands of February 10 and at the fifth node (72 degrees) from the recent major earthquakes off eastern Honshu, Japan of March 20 and may have been promoted by energy from those sources." (April 25-26, 2021)

 

Forecasts 133496 and 133503 had expected today's activity was likely within about 25 km of these epicenters to occur around May 6-9 with magnitude up to M 4.6.

 

O: 07MAY2021 04:35:13  39.5N  120.3W Mw=4.7  EMSC   NORTHERN CALIFORNIA

O: 07MAY2021 04:37:37  39.5N  120.3W ML=3.1  EMSC   NORTHERN CALIFORNIA

O: 07MAY2021 05:03:57  39.5N  120.3W Md=2.2  EMSC   NORTHERN CALIFORNIA

O:  7MAY2021 04:26:30  39.5N  120.3W ML=3.3  EMSC   NORTHERN CALIFORNIA           

P:  6MAY2021 133496    39.3N  120.0W 2.5-4.5 AAAAA  California/Nevada area     

P:  9MAY2021 133503    39.8N  120.6W 2.5-4.6 AAAAA  Central California         

 

O:  6MAY2021 13:18:34  39.1N  120.0W MD=2.5  EMSC   NORTHERN CALIFORNIA          

P:  6MAY2021 133496    39.3N  120.0W 2.5-4.5 AAAAA  California/Nevada area     

 

A pair of moderate earthquakes of M 4.1 and 4.2 also occurred in the Gulf of California today. Earthquakes of M>=4.2 have most recently occurred within about 100 km of these epicenters on April 1, 2021 (M 4.7) and February 13, 2020 (M 4.3). Forecast 133527 had expected this activity within about 25 km was likely to occur in early May.

 

O: 07MAY2021 02:03:48  30.1N  113.8W ML=4.1  EMSC   GULF OF CALIFORNIA

O:  6MAY2021 17:05:52  30.1N  113.9W ML=4.2  EMSC   GULF OF CALIFORNIA           

P:  1MAY2021 133527    30.2N  114.1W 2.0-4.1 BAAAA  SW U.S.A                   

 

A series of light earthquakes also occurred today in the region of northern

Kansas. This included an M 3.8 and afterhocks of M 3.0, 3.1 and 3.1.  An M 3.8 in northern Kansas today was widely felt.  NEIC reported this earthquake and aftershocks of M 3.1 in Kansas was felt with intensity IV in the area(s) of Kansas at Formoso, Courtland, Burr Oak, Hope and II-III in Jewel, Randall, Webber, Mankato, Belleville, Concordia, and Bend, Herington and Ramona. Other aftershocks of M 3.1 and 3.0 in Kansas were felt with intensity IV in Formoso and possibly in Sylvan Grove and in Peru, Nebraska.  This is the strongest earthquake within about 100 km of this epicenter in the past year. An M 4.5 occurred about 150 km southeast of this in Kansas on January 19, 2020. Forecast 133547 had expected today's activity in northern Kansas was likely around May 4. This activity is at 101-103 degrees from the major quakes in February and March, 2020 in the Kermadec and Loyalty Islands and was probably promoted by energy from those sources. Other events at this distance from these quakes occurred as an M 4.7 in Siberia, southern Alaska and Panama.

 

 

O: 06MAY2021 13:04:24  39.7N   98.0W mb=3.0  EMSC   KANSAS

O: 06MAY2021 11:35:32  39.8N   98.0W mb=3.8  EMSC   KANSAS

O:  7MAY2021 06:30:18  38.7N   97.0W mb=3.1  EMSC   KANSAS                       

O:  6MAY2021 18:20:33  39.8N   98.0W mb=3.1  EMSC   KANSAS                       

P:  4MAY2021 133547    39.0N   99.0W 2.0-4.3 AAAAA  Southern Plains            

 

An M 3.8 occurred in the region of southwestern Puerto Rico near Ponce today. NEIC reported this earthquake of M 3.8 in Southwest Puerto Rico was felt with intensity II-III in the area(s) of Southwest Puerto Rico with IV in Lajas, Sabana Grande and lesser shaking at Guanica, San German, Cabo Rojo, Yauco, Ponce and Guaynaco.  The last earthquake in this aftershock zone of larger magnitude occurred on December 24, 2020 with a series including an M 4.7 and M 4.8. Forecast 133463 had expected today's event was likely within about 10 km of the M 3.8 to occur around May 5.

 

O: 06MAY2021 13:02:30  17.9N   67.0W ML=3.4  EMSC   PUERTO RICO REGION

O: 06MAY2021 13:06:07  18.0N   67.0W Md=3.2  EMSC   PUERTO RICO REGION

O: 06MAY2021 13:08:56  18.0N   67.0W ML=3.8  EMSC   PUERTO RICO REGION

O: 06MAY2021 13:13:31  18.0N   67.0W Md=3.2  EMSC   PUERTO RICO REGION

O: 06MAY2021 13:25:34  18.0N   67.0W Md=3.1  EMSC   PUERTO RICO REGION

O:  6MAY2021 21:43:10  18.0N   67.0W Md=3.1  EMSC   PUERTO RICO REGION           

P:  5MAY2021 133463    18.0N   67.0W 3.4-5.0 AAAAA  Puerto Rico                

 

The strongest earthquake in the world today was an M 5.3 in Central Vanuatu.

It was not reported felt in this area. A similar M 5.3-5.4 quake hit about 100 km northeast of this on May 1, 2021 but the last of larger magnitude in the region was  an M 5.8 about 150 km south of this on February 28, 2020. Forecast 133649 had expected today's event was likely within about 75 km around May 3.

 

O:  6MAY2021 12:20:37  16.6S  167.5E mb=5.3  EMSC   VANUATU                      

P:  3MAY2021 133649    17.0S  167.0E 4.0-5.6 BAAAA  Vanuatu Islands            

 

 

 

 

 

MODERATE SEISMICITY IN OCEAN RIDGES

 

EARTHQUAKE SUMMARY FOR  MAY 5, 2021

 

Moderate activity  occurred today in the ocean ridges. This included an M 5.4 in the area west of the Macquarie Island area and an M 5.1 in the Southwest Indian Ridge. An M 6.1 hit the area west of Macquarie Island on March 20, 2021 about 400 km southeast of today's epicenter but the last of similar or larger magnitude within about 200 km of today's epicenter occurred as an M 5.7 on November 8, 2016 and prior to that as an M 5.5 on December 24, 2014. The antipode of this event is at 57N 33W in the Reykjanes Ridge in the north Atlantic Ridge south of Iceland. Some seismic enhancement in this region is possible following today's event in the Macquarie Island area.

 

O:  5MAY2021 19:20:09  57.0S  147.5E Mw=5.4  EMSC   WEST OF MACQUARIE ISLAND     

 

The last event of M>=5.1 within about 200 km of today's epicenter in the Southwest Indian Ridge occurred on March 6, 2020. Forecast 133697 expected this event within this area was likely around May 3. The antipode of this epicenter is located at 31N 121W off the coast of southern California, an area which may see increased seismicity in coming days. This event occurred at 103 degrees from the M 6.8 in Honshu, Japan of May 2 and was probably promoted by energy from that source. Other events at this distance from Honshu, Japan today occurred in Chiapas, Mexico, the Macquarie Island area and in the Azores.

 

O:  5MAY2021 21:22:59  30.9S   59.3E mb=5.1  EMSC   SOUTHWEST INDIAN RIDGE       

P:  3MAY2021 133697    32.0S   59.0E 4.0-5.7 ABAAA  So. Indian Ocean           

 

The strongest earthquakes in the U.S. or Canada today occurred in the Aleutians of Alaska. These were and M 4.8 in the Alaska Peninsula near Unimak Island and  an M 4.5 in the Near Islands in the western portion of the Aleutians. Neither of these event were reported felt in these areas. The only earthquake of M>=4.5 in this area of the Near Islands in the past year was an M 4.6 on November 30, 2020. Earthquakes about 200 km to the west of today's Near Islands epicenter occurred in the past year with M 5.3 on April 15, 2021 and on December 9, 2020. Forecast 133609 had expected today's event was likely around May 2. 

 

 

O:  5MAY2021 17:15:49  52.2N  173.6E mb=4.5  EMSC   NEAR ISLANDS, ALEUTIAN ISLANDS

P:  2MAY2021 133609    51.0N  176.0E 4.0-5.9 BBBAA  Rat Islands                

 

The last earthquake in the Alaska Peninsula within about 200 km of today's epicenter with M>=4.8 occurred as an M 4.9 on February 6, 2021. The last in the Unimak Island area with greater or equal magnitude than M 4.8 occurred as an M 5.1 on January 11, 2021. Other earthquakes in the Unimak Island area of larger magnitude in the past year occurred as an M 5.6 on August 13, 2020 and an M 5.0 on November 4, 2020. Forecast 133614 had expected today's event was likely within about 15 km to occur around May 5.

 

O:  6MAY2021 00:19:42  54.5N  161.6W mb=4.8  EMSC   ALASKA PENINSULA             

P:  5MAY2021 133614    54.5N  161.8W 3.5-5.3 AAAAA  Unimak Islands, Aleutians  

 

MODERATE QUAKES CONTINUE IN SOUTHERN SUMATRA, INDONESIA

 

EARTHQUAKE SUMMARY FOR  MAY 4, 2021

 

An M 5.7 earthquake in the Mentawai Region off southern Sumatra, Indonesia was the strongest in the world today.  BMG reported it was felt with intensity III-IV in the epicentral area of Mentawai. This area has been active since an M 6.3  on November 17, 2020, The last in this area of equal or larger magnitude in the Mentawai area. The last event near this was an M 5.6 on May 2, 2021. At that time this summary noted in this regard:

 

"An earthquake of M 5.6 (EMSC) -5.7 (BMG)  also occurred today in the area of Sumatra near Mentawai. BMG reported it was felt with intensity III-IV in the epicentral area of Mentawai. The last earthquake of M>=5.6 in this area was an M 5.6 north of this of March 5 following the M 8.1 in the Kermadec Islands of March 4, 2021 and prior to that an M 5.9 on November 17, 2020. Forecast 133431 had expected today's event within about 100 km was likely around May 4." (May 3, 2021)

 

Forecast 133431 had expected today's earthquake was likely within about 100 km  around May 4. The antipode of this epicenter is in southern Colombia and Ecuador at 2N 80W - an area which is currently active and could see triggered antipodal seismicity with strong events in this area of Indonesia.

 

 

O:  5MAY2021 01:24:35   1.9S   99.8E Mw=5.7  EMSC   KEP. MENTAWAI REGION, INDONESI

P:  4MAY2021 133431     2.0S   99.0E 4.0-5.4 AAAAA  So. of Sumatera            

 

A series of earthquakes of M 5.0, 5.2 and 5.5 occurred today in central Tonga. These were not reported felt in this remote area. The last earthquake within  about 150 km of this epicenter with M>=5.5 occurred as an M 5.5 September 6, 2020 but the last such quake of larger magnitude in ths area was an M 6.1 on June 15, 2019. Forecast 133672 had expected today's event within about 100 km of this epicenter was likely around May 4. This activity is at the fifth node (72 degrees) from the M 6.8 in Japan of May 3 and may have been promoted by energy from that source.

 

O: 05MAY2021 01:17:28  20.6S  173.8W mb=5.2  EMSC   TONGA

O: 05MAY2021 05:16:35  20.7S  173.3W mb=5.0  EMSC   TONGA

O:  4MAY2021 19:51:43  20.8S  173.8W Mw=5.5  EMSC   TONGA                        

P:  4MAY2021 133672    20.0S  174.0W 4.0-5.5 AAAAA  Tonga Islands              

 

The strongest earthquake in the U.S. or Canada today was an M 4.9 in the Fox Islands, Aleutians. It was not reported felt in this remote area. This is the largest earthquake within about 200 km of this epicenter this year and since an M 6.4 about 200 km to the east on December 1, 2020. The last within about 100 km of this epicenter was an M 5.8 on August 15, 2020 and a following event of M 5.6 on September 27, 2020. Forecast 133597 had expected today's event was likely within about 50 km around May 4.

 

O:  4MAY2021 16:47:43  52.4N  170.6W mb=4.9  EMSC   FOX ISLANDS, ALEUTIAN ISLANDS

P:  4MAY2021 133597    52.1N  171.3W 3.5-5.1 AAAAA  Andreanoff Isls, Aleutians 

 

A regional aftershock occurred in Siberia today about 300 km west of the M 5.7 on the Russia-Mongolia earthquake that occurred yesterday. The last earthquake within about 200 km of today's epicenter with M>=4.7 was an M 4.7 and 5.0 on September 13, 2019. An M 7.3 earthquake hit this area on September 27, 2003. Forecast 133611 had expected today's event within about 100 km was likely around May 1.

 

O:  5MAY2021 06:57:55  49.9N   86.7E mb=4.7  EMSC   RUSSIA-KAZAKHSTAN BORDER REGIO

P:  1MAY2021 133611    50.0N   88.0E 3.0-4.6 BAAAA  So. Siberia                

 

Two large asteroids will make a near approach to the earth this week. A meteor shower is also likely to occur. Asteroid 2021 AFB passed nearby at 12:14 UT today (May 4) with magnitude 20.2. The Eta Aquariids Meteor shower is also visible on the morning of May 5-6 especially in the southern Hemisphere. These phenomena are not expected to impact global seismicity.

 

MODERATE QUAKE FELT IN MONGOLIA AND SIBERIA

 

EARTHQUAKE SUMMARY FOR  MAY 3, 2021

 

The strongest earthquake in the world today was an M 5.6 on the Russia-Mongolia border. NEIC reported it was felt with intensity III in Irkutsk, Russia and in Mongolia at Zuumharaa and Ulaanbaatar. This is the first earthquake within about 200 km of this epicenter with M>=5.6 since an M 6.7 on January 11, 2021 and is probably an aftershock of that event, the largest in the area in at least 30 years. An M 5.6 occurred about 300 km to the northeast of this event on September 21, 2020, the first in this larger region since an M 6.2 on August 27, 2008. At the time of the event in January, 2021, this summary noted in this regard:

 

"The only earthquake within about 300 km of this epicenter of equal or larger magnitude in this region near the Russia-Mongolia border was an M 6.7 about 300 km to the west on February 26, 2012 - the only such event in this region in the past 30 years. This epicenter is at the seventh node (52 degrees) from both the Dodecanese Islands of October 30, 2020 and from the M 7.6 in the Alaska Peninsula of October 19, 2020. It was probably promoted by energy from these sources. One of the strongest earthquakes in this area in recent times occurred as an M 7.5 on January 12, 1862 .." (January 12, 2021)

 

Forecast 133611 had expected today's event in southern Siberia within about

150 km of this epicenter was likely around May 1. 

 

O: 03MAY2021 08:58:52  51.4N  100.4E mb=4.0  EMSC   RUSSIA-MONGOLIA BORDER REGION

O: 03MAY2021 14:11:38  51.4N  100.4E mb=4.2  EMSC   RUSSIA-MONGOLIA BORDER REGION

O:  3MAY2021 08:46:38  51.3N  100.5E Mw=5.6  EMSC   RUSSIA-MONGOLIA BORDER REGION

P:  1MAY2021 133611    51.0N   98.0E 3.0-4.7 AABAA  So. Siberia                

 

STRONG QUAKE NORTHEAST OF TAIWAN FELT IN OKINAWA, JAPAN AND TAIWAN

 

EARTHQUAKE SUMMARY FOR  MAY 2, 2021

 

The strongest earthquake in the world today was an M 5.5 (EMSC) - M 6.4 (CWB) which occurred northeast of Taiwan in the Ryukyu Islands of Japan. NEIC reported it was felt in Taiwan in Taipei and Taoyuan and in Okinawa, Japan at Chatan, Okinawa and Ishikawa. CWB reported this earthquake was felt with intensity II in Hualien and Taitung, I in Tainan, Yunlin, Chiayi, Changhua, Miaoli, Taichung, Nantou, Hsinchu, Yilan Counties, Taiwan. An earthquake of M 5.9 hit about 150 km northeast of this on March 25, 2021 with another of M 6.1 about 200 km southwest of this on December 10, 2020 but the last within about 150 km of this with M>=5.5 was an M 5.7 on February 2, 2016. A major earthquake of M 7.4 hit southwest of today's event exactly 23 years ago on May 3, 1998. It generated a local tsunami (see history section of this summary). The last event in the general area of M>=6.4 was an M 6.4 on May 31, 2016. Forecast 133486 had expected today's event in this area was likely around May 3. This earthquake occurred near local solar noon at a longitude which was expected to see maximum tidal stresses with the past full moon and may have been promoted by those tides.  The seismic forecast in this summary regarding this full moon had read:

 

"The full moon arrived on April 27, 2021 at 03:31 UT. Longitudes which were sub-solar (local solar noon) at this time were near 130 East Longitude while those near local solar midnight area near 50 West longitude. Those in the west include the Atlantic Ocean as far as the eastern Caribbean and the Shetland and South Sandwich Islands and in the east in western Japan, Taiwan, the Philippines and Central Indonesia. These areas may see enhanced seismicity within about 3 days of the full moon." (April 27, 2021)

 

 

O:  3MAY2021 05:07:29  25.8N  123.9E Mw=5.5  EMSC   NORTHEAST OF TAIWAN          

O:  3MAY2021 05:07:31  25.5N  123.9E ML=6.4  TAI    Hualien, Taiwan              

P:  3MAY2021 133485    24.0N  124.0E 4.0-5.5 ABAAA  Taiwan                     

 

An earthquake of M 5.6 (EMSC) -5.7 (BMG)  also occurred today in the area of Sumatra near Mentawai. BMG reported it was felt with intensity III-IV in the epicentral area of Mentawai. The last earthquake of M>=5.6 in this area was an M 5.6 north of this of March 5 following the M 8.1 in the Kermadec Islands of March 4, 2021 and prior to that an M 5.9 on November 17, 2020. Forecast 133431 had expected today's event within about 100 km was likely around May 4.

 

O:  2MAY2021 17:46:41   2.3S   99.8E Mw=5.6  EMSC   KEP. MENTAWAI REGION, INDONESI

P:  4MAY2021 133431     2.0S   99.0E 4.0-5.4 AAAAA  So. of Sumatera            

 

The strongest earthquake in the U.S. or Canada today was an M 3.8 in the Alaska Peninsula west of the aftershocks of the M 7.6 of October, 2020.  The last earthquake equal or greater magnitude in this region occurred hours before the M 7.3 near North Island New Zealand and the 8.1 in the Kermadec Islands on March 3, 2021 with M 4.3 and 3.9. Forecasts 133319 and 133614 had expected this activity was likely in the Unimak Islands within about 50 km of this epicenter in late April or early May. 

 

O: 03MAY2021 00:28:53  54.2N  161.3W mb=3.8  EMSC   ALASKA PENINSULA

O:  3MAY2021 00:16:47  54.2N  161.3W mb=3.4  EMSC   ALASKA PENINSULA             

P:  2MAY2021 133614    54.1N  164.4W 3.5-5.1 AABAA  Unimak Islands, Aleutians  

P: 24APR2021 133319    54.7N  161.2W 3.5-5.1 CAAAA  Unimak Islands, Aleutians  

 

An unusual earthquake of M 2.9 occurred in southeastern Brazil near Minas Gerais today where it was lightly felt. This is the first earthquake within about 500 km of this epicenter reported by NEIC since an M 4.2 on May 19, 2012 and prior to that an M 4.1 on May 22, 1990 about 400 km to the northwest of today's epicenter.

 

O:  2MAY2021 13:53:34  19.7S   44.0W ML=2.9  EMSC   MINAS GERAIS, BRAZIL         

 

MODERATELY STRONG QUAKE SHAKES COQUIMBO, CHILE

 

EARTHQUAKE SUMMARY FOR  MAY 1, 2021      

 

The strongest earthquake in the world today was an M 5.8 in the region of Coquimbo, Chile. NEIC reported maximum intensity VI in Coquimbo and V in La Serena and Ovalle with light shaking in Valparaiso, Copiapo, Atacama, Lampa, Puente Alto, Santiago, Chile. GUC reported this earthquake was felt with intensity  VI in  Coquimbo at Vicuna, Combarbalo, V at Andacollo, Coquimbo, Paiguano, IV in Canela, Monte Patria, Ovalle, Punitaqui, Rio Hurtado, Salamanca, III in Illapel; IV in Santiaog at Puente Alto, II in Lo Barnechea; in Valparaiso with II in Quillota, Atacama with IV in Alto del Carmen and Vallenar and III in Caldera, Copiapo, Freirina, HJuasco and Tierra Amarilla, Chile. This is the strongest earthquake within about 200 km of this epicenter in Coquimbo, Chile since an M 5.8 on October 28, 2020 and an M 6.3 on September 6, 2020, the first such events in the region since an M 6.4 on June 14, 2019. A great M 8.3 earthquake hit about 150 km south of today's epicenter on September 16, 2015 doing much regional damage. An M 5.7 hit about 800 km southeast of this in Nuquen Argentina on April 29, 2021 and may have helped promote today's event. Forecasts 133377 and 133688 had expected today's activity in Coquimbo was like in late April or early May. This epicenter is at the seventh node (51-52 degrees) from the M 6.6 in the South Atlantic of April 3, 2021 and was probably promoted by energy from that event.

 

O:  2MAY2021 06:57     30.1S   71.6W mb=5.8  GUC    Coquimbo at Vicuna, Combarbalo

O:  2MAY2021 06:57:36  30.0S   71.5W Mw=5.8  EMSC   OFFSHORE COQUIMBO, CHILE     

P:  2MAY2021 133688    30.0S   70.0W 4.0-5.6 AAAAA  Coast Central Chile        

P: 25APR2021 133377    30.0S   70.0W 4.0-5.6 CAAAA  Coast Central Chile        

 

The strongest earthquake in the U.S. or Canada today was an M 4.7 in Southeastern Alaska. NEIC reported this earthquake was felt with maximum intensity V in Alaska at Skagway, and II-III in Gustavus, Elfin Cove, Hoonan, Haines, Yakutat, Douglas, Juneau. A foreshock of M 3.6 was felt with intensity III in Douglas, Alaska.  This is the strongest earthquake in Southeastern Alaska within about 200 km of this epicenter since an M 5.2 on December 18m 2019 and prior to that an M 5.7 on September 10, 2019. A regional foreshock occurred at this epicenter with M 2.6 following the M 4.8 near Anchorage, Alaska on April 28 suggesting stress buildup in the area. This event had been noted in this summary at the time. Forecasts 133598 and 133318 had expected today's activity was likely within about 25 km of today's epicenter in late April or early May. Activity in the area had been noted on April 26 as:

 

"A glacial surge has been occurring in southeastern Alaska. It was accompanied today by an M 2.6 Ice quake, one of the strongest in recent history. The surge is happening in Denali Park in Muldrow glacier and on April 12 reached speeds up to 100 feet per day, about 100 times as fast as normal." (April 26, 2021)

 

This activity is at the fourth node (90 degrees) from the M 8.1 in the Kermadec Islands of March 5, 2021 and was probably promoted by energy from that source. It is also near the seventh node (52 degrees) from the M 6.9 off eastern Honshu, Japan which occurred on May 1 and was probably promoted by energy from that source.

 

O: 28APR2021 04:44:39  58.5N  136.8W ML=2.6  EMSC   SOUTHEASTERN ALASKA          

P: 26APR2021 133318    58.0N  139.0W 3.0-4.8 AABAA  Southeast Alaska           

 

Today's activity is at 103 degrees from the M 7.3 off the North coast of North Island, New Zealand of March 4, 2021 and at the fourth node (90 degrees) from the Loyalty Islands M 6.6 of February 10, 2021 and was probably promoted by strong energy from those sources. Similar activity at this distance from New Zealand today occurred with an M 3.9 in Nicaragua.

 

O: 01MAY2021 13:53:03  58.2N  137.9W ML=3.6  EMSC   SOUTHEASTERN ALASKA

O: 01MAY2021 15:23:22  58.4N  138.1W mb=4.5  EMSC   SOUTHEASTERN ALASKA

O: 01MAY2021 15:23:20  58.3N  137.9W mb=4.7  ANSS   SOUTHEASTERN ALASKA

O: 01MAY2021 15:23:26  58.5N  136.8W MB=4.9  ECAN OF SKAGWAY, AK   

O: 01MAY2021 15:23:21  58.3N  137.9W MB=4.9  ECAN Yakutat, AK    

O:  1MAY2021 16:40:27  58.1N  138.0W ML=3.0  EMSC   SOUTHEASTERN ALASKA          

P: 26APR2021 133318    58.0N  139.0W 3.0-4.8 BAAAA  Southeast Alaska           

P:  3MAY2021 133598    58.3N  138.5W 3.0-4.9 AAAAA  British Colombia           

 

A moderate earthquake of M 4.3 also occurred off the coast of northern California today. This joins the regional activation which in the past two days has included event of M 5.4 off the coast of Oregon and the M 4.7-4.9 in southeastern Alaska today (see above). Today's event off western California was not reported felt but is somewhat unusual. An event of M 4.3 or greater last occurred within about 75 km of this epicenter  on January 27, 2021 with M 4.6 while a series including an M 5.5 occurred in mid May, 2020 and early May 2019 which included an M 4.8. Forecast 133281 had expected today's event was likely around April 30.

 

O:  2MAY2021 03:30:52  41.1N  127.4W mb=4.3  EMSC   OFF COAST OF NORTHERN CALIFORN

P: 30APR2021 133281    41.8N  126.9W 2.5-4.4 AAAAA  Off Coast of No. Calif     

 

STRONG QUAKE SHAKES EASTERN HONSHU, JAPAN

 

EARTHQUAKE SUMMARY FOR  APRIL 30, 2021

 

The strongest earthquake in the world today was an M 6.8 off the northern coast of Eastern Honshu, Japan. NEIC reported intensity VII in Japan in Miyagi, Prefecture in Yamoto, Tagajo, Kogota, and VI in Natori, Sendai, Kesennauma and Ishinomaki and V in Shiogama, Rifu and Iwanuma. JMA reported this earthquake with M 6.6 and noted intensity 5+ in Miyagi with intensity up to 4 throughout most of western Honshu. It was preceded by an M 4.5 to the northwest which was felt with intensity II-III in Tomisato, Oamishirasato, Chiba and in Kanagawa, Japan. No tsunami was expected with this earthquake nor were significant tsunami waves observed. Trains and some company operations were suspended following the quake but operations returned after checks revealed no major damage. While some light injuries were reported no major casualties occurred. The mainshock occurred near local solar noon and was probably promoted by strong tidal stresses related to the Full Moon of April 27 as noted in previous issues of this summary:

 

"The full moon arrived on April 27, 2021 at 03:31 UT. Longitudes which were sub-solar (local solar noon) at this time were near 130 East Longitude while those near local solar midnight area near 50 West longitude. Those in the west include the Atlantic Ocean as far as the eastern Caribbean and the Shetland and South Sandwich Islands and in the east in western Japan, Taiwan, the Philippines and Central Indonesia. These areas may see enhanced seismicity within about 3 days of the full moon." (April 27, 2021)

 

Today's event follows similar earthquakes off eastern Honshu of M 7.0 on March 20, 2021 and M 7.1 on February 13, 2021 - an event closely linked to the new moon of February 11, 2021. The last such earthquake of M>=6.8 off the coast of eastern Honshu occurred as an M 6.9 on November 32, 2016. These all appear to be aftershocks of the great M 9.3 of March 11, 2011. Far-field seismicity  may be promoted by this event as noted following previous large earthquakes in this area:

 

"Far-field triggering is possible from the M 7.1 in Japan today. Areas at 144 degrees include the South Shetland Islands, northern Chile and southern Peru; near 103 degrees in central and western Mexico, the Madeira Islands, southern Spain, Madagascar, Mayotte, at 120 degrees (node 3) at Panama and Costa Rica and Puerto Rico; at 90 degrees (node 4) at Oklahoma and Texas, South Island, New Zealand; at 72 degrees (node 5) in Central and northern California, Iceland, Croatia, eastern Europe and Turkey, Fiji, Tonga, Loyalty Islands; in  western Indonesia at 60 degrees (node 6); in Tajikistan, Indonesia, Philippines  at node 7 (51 degrees) and in New Britain, Xizang, Alaska Peninsula at node 8 (45 degrees)." (February 14, 2021)

 

Forecast 133224 had expected this activity in Japan was likely within about 100 km around April 28.

 

O: 01MAY2021 03:01:30  38.3N  141.9E ML=3.6  EMSC   NEAR EAST COAST OF HONSHU, JAPAN

O: 01MAY2021 06:58:30  38.2N  141.7E ML=3.8  EMSC   NEAR EAST COAST OF HONSHU, JAPAN

O:  1MAY2021 01:27:28  38.2N  141.7E Mw=6.8  EMSC   NEAR EAST COAST OF HONSHU, JAP

P: 28APR2021 133224    39.0N  142.0E 4.0-5.4 BAAAA  Off East Coast Honshu      

 

O:  1MAY2021 00:10:06  39.4N  140.6E mb=4.5  EMSC   EASTERN HONSHU, JAPAN        

P: 28APR2021 133224    39.0N  142.0E 4.0-5.4 BABAA  Off East Coast Honshu      

 

The strongest earthquake in the U.S. or Canada today was an M 4.3 in the area of Central Alaska. NEIC reported this earthquake of M  4.3 in Central Alaska was felt with intensity II-III in the area(s) of Central Alaska at Fairbanks.  This is the strongest earthquake within about 200 km of this epicenter since an M 4.3 on August 4, 2020. The last event of larger magnitude in this area was an M 4.6 on September 6, 2019. Forecast 133326 had expected today's event in Central Alaska was likely around April 28. 

 

O: 30APR2021 17:19:24  64.8N  152.4W mb=4.3  EMSC   CENTRAL ALASKA               

P: 28APR2021 133326    62.8N  151.2W 3.2-5.1 ABAAA  Central Alaska             

 

MODERATE QUAKES OFF COAST OF OREGON RELATED TO FULL MOON

 

EARTHQUAKE SUMMARY FOR  APRIL 29, 2021

 

The enhanced seismicity off the coast of Oregon of the past several days maximized today with an M 5.4 and M 5.2 in the region today. These events were felt with maximum intensity VI in Oregon at Gold Beach, and II-III in Bandon, Brookings, Portland, Seaside and Salem and in California at Fortuna and Burnt Ranch. In recent history the largest earthquakes in this area have occurred with the full moon alignment and were probably tidally promoted. In the previous issue of this summary it had been noted in this regard:

 

"The strongest earthquake in the U.S. or Canada today was an M 4.4 off the coast of Oregon. This is the strongest earthquake within about 150 km of this epicenter since an M 5.1 and  an M 4.9 on February 20, 2021. A moderate quake of M 5.7 on December 29, 2020 was the only other such earthquake in the area in the past year. Forecast 133282 had expected today's event was likely around  April 29." (April 28-29, 2021)

 

Prior to the M 5.7 of December 29, 2020, the area had not seen an event of M>=5.4 since and M 5.9 on September 5, 2019, an aftershock of an M 6.3 on August 29, 2019.

 

Similar to today's event, the earthquake of December 29, 2020 occurred with the full moon of December 30, as noted  in this summary at the time:

 

"The strongest earthquake in the U.S. or Canada today was an M 5.7 off the Coast of Oregon. NEIC reported it was felt lightly along the coast in Bandon, Langlois, Port Orford, Coquille, Coos Bay, Gold Beach, Lakeside, North Bend, Florence, and Newport, Oregon. This event occurred near local solar midnight and may have been promoted by tidal triggering associated with the full moon on December 30 " (December 30, 2020)

 

and

 

"The third promoter of today's event off Oregon was probably high astronomical tides associated with the new moon." (August 30, 2019)

 

Previous events in the region including an M 6.2 on August 22, 2018; July 17, 2019 (M 5.4); August 16, 2019 (M 5.4). These events were also noted at the time to have been closely associated with the full moon as noted at the time in this summary:

 

"The strongest earthquake in the U.S. or Canada today was an M 5.4 off the coast of Oregon. NEIC reported it may have been felt lightly in Oregon at Eugene and Medford and in Seattle, Washington. A foreshock to the southeast of the M 5.4 occurred earlier in the day near local solar midnight and may have been promoted by strong tidal stresses associated with the full moon. The last event with M>=3.9 near the foreshock occurred a month ago on July 17, 2019 and prior to that as an M 4.1 on June 26, 2019. Both the event in June and July (2019) occurred with the full moon as noted at the time" (August 17, 2019)

 

Today's events of M 5.3, 5.4 and 5.2 occurred within about 25-50 km of the  epicenter expected in forecast 133282 which expected this activity was likely around April 29. This activity is at 142 degrees from the M 6.6 in the South Atlantic of April 3, 2021, the last strong global earthquake and at the fourth node (90 degrees) from the M 7.3 in the region of North Island, New Zealand of March 4, 2021 and may have been promoted by energy from those sources. Similar events at the fourth node from New Zealand occurred today in Guerrero, Mexico (M 5.0) and in California and the Gulf of California among others.

 

O: 29APR2021 13:24:55  43.8N  128.2W mb=4.1  EMSC   OFF COAST OF OREGON

O: 29APR2021 13:33:00  43.8N  128.4W mb=3.9  EMSC   OFF COAST OF OREGON

O: 29APR2021 10:30:21  43.9N  128.5W Mw=5.4  EMSC   OFF COAST OF OREGON

O: 29APR2021 10:35:45  43.9N  128.5W Mw=5.2  EMSC   OFF COAST OF OREGON

O: 29APR2021 10:58:35  43.9N  128.1W Mw=5.3  EMSC   OFF COAST OF OREGON

O: 29APR2021 10:25:16  44.0N  128.0W mb=4.3  EMSC   OFF COAST OF OREGON

O: 29APR2021 13:24:55  43.8N  128.2W mb=4.1  EMSC   OFF COAST OF OREGON          

P: 29APR2021 133282    44.1N  128.8W 3.0-4.7 AAAAA  Off Coast of Oregon        

 

The strongest seismicity in the world today continued to occur in the aftershock

zone of the Northern Kermadec Islands following the mainshock in that area of March 4, 2021. None of these events including an M 5.9 and two of M 5.5 were reported felt in this remote area. This continues elevated seismicity in this region as discussed in the previous issue of this summary:

 

 

"The strongest earthquake in the world that was not felt today was an M 5.9 in the continuing aftershock sequence in the northern Kermadec Islands, New Zealand. This followed an M 5.4 off northern North Island, New Zealand. The last earthquake in this aftershock zone in northern Kermadec Islands with M>=5.9 occurred on April 27, 2021 also with M 5.9. Earthquakes of M 6.0 on April 7 and M 6.5 on April 1 complete the list of similar earthquakes since the immediate aftershocks of the M 8.1 on March 4.  Forecasts 133362 had expected today's activity in the aftershock zone within about 50 km of this epicenter around April 26-30." (April 28-29, 2021) 

 

O: 29APR2021 13:55:31  29.2S  176.5W mb=5.0  EMSC   KERMADEC ISLANDS REGION

O: 29APR2021 06:50:30  29.4S  176.7W Mw=5.9  EMSC   KERMADEC ISLANDS REGION

O: 29APR2021 07:06:37  29.5S  176.6W mb=5.0  EMSC   KERMADEC ISLANDS REGION

O: 29APR2021 13:54:12  29.5S  176.5W mb=4.9  EMSC   KERMADEC ISLANDS REGION

O: 29APR2021 12:25:27  29.7S  176.8W mb=5.1  EMSC   KERMADEC ISLANDS REGION

O: 29APR2021 09:19:33  29.8S  177.7W mb=4.6  EMSC   KERMADEC ISLANDS, NEW ZEALAND

O: 30APR2021 02:06:15  29.8S  177.6W mb=5.5  EMSC   KERMADEC ISLANDS, NEW ZEALAND

O: 29APR2021 07:44:57  29.9S  177.7W mb=4.8  EMSC   KERMADEC ISLANDS, NEW ZEALAND

O: 29APR2021 21:39:04  30.6S  177.6W mb=5.0  EMSC   KERMADEC ISLANDS, NEW ZEALAND

O: 29APR2021 06:53:53  29.2S  176.9W mb=5.5  EMSC   KERMADEC ISLANDS REGION      

P: 26APR2021 133362    29.0S  177.0W 4.0-5.7 BAAAA  No. Kermadec Islands       

P: 30APR2021 133362    28.0S  176.0W 4.0-5.8 ABAAA  No. Kermadec Islands