MODERATE QUAKE SHAKES CALIFORNIA-MEXICO BORDER

 

EARTHQUAKE SUMMARY FOR AUGUST 10, 2020

 

The swarm of light earthquakes in southern California near the Mexico border continued today, maximizing with several events of M 4.0. NEIC reported maximum intensity up to IV in Calipatria, Westmorland and II-III in Brawley, El Centro and Trabuco Canyon among others. This summary had reported on this swarm in the previous issues as:

 

"A swarm of light earthquakes has been occurring in southeastern California near the Mexican border. This swarm began shortly after a C-class solar flare the strongest in more than two months. Swarms in this area of high heat flow are often associated with unusual flares or solar activity. Such swarms occasionally grow over several days and include a moderate sized event. But it also occurs that they grow without a recognizable mainshock and gradually dissipate. The C-Class solar flare was noted in the previous issues of this report as:

 

"The first solar flare of C-class or higher since May 29, 2020 (C9.3, M1.0) occurred near local solar midnight in North Carolina on August 8. This is the second largest solar flare in the past year following the May 29 event. Solar flares, especially rare ones such as this, can also help trigger seismicity in earthquake-prone areas.

 

Flare #    START  MAX       END    CLASS     DATE    Flux (Jm-2)

 

6190       0342   0349      0355   C1.5      (August 8, 2020)   5.5E-04  

" (August 9, 2020)

 

The last series in this region which included an M 4.0 or greater event occurred on January 12, 2020; November 12, 2019 and November 19, 2018. Forecast 126102 had expected today's activity was likely around August 6-11. This activity is located at the 10th node (36 degrees) from the Alaska Peninsula and was probably promoted by energy from that source." (August 10, 2020)

 

The largest of today's earthquakes in Southern California was an M 4.6. NEIC reported It was felt with maximum intensity IV in Southern California at Niland and II-III in Calipatria, Thermal, Mecca, Brawley, El Centro, Coachella, Desert Center, Indio and La Quinta. Following is a listing of events in this swarm tpday of M>=3. A more extensive list of M>=2 events can be found in the "CALIFORNIA" regional listing below. It is also located at 100 degrees from the epicenter of the M 7.3 in New Guinea of July 17, 2020 and was probably promoted by energy from that event. Forecast 126120 had expected today's activity within about 50 km was likely around August 11. A foreshock to today's activity occurred several hours after the New Guinea quake on July 17.

 

O: 10AUG2020 22:44:51  33.1N  115.7W ML=3.3  EMSC   SOUTHERN CALIFORNIA

O: 10AUG2020 13:33:56  33.2N  115.7W ML=3.0  EMSC   SOUTHERN CALIFORNIA

O: 10AUG2020 15:58:16  33.2N  115.7W ML=3.2  EMSC   SOUTHERN CALIFORNIA

O: 10AUG2020 16:03:39  33.2N  115.7W Mw=4.0  EMSC   SOUTHERN CALIFORNIA

O: 10AUG2020 17:39:15  33.2N  115.7W Mw=3.5  EMSC   SOUTHERN CALIFORNIA

O: 10AUG2020 18:29:59  33.2N  115.7W ML=3.2  EMSC   SOUTHERN CALIFORNIA

O: 10AUG2020 18:53:21  33.2N  115.7W ML=3.1  EMSC   SOUTHERN CALIFORNIA

O: 10AUG2020 18:58:52  33.2N  115.7W ML=3.1  EMSC   SOUTHERN CALIFORNIA

O: 10AUG2020 16:00:13  33.3N  115.7W ML=3.0  EMSC   SOUTHERN CALIFORNIA

O: 10AUG2020 16:13:55  33.3N  115.7W Mw=3.7  EMSC   SOUTHERN CALIFORNIA

O: 10AUG2020 19:29:29  33.3N  115.7W Mw=4.0  EMSC   SOUTHERN CALIFORNIA

O: 10AUG2020 15:55:47  33.3N  115.7W ML=4.0  EMSC   SOUTHERN CALIFORNIA

O: 10AUG2020 15:56:14  33.2N  115.7W mw=4.6  ANSS   SSE of Bombay Beach          

P: 11AUG2020 126102    32.8N  116.0W 2.5-4.5 AAAAA  So. California             

 

The largest earthquake in the world today was an M 5.7 near Savannah, Honduras.

NEIC reported maximum intensity V was felt in Honduras at Islas de la Bahia in Jose Santos Guardiola, Roatan, and Tocca Colon with IV in Savannah Bight, Monte Placentero, Sandy Bay, Trujillo Colon and lesser shaking at French Harbor, Rio Estebanand Utila, Honduras. This is the strongest earthquake in the area of Honduras within about 250 km of today's epicenter since an M 6.0 on April 16, 2020. Both may be aftershocks of an M 7.6 quake to the northeast on January 10, 2018.  Forecast 126039 had expected today's event within about 15 km of the epicenter was likely around August 9. This earthquake is at the sixth node (60 degrees) from the M 7.8 in the Alaska Peninsula of July 22 and was probably promoted from that source.

 

O: 10AUG2020 14:13:28  16.9N   85.9W Mw=5.7  EMSC   OFFSHORE HONDURAS            

P:  9AUG2020 126039    17.0N   86.0W 3.5-5.3 AAAAA  Nicaragua                  

 

An unusual earthquake of M 4.9 was felt in northern Mozambique today. NEIC reported it was felt with intensity II in Nacala, Nampula, Mozambique.  This is the strongest earthquake in northern Mozambique within about 300 km of this epicenter since an M  4.9 on August 11, 2020 and prior to that an M 5.2 on July 15, 2015.

 

O: 11AUG2020 05:10:18  14.0S   40.8E mb=4.9  EMSC   MOZAMBIQUE                   

 

Earthquakes of M 4.5 and 4.6 also continued in Alaska today - in the Alaska Peninsula and in the Rat Islands, Aleutians. These were not reported felt. They had been expected in early August in forecasts 126174, 126166 and 126159.

 

O: 10AUG2020 14:30:21  51.3N  178.7E mb=4.5  EMSC   RAT ISLANDS, ALEUTIAN ISLANDS

P:  3AUG2020 126174    52.0N  178.0E 4.0-5.8 CAAAA  Rat Islands                

 

O: 10AUG2020 12:54:39  55.1N  158.0W mb=4.6  EMSC   ALASKA PENINSULA

O: 10AUG2020 18:53:37  55.9N  157.5W ML=2.7  EMSC   ALASKA PENINSULA

O: 11AUG2020 03:06:58  56.0N  156.1W ML=3.1  EMSC   SOUTH OF ALASKA

O: 10AUG2020 15:33:20  54.6N  160.6W mb=3.7  EMSC   ALASKA PENINSULA             

P:  7AUG2020 126159    54.7N  156.9W 3.5-5.1 BAAAA  Alaska Peninsula           

P:  8AUG2020 126166    55.0N  161.3W 3.5-4.9 AAAAA  Alaska Peninsula           

 

 

MODERATE SWARM ON CALIFORNIA-MEXICO BORDER

 

EARTHQUAKE SUMMARY FOR AUGUST 9, 2020

 

A swarm of light earthquakes has been occurring in southeastern California near the Mexican border. This swarm began shortly after a C-class solar flare the strongest in more than two months. Swarms in this area of high heat flow are often associated with unusual flares or solar activity. Such swarms occasionally grow over several days and include a moderate sized event. But it also occurs that they grow without a recognizable mainshock and gradually dissipate. The C-Class solar flare was noted in the previous issues of this report as:

 

"The first solar flare of C-class or higher since May 29, 2020 (C9.3, M1.0) occurred near local solar midnight in North Carolina on August 8. This is the second largest solar flare in the past year following the May 29 event. Solar flares, especially rare ones such as this, can also help trigger seismicity in earthquake-prone areas.

 

Flare #    START  MAX       END    CLASS     DATE    Flux (Jm-2)

 

6190       0342   0349      0355   C1.5      (August 8, 2020)   5.5E-04  

" (August 9, 2020)

 

The last series in this region which included an M 4.0 or greater event occurred on January 12, 2020; November 12, 2019 and November 19, 2018. Forecast 126102 had expected today's activity was likely around August 6-11. This activity is located at the 10th node (36 degrees) from the Alaska Peninsula and was probably promoted by energy from that source.

 

O: 08AUG2020 12:49:50  32.9N  115.5W Ml=2.0  EMSC   SOUTHERN CALIFORNIA

O: 08AUG2020 12:42:19  32.9N  115.5W Ml=2.4  EMSC   SOUTHERN CALIFORNIA

O: 09AUG2020 02:45:11  33.0N  115.9W ML=2.8  EMSC   SOUTHERN CALIFORNIA

O: 09AUG2020 01:14:48  33.0N  115.9W Ml=2.2  EMSC   SOUTHERN CALIFORNIA

O: 09AUG2020 01:11:06  33.0N  115.9W Ml=2.0  EMSC   SOUTHERN CALIFORNIA

O:  8AUG2020 23:40:31  33.2N  115.6W Ml=2.0  EMSC   SOUTHERN CALIFORNIA          

O: 09AUG2020 21:03:23  33.3N  115.7W Ml=2.1  EMSC   SOUTHERN CALIFORNIA

P:  6AUG2020 126102    32.4N  115.8W 2.5-4.4 AAAAA  So. California             

P: 11AUG2020 126102    32.8N  116.0W 2.5-4.5 BAAAA  So. California             

 

The strongest earthquake in the world today was an M 5.9 in the area south of

Africa. It was accompanied by an M 5.4 aftershock of the M 6.3 in the Prince

Edward Islands in the same general region of the South Indian Ocean. This epicenter is near the antipode of the M 7.8 quake of July 22 in the Alaska Peninsula and had been expected to see antipodal triggering at this times in this summary as:

 

 

"Far field triggering is likely with the earthquake in Alaska. The antipode is located south of South Africa in the Indian Ocean east of Bouvet Island and is a possible site for triggered activity." (July 22, 2020)

 

The last earthquake within about 400 km of this epicenter with M>=5.9 was an M 6.6 on January 28, 2019 and prior to that an M 6.7 on October 10, 2017. Forecast 126237 had expected today's event to the east around August 11.

 

O:  9AUG2020 23:42:36  53.0S   11.7E Mw=5.9  EMSC   SOUTHWEST OF AFRICA           

P: 11AUG2020 126237    53.0S   19.0E 4.0-5.4 AACAA  Atlantic-Indian Ridge      

 

Other areas of the mid-ocean ridges were also active today. These included  an M 5.2 in the Central Mid-Atlantic Ridge and an M 4.7 in the Southern East Pacific Rise. These had been anticipated in early August in forecasts 125971 and 125982 within about 50 km of these epicenters.

 

O:  9AUG2020 16:30:30  41.7S   42.6E Mw=5.4  EMSC   PRINCE EDWARD ISLANDS REGION 

P: 30JUL2020 125971    41.0S   43.0E 4.0-5.4 CAAAA  So. Indian Ocean           

 

O:  9AUG2020 12:42:12   0.9N   27.7W Mw=5.2  EMSC   CENTRAL MID-ATLANTIC RIDGE   

P:  8AUG2020 125982     1.0N   28.0W 4.0-5.9 AAAAA  Central Mid-Atlantic Ridg  

 

O: 10AUG2020 01:39:13  23.5S  115.2W mb=4.7  EMSC   SOUTHERN EAST PACIFIC RISE   

P: 11AUG2020 126214    24.0S  115.0W 4.0-5.7 AAAAA  So. East Pacific Rise      

 

The strongest seismicity in the U.S. or Canada once again occurred in the Alaska Peninsula aftershock zone with M 5.2. It was not reported felt in this remote area. Forecasts 126166 and 126177 had expected this aftershock activity around August 8-9.

 

O: 09AUG2020 20:48:14  54.7N  161.2W ml=3.7  EMSC   ALASKA PENINSULA

O: 09AUG2020 12:39:46  54.9N  158.6W ml=3.4  EMSC   SOUTH OF ALASKA

O: 10AUG2020 06:49:42  54.9N  160.3W ML=4.1  EMSC   ALASKA PENINSULA

O:  9AUG2020 14:57:53  55.2N  158.1W Mw=5.2  EMSC   ALASKA PENINSULA             

P:  5AUG2020 126166    55.1N  159.3W 3.5-4.9 BAAAA  Alaska Peninsula           

P:  8AUG2020 126166    55.0N  161.3W 3.5-4.9 AAAAA  Alaska Peninsula           

P:  9AUG2020 126177    54.1N  162.8W 3.5-5.0 AAAAA  Unimak Islands, Aleutians  

 

MODERATE QUAKE IN VIRGINIA-NORTH CAROLINA WIDELY FELT

 

EARTHQUAKE SUMMARY FOR AUGUST 8, 2020

 

An earthquake of M 5.1 shook large areas of eastern U.S. today. This event was centered on the North Carolina-Virginia border. It was reported by nearly 100,000 persons to NEIC. Maximum intensity V was felt in North Carolina at Sarta, Glade Valle, Ennice, Roaring Gap, Traphill and Hays with IV in Laurel Springs, Thurmond, North Carolina and Independence, Virginia. Light to moderate shaking was reported throughout most of the eastern U.S. including in Tennessee, Virginia, Kentucky, North and South Carolina. It was also reported up to 1500 km from the epicenter in South Dakota, Kansas, Ontario, Nova Scotia, and Arizona among most other states in between.  While lighter foreshocks of M 2.2 and 2.1 occurred about a day earlier, an M 2.6 foreshock near local solar midnight may have been tidally enhanced. It was reported felt with maximum intensity V in North Wilkesboro, North Carolina; IV in North Carolina at Sparta, Hiddenite, Lenoir and Statesville among other localities. Damage was minimal but internet pictures showed store items thrown to the floor in many areas and cleanup will be extensive. Some structural damage was reported including the collapse of a chimney in Sparta, North Carolina. The last earthquake of similar or larger magnitude in the area was an M 5.2 on 1916 in the Great Smoky Mountains.

The earthquake of August, 2011 near Mineral, Virginia of M 5.8 was one of the largest in east coast history and did extensive damage as far as Washington, D.C. A series of foreshocks hit the region in the day prior to the mainshock with M 2.1-2.6.

 

Hurricane Isaias passed near this epicenter 5-6 days ago and stresses associated with that storm, the second in the region this year (following TS Arthur on May 17-18, 2020), probably enhanced the likelihood of today's seismicity. This was reported in this summary as possibly affecting regional seismicity at the time as:

 

TROPICAL STORM ISAIAS  

 

----  -------  ----------  --------  -----  ------  -------  ---------------

TS    ISAIAS   2020-08-03  00:00 UT  35.0N   74.9W   45 kts  U.S. east coast

 

TS Isaias continued today in the area along the U.S. east coast with winds up to 45 kts. It is expected to track to the north and west over the next several days. Enhanced seismicity in Puerto Rico and the Dominican Republic is expected with this storm while it is in the area. It is then expected track along the eastern seaboard of the U.S. at category 1 hurricane levels. Some minor seismicity in the region is possible with this weak storm, but no major earthquakes on the east or west coasts of the U.S. are thought likely with the track of this storm." (August 4-5, 2020)

 

 

Some of this activity may have also been promoted by tidal stresses. The main foreshocks of M 2.6 occurred within minutes of local solar midnight, a prime time for tidal stresses to trigger seismicity. The longitude is also near the longitude of maximum tidal stress with the previous full moon of August 3 as noted in previous issues of this summary:

 

"The full moon  arrived at 15:59 UT on August 3, 2020. Longitudes which were sub-solar (local solar noon) at this time are 60 West and 120 East and include in the west the Caribbean and Puerto Rico and portions of northern and western South America. Those in the east include the Philippines and central Indonesia near Sulawesi. These areas may see moderate seismic enhancement at this time. Many areas can see tidal enhancement with lunar-solar alignments so the seismicity of the earth is expected to be at active conditions through August 7." (August 2-5, 2020)

 

The first solar flare of C-class or higher since May 29, 2020 (C9.3, M1.0) occurred near local solar midnight in North Carolina on August 8. This is the second largest solar flare in the past year following the May 29 event. Solar flares, especially rare ones such as this, can also help trigger seismicity in earthquake-prone areas.

 

Flare #    START  MAX       END    CLASS     DATE    Flux (Jm-2)

 

6190       0342   0349      0355   C1.5      (August 8, 2020)   5.5E-04  

 

Today's epicenter in North Carolina is near the seventh node (52 degrees) from the M 7.8 of July 22 in the Alaska Peninsula and was probably enhanced by energy from that source.

 

This is the strongest earthquake within about 250 km of this epicenter in the North Carolina-Virginia border region since an M 5.2 on July 8, 1926 and prior to that an M 5.5 on February 21, 1916 and 5.2 on January 1, and March 28, 1913. The largest quake in the area in recorded history was an M 5.8 on May 31, 1897.

The only event of M>=5.2 in this region  in the past 75 years was an M 5.6 west of this on November 30, 1973. This summary had noted this event in the history section of this report as:

 

 

"Felt over an area of about 150,000 sq. km. in Georgia, Kentucky, South Carolina, Tennessee, North Carolina, Tennessee, Virginia and West Virginia.  Cracks in walls were observed at the University of Tennessee Hospital in Knoxville.  Minor damage to walls and chimneys and cracked windows reported in Alcoa and Maryville, Tennessee. Electrical power was cut. This was the largest shock in eastern Tennessee in more than 60 years - since March 28, 1913." (November 30, 1919)

 

The M 5.2  on July 8, 1926 had been noted:

 

"Houses rattled, chimneys cracked, building foundations cracked, water pipelines broke and small objects moved within 6 miles of the epicenter." (July 8, 2020)

 

and that of M 5.3 on March 28, 2013 as:

 

"Near Knoxville, Tenn. Two shocks were felt over an area 70 by 40 miles, with noticeable rise and fall of ground in some places.  Fire alarms were set off. Knox County Courthouse, a massive structure trembled for two minutes. Movable objects were overthrown and bricks fell from chimneys. Nausea was reported by some." (March 28, 2020)

 

Forecast 126086 had expected enhanced seismicity within about 100 km of this epicenter was likely around August 9.

 

O: 08AUG2020 11:05:39  36.5N   81.1W ML=2.0  EMSC   VIRGINIA-N CAROLINA BORDER REG

O: 08AUG2020 11:12:32  36.5N   81.1W Md=2.3  EMSC   VIRGINIA-N CAROLINA BORDER REG

O: 09AUG2020 05:57:16  36.5N   81.1W mb=2.7  EMSC   VIRGINIA-N CAROLINA BORDER REG

O:  9AUG2020 12:07:37  36.5N   81.1W Mw=5.1  EMSC   VIRGINIA-N CAROLINA BORDER REG

O:  9AUG2020 12:07:37  36.5N   81.1W Mw=5.2  ANSS   VIRGINIA-N CAROLINA BORDER REG

P:  9AUG2020 126086    37.2N   81.9W 2.0-4.2 AAAAA  Kentucky/Tennessee/NC      

 

Earthquakes of M 3.7-3.8 off the coast of Northern California were also felt along the coastline. NEIC reported it was felt with intensity II-III in California at Ferndale, Whitethorn, Eureka, Arcata and Fort Bragg. Forecast 126143 had expected this activity was likely around August 6.

 

O: 09AUG2020 00:00:34  40.3N  124.7W Mw=3.7  EMSC   OFFSHORE NORTHERN CALIFORNIA

O:  9AUG2020 03:23:49  40.3N  124.9W ML=3.1  EMSC   OFFSHORE NORTHERN CALIFORNIA 

P:  6AUG2020 126143    40.2N  124.2W 2.5-4.6 BAAAA  Off Coast of No. Calif     

 

 

An earthquake of M 3.6 also occurred today off the coast of Oregon. NEIC reported it was felt lightly in Florence and Eugene, Oregon. When an M 6.3 earthquake occurred in the Prince Edward Island region yesterday, this summary noted the antipodal relation to areas off western Oregon and northwestern California as:

 

"This epicenter (in Prince Edward Islands) is near the antipode off the coast of Northern California and Oregon and could help enhance seismicity in that area in the next several days." (August 7, 2020)

 

Forecast 126145 had expected the event off Oregon was likely within about 50 km around August 5. The last event in this region of equal or larger magnitude was an M 3.9 on July 6, 2020.

 

O:  8AUG2020 08:51:25  43.9N  129.0W mb=3.6  EMSC   OFF COAST OF OREGON          

P:  5AUG2020 126145    44.4N  129.3W 3.0-4.5 BAAAA  Off Coast of Oregon        

 

The largest earthquake in the U.S. or Canada today was an M 5.5 aftershock in the Alaska Peninsula. NEIC reported it was felt with intensity IV in King Cove ad III in Chignik, Alaska. After an initial lull in aftershocks following the M 7.8 of July 22, 2020, earthquakes of M>=5 have been nearly a daily occurrence in the aftershock zone. Forecasts 126177 and 126166 had expected today's activity was likely around August 5-7.

 

O: 08AUG2020 16:12:02  54.7N  161.1W ML=3.4  EMSC   ALASKA PENINSULA

O: 09AUG2020 01:51:41  54.7N  161.2W mb=4.5  EMSC   ALASKA PENINSULA

O: 09AUG2020 03:30:21  54.7N  161.0W mb=3.9  EMSC   ALASKA PENINSULA

O: 08AUG2020 14:42:54  54.8N  161.2W Mw=5.5  EMSC   ALASKA PENINSULA

O: 08AUG2020 18:13:19  54.8N  161.2W ml=3.5  EMSC   ALASKA PENINSULA

O:  9AUG2020 06:39:49  54.6N  161.1W ML=3.3  EMSC   ALASKA PENINSULA             

P:  7AUG2020 126177    54.7N  161.2W 3.5-5.1 AAAAA  Unimak Islands, Aleutians  

 

O:  8AUG2020 12:53:00  55.0N  158.5W Mw=5.4  EMSC   SOUTH OF ALASKA              

P:  5AUG2020 126166    55.1N  159.3W 3.5-4.9 BAAAA  Alaska Peninsula           

 

An M 4.3 shook areas of South Island, New Zealand today. NEIC reported intensity II-III in Richmond, Nelson, Blenheim, Wellington and Christchurch. GEONET reported it was felt with moderate intensity in northern South Island. 2726 people reported feeling this event; 1765 with weak intensity; 883 with light shaking; 70 moderate; 5 strong; 2 with severe and 1 with extreme shaking. The last event listed by NEIC with M>=4.7 within about 150 km of this epicenter occurred October 22, 2017 with M 4.9. Forecast 126233 had expected today's event within about 10 km of the epicenter was  likely around August 7. This epicenter is at 100 degrees from the  Alaska Peninsula M 7.8 of July 22 and was probably promoted by energy from that event concentrated at the surface at this distance.

 

O: 08AUG2020 07:51:34  41.9S  173.0E ML=4.7  GEONET Felt with moderate intensity

O:  8AUG2020 07:51:32  41.9S  173.0E Mw=4.3  EMSC   SOUTH ISLAND OF NEW ZEALAND  

P:  7AUG2020 126233    42.0S  173.0E 3.0-5.1 AAAAA  So. Island, N.Z.           

 

MODERATE QUAKE RATTLES NORTHERN XINJIANG, CHINA

 

EARTHQUAKE SUMMARY FOR AUGUST 7, 2020

 

A moderate earthquake of M 5.3 shook regions of northern Xinjiang, China today.

NEIC reported this earthquake of M 5.3 in northern Xinjiang, China  was felt with intensity II-III in the area(s) of northern Xinjiang, China at Urumqi.

It was not reported with damage. This is the strongest earthquake in northern

Xinjiang, China within about 250 km of this epicenter since an M 5.5 about 100 km to the west on March 29, 2013.  Forecast 126130 had expected today's activity to the southwest was likely around August 10. Recent flooding in China may have helped promote this activity.

 

O:  8AUG2020 00:35:07  43.3N   87.7E mb=5.3  EMSC   NORTHERN XINJIANG, CHINA     

P: 10AUG2020 126130    42.0N   83.0E 4.0-5.4 ABCAA  Kirgizstan/Xinjiang        

 

An unusual visitor to modern seismicity occurred today in the Gilbert Islands, Kiribati area of the Pacific Ocean with  4.8.     This is the strongest earthquake in the Gilbert Islands regions within about 400 km of this epicenter in at least 30 years. A major swarm hit the region beginning in late 1981 and lasting through March, 1983 with many moderately large earthquakes. The area has been quiet since that time. There are no major tectonic features suggesting the region should be subject to this type of seismicity so this swarm remains largely unexplained. Today's event bears watching as it may be the first in renewed regional activity in this area.

 

O:  7AUG2020 14:12:56   3.6S  177.6E mb=4.8  EMSC   GILBERT ISLANDS, KIRIBATI REGI

 

A moderate aftershock in southern Idaho occurred today with M 4.2. NEIC reported it was felt with maximum intensity V in Idaho at Ketchum and IV in Lowman with II-III shaking in Stanley, Idaho City, Horseshoe Bend, Hailey, Garden City, Boise and Mountain Home and in general within about 100 km of the epicenter. This is the strongest aftershock in this long-lasting aftershock sequence of the M 6.5 of March 31, 2020 since an M 4.6 on June 25, 2020. Forecast 126133 had expected today's event within about 25 km was likely around August 6.

 

O:  8AUG2020 02:11:30  44.2N  115.1W mb=4.2  EMSC   SOUTHERN IDAHO               

P:  6AUG2020 126133    44.5N  115.1W 2.0-4.2 AAAAA  Montana/Idaho              

 

High latitude seismicity in the Arctic Ocean continued today was an M 4.5 in the Svalard region and an M 4.6 in Iceland. The event in Svalbard is the strongest in that region within about 250 km since an M 4.5 on May 10, 2020 although more recent events of M 5.0-5.2 have occurred on June 5 and most recently north ot this on August 5 (M 5.3) in this region. This summary noted the event on August 5 as:

 

"An unusual M 5.3 struck near the North Pole north of Svalbard today. It was not reported felt in this remote area. This is the farthest north of any event of M>=5.3 in at least 30 years. Activity had been expected at high latitudes such as this associated with the geomagnetic  disturbance as noted in previous issues of this report:

 

"The geomagnetic field saw disturbed conditions today. The AP level was 16.  High latitude geomagnetic field active conditions  with AP at 26. This is the most active the geomagnetic field has been in the past month. The last period of more disturbance was on April 20, 2020 when AP was 18. Moderate geomagnetic storms such as this can help promote seismicity at high latitudes and near the geomagnetic equator within several days of the storm.." (August 3-5, 6, 2020)

 

Forecast 125923 had expected today's event within about 50 km was likely at the end of July or in early August.

 

O:  7AUG2020 13:18:57  78.6N    7.1E mb=4.5  EMSC   SVALBARD REGION              

P: 29JUL2020 125923    79.0N    7.0E 4.0-5.6 CAAAA  Arctic Ocean Region        

 

The M 4.6 in Iceland is the strongest in that area since an M 6.0 shook the area on June 21, 2020. Forecast 126186 had expected this activity was likely to the southeast around August 7.

 

O: 08AUG2020 03:52:58  66.3N   18.4W ML=3.7  EMSC   ICELAND REGION

O:  8AUG2020 03:42:33  66.3N   18.4W ML=4.6  EMSC   ICELAND REGION               

P:  7AUG2020 126186    65.0N   16.0W 3.0-4.8 ABAAA  Iceland area               

 

 

M 6.3 NEAR ALASKA ANTIPODE IN PRINCE EDWARD ISLAND REGION, INDIAN OCEAN

 

EARTHQUAKE SUMMARY FOR AUGUST 6, 2020

 

Ocean ridges were active today with moderately large to large events in the region of the Prince Edward Islands (M 6.3) and in the Easter Island area of the south Pacific (M 5.4). The largest earthquake in the world today was an  6.3 in the south Indian Ocean near Prince Edward Islands. While not exact, this is in the antipodal region of the M 7.8 in the Alaska Peninsula of July 22, 2020 and may have been promoted by energy from that event as noted in previous issues of this report:

 

"Far field triggering is likely with the earthquake in Alaska. The antipode is located south of South Africa in the Indian Ocean east of Bouvet Island and is a possible site for triggered activity." (July 22, 2020)

 

This epicenter is near the antipode off the coast of Northern California and Oregon and could help enhance seismicity in that area in the next several days. The only events in this area of M>=6.3 in the past 20 years were an M 6.7 on January 22, 2019 and an M 6.3 on July 4, 2005. Forecast 125971 had expected today's activity within about 100 km was likely in late July or early August, 2020.

 

O:  6AUG2020 23:36:45  41.7S   42.5E Mw=6.3  EMSC   PRINCE EDWARD ISLANDS REGION 

P: 30JUL2020 125971    41.0S   43.0E 4.0-5.4 CAAAA  So. Indian Ocean           

 

The earthquake of M 5.5 in the Easter Island region, South Pacific was not felt in that remote area. The last event within about 300 km of this epicenter with M>=5.5 was an M 5.5 on January 23, 2016. Forecast 126214 had expected today's activity about 200 km to the south around August 5.

 

O:  6AUG2020 13:57:37  22.8S  112.4W mb=5.5  EMSC   EASTER ISLAND REGION         

P:  5AUG2020 126214    25.0S  112.0W 4.0-5.4 ACAAA  So. East Pacific Rise      

 

The strongest earthquake felt in the world today was another of M 5.5 in the series in southern Peru which has been ongoing since the M 7.8 in the Alaska Peninsula of July 22. This area is at about 103 degrees from the Alaskan epicenter and subject to triggering from energy concentration related to that event. NEIC reported today's event was felt with intensity V in Acari, Arequipa and II in Marcona, Ica, Peru. There have been several moderately large quakes felt in southern Peru in the past several days. In a previous summary some of this activity was summarized as:

 

 

"The strongest earthquake in the world today was an M 5.5 in northern Chile. NEIC reported it was felt in Northern Chile with IV in Iquique, Tarapaca and in Arica and Calama, Antofagasta and in southern Peru with II-III in Arequipa and Tacna. This area has been active with moderate earthquakes since the M 7.8 in the Alaska Peninsula of July 22. It is located at 102-104 degrees from that epicenter and is likely being promoted by concentrated energy from that source.

GUC reported this earthquake was felt with intensity V in  Tarapaca at Camina, La Tirana; IV in Alto Hospicio, Huara, Iquique, Mamina, Pica; III in Pisagua and Pozo Almonte; in Arica with IV in Codpa and Cuya and III in Arica, San Miguel de Azapa and Cocon Chile, Chile. An aftershock about 100 km to the south occurred later with M 4.5-4.7. GUC reported the earthquake of M 4.5 was felt with intensity IV in  Tarapaca at Pica; III in Alto Hospicio and Iquique and II in Camina and in Arica at Arica with intensity III, Chile. NEIC reported this earthquake of M 4.7 in northern Chile  was felt with intensity II-III in the area(s) of northern Chile at Iquique, Tarapaca. The only similar event within about 100 km of this epicenter in the past two years was an M 6.3 6.2 on November 1, 2018 near today's epicenter. Forecasts 126217 and 126203 had expected today's activity within this area was likely around August 4-5. Other recent activity in southern Peru and northern Chile commented on in this summary may have been precursory to today's event. This event is at 104-105 degrees from the M 7.8 of July 22 n the Alaska Peninsula and was probably promoted by energy from that source." (August 4, 2020)

 

Forecasts 126196 and 126202 had expected this activity in early August in southern Peru. Today's epicenter is at 101-102 degrees from the western edge of the Alaska Peninsula M 7.8 of July 22, the region current showing the most aftershock activity.

 

O:  6AUG2020 22:18:06  15.9S   74.9W Mw=5.5  EMSC   NEAR COAST OF SOUTHERN PERU  

P:  8AUG2020 126202    16.0S   72.0W 4.0-5.7 AABAA  So. Peru/Bolivia           

P: 11AUG2020 126196    15.0S   76.0W 4.0-5.4 BAAAA  Central Peru               

 

An earthquake of M 4.9 was widely felt with minor damage in Algeria today. NEIC reported maximum intensity IV in Algeria at Qararim, Milah; V in Constantine, IV in Ruwasad, Faji Mazallah, Hamma, Ayn Samara, al-Hurub and III in Tamalus and al-Harus. Two similar events hit northern Algeria in the past year - an M 5.0 on March 24 and an M 4.9 on January 24, 2020. These events occurred northwest of today's epicenter. An earthquake of M 4.6 in Northern Algeria occurred on July 4, 2020 and two of M 4.5 hit south of today's event on July 14 and 17, part of a minor regional swarm. Forecast 126119 had expected today's activity was likely to the west of this epicenter around August 5. This is at the fifth node (72 degrees) from the M 7.8 in the Alaska Peninsula of July 22 and at twice this distance (144 degrees) from the M 6.8 in New Guinea and may have been promoted by energy from these sources. Puerto Rico often sees enhanced seismicity at this time of year due to interactions of strong hurricanes with regional plates. The last great tsunami-genic earthquake in the region of Puerto Rico occurred 74 year ago as an M 8.0+ event on August 4, 1946 in the Puerto Rico trench far to the north of today's epicenter. A repeat of this event is overdue in the area.

 

O:  7AUG2020 06:15:37  36.5N    6.3E Mw=4.9  EMSC   NORTHERN ALGERIA             

O:  6AUG2020 15:09:24  36.9N    5.9E mb=4.1  EMSC   NORTHERN ALGERIA             

P:  5AUG2020 126119    37.0N    3.0E 3.0-4.5 AABAA  Western Mediterranean      

 

An aftershock of M 4.8-5.1 in the southern region of Puerto Rico was felt throughout the island today. NEIC reported maximum intensity IV in Yauco, Adjuntas, Laja, Lares, Hatillo and II-III at Ponce, Ciales, Cabo Rojo, Isabela and Corozal among other communities in Puerto Rico. The last earthquake in the southern aftershock of M>=5.1 was an M 5.3 on July 3, 2020. These are the strongest far-period aftershocks of the M 6.5 in the area of January 7, 2020. An M 5.3-5.4 also hit the area on May 2, 2020, the first such from mid-January through July. Forecast 126045 had expected today's event was likely within  the aftershock zone around August 6.

 

O:  6AUG2020 22:28:49  17.9N   66.7W mb=4.0  EMSC   PUERTO RICO REGION           

O:  7AUG2020 03:26:59  18.0N   66.8W mb=5.1  EMSC   PUERTO RICO REGION            

P:  6AUG2020 126045    18.0N   67.0W 3.4-4.9 AAAAA  Puerto Rico                

 

An unusually large M 5.4 also occurred in the Buru area of Indonesia today.

The last earthquake within about 200 km of this epicenter with M>=5.4 was an

M 5.6 on June 9, 2020, the only such event since a similar M 5.6 on October 11, 2018. Forecast 125999 had expected today's event within about 100 km was likely around

August 5.

 

O:  7AUG2020 03:00:39   3.8S  126.3E Mw=5.4  EMSC   BURU, INDONESIA              

P:  5AUG2020 125999     4.0S  127.0E 4.0-5.4 AAAAA  Ceram area                 

 

An earthquake of M 3.0 was widely felt south of San Francisco, California today. It was reported with intensity II-III in California at Pescadero, Davenport, Santa Cruz, Boulder Creek, Felton, Scotts Valley, Portola Valley, Los Altos and Los Gatos among others. It occurred at a somewhat unusual epicenter off the coast. In the past unusual quake off the coast of central California have occasionally been followed within days by larger events on the San Andreas Fault Zone.  The last such event of M>=3 off the coast of southern San Francisco was an  M 3.4 on June 4, 2016. An M 2.8-2.9 hit near this epicenter on June 23, 2020, the last of M>=2.8 since an M 2.8 on June 22, 2018. Forecast 126078 had expected today's activity was likely around August 7.

 

O:  6AUG2020 16:00:27  37.1N  122.4W ML=2.7  EMSC   OFFSHORE NORTHERN CALIFORNIA 

O:  6AUG2020 16:00:27  37.1N  122.4W ML=3.0  ANSS   OFFSHORE NORTHERN CALIFORNIA 

P:  7AUG2020 126078    37.3N  121.6W 2.5-4.5 AAAAA  Central California         

 

STRONG EARTHQUAKE IN VANUATU TIDALLY PROMOTED

 

EARTHQUAKE SUMMARY FOR AUGUST 5, 2020

 

A strong M 6.5 earthquake shook central Vanuatu today. It occurred less than

an hour from local solar midnight, a time when tidal stresses are maximized

and was probably enhanced by stresses associated with the full moon of

August 3. The last earthquake within about 200 km of today's epicenter in

Vanuatu of M>=6.5 was an M 6.6 on July 31, 2019 and prior to that an M 6.8 on May 9, 2017.  Forecasts 125941 and 126207 had expected this activity was likely within about 100 km in late July or early August. Vanuatu is located near the geomagnetic equator and may have been promoted by the geomagnetic storm yesterday, the strongest in at least three months. This epicenter is also at 144-145 degrees from the M 7.5 in Oaxaca, Mexico of June 23, a distance at which energy is concentrated on the earth's surface following major earthquake and was probably enhanced by energy from that source.

 

O:  5AUG2020 12:05:36  16.1S  168.1E Mw=6.5  EMSC   VANUATU                      

P:  6AUG2020 126207    18.0S  168.0E 4.0-5.5 ABAAA  Vanuatu Islands            

P: 30JUL2020 125941    17.0S  168.0E 4.0-5.6 BAAAA  Vanuatu Islands            

 

An antipodal pair was completed today when an M 5.5 occurred in the Sunda area of Indonesia. The antipode in northern Venezuela saw an M 5.0 on August 2.  NEIC reported the earthquake of M 5.0 in northern Venezuela  was felt with intensity II-III in the area(s) of northern Venezuela at Mucurapo Diego, Port of Spain, Tunapuna, Trinidad and Tobago and at Saint Georges and Saint Davids, Grenada.  Forecast 126049 had expected this event in Venezuela was likely around August 7. Earthquakes of larger magnitude in northern Venezuela in the past year occurred on April 7, 2020 (M 5.2) and September 9, 2019 (M 5.5).

 

O:  2AUG2020 00:03:47  10.8N   62.6W Mw=5.0  EMSC   OFFSHORE SUCRE, VENEZUELA    

P:  7AUG2020 126049    10.0N   63.0W 3.4-5.1 BAAAA  Windward Islands           

 

The M 5.5 in Sunda, Indonesia was reported by BMG to have been felt with intensity III in Kota Bima, Tambolaka, Wainngapu and Waitabula, Sumba, Indonesia. It is the strongest within about 250 km of that epicenter since an M 6.4 on January 22, 2019 and an M 6.0 on January 21, 2019. The last such earthquake within about 200 km of today's epicenter was an M 6.2 on December 29, 2016. It is likely that the earthquake in Indonesia and the Venezuelan quake were promoted by strong tidal stresses as they occur very near the longitudes of maximum tidal stress with the full moon of August 3 as earlier reported in this summary:

 

"The full moon  arrived at 15:59 UT on August 3, 2020. Longitudes which were sub-solar (local solar noon) at this time are 60 West and 120 East and include in the west the Caribbean and Puerto Rico and portions of northern and western South America. Those in the east include the Philippines and central Indonesia near Sulawesi. These areas may see moderate seismic enhancement at this time. Many areas can see tidal enhancement with lunar-solar alignments so the seismicity of the earth is expected to be at active conditions through August 7." (August 2-5, 2020)

 

Forecasts 125937 and 126001 had expected this activity in late July or early August within about 150 km of this epicenter. This is near geomagnetic equator and the fourth node (90 degrees) from the M 7.8 in the Alaska Peninsula of July 22 and may have been promoted by energy from those sources.

 

O: 05AUG2020 09:18:17   9.8S  119.1E ML=4.3  EMSC   SUMBA REGION, INDONESIA

O: 05AUG2020 12:04:51   9.9S  119.2E ML=4.1  EMSC   SUMBA REGION, INDONESIA

O:  5AUG2020 08:27:11   9.7S  119.1E mb=5.5  EMSC   SUMBA REGION, INDONESIA      

P: 11AUG2020 126001     7.0S  120.0E 4.0-5.6 ACAAA  Flores Island area         

P: 27JUL2020 125937    11.0S  119.0E 4.0-5.5 CBAAA  So. of Indonesia           

 

An unusually large earthquake of M 5.4 shook areas of eastern Honshu, Japan today northeast of Tokyo. This epicenter is at 103-104 degrees from the M 7.5 in Oaxaca, Mexico of June 23, 2020 and may have been enhanced by concentrated energy from that source. The last earthquake with M>=5.4 within about 200 km of this epicenter occurred on June 24, 2020 as an M 5.9 south of this epicenter. The last earthquake in this area of M>=6.0 was an M 6.3 a year ago on August 4, 2019 about 200 km north of today's event. Quakes within about 150 km of this epicenter in the past year of M>=5.4 occurred on May 10 (M 5.8) and January 2, 2020 (M 5.6). Forecast 126097 had expected today's event within about 100 km of this epicenter was likely around August 6.

 

NEIC reported this earthquake of M 5.4  off eastern Honshu, Japan  was felt with intensity II-III in the area(s) of eastern Honshu, Japan in Chiba and Ibaraki.

 

O:  5AUG2020 17:53:59  36.1N  141.7E Mw=5.4  EMSC   NEAR EAST COAST OF HONSHU, JAP

P:  6AUG2020 126097    37.0N  142.0E 4.0-5.4 AAAAA  Off East Coast Honshu      

 

The strongest earthquake in the U.S. or Canada today was an M 5.2 aftershock in the Alaska Peninsula zone. It was reported by NEIC to have been felt with intensity III in King Cove, Alaska. This aftershock zone has been active with such events over the past week to 10 days. but this and a similar event of M 5.2 yesterday is the strongest aftershock in the area since an M 5.6 on July 29. Forecast 126177 had expected today's event was likely within about 10 km of this epicenter around August 7. It was preceded by an M 3.7 foreshock about 1.5 minutes earlier.

 

O: 05AUG2020 16:16:13  54.1N  160.3W mb=3.7  EMSC   ALASKA PENINSULA

O: 05AUG2020 20:36:57  54.5N  160.5W mb=4.0  EMSC   ALASKA PENINSULA

O:  5AUG2020 16:17:41  54.6N  161.2W Mw=5.2  EMSC   ALASKA PENINSULA             

P:  7AUG2020 126177    54.7N  161.2W 3.5-5.1 AAAAA  Unimak Islands, Aleutians  

 

An unusual M 5.3 struck near the North Pole north of Svalbard today. It was not reported felt in this remote area. This is the farthest north of any event of M>=5.3 in at least 30 years. Activity had been expected at high latitudes such as this associated with the geomagnetic  disturbance as noted in previous issues of this report:

 

"The geomagnetic field saw disturbed conditions today. The AP level was 16.  High latitude geomagnetic field active conditions  with AP at 26. This is the most active the geomagnetic field has been in the past month. The last period of more disturbance was on April 20, 2020 when AP was 18. Moderate geomagnetic storms such as this can help promote seismicity at high latitudes and near the geomagnetic equator within several days of the storm.." (August 3-5, 2020)

 

Forecast 125923 had expected a moderate event to the south of this was likely in late July or early August.

 

O:  5AUG2020 08:48:05  87.4N    7.6E mb=5.3  EMSC   NORTH OF SVALBARD            

P: 29JUL2020 125923    79.0N    7.0E 4.0-5.6 CDAAA  Arctic Ocean Region        

 

MODERATELY STRONG QUAKES SHAKE TURKEY; GUATEMALA

 

EARTHQUAKE SUMMARY FOR AUGUST 4, 2020

 

Moderately strong earthquakes of M 5.8 and M 5.5  occurred in the regions of

Guatemala and eastern Turkey today.  The earthquake of M 5.8 shook regions of Guatemala today. NEIC reported it was felt with intensity II-III in San Marcos, Guatemala and in Villahermosa, Tabasco, Mexico. An M 4.1 aftershock followed the mainshock half an hour later. The only quake in or near Guatemala of equal or larger magnitude in the past year was an M 5.9 about 100 km northeast of today's epicenter on December 19, 2019. The last of M>=6 in Guatemala was an M 6.8 on June 22, 2017. Forecasts 126030 and 126025 had expected this activity in Guatemala was like around August 6. Today's mainshock in Guatemala occurred within about an hour of local solar noon, a prime time for tidal triggering and may have been enhanced by tidal stresses associated with the full moon of August 3.

 

O:  4AUG2020 19:17:52  13.3N   92.0W Mw=5.8  EMSC   OFFSHORE GUATEMALA           

O:  4AUG2020 19:48:12  13.3N   92.5W ML=4.1  EMSC   OFF THE COAST OF GUATEMALA   

P:  6AUG2020 126030    13.0N   91.0W 3.5-5.3 AAAAA  Guatemala                  

P:  6AUG2020 126025    14.0N   93.0W 3.5-5.3 AAAAA  Chiapas, Mexico             

 

A moderate earthquake of M 5.5 also occurred in eastern Turkey today. NEIC reported it was felt with intensity V in Turkey at Diyarbakir and IV in Malatya and Elazig. An aftershock of M 4.5 was also felt with intensity III in Arapkir, Malatya, Turkey. This appears to be the strongest aftershock to date of an M 6.8 on January 24, 2020. It was followed by moderate aftershocks of its own of M 4.8, 4.4 and 4.0. Today's M 5.5 occurred within minutes of local solar noon when tidal stresses are maximized and was probably enhanced by tidal stresses associated with the full moon of August 3. Forecasts 125835 and 126116 had expected today's activity was likely within about 50 km of this epicenter in late July or early August.

 

O: 04AUG2020 13:10:18  38.2N   38.8E mb=4.0  EMSC   EASTERN TURKEY

O: 04AUG2020 15:30:58  38.2N   38.8E ML=4.4  EMSC   EASTERN TURKEY

O: 04AUG2020 18:40:03  38.2N   38.8E Mw=4.8  EMSC   EASTERN TURKEY

O:  4AUG2020 09:37:36  38.2N   38.7E Mw=5.5  EMSC   EASTERN TURKEY               

P:  7AUG2020 126116    39.0N   40.0E 3.5-5.2 BAAAA  Turkey                     

P: 26JUL2020 125835    38.0N   39.0E 3.5-5.0 CAAAA  Turkey                     

 

The strongest earthquake in the U.S. or Canada today was an M 5.2 aftershock in the Alaska Peninsula zone. It was reported by NEIC to have been felt with intensity III in King Cove, Alaska. This aftershock zone has been active with such events over the past week to 10 days. but this is the strongest aftershock in the area since an M 5.6 on July 29. Forecast 126177 had expected today's event was likely within about 10 km of this epicenter around August 7.

 

O:  4AUG2020 12:47:18  54.7N  161.1W Mw=5.2  EMSC   ALASKA PENINSULA             

P:  7AUG2020 126177    54.7N  161.2W 3.5-5.1 BAAAA  Unimak Islands, Aleutians  

 

An unusual earthquake in the Arctic Ocean north of Siberia in the area north of Severnaya Zemlya, Russia occurred today with M 4.6. It was not reported felt in this remote area. This continues activation of the Arctic area which has included mostly light to moderate sized quakes in the past several days. This may be related  to the geomagnetic storm which occurred yesterday. This summary had previously noted in this regard:

 

"The geomagnetic field saw disturbed conditions today. The AP level was 16.  High latitude geomagnetic field active conditions  with AP at 26. This is the most active the geomagnetic field has been in the past month. The last period of more disturbance was on April 20, 2020 when AP was 18. Moderate geomagnetic storms such as this can help promote seismicity at high latitudes and near the geomagnetic equator within several days of the storm.." (August 3-5, 2020)

 

It may also be related to the full moon tidal stresses which maximized near this longitude on August 3 and occurred near local solar midnight, a prime time for high tidal stresses. Tidal stresses had been thought to be triggers for enhanced seismicity in previous issues at this time as:

 

"The full moon  arrived at 15:59 UT on August 3, 2020. Longitudes which were sub-solar (local solar noon) at this time are 60 West and 120 East and include in the west the Caribbean and Puerto Rico and portions of northern and western South America. Those in the east include the Philippines and central Indonesia near Sulawesi. These areas may see moderate seismic enhancement at this time. Many areas can see tidal enhancement with lunar-solar alignments so the seismicity of the earth is expected to be at active conditions through August 7." (August 2-5, 2020)

 

The last earthquake of similar size in the area within about 300 km of this epicenter was an M 4.7 on January 12, 2020. The last of larger magnitude was an M 5.1 on September 13, 2012. Forecast 126195 had expected this event within about 200 km was likely in early August.

 

O:  4AUG2020 14:52:14  83.5N  115.1E mb=4.6  EMSC   NORTH OF SEVERNAYA ZEMLYA    

P: 11AUG2020 126195    82.0N  119.0E 4.0-5.5 CrBAA  Arctic Ocean Region        

 

SO

GEOMAGNETIC DISTURBANCE ENHANCES SEISMICITY NEAR GEOMAGNETIC EQUATOR

 

EARTHQUAKE SUMMARY FOR AUGUST 3, 2020

 

A new geomagnetic storm began today near mid-day. It was accompanied by a series of B-class solar flares, the first since early June, 2020. It was followed by moderately large earthquake of M 5.5-5.6 near the geomagnetic equator in the Mariana Islands and in Northern Chile/Southern Peru. This summary had expected this activity as:

 

"The geomagnetic field saw disturbed conditions today. The AP level was 16.  High latitude geomagnetic field active conditions  with AP at 26. This is the most active the geomagnetic field has been in the past month. The last period of more disturbance was on April 20, 2020 when AP was 18. Moderate geomagnetic storms such as this can help promote seismicity at high latitudes and near the geomagnetic equator within several days of the storm." (August 3-4, 2020)

 

The strongest earthquake in the world today was an M 5.5 in northern Chile. NEIC reported it was felt in Northern Chile with IV in Iquique, Tarapaca and in Arica and Calama, Antofagasta and in wouthern Peru with II-III in Arequipa and Tacna. This area has been active with moderate earthquakes since the M 7.8 in the Alaska Peninsula of July 22. It is located at 102-104 degrees from that epicenter and is likely being promoted by concentrated energy from that source.

GUC reported this earthquake was felt with intensity V in  Tarapaca at Camina, La Tirana; IV in Alto Hospicio, Huara, Iquique, Mamina, Pica; III in Pisagua and Pozo Almonte; in Arica with IV in Codpa and Cuya and III in Arica, San Miguel de Azapa and Cocon Chile, Chile. An aftershock about 100 km to the south occurred later with M 4.5-4.7. GUC reported the earthquake of M 4.5 was felt with intensity IV in  Tarapaca at Pica; III in Alto Hospicio and Iquique and II in Camina and in Arica at Arica with intensity III, Chile. NEIC reported this earthquake of M 4.7 in northern Chile  was felt with intensity II-III in the area(s) of northern Chile at Iquique, Tarapaca. The only similar event within about 100 km of this epicenter in the past two years was an M 6.3 6.2 on November 1, 2018 near today's epicenter. Forecasts 126217 and 126203 had expected today's activity within this area was likely around August 4-5.

Other recent activity in southern Peru and northern Chile commented on in this summary may have been precursory to today's event.

 

O:  3AUG2020 11:56:51  19.6S   69.3W Mw=5.5  EMSC   TARAPACA, CHILE              

O:  3AUG2020 11:56     19.6S   69.2W mb=5.5  GUC    Tarapaca at Camina, La Tirana;

P:  4AUG2020 126217    20.0S   69.0W 4.0-5.9 AAAAA  So. Peru/Bolivia           

P:  5AUG2020 126203    19.0S   69.0W 4.0-5.7 AAAAA  So. Peru/Bolivia           

 

O:  3AUG2020 18:26     20.5S   69.0W mb=4.5  GUC    Tarapaca at Pica; III in Alto

P:  3AUG2020 126210    21.0S   69.0W 4.0-5.9 AAAAA  Coast No. Chile            

 

An M 5.5-5.6 also shook regions of the Northern Mariana Islands today. NEIC reported intensity II in Tinian to the south of the epicenter. This is the strongest earthquake in the northern Marianas within about 200 km of this epicenter since an M 5.9 on October 26, 2018. Forecast 125761 had expected today's activity was likely within about 50 km these epicenters in late July.

 

O:  3AUG2020 12:45:52  17.0N  147.5E mb=4.9  EMSC   MARIANA ISLANDS REGION       

O:  3AUG2020 08:31:10  17.1N  147.4E Mw=5.6  EMSC   MARIANA ISLANDS REGION       

P: 28JUL2020 125761    17.0N  147.0E 4.0-5.5 BAAAA  No. Marianas               

 

A light M 3.5 earthquake was felt widely in the Los Angeles, California area today. NEIC reported intensity IV in Anaheim, Placenta, Fullerton, Villa Park, Yorba Linda, Brea and III in Orange, among other communities. This is the largest earthquake in eastern Los Angeles since an M 3.6 on April 3, 2019. Earthquakes of M 3.8 and 4.2 hit the San Fernando Valley area west of Los Angeles on July 30, 2020. Forecast 126105 had expected today's activity within about 30 km of this epicenter was likely around August 4.

 

O:  3AUG2020 22:18:50  33.9N  117.8W ML=3.4  EMSC   GREATER LOS ANGELES AREA, CALI

O:  3AUG2020 22:20:05  33.9N  117.8W Ml=2.0  EMSC   GREATER LOS ANGELES AREA, CALI

P:  4AUG2020 126105    34.2N  117.8W 2.5-4.4 AAAAA  So. California             

 

 

UTHWEST PACIFIC REMAINS ACTIVE

 

EARTHQUAKE SUMMARY FOR AUGUST 2, 2020

 

The strongest earthquake in the world today was an M 5.8 in the Bismarck Sea. This is part of the regional activity which began yesterday in the area. This summary had noted with the M 6.0 yesterday in this regard:

 

"Earthquake of M 5.7 and 6.0 (in that order) also occurred in eastern Indonesia today in the region of the Bismarck Sea. They were not reported felt in this remote area. The  6.0 is the strongest in the Bismarck Sea since an M 6.4 on July 25, 2016. Forecast 126005 had expected today's activity was likely within about 50 km of this epicenter around August 6. Like the M 5.6 in the D'entrecasteaux Islands yesterday this epicenter is at the fifth node (72 degrees ) from the Alaska Peninsula and was probably promoted by energy from that source. Other such events today occurred at or near 72 degrees from Alaska in Mindanao, Philippines (M 6.4)," (August 1-2, 2020)

 

O:  2AUG2020 09:29:57   3.1S  149.0E Mw=5.8  EMSC   BISMARCK SEA                  

P:  6AUG2020 126005     3.0S  149.0E 4.0-5.4 BAAAA  New Ireland                

 

An M 5.4 was felt widely in eastern New Guinea today. NEIC reported felt intensity IV in the Eastern Highlands at Goroka and in Kindiawa and II-III in Madang, Kainantu, Mount Hage, Lalibu and Port Moresby, Papua New Guinea. This is the strongest earthquake in this area within about 200 km of this epicenter

since events of M 5.7 to the north on January 30, 2020 and M 5.9 on March 4, 2019. Forecast 126006 had expected today's activity was likely around August 5 within about 100 km.

 

O:  2AUG2020 14:15:48   5.0S  145.4E Mw=5.3  EMSC   EASTERN NEW GUINEA REG., P.N.G

O:  3AUG2020 02:35:19   5.0S  145.4E mb=4.4  EMSC   EASTERN NEW GUINEA REG., P.N.G

P:  5AUG2020 126006     4.0S  146.0E 4.0-5.6 AAAAA  New Ireland                

 

The strongest earthquake in the world today was an M 4.9 in the Alaska Peninsula area. This area has seen daily aftershocks of this size each day for the past week. Forecast 125905 had expected this event within about 25 km of this epicenter was likely around July 31.

 

O: 02AUG2020 07:44:52  54.7N  161.1W ML=3.0  EMSC   ALASKA PENINSULA

O: 02AUG2020 18:58:33  54.9N  160.3W ml=3.4  EMSC   ALASKA PENINSULA

O: 02AUG2020 12:16:09  55.1N  158.3W ML=3.4  EMSC   ALASKA PENINSULA

O: 03AUG2020 03:36:58  55.2N  159.5W mb=3.8  EMSC   ALASKA PENINSULA

O:  2AUG2020 14:39:23  54.6N  161.1W mb=4.9  EMSC   ALASKA PENINSULA             

P: 31JUL2020 125905    54.3N  161.4W 3.5-4.9 AAAAA  Unimak Islands, Aleutians  

 

A moderate earthquake also occurred today in the area south of Africa with M 4.7. This epicenter is in the antipodal area of the M 7.8 in the Alaska Peninsula of July 22 and was probably promoted by focused energy at the antipode of that event. The last earthquake in this area south of Africa with M>=4.7 was an M 5.1 on February 9, 2020 and prior to that an M 5.4 on January 10, 2020 and an M 5.6 on August 22, 2018. This forecast had expected this area would be active following the Alaska Peninsula quake at this time as:

 

"Far field triggering is likely with the earthquake in Alaska. The antipode is located south of South Africa in the Indian Ocean east of Bouvet Island and is a possible site for triggered activity." (July 22, 2020)

 

O:  3AUG2020 00:36:04  52.9S   27.7E mb=4.7  EMSC   SOUTH OF AFRICA              

 

Earthquakes at 103 degrees from the Alaska Peninsula epicenter today included the continuing swarm in southern Peru and northern Chile, Indonesia and an M 4.1 in the South Island of New Zealand. The New Zealand event had been expected in forecast 126234 within about 100 km of the epicenter was likely around August 3. This summary had expected in its far-field forecast that both of these areas would see enhanced seismicity at this time as:

 

"Far field triggering is likely with the earthquake in Alaska ... those near 103 degrees include northern Chile and southern Peru; South Island, New Zealand; Sumatra and southwestern Indonesia." (July 22, 2020)

 

O:  2AUG2020 21:40:15  45.1S  167.5E ML=4.1  EMSC   SOUTH ISLAND OF NEW ZEALAND  

P:  3AUG2020 126234    44.0S  169.0E 3.0-4.9 ABAAA  So. Island, N.Z.           

 

O:  2AUG2020 11:01:01  19.8S   69.9W mb=3.9  EMSC   TARAPACA, CHILE              

P:  4AUG2020 126217    20.0S   69.0W 4.0-5.9 AAAAA  So. Peru/Bolivia           

 

STRONG QUAKES SHAKE MINDANAO, PHILIPPINES; BISMARCK SEA

 

EARTHQUAKE SUMMARY FOR AUGUST 1, 2020

 

It was an active day in global seismicity. A series of moderately strong to strong earthquakes were recorded around the world.  Many of today's stronger events occurred in areas and at times suggesting tidal enhancement with the full moon of August 3 which effects on seismicity were expected as:

 

"The full moon will arrive at 15:59 UT on August 3, 2020. Longitudes which are sub-solar (local solar noon) at this time are 60 West and 120 East and include in the west the Caribbean and Puerto Rico and portions of northern and western South America. Those in the east include the Philippines and central Indonesia near Sulawesi. These areas may see moderate seismic enhancement at this time. Many areas can see tidal enhancement with lunar-solar alignments so the seismicity of the earth is expected to be at active conditions through August 7." (August 1-2, 2020)

 

The strongest earthquake in the world today was an M 6.4 in Mindanao, Philippines. It was reported by NEIC to have been felt with intensity IV in Mindano at Simuay and Taviran and with light intensity in Libertad. This earthquake is located at 124 East longitude, near the maximum tidal stress with this full moon.  This is the strongest earthquake in Mindanao within about

200 km of this epicenter during 2020 - the last such event was an M 6.8 on December 15, 2019. The area was in an active period with events of M 5.6 on July 31 and M 5.8 on July 27, 2020 recently occurring. Forecasts 125707 and 125991 had expected today's activity in late July or early August.

 

 

O:  1AUG2020 17:09:01   7.3N  124.1E Mw=6.4  EMSC   MINDANAO, PHILIPPINES        

P:  5AUG2020 125991     6.0N  125.0E 4.0-5.6 BBAAA  Mindanao, Philippines       

P: 24JUL2020 125707     7.0N  124.0E 4.0-5.6 CAAAA  Central Philippines        

 

Earthquake of M 5.7 and 6.0 (in that order) also occurred in eastern Indonesia today in the region of the Bismarck Sea. They were not reported felt in this remote area. The  6.0 is the strongest in the Bismarck Sea since an M 6.4 on July 25, 2016. Forecast 126005 had expected today's activity was likely within about 50 km of this epicenter around August 6. Like the M 5.6 in the D'entrecasteaux Islands yesterday this epicenter is at the fifth node (72 degrees ) from the Alaska Peninsula and was probably promoted by energy from that source. Other such events today occurred at or near 72 degrees from Alaska in Mindanao, Philippines (M 6.4), the Solomon Islands, Samoa, Poland, Tajikistan, Costa Rica, the Dominican Republic and Puerto Rico.

 

O: 01AUG2020 19:18:12   3.1S  148.9E mb=4.6  EMSC   BISMARCK SEA

O: 01AUG2020 19:08:50   3.2S  148.7E Mw=5.7  EMSC   BISMARCK SEA

O:  1AUG2020 19:22:06   3.3S  148.6E Mw=6.0  EMSC   BISMARCK SEA                 

P:  6AUG2020 126005     3.0S  149.0E 4.0-5.4 BAAAA  New Ireland                

 

Moderately large events also occurred today with M 5.6 in Tonga and M 5.7 in  southern Vanuatu. They were not reported felt. Forecasts 125956 and 126211 had expected this activity in late July or early August.

 

O:  1AUG2020 19:45:45  23.1S  175.9W Mw=5.6  EMSC   TONGA REGION                 

P: 29JUL2020 125956    23.0S  175.0W 4.0-5.4 AAAAA  Tonga Islands              

 

O:  2AUG2020 03:01:33  20.8S  173.5E Mw=5.7  EMSC   VANUATU REGION               

O:  2AUG2020 03:03:06  26.8S  174.7E ML=4.8  EMSC   SOUTHEAST OF LOYALTY ISLANDS 

P:  3AUG2020 126211    22.0S  171.0E 4.0-5.5 ABBAA  Loyalty Islands            

 

The strongest earthquake in the U.S. or Canada today was an M 4.9 aftershock in the Alaska Peninsula area. Aftershock of this size or greater have occurred each of the past five days in the area, but were absent for several days before that. NEIC reported this earthquake of M 4.9 in the Alaska Peninsula  was felt with intensity II-III in the area(s) of the Alaska Peninsula at Sand Point.  Forecast 125905 had expected today's activity within about 50 km was likely around July 31.

 

O: 01AUG2020 14:53:24  54.9N  160.3W ml=3.0  EMSC   ALASKA PENINSULA

O: 01AUG2020 21:05:12  55.0N  159.1W mb=3.5  EMSC   SOUTH OF ALASKA

O: 01AUG2020 23:28:10  55.2N  159.6W ML=3.0  EMSC   ALASKA PENINSULA

O:  1AUG2020 07:00:11  54.6N  160.4W mb=4.9  EMSC   ALASKA PENINSULA             

P: 31JUL2020 125905    54.3N  161.4W 3.5-4.9 AAAAA  Unimak Islands, Aleutians  

 

A moderate earthquake of M 4.4 also occurred today in Hawaii. NEIC reported this earthquake of M 4.2-4.4 in Hawaii  was felt with intensity II-III in the area(s) of Hawaii at Naalehu, Volcano, Captain Cook, Pahoa, Mountain View, Hilo, Holualoa, Kurtistown, Keaau and Kealakekua. This follows an M 4.6 on July 27 and events of M 4.5 and 4.7 on July 3, an active period in Hawaiian seismicity.

Forecast 125750 had expected today's event within about 25 km was likely around July 30.

 

O:  1AUG2020 20:03:06  19.3N  155.4W mb=4.4  EMSC   ISLAND OF HAWAII, HAWAII     

P: 30JUL2020 125750    19.2N  155.2W 3.0-4.4 AAAAA  Hawaii                     

 

The strongest earthquake today in South America was an M 5.1 in southern Peru.

 

NEIC reported this earthquake of M 5.1 in Southern Peru  was felt with intensity II-III in the area(s) of Southern Peru at Camana, Mollendo and Arequipa, Peru.  This area has been active for the past 10 days following the Alaska Peninsula quake of M 7.8 on July 22. It is located at 102-104 degrees from that epicenter a distance at which strong concentration of energy occurs due to internal  earth reflections of discontinuities. Today's event had been expected in early August in forecast 126202. More such activity in northern Chile and southern Peru may be expected in the coming days. This activity is near the longitude of maximum tidal stress with the upcoming full moon and may have been enhanced by stresses associated with that alignment. Other such earthquakes near 60 West longitude today included an M 4.0 in Puerto Rico; an M 5.0 in northern Venezuela and several moderate event in Sulawesi, Indonesia near 120 East longitude.

 

O:  1AUG2020 08:25:26  16.3S   72.6W Mw=5.1  EMSC   NEAR COAST OF SOUTHERN PERU  

P:  6AUG2020 126202    17.0S   71.0W 4.0-6.1 BAAAA  So. Peru/Bolivia           

P:  8AUG2020 126202    16.0S   72.0W 4.0-5.7 CAAAA  So. Peru/Bolivia           

 

 

NEIC reported the earthquake of M 3.5-4.0 in Southern Puerto Rico  was felt with intensity II-III in the area(s) of Southern Puerto Rico at Corozal.

 

O:  1AUG2020 20:07:58  18.0N   66.7W ML=4.0  EMSC   PUERTO RICO                  

P:  4AUG2020 126045    18.0N   67.0W 3.4-4.9 BAAAA  Puerto Rico                

 

NEIC reported the earthquake of M 5.0 in northern Venezuela  was felt with intensity II-III in the area(s) of northern Venezuela at Mucurapo Diego, Port of Spain, Tunapuna, Trinidad and Tobago and at Saint Georges and Saint Davids, Grenada.

 

O:  2AUG2020 00:03:47  10.8N   62.6W Mw=5.0  EMSC   OFFSHORE SUCRE, VENEZUELA    

P:  7AUG2020 126049    10.0N   63.0W 3.4-5.1 BAAAA  Windward Islands           

 

O:  1AUG2020 07:56:36   0.1S  122.9E mb=4.5  EMSC   SULAWESI, INDONESIA          

P:  6AUG2020 125990     0.0N  123.0E 4.0-5.6 BAAAA  Mindanao, Philippines      

 

O:  1AUG2020 20:28:20   2.1S  123.0E ML=4.0  EMSC   SULAWESI, INDONESIA          

P:  4AUG2020 126017     1.0S  124.0E 4.0-5.4 BBAAA  Sulawesi area              

 

ENHANCED SEISMICITY IN SOUTHWEST PACIFIC

 

EARTHQUAKE SUMMARY FOR JULY 31, 2020

 

The strongest seismicity today was in the Southwest Pacific where several events of M>=5.2 occurred in the D'entrecasteaux area. These were not reported felt in this remote area. The last earthquake of M>=5.6 in the D'entrecasteaux region occurred on March 10, 2019 with M 6.1. Today's event was followed by aftershocks of M 4.7 and 4.2. An earthquake of M 5.2 also occurred in the Solomon Islands and in New Britain  with M 5.3 today These events had been forecast in 125736 and 126016 in late July or early August. This activity is near the fifth node (72 degrees) from the M 7.8 in the Alaska Peninsula of July 22 and may have been promoted by energy from that source.

 

O: 31JUL2020 17:05:59   7.5S  156.8E Mw=5.2  EMSC   SOLOMON ISLANDS              

P:  3AUG2020 126016     7.0S  155.0E 4.0-5.4 BABAA  Solomon Islands            

P: 24JUL2020 125736     8.0S  155.0E 4.0-5.4 CABAA  Solomon Islands            

 

O: 31JUL2020 10:02:16   8.7S  152.7E Mw=5.6  EMSC   D'ENTRECASTEAUX ISLANDS REGION

O: 31JUL2020 16:17:15   8.8S  152.9E mb=4.7  EMSC   D'ENTRECASTEAUX ISLANDS REGION

P: 24JUL2020 125736     8.0S  155.0E 4.0-5.4 CABAA  Solomon Islands            

 

O: 31JUL2020 20:37:44  10.8S  151.0E mb=4.2  EMSC   D'ENTRECASTEAUX ISLANDS REGION

P:  3AUG2020 126199    10.0S  151.0E 4.0-5.4 BAAAA  New Ireland                

 

O: 31JUL2020 16:04:18   5.5S  151.9E mb=5.3  EMSC   NEW BRITAIN REGION, P.N.G.   

P: 31JUL2020 125726     6.0S  154.0E 4.0-5.5 BABAA  New Britain                

 

Two factors were setting up today which may help enhance global seismicity in the next several days. The first is an upcoming geomagnetic storm which is expected in early August, but has not yet begun. The other is the full moon expected August 3. This summary expects seismicity related to the full moon as:

 

"The full moon will arrive at 15:59 UT on August 3, 2020. Longitudes which are sub-solar (local solar noon) at this time are 60 West and 120 East and include in the west the Caribbean and Puerto Rico and portions of northern and western South America. Those in the east include the Philippines and central Indonesia near Sulawesi. These areas may see moderate seismic enhancement at this time. Many areas can see tidal enhancement with lunar-solar alignments so the seismicity of the earth is expected to be at active conditions through August 7." (July 31-August 1)

 

The strongest earthquake in the U.S. or Canada today was an M 4.4 in the Fox Islands, Aleutians, Alaska. It was not reported felt in this remote epicentral area. It was followed by an energetic aftershock sequence including two events of M 3.9. This is the strongest earthquake in the Fox Islands since an M 4.6 on July 12, 2020 and prior to that on June 15, 2020. Forecast 125895 had expected today's quake was likely within about 100 km of this epicenter around July 28.

 

O: 31JUL2020 18:43:56  51.3N  168.5W ml=3.3  EMSC   FOX ISLANDS, ALEUTIAN ISLANDS

O: 31JUL2020 18:43:56  51.3N  168.5W ml=3.3  EMSC   FOX ISLANDS, ALEUTIAN ISLANDS

O: 31JUL2020 19:10:03  51.3N  168.6W mb=3.9  EMSC   FOX ISLANDS, ALEUTIAN ISLANDS

O: 31JUL2020 19:47:58  51.4N  168.6W mb=3.9  EMSC   FOX ISLANDS, ALEUTIAN ISLANDS

O: 31JUL2020 19:51:41  51.4N  168.6W mb=4.4  EMSC   FOX ISLANDS, ALEUTIAN ISLANDS

O: 31JUL2020 07:45:29  51.3N  168.6W ml=3.4  EMSC   FOX ISLANDS, ALEUTIAN ISLANDS

P: 28JUL2020 125895    52.4N  169.4W 3.5-5.1 BAAAA  Fox Islands, Aleutians     

 

 

 

WESTERN LOS ANGELES, CALIFORNIA VALLEYS SHAKE

 

EARTHQUAKE SUMMARY FOR JULY 30, 2020

 

A series of light to moderate earthquakes shook the valleys west of Los Angeles, California today. The largest of these was an M 4.2 near San Fernando. It was felt with maximum intensity V in San Fernando, California, Mission Hils, North Hills; IV in Pacoima, Granada Hills, Panorama City, Northridge, Porter Ranch, Sun Valley and III in Newhall. Moderate earthquakes in this series were reported felt with intensity V in Pacoima and IV in San Fernando, Van Nuys and II-III in Mission Hills, Granada Hills, Newhall, Panorama, Northridge, Sun Valley. An M 4.1 off the coast of northern California occurred minutes before the Los Angeles activity. It was possibly felt on the coast of Northern California with light intensity. This is the strongest earthquake in the San Fernando Valley, California area since an M 4.2-4.3 on January 4, 2015. At the time this summary noted in this regard:

 

"The last earthquake of similar or larger magnitude within 50 km of this epicenter in the Los Angeles area occurred as an M 4.4 on March 17, 2014 and as an M 4.3 on September 1, 2011. A foreshock to the south occurred on December 30, 2014 and was followed several hours later by a foreshock of M 3.1 at today's epicenter. A similar sequence preceded the 1994 Northridge earthquake." (January 4, 2015)

 

The effects of Hurricane Hanna which hit southern Texas over the past several days cannot be discounted in today's earthquake series. This summary had previously noted in this regard:

 

"Hurricane Hanna dissipated south of Southern Texas with winds up to 25 kts.  Some regional seismicity and some effects on the western edge of the North America plate may accompany landfall of this storm." (July 29, 2020)

 

Similar conditions accompanied the M 4.3 of September 1, 2011 as noted in this summary at the time:

 

"As noted in this summary over the past week, a series of unusually large earthquakes has been occurring in California and has been migrating to the south since Hurricane Irene hit the continental shelf in late August. This sequence began with an M 3.6 and 3.7 in San Francisco, then an M 4.6 near Hollister and an M 3.7 in the San Simeon area. Our summary speculated that this was likely to include an unusually large earthquake in southern California." (September 2, 2011)

 

Triggering effects from the Alaska Peninsula earthquake of M 7.8 of July 22 should also not be discounted in this case. The epicenters in Los Angeles area near the 10th node (36 degrees) from the western edge of that aftershock zone and at exactly 36.0 degrees from the M 6.1 of July 28 in Alaska.

 

This summary had previously expected this area was close to a strong local event as part of the approximately 22-year repeat cycle. Today’s events may help to elucidate where the progress towards that event is at this time.

 

O: 30JUL2020 11:31:07  34.3N  118.5W Ml=2.1  EMSC   GREATER LOS ANGELES AREA, CALIF.

O: 30JUL2020 11:34:26  34.3N  118.4W Ml=2.1  EMSC   GREATER LOS ANGELES AREA, CALIF.

O: 30JUL2020 11:38:38  34.3N  118.4W ML=2.9  EMSC   GREATER LOS ANGELES AREA, CALIF.

O: 30JUL2020 11:39:19  34.3N  118.5W Ml=2.2  EMSC   GREATER LOS ANGELES AREA, CALIF.

O: 30JUL2020 12:02:25  34.3N  118.4W Ml=2.1  EMSC   GREATER LOS ANGELES AREA, CALIF.

O: 30JUL2020 13:48:18  34.3N  118.4W ML=3.8  EMSC   GREATER LOS ANGELES AREA, CALIF.

O: 30JUL2020 13:59:17  34.3N  118.4W ML=2.3  EMSC   GREATER LOS ANGELES AREA, CALIF.

O: 30JUL2020 14:24:50  34.3N  118.4W ML=2.3  EMSC   GREATER LOS ANGELES AREA, CALIF.

O: 30JUL2020 21:11:02  34.3N  118.5W Ml=2.0  EMSC   GREATER LOS ANGELES AREA, CALIF.

O: 30JUL2020 22:04:57  34.3N  118.4W Ml=2.3  EMSC   GREATER LOS ANGELES AREA, CALIF.

O: 30JUL2020 11:29:29  34.3N  118.4W Mw=4.2  EMSC   GREATER LOS ANGELES AREA, CALI

P: 27JUL2020 125826    34.4N  118.6W 2.5-4.5 AAAAA  So. California             

 

The M 4.1 off the coast of northern California that occurred about 40 minutes before the M 4.2 in San Fernando had been expected within about 15 km of that epicenter in forecast 125869.

 

O: 30JUL2020 10:50:23  40.5N  127.1W mb=4.1  EMSC   OFF COAST OF NORTHERN CALIFORN

P: 29JUL2020 125869    40.4N  127.2W 2.5-4.5 AAAAA  Off Coast of No. Calif     

 

The largest earthquake in the U.S. or Canada today was an M 4.9-5.0 in the Alaska Peninsula aftershock zone. NEIC reported it was felt with intensity II-III in Alaska at Chignik and Sand Point. This follows several days of enhanced seismicity in the Alaska Peninsula aftershock zone. This activity had been expected at this time in forecast 125887.

 

O: 30JUL2020 11:46:14  54.6N  161.1W ml=3.3  EMSC   ALASKA PENINSULA

O: 30JUL2020 13:11:22  54.6N  161.0W ml=3.6  EMSC   ALASKA PENINSULA

O: 30JUL2020 16:08:19  55.0N  158.4W Mw=4.9  EMSC   ALASKA PENINSULA             

P: 28JUL2020 125887    54.7N  157.9W 4.5-6.0 AAAAA  Alaska Peninsula           

 

The strongest earthquakes in the world today were an M 5.6 in Mindanao, Philippines. and an M 5.7 in the Tonga Islands. NEIC reported maximum intensity V for the Mindanao quake in Rosariao, Caraga, Philippines; IV in Bag-asa, Southern Mindanao and II-III in Butuan, Caraga and Davao and Mandawa, Central Visayas. This event near the fifth node (72 degrees) from the Alaska Peninsula continues quakes near this magnitude over the past several days including an M 5.8 on July 27. Forecast 125712 had expected today's activity was likely around July 30.

 

O: 31JUL2020 06:06:44   8.5N  126.6E Mw=5.6  EMSC   MINDANAO, PHILIPPINES        

P: 30JUL2020 125712     7.0N  127.0E 4.0-5.9 ABAAA  Halmahera                   

 

The last event in Tonga of larger magnitude than M 5.7 was an M 6.2 north of today's epicenter on July 18, 2020. The last such event within about 200 km of today's event was an M 5.8 on February 28, 2020. The last of M>=6 was aa November 11, 2019 with M 6.1. Forecast 125955 had expected today's activity at the end of July. NEIC reported this earthquake of M 5.7 in Tonga  was felt with intensity II-III in the area(s) of Tonga at Neiafu, Vava'u.

 

O: 30JUL2020 19:16:49  18.9S  173.5W Mw=5.7  EMSC   TONGA                        

P: 29JUL2020 125955    20.0S  175.0W 4.0-5.7 ABBAA  Tonga Islands              

 

An unusual M 4.7 quake hit the Falkland Islands off the east coast of southern Argentina today. The only other such earthquake in the area in the past year was an M 4.6 on July 8, 2020. This is an unusual epicenter. The last earthquake of M>=4.7 within about 300 km of this was an M 4.8 on December 8, 2018 but the last of larger magnitude occurred on November 25, 2013 with M 7.0 and several aftershocks of M 5.4-5.5. Hours before the San Fernando, California earthquake (M 6.9) of February 9, 1971 an M 7.1 occurred southwest of today's epicenter. The distance between the San Fernando quakes today and the M 4.7 in the Falkland Islands is 103 degrees.

 

O: 30JUL2020 07:09:40  54.4S   55.8W mb=4.7  EMSC   FALKLAND ISLANDS REGION      

 

An M 3.7 was also widely felt in northern New Mexico today. NEIC reported it was felt with intensity V in New Mexico at Coyote; IV in Lindrith and Ouba; and II-III in Gallina, Counselor, La Jara, Jemez Springs, El Rito, Abiqulu and Tierra Amarilla. This epicenter is at the ninth node (40.0 degrees) from the epicenter of the  M 7.8 in the Alaska Peninsula and was probably promoted by energy from that  source. Other areas at the ninth node include areas of Baja California.  Only two other such earthquakes within about 100 km of today's epicenter in Northern New Mexico have occurred in the past 30 years - an M 3.7 on June 4, 2008 and an M 4.3 on August 1, 2004.

 

O: 30JUL2020 15:04:11  36.2N  106.8W mb=3.7  EMSC   NEW MEXICO                   

P: 26JUL2020 125802    37.0N  105.2W 2.0-3.9 BABAA  Colorado area              

 

M 5.8 FELT IN SOUTHERN JAPAN

 

EARTHQUAKE SUMMARY FOR JULY 29, 2020

 

The strongest earthquake in the world today was an M 5.8 in the Izu Islands south of Honshu, Japan. NEIC reported it was felt with intensity I-II in Japan at Chiba, Tokyo, Shizuoka and Saitama. This is the strongest earthquake in the Izu Islands, Japan since an M 5.9 near this epicenter occurred on December 10, 2019. Forecast 125816 had expected today's activity was likely around July 28 within about 50 km of this epicenter. This epicenter is located near the seventh node (51 degrees) from the Alaska Peninsula mainshock and was probably promoted by energy from that source.

 

O: 30JUL2020 06:55:59  30.7N  141.6E mb=4.7  EMSC   IZU ISLANDS, JAPAN REGION    

O: 30JUL2020 00:35:56  30.7N  141.8E Mw=5.8  EMSC   IZU ISLANDS, JAPAN REGION    

P: 28JUL2020 125816    30.0N  142.0E 4.0-5.4 AAAAA  Off East Coast Honshu      

 

The largest earthquake in the U.S. or Canada today was an M 5.6 aftershock in the Alaska Peninsula area. NEIC reported it was felt with maximum intensity IV in Alaska at Sand Point and II-III in Cold Bay, King Cove and Chignik.

This follows an M 6.1 in the area yesterday. At that time this summary noted:

 

"The strongest earthquake in the world today was an M 6.1 in the westernmost portion of the Alaska Peninsula aftershock zone of the M 7.8 of July 22. NEIC reported today's event was felt with intensity VI in Sand Point and IV in King Cove, Alaska and III in Cold Bay and Chignik. This is the strongest aftershock to date of the July 22, 2020 event. It continues revitalization of regional aftershock activity noted in this summary in the previous issues.

 

 

Forecast 125905 had expected today's activity was likely around July 29." (July 28, 2020)

 

O: 29JUL2020 08:47:39  54.9N  160.3W ml=3.9  EMSC   ALASKA PENINSULA

O: 29JUL2020 10:06:38  54.9N  160.3W ML=3.2  EMSC   ALASKA PENINSULA

O: 29JUL2020 13:55:13  54.9N  160.4W ml=3.4  EMSC   ALASKA PENINSULA

O: 29JUL2020 09:12:17  55.1N  160.4W Mw=5.6  EMSC   ALASKA PENINSULA

O: 29JUL2020 16:14:09  54.6N  163.5W mb=3.4  EMSC   UNIMAK ISLAND REGION, ALASKA 

O: 29JUL2020 13:09:11  54.8N  161.1W Mw=4.8  EMSC   ALASKA PENINSULA             

P: 29JUL2020 125905    54.6N  161.7W 3.5-4.9 AAAAA  Unimak Islands, Aleutians  

 

A pair of moderate earthquakes today occurred in the South Sandwich Islands and to the west in the Scotia Sea of the South Atlantic. Neither of these events were reported felt in this remote area. An M 6.4 on July 26 in the South Sandwich Islands was probably not associated with today's event as it occurred nearly 150 km northeast of today's epicenter. Forecast 125978 had expected today's activity within this area around July 29.

 

O: 29JUL2020 10:00:53  59.7S   26.3W mb=5.0  EMSC   SOUTH SANDWICH ISLANDS REGION

P: 29JUL2020 125978    58.0S   26.0W 4.0-6.0 ABAAA  So. Sandwich Islands       

 

Two earthquakes in the Scotia Sea have exceeded N 4.9 in the past year - an M 5.6 on November 28, 2019 and an M 5.2 on November 10, 2019. Today's event of M 4.9 is located near the area of 144 degrees from the M 7.8 in the Alaska Peninsula of July 22 and had been expected a this time in the far-field forecast of July 23 as:

 

"Far field triggering is likely with the earthquake in Alaska. The antipode is located south of South Africa in the Indian Ocean east of Bouvet Island and is a possible site for triggered activity. Areas at 144 degrees from Alaska include Mozambique, the South Atlantic and Georgia and the western South Sandwich Islands; those near 103 degrees include northern Chile and southern Peru; South Island, New Zealand; Sumatra and southwestern Indonesia. Recent unusual quakes at the fourth node (90 degrees) may continue in northern Peru, Tunisia, Andaman Islands, Spain and Peninsular India, the southern Kermadec Island among others. California lies near 40-51 degrees (nodes 8, 9 and 10) and central Mexico at the sixth node (60 degrees). Since the Alaska Peninsula event is unusual it is likely it will be followed by strong far-field triggering with a strong local aftershock sequence." (July 22, 2020)

 

O: 29JUL2020 17:21:16  60.6S   34.2W mb=4.9  EMSC   SCOTIA SEA                   

P: 30JUL2020 125979    61.0S   34.0W 4.0-5.6 AAAAA  Southern  Ocean            

 

A light to moderate earthquake of M 3.9 occurred today in Central California.

NEIC reported this earthquake of M 3.9 in Central California  was felt with intensity II-III in the area(s) of Central California at San Ardo, King City, Coalinga, Paicines, Bradley, San Miguel, Lockwood, Greenfield, Paso Robles and San Simeon. This epicenter is at the 11th node (32.7 degrees) from the mainshock in the Alaska Peninsula and was probably promoted by strong energy from that source. The only other event within about 100 km of this epicenter during 2020 with M>=3.9 was an M 4.0  on March 3, 2020.

 

O: 30JUL2020 03:23:01  36.2N  120.7W Mw=3.9  EMSC   CENTRAL CALIFORNIA           

O: 30JUL2020 05:43:07  36.2N  120.8W Md=2.3  EMSC   CENTRAL CALIFORNIA

P: 28JUL2020 125795    36.2N  120.8W 2.5-4.7 AAAAA  Central California         

 

M6.1 AFTERSHOCK IN ALASKA PENINSULA/UNIMAK AREA. ALASKA

 

EARTHQUAKE SUMMARY FOR JULY 28, 2020

 

The strongest earthquake in the world today was an M 6.1 in the westernmost portion of the Alaska Peninsula aftershock zone of the M 7.8 of July 22. NEIC reported today's event was felt with intensity VI in Sand Point and IV in King Cove, Alaska and III in Cold Bay and Chignik. This is the strongest aftershock to date of the July 22, 2020 event. It continues revitalization of regional aftershock activity noted in this summary in the previous issue as:

 

 

"The strongest earthquake in the U.S. or Canada today was an M 5.5 in the Alaska Peninsula aftershock zone. NEIC reported it was felt with intensity IV in Alaska at Sand Point and III in Cold Bay and King Cove. This is the strongest aftershock in the Alaska Peninsula since a similar M 5.5 hit the area hours after the M 7.8 mainshock on July 22. No damage was reported with today's event. Forecast 125905 had expected today's event was likely around July 25." (July 27, 2020)

 

Forecast 125905 had expected today's activity was likely around July 29. Far-field seismicity continued today in regions at nodal distances from the Alaska

Peninsula as noted in previous issues of this summary:

 

 

Areas at 36 degrees from Alaska in California include the greater Los Angeles area in the south and areas near Ridgecrest, California and Mina, Nevada. Thus far California, while close to the Alaska epicenter, has seen only a few clear-cut epicenters related to that great earthquake. Most notably these included a major swarm in the Mammoth Lakes, California area of July 22. Further enhancement of seismicity in these areas is possible in the next several days. When the swarm in Mammoth Lakes occurred on July 22 this summary noted:

 

"The swarm in the Mammoth Lakes area of the California-Nevada border was likely

promoted by energy from the Alaska Peninsula. The first of these today was an M 1.5 about 2 hours after the Alaska quake. This grew in magnitude throughout much of the remainder of the day. In previous issues of this summary, the California-Nevada area, like the area of the Alaska Peninsula, had been noted to have been at 90 degrees from the Kermadec Islands, indicative of upcoming seismic enhancement. 

 

Following is a listing of events in the Mammoth Lakes swarm of M>=2 today.

These events occurred at 32 degrees (node 11) from the Alaska Peninsula mainshock and were likely triggered by energy from that source. More such regional activity is likely in the next several days." (July 23-25, 2020)

 

Other active areas in the U.S. at nodal distances include southern Idaho at node 12 (30 degrees) which is still active following the M 6.5 there on March 31, 2020.

 

O: 28JUL2020 08:38:26  54.6N  161.0W ML=3.3  EMSC   ALASKA PENINSULA

O: 29JUL2020 01:03:23  54.7N  161.1W Mw=4.0  EMSC   ALASKA PENINSULA

O: 28JUL2020 08:27:25  54.8N  160.3W ML=3.4  EMSC   ALASKA PENINSULA

O: 28JUL2020 17:03:55  54.8N  160.2W Mw=3.7  EMSC   ALASKA PENINSULA

O: 28JUL2020 09:14:37  54.9N  160.3W mb=4.3  EMSC   ALASKA PENINSULA

O: 28JUL2020 12:54:34  54.9N  160.3W mb=3.9  EMSC   ALASKA PENINSULA

O: 28JUL2020 12:42:51  55.0N  160.4W Mw=5.0  EMSC   ALASKA PENINSULA

O: 28JUL2020 08:03:45  54.9N  161.2W Mw=6.1  EMSC   ALASKA PENINSULA             

P: 29JUL2020 125905    54.6N  161.7W 3.5-4.9 AAAAA  Unimak Islands, Aleutians  

 

After a day of quiet, moderate seismicity returned to southern Peru today. The strongest earthquake in the recent series in the area - an M 4.9 was felt with intensity IV in Arequipa, Peru to the north of the previous epicenters. An M 4.2 in the site to the south was also recorded. NEIC reported the earthquake of M 4.2 in Southern Peru  was felt with intensity II-III in the area(s) of Southern Peru at Tarata, Tacna. Forecasts 125936 had expected this activity in late July. The earthquake of M 4.9 was the strongest is South America today. This area is located at 103 degrees from the Alaska Peninsula epicenter and is expected to show strong triggering from energy from that source.

 

O: 28JUL2020 16:40:06  16.8S   72.4W Mw=4.9  EMSC   NEAR COAST OF SOUTHERN PERU  

P: 26JUL2020 125936    17.0S   72.0W 4.0-5.8 AAAAA  So. Peru/Bolivia           

 

O: 28JUL2020 23:38:52  17.4S   69.8W ML=3.1  EMSC   SOUTHERN PERU                

O: 29JUL2020 03:53:00  17.6S   69.8W mb=4.2  EMSC   SOUTHERN PERU                

P: 26JUL2020 125936    17.0S   72.0W 4.0-5.8 BABAA  So. Peru/Bolivia           

P: 29JUL2020 125936    16.0S   70.0W 4.0-5.7 ABAAA  So. Peru/Bolivia           

 

 

 

 

 

ALASKA PENINSULA HEATS UP (AGAIN)

 

EARTHQUAKE SUMMARY FOR JULY 27, 2020

 

The largest earthquake in the world today was an M 5.8 in the Northern Mindanao region of the Philippines. NEIC reported it was felt with damage at Buena Vista and IV in San Isidro, Surigao del Sur, Caraga. Intensity IV-V was reported from Slavacion, Parang, Bayugan, Butuan, Nabuturan, Dumian and Barra, Mindanao. Minor damage was reported in the local epicentral area. This is the strongest earthquake in Mindanao, Philippines within about 200 km of this epicenter in more than a year - since a similar M 5.8 on July 12, 2019. The last of significantly larger magnitude in the area was an M 6.2 on September 8, 2018. Forecasts 125752 and 125712 had expected today's event was likely in this area between July 27 and 30. This epicenter is at the sixth node (60 degrees) from the epicenter of M 7.8 in the Alaska Peninsula of July 22 and was probably promoted by energy from that source.

 

O: 27JUL2020 17:32:45   9.0N  126.3E Mw=5.8  EMSC   MINDANAO, PHILIPPINES        

P: 27JUL2020 125752    11.0N  125.0E 3.5-4.9 ABAAA  Luzon, Philippines         

P: 30JUL2020 125712     7.0N  127.0E 4.0-5.9 BBAAA  Halmahera                  

 

The strongest earthquake in the U.S. or Canada today was an M 5.5 in the Alaska Peninsula aftershock zone. NEIC reported it was felt with intensity IV in Alaska at Sand Point and III in Cold Bay and King Cove. This is the strongest aftershock in the Alaska Peninsula since a similar M 5.5 hit the area hours after the M 7.8 mainshock on July 22. No damage was reported with today's event. Forecast 125905 had expected today's event was likely around July 25.

 

O: 27JUL2020 21:20:11  54.9N  160.3W mb=3.7  EMSC   ALASKA PENINSULA

O: 27JUL2020 21:44:13  55.0N  159.4W mb=3.5  EMSC   ALASKA PENINSULA

O: 27JUL2020 19:34:39  55.1N  160.5W Mw=5.5  EMSC   ALASKA PENINSULA

O: 27JUL2020 12:31:14  54.7N  161.0W ML=3.6  EMSC   ALASKA PENINSULA             

P: 25JUL2020 125905    54.5N  161.8W 3.5-4.9 AAAAA  Unimak Islands, Aleutians  

 

A moderate M 4.6-4.7 occurred today near the Loi'hi Seamount south of Hawaii today. NEIC reported it was felt with intensity II-III in Hawaii at Naalehu, Pahala, Hawaii National Park, Captain Cook,  Volcano, Pahoa, Holualoa, Mountain View, Kealakekua and Hilo. This was probably triggered by stresses from Hurricane Douglas which made landfall in Honolulu, Hawaii at about the same time as the earthquake. This summary had expected this was likely in previous issues as:

 

"Hurricane Douglas made landfall new Honolulu, Hawaii today with winds up to 90 kts. Hawaii is currently moderately active and could see increased seismicity with this storm." (July 26-28, 2020)

 

Hawaii has experienced two earthquake of M>=4.6 since August, 2019 - an M 4.9 on November 11, 2019 and an M 4.7 on July 3, 2020. NEIC reported the earthquake of M 3.2 in Hawaii  was felt with intensity II-III in the area(s) of Hawaii at Mililani. Forecast 125750 had expected today's event within about 25 km of the epicenter was likely around July 27.

 

O: 28JUL2020 05:24:52  19.0N  155.5W ML=3.2  EMSC   ISLAND OF HAWAII, HAWAII     

O: 27JUL2020 16:05:55  19.0N  155.5W mb=4.6  EMSC   HAWAII REGION, HAWAII        

P: 25JUL2020 125750    19.2N  155.2W 3.0-4.4 AAAAA  Hawaii                     

 

 

PERU AND MOZAMBIQUE SEE ENHANCED SEISMICITY AFTER ALASKA PENINSULA QUAKE

 

EARTHQUAKE SUMMARY FOR JULY 26, 2020

 

Two areas of the world continued to see unusual enhanced seismicity today. These

area in southern Peru and in Mozambique lie at 103 and 144 degrees from the epicenter of the M 7.8 in the Alaska Peninsula of July 22 respectively, distances where strong seismic energy in concentrated following major events due to internal energy reflection and refraction off internal earth boundaries. Mozambique and southern Peru seismicity today rose and fell in sync and was probably enhanced by these distance relations with Alaska. As noted in previous issues of this summary areas of southwestern Indonesia and Southern New Zealand may also be subject to this distance-related seismicity as:

 

"Far field triggering is likely with the earthquake in Alaska.  ..  areas at 144 degrees from Alaska include Mozambique, the South Atlantic and Georgia and the western South Sandwich Islands; those near 103 degrees include northern Chile and southern Peru; South Island, New Zealand" (July 22, 2020)

 

The strongest activity in the world today occurred in Southern Peru where a series of earthquakes of M 4.4-4.7 occurred. These were being felt with intensity IV in Tarata, Tacna, Peru and are enhanced over previous regional activity over the past two days. In the previous issue of this summary this area had been noted as:

 

"What is going on in southern Peru? A series of moderate earthquakes in southern Peru followed the M 6.3 in the South Sandwich Islands. None of these has exceeded M 4.6 but the series is strong and energetic. In the data the series appears to be aftershocks without a mainshock. This is typical of an ongoing volcanic episode but with larger than normal shocks. The volcano Sabanaya to the north of this has been in the process of ash and steam eruptions during late July and may be associated with this swarm about 100 km to the south. The one thing about this that is certain is that it is at 103 degrees (also 7th node) from the great M 7.8 in the Alaska Peninsula four days ago. This is the only seismic area of South America located at this distance where triggered seismicity often occurs following major earthquakes. It is also located at the seventh node (52 degrees) from the M 6.3 in the South Sandwich Islands today. Constructive interference from energy from the South Sandwich Islands and Alaska may have set this swarm in motion. Today's activity is being felt with intensity IV in Tarata, Peru and II in Tacna. Forecast 125936 had expected this activity in late July within about 100 km  of these epicenters. This is the strongest swarm in the area since June 2016. The last strong earthquake in the area was an 7.5 on July 7, 2001." (July 26, 2020)

 

O: 26JUL2020 11:42:21  17.2S   69.8W ML=3.2  EMSC   SOUTHERN PERU

O: 27JUL2020 02:51:28  17.2S   69.9W ML=3.1  EMSC   SOUTHERN PERU

O: 26JUL2020 10:25:18  17.3S   69.9W ML=3.1  EMSC   SOUTHERN PERU

O: 26JUL2020 10:48:00  17.3S   69.9W ML=3.1  EMSC   SOUTHERN PERU

O: 26JUL2020 10:54:46  17.3S   69.9W ML=3.0  EMSC   SOUTHERN PERU

O: 26JUL2020 10:57:22  17.3S   69.9W ML=3.5  EMSC   SOUTHERN PERU

O: 26JUL2020 11:40:34  17.3S   69.9W ML=3.1  EMSC   SOUTHERN PERU

O: 26JUL2020 12:01:27  17.3S   69.9W ML=3.6  EMSC   SOUTHERN PERU

O: 26JUL2020 12:44:57  17.3S   69.8W ML=3.0  EMSC   SOUTHERN PERU

O: 26JUL2020 12:44:57  17.3S   69.8W ML=3.0  EMSC   SOUTHERN PERU

O: 26JUL2020 13:17:54  17.3S   69.9W ML=3.0  EMSC   SOUTHERN PERU

O: 26JUL2020 13:29:33  17.3S   69.9W ML=3.1  EMSC   SOUTHERN PERU

O: 26JUL2020 14:19:25  17.3S   69.8W ML=3.4  EMSC   SOUTHERN PERU

O: 27JUL2020 01:16:19  17.3S   69.9W ML=3.5  EMSC   SOUTHERN PERU

O: 26JUL2020 10:04:00  17.5S   69.9W mb=4.6  EMSC   SOUTHERN PERU

O: 26JUL2020 11:06:24  17.5S   69.9W mb=4.6  EMSC   SOUTHERN PERU

O: 26JUL2020 11:28:48  17.5S   69.9W mb=4.6  EMSC   SOUTHERN PERU

O: 26JUL2020 13:14:24  17.5S   69.9W mb=4.5  EMSC   SOUTHERN PERU

O: 26JUL2020 10:07:13  17.6S   69.9W mb=4.6  EMSC   SOUTHERN PERU                

P: 26JUL2020 125936    17.0S   72.0W 4.0-5.8 AABAA  So. Peru/Bolivia           

P: 29JUL2020 125936    16.0S   70.0W 4.0-5.7 BBAAA  So. Peru/Bolivia           

 

Aftershocks of the M 4.8 in Mozambique yesterday also continued with an energetic aftershock sequence today. Earthquake in the area also included a minor swarm in northern South Africa and a moderate quake in the Congo. The activity in Mozambique had been noted in the previous issue of this summary as:

 

"An unusual earthquake of M 4.8 also occurred in the region of Mozambique today.

This is the strongest earthquake within about 250 km of this epicenter since an  M 5.4 on December 22, 2018 and prior to that an M 5.6 on September 22, 2016. Forecast 125951 had expected this activity within about 100 km of this epicenter was likely around July 25. The epicenter is at 144 degrees from the M 7.8 in the Alaska Peninsula of July 22 and was among the areas expected to see far-field at this time in previous issues of this summary:

 

"Far field triggering is likely with the earthquake in Alaska...  areas at 144 degrees from Alaska include Mozambique, the South Atlantic and Georgia and the western South Sandwich Islands" (July 22-24, 26, 2020)

 

 

O: 26JUL2020 07:52:53  22.1S   32.7E ML=2.5  EMSC   MOZAMBIQUE

O: 27JUL2020 01:32:17  22.1S   32.7E ML=2.7  EMSC   MOZAMBIQUE

O: 26JUL2020 20:32:03  22.2S   32.9E ML=3.5  EMSC   MOZAMBIQUE

O: 26JUL2020 21:37:43  22.4S   32.4E ML=2.8  EMSC   MOZAMBIQUE

O: 26JUL2020 08:05:26  22.5S   31.8E ML=2.6  EMSC   MOZAMBIQUE

O: 26JUL2020 19:24:08  22.5S   32.8E ML=3.4  EMSC   MOZAMBIQUE

O: 26JUL2020 19:31:12  21.8S   33.2E ML=3.4  EMSC   MOZAMBIQUE                   

P: 25JUL2020 125951    21.0S   33.0E 4.0-5.6 AAAAA  So. Indian Ocean           

 

The strongest earthquake in the world today was an M 5.3-6.0 off the east coast of Taiwan. NEIC reported it was felt in Taiwan with intensity II-III at Taipei, Taoyuan, Taichung and Changhua. CWB reported this earthquake was felt with intensity IV in Hualien; III in Yilan, Nantou, Yunlin and II in Taichung, Changhua, Taipei, Chiayi, Miaoli, Taoyuan, Tainan, Hsinchu and Pingtung Counties, Taiwan. No damage was reported with this offshore earthquake. The last earthquake in Taiwan with M>=6.1 was an M 6.1 on April 18, 2019 an prior to that an M 6.4 on February 4, 2018. Forecast 125784 had expected today's event was likely within about 100 km around July 26. Like Oaxaca, Mexico this epicenter is near the sixth node (60 degrees) from Alaska and may have been promoted by energy from that epicenter. Forecasts 125785 and 125784 had expected today's activity around July 24-26.

 

O: 26JUL2020 12:52:29  24.3N  122.5E Mw=5.3  EMSC   TAIWAN REGION                

O: 26JUL2020 12:52:29  24.3N  122.4E ML=6.1  TAI    Hualien, Taiwan              

P: 24JUL2020 125785    24.0N  122.0E 4.0-5.5 AAAAA  Taiwan                     

P: 26JUL2020 125784    24.0N  121.0E 4.0-5.5 AAAAA  Taiwan                     

 

The strongest earthquake in the U.S. or Canada today was an M 5.0 and 4.9 aftershock in the Alaska Peninsula. NEIC reported it was felt with intensity III in Sand Point, Alaska. This occurred after two days of quiet in the aftershock zone. Forecast 125905 had expected this aftershock activity at the end of July.

 

O: 26JUL2020 21:35:54  54.9N  160.3W Mw=4.9  EMSC   ALASKA PENINSULA

O: 27JUL2020 03:19:30  54.9N  160.3W mb=3.8  EMSC   ALASKA PENINSULA

O: 26JUL2020 10:00:28  55.1N  158.8W mb=4.7  EMSC   ALASKA PENINSULA

O: 26JUL2020 08:29:21  54.8N  160.3W mb=4.4  EMSC   ALASKA PENINSULA             

P: 29JUL2020 125905    54.6N  161.7W 3.5-4.9 BAAAA  Unimak Islands, Aleutians  

 

The strongest far-field seismicity from the Alaska Peninsula today was occurring near the fifth node (72 degrees). This was expected in previous issues of this summary and has included events in the past several days in Laos, Mindanao, Samoa, and Xizang among others. An unusual earthquake of M 4.8 was felt today along the Laos-Vietnam border. NEIC reported maximum intensity in Trung Du and Bang Song Hong, Vietnam of IV with intensity III felt within about 200 km of the epicenter.

 

While Hawaii remained relatively quiet today, Hurricane Douglas made a direct hit in the area of Honolulu doing damage in that area. Pacific Hurricanes seldom make a direct hit on the islands of Hawaii, usually turning north or south on approach, so this is an unusual storm. This summary still expects enhanced seismicity in the area with Hurricane Douglas, especially since Hawaii also lies at the 10th node from the Alaska Peninsula (36 degrees), a node which can see enhanced seismicity after major earthquakes.  In previous  issues this summary had noted the seismic potential of Hurricane Douglas as:

 

"Hurricane Douglas continued in the area east of Hawaii today with winds up to 100 kts. It is expected to track towards Hawaii reaching that Island around July 26-27 as a hurricane making landfall near Honolulu. Hawaii is currently moderately active and could see increased seismicity with this storm." (July 23-26, 2020)

 

Forecast 125750 had expected seismic enhancement in Hawaii at this time.

 

O: 26JUL2020 11:20:39  19.2N  155.5W ML=3.2  EMSC   ISLAND OF HAWAII, HAWAII     

O: 26JUL2020 10:10:14  19.4N  155.2W ML=2.9  EMSC   ISLAND OF HAWAII, HAWAII     

P: 25JUL2020 125750    19.2N  155.2W 3.0-4.4 AAAAA  Hawaii                     

 

Other seismic areas at 36 degrees from the Alaska Peninsula include Hokkaido and the Kuril Islands and Southern California to Utah.

 

Seismicity also continued at the fourth node from Alaska today. A minor swarm in the Etna region of Sicily, Italy and an M 4.2 in Crete, Greece may be related to increases in volcanism at that volcano which is at the fourth node from Alaska.

 

"Far field triggering is likely with the earthquake in Alaska...  Recent unusual quakes at the fourth node (90 degrees) may continue in northern Peru, Tunisia, Andaman Islands, Spain and Peninsular India, the southern Kermadec Island among others." (July 22, 2020)

 

O: 26JUL2020 12:42:18  34.3N   25.8E mb=4.2  EMSC   CRETE, GREECE                

P: 30JUL2020 125787    35.0N   26.0E 3.0-4.7 BAAAA  Aegean Sea                 

 

STRONG EARTHQUAKE IN WESTERN SOUTH SANDWICH ISLANDS

 

EARTHQUAKE SUMMARY FOR JULY 25, 2020

 

The strongest earthquake in the world today was an M 6.4 in the South Sandwich Islands. It was not reported felt in this remote area north of Antarctica in the South Atlantic Ocean. This summary had noted the possibility of enhanced seismicity in this region at this time due to its near antipodal location to the M 7.8 in the Gulf of Alaska of July 22 in previous issues as:

 

"Far field triggering is likely with the earthquake in Alaska. The antipode is located south of South Africa ..  areas at 144 degrees from Alaska include Mozambique, the South Atlantic and Georgia and the western South Sandwich Islands; those near 103 degrees include northern Chile and southern Peru; South Island ... Recent unusual quakes at the fourth node (90 degrees) may continue in northern Peru, Tunisia, Andaman Islands, Spain and Peninsular India, the southern Kermadec Island among others. California lies near 40-51 degrees (nodes 8, 9 and 10) and central Mexico at the sixth node (60 degrees). Since the Alaska Peninsula event is unusual it is likely it will be followed by strong far-field triggering with a strong local aftershock sequence." (July 22, 2020)

 

This is the strongest earthquake recorded in the South Sandwich Islands within  about 300 km of this epicenter since an M 6.6 northwest of today's event on August 27, 2019.  Earthquakes about 250 km to the north also occurred as an M 6.5 on April 9, 2019 and an M 7.1 on December 11, 2018, the only other such regional events since July 15, 2013. The mainshock was followed by an M 5.2 aftershock. The mainshock occurred within about an hour of local solar midnight and may have also been promoted by strong tidal effects. Forecast 125979 had expected today's activity in this region was likely around July 26. The mainshock was located in the antipodal area of the Alaska Peninsula event

(60S vs 56N and 25W vs 158W) and was probably enhanced by that event.

 

O: 26JUL2020 03:59:17  60.7S   25.4W mb=5.2  EMSC   SOUTH SANDWICH ISLANDS REGION

O: 26JUL2020 00:53:58  60.7S   25.5W Mw=6.4  EMSC   SOUTH SANDWICH ISLANDS REGION

P: 26JUL2020 125979    61.0S   22.0W 4.0-5.6 AABAA  Southern  Ocean            

 

What is going on in southern Peru? A series of moderate earthquakes in southern Peru followed the M 6.3 in the South Sandwich Islands. None of these has exceeded M 4.6 but the series is strong and energetic. In the data the series appears to be aftershocks without a mainshock. This is typical of an ongoing volcanic episode but with larger than normal shocks. The volcano Sabanaya to the north of this has been in the process of ash and steam eruptions during late July and may be associated with this swarm about 100 km to the south. The one thing about this that is certain is that it is at 103 degrees (also 7th node) from the great M 7.8 in the Alaska Peninsula four days ago. This is the only seismic area of South America located at this distance where triggered seismicity often occurs following major earthquakes. It is also located at the seventh node (52 degrees) from the M 6.3 in the South Sandwich Islands today. Constructive interference from energy from the South Sandwich Islands and Alaska may have set this swarm in motion. Today's activity is being felt with intensity IV in Tarata, Peru and II in Tacna. Forecast 125936 had expected this activity in late July within about 100 km of these epicenters. This is the strongest swarm in the area since June 2016. The last strong earthquake in the area was an 7.5 on July 7, 2001.

 

O: 25JUL2020 12:43:42  17.3S   69.9W ML=3.1  EMSC   SOUTHERN PERU

O: 25JUL2020 16:54:00  17.3S   69.9W ML=3.6  EMSC   SOUTHERN PERU

O: 25JUL2020 17:12:55  17.3S   69.9W ML=3.1  EMSC   SOUTHERN PERU

O: 25JUL2020 18:54:09  17.3S   69.8W ML=3.5  EMSC   SOUTHERN PERU

O: 25JUL2020 19:11:35  17.3S   69.8W ML=3.6  EMSC   SOUTHERN PERU

O: 26JUL2020 02:26:09  17.3S   69.9W ML=2.9  EMSC   SOUTHERN PERU

O: 26JUL2020 03:11:26  17.3S   69.9W ML=2.5  EMSC   SOUTHERN PERU

O: 25JUL2020 16:31:15  17.4S   69.9W mb=4.3  EMSC   SOUTHERN PERU

O: 25JUL2020 17:31:18  17.5S   70.2W ML=3.5  EMSC   SOUTHERN PERU

O: 25JUL2020 17:31:18  17.5S   70.2W ML=3.5  EMSC   SOUTHERN PERU

O: 25JUL2020 17:02:16  17.2S   69.9W ML=3.2  EMSC   SOUTHERN PERU                

P: 26JUL2020 125936    17.0S   72.0W 4.0-5.8 AABAA  So. Peru/Bolivia           

P: 29JUL2020 125936    16.0S   70.0W 4.0-5.7 BAAAA  So. Peru/Bolivia           

 

 

The largest earthquake in the U.S. or Canada today was an M 4.4 in western Nevada. NEUC reported intensity II-III in Nevada at Luning, Gabbs, Hawthorne and Tonopah. This appears to be a new epicenter in the region, not part of an ongoing aftershock sequence. Forecast 125791 had expected today's activity was likely around July 25.

 

O: 26JUL2020 02:06:28  38.2N  117.7W mb=4.2  EMSC   NEVADA

P: 25JUL2020 125791    38.0N  118.7W 2.5-4.6 AAAAA  California/Nevada area     

 

The Alaska Peninsula area was relatively quiet today. No aftershocks of M>=4.0 were recorded in the region. The largest aftershock today was an M 3.9 in the Unimak Island area. Forecasts 125905 and 125887 had expected this activity around July 25-26.

 

O: 25JUL2020 22:38:55  54.7N  160.6W ML=3.3  EMSC   ALASKA PENINSULA

O: 25JUL2020 07:02:30  55.1N  158.5W ML=3.5  EMSC   ALASKA PENINSULA

O: 25JUL2020 09:19:29  55.1N  158.3W mb=3.8  EMSC   ALASKA PENINSULA

O: 25JUL2020 07:23:50  55.2N  159.6W ML=3.2  EMSC   ALASKA PENINSULA

O: 25JUL2020 12:39:08  54.3N  160.4W mb=3.9  EMSC   ALASKA PENINSULA             

P: 25JUL2020 125905    54.5N  161.8W 3.5-4.9 AAAAA  Unimak Islands, Aleutians  

P: 26JUL2020 125887    55.0N  159.9W 4.5-6.2 AAAAA  Alaska Peninsula           

 

An unusual earthquake of M 4.7-4.8 shook the region of the Strait of Gibraltar today. While this area southwest of Spain does see an occasional moderate sized

earthquake of M>=4.8 was an M 4.8 on July 11, 2018 and a series up to M 5.6 in mid-March, 2016. Forecast 125808 had expected today's event within about 50 km was likely around July 26. This epicenter is near the fourth node (90 degrees) from the M 7.8 in the Alaska Peninsula and may have been promoted by energy from that source. It is also nearly antipodal to the M 7.5 in the Kermadec Islands of June 18 and may have been promoted by energy focusing from that source.

 

O: 25JUL2020 12:13:00  35.4N    3.9W mb=4.8  ANSS   STRAIT OF GIBRALTAR          

O: 25JUL2020 12:12:59  35.4N    3.8W mb=4.7  EMSC   STRAIT OF GIBRALTAR          

P: 26JUL2020 125808    36.0N    4.0W 3.5-5.3 AAAAA  Morocco/Spain              

 

Another area which is at the fourth node (90 degrees) from the Alaska Peninsula is the Canary Islands south of western Spain in the Atlantic Ocean. This area can see volcanism and the current swarm suggests this may be beginning anew. Forecast 125773 had expected today's activity within about 25 km was likely around July 29.

 

O: 25JUL2020 18:56:33  28.5N   17.8W ML=2.1  EMSC   CANARY ISLANDS, SPAIN REGION

O: 25JUL2020 18:20:08  28.6N   17.7W ML=2.0  EMSC   CANARY ISLANDS, SPAIN REGION

O: 25JUL2020 18:22:20  28.6N   17.7W ML=2.0  EMSC   CANARY ISLANDS, SPAIN REGION

O: 25JUL2020 18:25:40  28.6N   17.8W ML=2.0  EMSC   CANARY ISLANDS, SPAIN REGION

O: 25JUL2020 18:37:20  28.6N   17.8W ML=2.5  EMSC   CANARY ISLANDS, SPAIN REGION

O: 25JUL2020 18:49:45  28.6N   17.8W ML=2.4  EMSC   CANARY ISLANDS, SPAIN REGION

O: 25JUL2020 19:00:25  28.6N   17.8W ML=2.1  EMSC   CANARY ISLANDS, SPAIN REGION

O: 26JUL2020 00:11:35  28.1N   16.2W ML=2.0  EMSC   CANARY ISLANDS, SPAIN REGION 

P: 29JUL2020 125773    28.0N   16.0W 3.0-4.5 BAAAA  Canary Islands              

 

An unusual earthquake of M 4.8 also occurred in the region of Mozambique today.

This is the strongest earthquake within about 250 km of this epicenter since an  M 5.4 on December 22, 2018 and prior to that an M 5.6 on September 22, 2016. Forecast 125951 had expected this activity within about 100 km of this epicenter was likely around July 25. The epicenter is at 144 degrees from the M 7.8 in the Alaska Peninsula of July 22 and was among the areas expected to see far-field at this time in previous issues of this summary:

 

"Far field triggering is likely with the earthquake in Alaska...  areas at 144 degrees from Alaska include Mozambique, the South Atlantic and Georgia and the western South Sandwich Islands" (July 22-24, 2020)

 

O: 26JUL2020 03:40:53  21.6S   33.4E mb=4.8  EMSC   MOZAMBIQUE                   

P: 25JUL2020 125951    21.0S   33.0E 4.0-5.6 AAAAA  So. Indian Ocean           

 

M 4.7-5.3 IN NORTHWEST TERRITORIES, CANADA LIKELY TRIGGERED BY ALASKA M 7.8

 

EARTHQUAKE SUMMARY FOR JULY 24, 2020

 

Seismicity around the world is not behaving. Generally after a major M 7.8 earthquake the classical aftershock series is energetic and long. But after the Alaska Peninsula quake of July 22, the aftershock sequence has almost returned to near background levels just three days after. This should tend to dampen far-field triggering and this appears to be the case. The one exception of regional seismicity - there have been two significant earthquakes in Canada - an M 5.1-5.4 in Vancouver and  an M 4.7-5.3 in Northwest Territories today since the Alaska earthquake. Both appear to have been promoted by energy from the Alaska earthquake. Far-field seismicity has not picked up appreciably and was not expected to, as seismicity at nodal distance is not high at background rates even without a trigger. Several volcanic areas, including Mammoth Lakes, California, the Komandorsky Island, Russia, Iceland and the Canary Islands have shown significant swarms and this may be the pattern in the next week.

 

The largest earthquake in the world today was an M 4.7-5.3 in the Northwest Territories of Canada. It was not reported felt in this remote area. This is the strongest earthquake within about 250 km of this epicenter in the Northwest Territories since an M 5.3 on September 26, 2011. The last of larger magnitude in this area, and the only other such event in the past 30 years was an M 5.6 on June 10, 1990. Forecasts 125653 and 125921 had expected moderate regional seismicity in the Yukon Territory about 250 km to the west of today's epicenter was likely between July 18 and 27. This event is at the seventh node (51 degrees) from the M 7.5 in Oaxaca, Mexico of June 23 - the Alaska Peninsula  quake was at the sixth node (60 degrees). This epicenter is also located at 104 degrees from the M 7.4 in the Kermadec Islands of June 18 and may have been promoted by concentrated energy from that source. Similar events at this distance from the Kermadec Islands in the past several days have been occurring in Xizang, China.

 

O: 25JUL2020 03:05:24  62.2N  124.5W mb=4.7  EMSC   NORTHWEST TERRITORIES, CANADA

O: 25JUL2020 03:05:25  62.2N  124.5W mb=4.7  ANSS   Northwest Territories Canada"

O: 25JUL2020 03:05:25  62.2N  124.8W MB=5.3  ECAN   Wrigley, NT   

P: 18JUL2020 125653    63.0N  130.0W 2.5-4.2 CACAA  Yukon Territory, Canada    

P: 27JUL2020 125921    64.0N  130.0W 2.5-4.3 ABCAA  Yukon Territory, Canada    

 

The largest aftershock in the Alaska Peninsula today was an M 5.0 but only two other events of M>=4 were recorded today in the area. This activity is close to Unimak Island and appears to be migrating to the west. Forecast 125886 had expected today's events were likely around July 23.

 

O: 24JUL2020 13:24:38  55.0N  160.8W Mw=5.0  EMSC   ALASKA PENINSULA

O: 24JUL2020 07:17:30  55.2N  159.3W Mw=4.5  EMSC   ALASKA PENINSULA

O: 24JUL2020 11:41:35  54.6N  160.7W ml=4.0  EMSC   ALASKA PENINSULA             

P: 23JUL2020 125886    55.0N  158.9W 3.5-6.2 AAAAA  Alaska Peninsula           

 

M 5.5 AFTERSHOCK IN OAXACA, MEXICO

 

EARTHQUAKE SUMMARY FOR JULY 23, 2020

 

The strongest earthquake in the world today was an M 5.5 off the coast of Oaxaca, Mexico. NEIC reported it was felt with intensity VI in Oaxaca at Huatulco with lesser shaking in Salina Cruz, Atzompa, Villhermosa, Tasbasc, Tlalnepantla, Mexico. This is an aftershock of the M 7.5 which hit this epicenter a month ago on June 23, 2020. Both of these were probably enabled by strong tidal stresses associated with the new moon as previously noted in this summary:

 

"The new moon will arrive on July 20, 2020 at 17:33 UT. Areas which are sub-solar (local solar noon) at this hour center at longitude 85 West and 95 East longitudes. These include areas of Central and western South America in the west and western Indonesia and eastern Asia in the east. Tidal triggering will be most prominent in these regions. A strong earthquake is likely within the period July 17-23, most likely in this area. Tidal triggering of seismicity is also possible in many other areas and is most likely near local solar noon and local solar midnight." (July 14-17, 2020)

 

This is the strongest aftershock in Oaxaca to date of the M 7.5 there on June 23, 2020. Forecast 125763 had expected a moderate aftershock in Oaxaca was likely around July 28 within about 25 km of today's epicenter. This activity is located near the sixth node (60 degrees) from the Alaska Peninsula and ths summary had expected this region to see far-field triggering at this time as:

 

 

" (The Alaskan) epicenter is located at the exact fourth node (90.0 degrees) from the M 7.4 in the Kermadec Islands, New Zealand of June 18, 2020 and at the sixth node (60 degrees) from the M 7.5 in Oaxaca, Mexico of June 23, 2020 and was probably promoted by energy from those sources." (July 22, 2020)

 

"Far field triggering is likely with the earthquake in Alaska  ... in  central Mexico at the sixth node (60 degrees)." (July 22, 2020)

 

Forecast 125763 had expected today's activity within about 25 km of this aftershock was likely at the end of July.

 

O: 23JUL2020 21:34:21  15.5N   95.0W ML=4.1  EMSC   OFFSHORE OAXACA, MEXICO      

O: 24JUL2020 03:19:51  15.7N   95.8W Mw=5.5  EMSC   OFFSHORE OAXACA, MEXICO      

P: 28JUL2020 125763    16.0N   96.0W 3.5-5.1 BAAAA  Oaxaca, Mexico              

 

The largest earthquakes in the U.S. or Canada today were of M 5.1 and 5.0 in the Sand Point, Alaska area. This is at the western edge of the aftershock zone of the M 7.8 in the Alaska Peninsula of July 22. NEIC reported today's event was felt with intensity II in King Cove, Alaska. Aftershocks of M>=4 are listed here. Those of M>=3 can be found in the regional "Alaska" section further in this summary. The aftershock zone appears to be moving to the west with an M 5.1 near Unimak Island today. Initial aftershocks of M>=4 today occurred near local solar midnight with M 4.2 and 4.9 and were probably promoted by tidal stresses which maximize at this hour. Forecast 125886 had expected further aftershocks activity in this region around July 23.

 

O: 23JUL2020 10:40:50  54.7N  159.8W mb=4.2  EMSC   SOUTH OF ALASKA

O: 24JUL2020 03:07:09  54.9N  160.7W Mw=5.0  EMSC   ALASKA PENINSULA

O: 23JUL2020 19:56:49  55.0N  160.9W mb=5.1  EMSC   ALASKA PENINSULA

O: 24JUL2020 05:53:54  55.0N  158.4W mb=4.3  EMSC   ALASKA PENINSULA

O: 23JUL2020 11:08:37  55.3N  159.6W Mw=4.9  EMSC   ALASKA PENINSULA             

P: 23JUL2020 125886    55.0N  158.9W 3.5-6.2 AAAAA  Alaska Peninsula           

 

An unusually large M 3.9 in Southeastern Alaska today extended activity to the west today following a series of light earthquakes in the Juneau, Alaska earlier. NEIC reported this earthquake of M 3.7-3.9 in Southeastern Alaska  was felt with intensity II-III in the area(s) of Southeastern Alaska at Yakutat.

Similar activity at M 3.9 hit the area on January 20 and 22 (both with M 3.9) but the last such event within about 200 km of this epicenter with M>3.9 was an M 4.2 on January 3, 2020. Today's earthquake occurred within about 30 minutes of local solar noon and was probably enhanced by strong tidal stresses which maximize near this hour. Forecasts 125640 and 125904 had expected today's activity in this area in later July (19-29).

 

O: 23JUL2020 21:59:41  59.6N  139.5W ML=3.9  EMSC   SOUTHEASTERN ALASKA          

P: 19JUL2020 125640    58.0N  139.0W 3.0-4.4 BBAAA  Southeast Alaska           

P: 29JUL2020 125904    59.0N  138.0W 3.0-4.4 CAAAA  Southeast Alaska           

 

A strong series of moderate earthquakes in the Komandorsky Islands of Russia today included an M 4.7 and an M 4.9. These events tended to occur near local solar midnight and noon and were probably enhanced by tidal stresses. That they occurred a day after the M 7.8 in the Alaska Peninsula about 17 degrees directly to the west strongly suggests they were promoted by movement associated with that major regional earthquake. A major earthquake M 7.3 hit the region on December 20, 2018 with moderate aftershocks through October, 2019. But in the past nine months only two event of M>=4.9 have occurred - both with M 5.4 on December 23, 2019 and April 4, 2020. Forecast 125896 had expected today's activity in the Komandorsky Islands as far-field activity to the southeast of today's series around July 27.

 

O: 23JUL2020 14:31:26  56.1N  164.6E mb=4.0  EMSC   KOMANDORSKIYE OSTROVA REGION

O: 23JUL2020 15:47:42  56.2N  164.3E mb=4.9  EMSC   KOMANDORSKIYE OSTROVA REGION

O: 23JUL2020 22:11:36  56.2N  164.2E mb=4.4  EMSC   KOMANDORSKIYE OSTROVA REGION

O: 23JUL2020 22:11:36  56.2N  164.2E mb=4.4  EMSC   KOMANDORSKIYE OSTROVA REGION

O: 23JUL2020 22:12:49  56.3N  164.4E mb=4.7  EMSC   KOMANDORSKIYE OSTROVA REGION 

P: 27JUL2020 125896    55.0N  165.0E 4.0-6.1 BBAAA  Komandorsky Isl            

 

A series of light to moderate quakes also occurred today in the northern Gulf of California with maximum event of M 4.1. They were not reported felt and occurred around local solar midnight suggesting tidal triggering. This series is at the eighth node (45 degrees) from the major Alaska Peninsula quake and may have been promoted by energy from that source. The only events within about 200 km of these epicenters with M>=4.1 in the past year were of M 4.3 on February 13 and April 7, 2020. Stresses from earthquakes in this area can migrate to the north triggering larger earthquakes in the region of Southern  California. Forecast 125820 had expected today's activity to the nor around July 24.

 

O: 23JUL2020 09:01:06  27.9N  112.1W ML=3.4  EMSC   GULF OF CALIFORNIA

O: 23JUL2020 08:57:23  28.0N  112.1W ML=3.7  EMSC   GULF OF CALIFORNIA

O: 24JUL2020 05:19:07  28.0N  112.1W ML=4.1  EMSC   GULF OF CALIFORNIA

O: 23JUL2020 09:01:06  27.9N  112.1W ML=3.4  EMSC   GULF OF CALIFORNIA           

P: 24JUL2020 125820    30.2N  114.1W 2.0-4.0 ACBAA  SW U.S.A                   

 

FAR AND NEAR FIELD TRIGGERING FROM ALASKA PENINSULA M 7.8

 

EARTHQUAKE SUMMARY FOR JULY 22, 2020

 

Tidal triggering remained at high levels today, the third day of the new lunar month. These, combined with far- and near-field triggering from the M 7.8 in the Alaska Peninsula on July 22 made for an active day in seismicity. The largest earthquake of the day was an M 6.3 in western Xizang, China. But a series of events in the Mammoth Lakes area of the California-Nevada area was also probably triggered by far-field effects from Alaska. An earthquake of M 5.1-5.4 was also felt in the Vancouver Island area of western Canada today and was probably enhanced by energy from the Alaska quake.

 

The earthquake in Xizang, China was felt with damage in the epicentral area. NEIC also reported intensity II in Gangtok, Sikkim, India. This earthquake located near the fifth node from the M 7.8 in Alaska earlier in the day and was probably promoted by energy from that source. China has experienced extensive flooding in recent weeks and some of that probably helped enhance today's event, but the region became active with the solar eclipse of June 20 and has seen several large earthquakes since that tidal event including an M 6.3 to the northwest of today's epicenter on June 25, 2020. Previous issues of this summary had emphasized the possible seismic connection to this flooding as:

 

 

"The earthquake Xizang, China is near the point of maximum solar eclipse with the last new moon of June 21 and probably will see more of this type of event in coming days. Floods and a series of moderate earthquakes have hit many areas of China including the Three Gorges Dam area and could help promote further seismicity. Floods load the area and help lubricate faults and have been known to trigger significant earthquakes, including the Three Gorges Dam earthquake of May 12, 2008 (M 7.9). At the time this summary noted in this regard:

 

"A great earthquake of M 7.9 destroyed a large portion of eastern Sichuan China near the Gansu border today leaving more than 10,000 people dead. News reports from Xinhua, AP and Reuters place the epicenter about 100 km south of the capital of Sichuan province, Chengdu. Chengdu is a major city of 11 million." (May 12, 2008)

 

"The Sichuan earthquake was most likely triggered by motion of the faults in southeastern Asia initiated a week ago by the unusual landfall of the tropical cyclone Nargis which hit the Irrawady Basin killing more than 100,000 people on May 3-5. The faults in this region are strike-slip for the  most part allowing the plastic indentation of Asia by India. The slippage occurs along several long faults generally oriented North-South. It is on one of these that the earthquake today probably occurred. While this was likely the major external trigger for today's earthquake the event was also promoted by several recent strong earthquakes. As we noted in our summary two days ago a series of unusual earthquakes were occurring at distances from the M 6.7 in Alaska on May 2, 2008. The distance between the Andreanof epicenter and the Sichuan quake is exactly 60.0 degrees, a distance (360/6 degrees) where strong triggering is expected following large earthquakes. Another earthquake which lay at a distance of 60 degrees from  the Andreanof Islands was the earthquake of M 5.2 in southern Illinois which occurred earlier this month. It also lies near distances from Guam (40-41 degrees, n=9) and Honshu, Japan (32.5 degrees, n=11) such that some triggering may have occurred from those events.

... triggering may have been associated with the filling of the Three Gorges dam about 400 miles to the east but loading associated with new dams often triggers strong region seismicity." (May 13, 2008, July 20, 2020)

 

Today's Xizang quake is not an aftershock of the M 6.3 of June 25 which occurred 400-500 km to the northwest of today's epicenter on the Xinjiang-Xizang border. The only other such event of M>=6.3 within about 250 km of today's epicenter within the past 30 years was an M 6.4 on January 9, 2008 about 200 km southwest of today's epicenter. Forecasts 125587 and 125842 had expected today's activity was likely around July 18-24.

 

O: 23JUL2020 01:04:25  33.1N   86.8E mb=4.1  EMSC   WESTERN XIZANG

O: 22JUL2020 22:28:34  33.2N   86.9E mb=4.5  EMSC   WESTERN XIZANG

O: 23JUL2020 06:48:42  33.2N   86.9E mb=4.1  EMSC   WESTERN XIZANG

O: 23JUL2020 10:50:09  33.3N   87.0E mb=4.9  EMSC   WESTERN XIZANG

O: 22JUL2020 20:07:19  33.1N   86.9E Mw=6.3  EMSC   WESTERN XIZANG               

P: 18JUL2020 125587    35.0N   90.0E 3.8-5.4 BBBAA  Xizang                     

P: 24JUL2020 125842    34.0N   89.0E 3.8-5.5 AABAA  Xizang                     

 

Strong aftershocks in the Alaska Peninsula today continued to be felt in the Perryville, Alaska region with moderate intensity. The strongest to date have been of M 6.1 and 5.8 and 5.7.

 

Following is a listing of events in the Alaska Peninsula aftershock sequence of M>=4 today. A listing of events of M>=3 can be found in the regional ALASKA section of this summary. Forecasts 125641 and 125886 had expected moderate to strong seismicity in this area around July 16-23.

 

O: 22JUL2020 11:02:11  54.7N  160.5W mb=5.1  EMSC   ALASKA PENINSULA

O: 22JUL2020 07:42:13  54.8N  160.2W mb=4.0  EMSC   ALASKA PENINSULA

O: 22JUL2020 12:33:36  54.8N  158.3W mb=4.4  EMSC   SOUTH OF ALASKA

O: 23JUL2020 10:40:53  54.8N  159.9W mb=4.2  EMSC   SOUTH OF ALASKA

O: 22JUL2020 10:18:25  55.0N  158.5W mb=4.6  EMSC   SOUTH OF ALASKA

O: 22JUL2020 13:33:39  55.0N  158.1W mb=4.7  EMSC   SOUTH OF ALASKA

O: 22JUL2020 07:17:30  55.1N  158.4W mb=4.2  EMSC   ALASKA PENINSULA

O: 22JUL2020 08:04:38  55.1N  159.3W mb=4.0  EMSC   ALASKA PENINSULA

O: 22JUL2020 15:31:07  55.1N  159.1W mb=4.4  EMSC   ALASKA PENINSULA

O: 23JUL2020 04:53:03  55.1N  158.3W mb=4.1  EMSC   ALASKA PENINSULA

O: 23JUL2020 05:42:24  55.1N  158.8W mb=4.0  EMSC   ALASKA PENINSULA

O: 22JUL2020 10:08:40  55.2N  158.8W mb=4.8  EMSC   ALASKA PENINSULA

O: 22JUL2020 08:13:30  55.3N  159.4W mb=6.2  EMSC   ALASKA PENINSULA

O: 22JUL2020 21:40:00  55.3N  159.4W Mw=5.5  EMSC   ALASKA PENINSULA

O: 22JUL2020 13:22:19  54.3N  160.3W ml=4.3  EMSC   ALASKA PENINSULA             

P: 16JUL2020 125641    54.3N  161.4W 3.5-5.0 CAAAA  Unimak Islands, Aleutians  

P: 23JUL2020 125886    55.0N  158.9W 3.5-6.2 AAAAA  Alaska Peninsula           

 

An M 4.9 in the western Andreanof Islands today was not reported felt in this region. The last event within about 150 km of this epicenter with M>=4.9  occurred as an M 5.3 on July 15. Forecast 125627 had expected today's event within about 100 km of this epicenter was likely around July 19.

 

O: 22JUL2020 23:06:37  51.3N  178.9W mb=4.9  EMSC   ANDREANOF ISLANDS, ALEUTIAN IS

P: 19JUL2020 125627    50.7N  179.5W 3.5-4.9 BAAAA  Andreanoff Isls, Aleutians 

 

The M 5.1-5.4 in Vancouver, Canada was reported by NEIC to have been felt with intensity II-III in British Columbia, Canada at Ucluelet, Parksville, Victoria, and in Washington State, US., at Lopez Island, Blaine, Ferndale, Bellingham, Lynden, and Freeland. About four minutes after the M 7.8 in Alaska an M 4.6 was recorded in the Vancouver Island area, probably triggered by S- and Surface waves from the Alaska Peninsula. This event was noted in this summary in the previous issue as:

 

 

"A moderate earthquake of M 4.6 was recorded in the Queen Charlotte Sound, Canada about four minutes after the M 7.8 in the Alaska Peninsula. S-waves and surface waves take about this time to travel the 17 degrees between these epicenter and were present in the Queen Charlotte Sound, Canada at the time of the M 4.6." (July 22, 2020)

 

The Vancouver event is the strongest in the region within about 200 km of this epicenter during the current year - an event of M 6.3 last hit on December 25, 2019, part of a regional activation that began on December 23, 2019. The area was also active on July 4 and 5, 2019 with an M 6.2 and 5.6 in the regional  activation which preceded the M 7.1 in Ridgecrest, California and other activity there on July 4-7, 2019. Forecasts 125628 and 125880 had expected today's activity was likely within about 150 km of the epicenter between July 19 and 26.

 

O: 22JUL2020 11:33:21  48.8N  129.4W MB=5.1  ECAN Port Alice, BC   

O: 22JUL2020 11:33:25  49.1N  129.0W Mw=5.4  EMSC   VANCOUVER ISLAND, CANADA REGIO

P: 19JUL2020 125628    50.6N  130.5W 3.0-5.0 BBAAA  British Colombia           

P: 26JUL2020 125880    49.3N  129.0W 2.8-5.1 BAAAA  Vancouver Island area      

 

The swarm in the Mammoth Lakes area of the California-Nevada border was likely  promoted by energy from the Alaska Peninsula. The first of these today was an M 1.5 about 2 hours after the Alaska quake. This grew in magnitude throughout much of the remainder of the day. In previous issues of this summary, the California-Nevada area, like the area of the Alaska Peninsula, had been noted to have been at 90 degrees from the Kermadec Islands, indicative of upcoming seismic enhancement. 

 

"This epicenter is located at the exact fourth node (90.0 degrees) from the M 7.4 in the Kermadec Islands, New Zealand of June 18, 2020 ...  It may be of interest to note that the major activity in the Ridgecrest and Lone Pine areas of the California-Nevada area was also at 90 degrees from the Kermadec epicenter as noted at the time in this summary." (July 22, 2020)

 

Following is a listing of events in the Mammoth Lakes swarm of M>=2 today.

These events occurred at 32 degrees (node 11) from the Alaska Peninsula mainshock and were likely triggered by energy from that source. More such regional activity is likely in the next several days.

 

This activity had been expected around July 25 in forecast 125792.

 

O: 22JUL2020 16:14:45  37.6N  118.8W Md=2.2  EMSC   LONG VALLEY AREA, CALIFORNIA

O: 22JUL2020 16:36:23  37.6N  118.8W Md=2.4  EMSC   LONG VALLEY AREA, CALIFORNIA

O: 22JUL2020 16:40:39  37.6N  118.8W Md=2.1  EMSC   LONG VALLEY AREA, CALIFORNIA

O: 22JUL2020 17:10:26  37.6N  118.8W Md=2.0  EMSC   LONG VALLEY AREA, CALIFORNIA

O: 22JUL2020 17:13:13  37.6N  118.8W Md=2.3  EMSC   LONG VALLEY AREA, CALIFORNIA

O: 22JUL2020 17:19:23  37.6N  118.8W Md=2.4  EMSC   LONG VALLEY AREA, CALIFORNIA

O: 22JUL2020 17:23:44  37.6N  118.8W Md=2.3  EMSC   LONG VALLEY AREA, CALIFORNIA

O: 22JUL2020 17:28:53  37.6N  118.8W Md=2.1  EMSC   LONG VALLEY AREA, CALIFORNIA

O: 22JUL2020 18:21:19  37.6N  118.8W MD=2.7  EMSC   LONG VALLEY AREA, CALIFORNIA

O: 23JUL2020 06:39:55  37.6N  118.8W Md=2.3  EMSC   CENTRAL CALIFORNIA

O: 22JUL2020 16:51:34  37.7N  118.8W Md=2.0  EMSC   LONG VALLEY AREA, CALIFORNIA

O: 22JUL2020 16:06:22  37.6N  118.8W Md=2.0  EMSC   LONG VALLEY AREA, CALIFORNIA 

P: 25JUL2020 125792    37.6N  118.7W 2.5-4.6 BAAAA  California/Nevada area     

 

Light earthquakes in western Texas near Odessa and in the southern Idaho aftershock zone also occurred today with M 3.5 and 3.6 respectively. This activity is located in Texas at the eighth node (45 degrees) and in Idaho at the 12th node (30 degrees) from the Alaska Peninsula mainshock and was probably promoted by energy from that source. Forecasts 125572 and 125602 had expected this activity in mid-July.

 

O: 22JUL2020 17:01:32  31.2N  103.3W ML=3.5  EMSC   WESTERN TEXAS                

P: 16JUL2020 125572    31.4N  104.8W 2.0-4.1 CAAAA  SW U.S.A                   

 

NEIC reported the earthquake of M 3.1-3.6 in Southern Idaho  was felt with intensity II-III in the area(s) of Southern Idaho at Stanley and Star.

 

O: 22JUL2020 21:21:48  44.3N  115.0W Ml=3.6  EMSC   SOUTHERN IDAHO               

P: 17JUL2020 125602    44.4N  115.1W 2.0-4.1 BAAAA  Montana/Idaho              

 

An M 3.9-4.1 in southern Puerto Rico also restarted that aftershock sequence which in the past several days has been at its lowest level since January, 2020. Today's event was reported by NEIC to have been felt with intensity II-III in Lares, Puerto Rico. The last earthquake with M>=4.1 in the southern Puerto Rico aftershocks zone was an M 4.1 and 5.3 on July 3, 2020. Forecast 125523 had expected today's event was likely around July 18. Like the activity in Xizang, China, this epicenter is located near the fifth node (72 degrees) from the Alaska  Peninsula and at 144 degrees from the New Guinea quake of M 7.3 of July 17, 2020 and may have been promoted from those sources. It occurred within about 15 minutes of local solar midnight and was also probably affected by tidal stresses which maximize at this hour.

 

O: 23JUL2020 04:44:16  17.9N   66.8W ML=4.1  EMSC   PUERTO RICO REGION           

P: 18JUL2020 125523    19.0N   67.0W 3.4-5.1 BBAAA  Puerto Rico                

 

MAJOR TO GREAT QUAKE SHAKES ALASKA PENINSULA

 

EARTHQUAKE SUMMARY FOR JULY 21, 2020

 

A major earthquake of M 7.8-7.9 shook areas south of Alaska and the Alaska Peninsula today. NEIC reported the mainshock at M 7.8 was felt with intensity VIII in Alaska at Cold Bay; IV in Perryville, King Cove and VI at Sand Point with lesser shaking up to 500 km away at Pilot Point, Egegik, South Naknek, Kodia, King Salmon and Manokotak, Alaska. Strong aftershocks of M 6.2 and 5.8 among others were also felt at Perryvill, Alaska with intensity III. This ranks among the largest earthquakes in the U.S or Canada in the past 30 years. No earthquakes of M>7.9 have been recorded in the area in at least 30 years. Four other events of M 7.8-7.9 have been recorded in the area in the past 30 years -  the last was on January 23, 2018 south of Alaska about 600 km to the east of today's epicenter. Others occurred with M 7.8 on October 28, 2012 in Queen Charlotte Islands, Canada; in Denali National Park, Alaska on November 3, 2002 and in the western Andreanof Islands, Alaska on June 10, 1996. The last earthquake within about 500 km of today's epicenter in the Alaska Peninsula with M>=7.0 occurred on May 30, 1991 in the Unimak area with M 7.0.

 

This epicenter is located at the exact fourth node (90.0 degrees) from the M 7.4 in the Kermadec Islands, New Zealand of June 18, 2020 and at the sixth node (60 degrees) from the M 7.5 in Oaxaca, Mexico of June 23, 2020 and was probably promoted by energy from those sources. It may be of interest to note that the major activity in the Ridgecrest and Lone Pine areas of the California-Nevada area was also at 90 degrees from the Kermadec epicenter as noted at the time in this summary.

 

A tsunami watch was immediately called by PTWC but cancelled two hours later when no major waves were observed. Minor tsunami waves are likely however. There was no immediate major damage associated with this earthquake which occurred in a remote area.

 

Far field triggering is likely with the earthquake in Alaska. The antipode is located south of South Africa in the Indian Ocean east of Bouvet Island and is a possible site for triggered activity. Areas at 144 degrees from Alaska include Mozambique, the South Atlantic and Georgia and the western South Sandwich Islands; those near 103 degrees include northern Chile and southern Peru; South Island, New Zealand; Sumatra and southwestern Indonesia. Recent unusual quakes at the fourth n ode (90 degrees) may continue in northern Peru, Tunisia, Andaman Islands, Spain and Peninsular India, the southern Kermadec Island among others. California lies near 40-51 degrees (nodes 8, 9 and 10) and central Mexico at the sixth node (60 degrees). Since the Alaska Peninsula event is unusual it is likely it will be followed by strong far-field triggering with a strong local aftershock sequence.

 

There has been some indication of enhanced seismicity in Alaska following the past geomagnetic storms. In the previous issue of this summary this had been noted as:

 

 

"The strongest earthquake in the U.S. or Canada today was an M 3.8 in the area of Southern Alaska. This was probably promoted by tidal stresses from the new moon and geomagnetic stresses as noted above. NEIC reported it was felt in Alaska at Sterling, Soldotna, Kasilof, Kenai, Anchorage, Cooper Landing.  Further activity in the region of southern Alaska is likely with the new moon in the next several days. The most active region in Alaska in recent weeks has been the Fox Islands and the Unimak Island area where a moderate to strong earthquake may be possible at this time.  The last earthquake within about 200 km of this epicenter with larger magnitude was an M 4.2 on February 15, 2020 more than five months ago." (July 20-21, 2020)

 

 

"While global seismicity remained at low levels today, it was the first day of the new moon. This is a period in the lunar month which often sees tidally triggered seismicity. This summary continues to contend that the situation could bring a major earthquake in the next several days especially at high latitudes or near the geomagnetic equator as noted in previous summaries:

 

and

 

"The new moon will arrive on July 20, 2020 at 17:33 UT. Areas which are sub-solar (local solar noon) at this hour center at longitude 85 West and 95 East longitudes. These include areas of Central and western South America in the west and western Indonesia and eastern Asia in the east. Tidal triggering will be most prominent in these regions. A strong earthquake is likely within the period July 17-23, most likely in this area. Tidal triggering of seismicity is also possible in many other areas and is most likely near local solar noon and local solar midnight." (July 14-17, 2020)

 

and

 

"High latitude geomagnetic field also saw unsettled conditions  with AP at 11. Active geomagnetic conditions such as these often enable stronger seismicity especially near the geomagnetic equator and at high latitudes. Moderate large quakes are expected at these latitudes in the next several days." (July 15-16, 20-21, 2020)

 

A foreshock of M 5.5 was recorded in the area to the west of today's mainshock on July 5, the strongest earthquake in the region of Alaska this year. It was followed by an M 5.1 on July 8 to the northeast. In regard to the M 5.5 on July this summary noted at the time:

 

 

"The strongest earthquake in the U.S. or Canada today was an M 5.5 in the Alaska Peninsula near Unimak Island. It was not reported felt in this remote area.

This event occurred near local solar midnight and was probably enhanced by

tidal stresses associated with the full moon which was nearly coincident

with it (as well as with the maximum of today's geomagnetic disturbance)." (July 5-6, 2020)

 

Another regional foreshock may have occurred on July 8 with M 5.1. At the time this summary noted:

 

"The strongest earthquake in the U. S. or Canada today was also the largest in the world today. This event of M 5.1 in the Kodiak Island area of Alaska was not reported felt in this epicentral area. It is the largest event in this area since an M 5.2-5.3 on April 17, 2020 - the only  other such event in the past 8 months." (July 8, 2020)

 

A moderate earthquake of M 4.6 was recorded in the Queen Charlotte Sound, Canada about four minutes after the M 7.8 in the Alaska Peninsula. S-waves and surface waves take about this time to travel the 17 degrees between these epicenter and were present in the Queen Charlotte Sound, Canada at the time of the M 4.6. Forecast 125628 had expected this event to the southwest was likely around July 19.

 

O: 22JUL2020 06:16:44  51.2N  129.1W ML=4.6  EMSC   QUEEN CHARLOTTE SOUND, CANADA

P: 19JUL2020 125628    50.6N  130.5W 3.0-5.0 BAAAA  British Colombia           

 

Forecast 125641 had expected today's activity was likely in mid-July in the Unimak Island area about 150 km to the west of today's epicenter.

 

O: 22JUL2020 06:59:01  54.5N  161.0W ML=3.9  EMSC   ALASKA PENINSULA

O: 22JUL2020 06:40:23  54.6N  160.7W ml=3.8  EMSC   ALASKA PENINSULA

O: 22JUL2020 06:20:07  54.7N  158.9W mb=5.7  EMSC   SOUTH OF ALASKA

O: 22JUL2020 06:26:09  54.8N  158.8W ml=3.9  EMSC   SOUTH OF ALASKA

O: 22JUL2020 06:16:15  54.9N  158.8W ml=5.9  EMSC   SOUTH OF ALASKA

O: 22JUL2020 06:30:02  54.9N  158.9W mb=4.2  EMSC   SOUTH OF ALASKA

O: 22JUL2020 06:33:50  55.0N  158.7W ml=4.1  EMSC   ALASKA PENINSULA

O: 22JUL2020 06:53:53  55.1N  158.3W ml=4.2  EMSC   ALASKA PENINSULA

O: 22JUL2020 06:12:44  55.1N  158.6W Mw=7.8  EMSC   ALASKA PENINSULA             

P: 16JUL2020 125641    54.3N  161.4W 3.5-5.0 CABAA  Unimak Islands, Aleutians  

 

A strong earthquake of M 6.0 also shook the Fiji Islands today. It is the largest in the region of the Fiji Islands since an M 6.5 on November 8, 2019. An M 5.9 hit the area on June 3 and 6. Forecast 125682 had expected this region of the Fiji Islands would be active in mid-July.

 

O: 21JUL2020 20:56:24  20.9S  178.5W Mw=6.0  EMSC   FIJI REGION                  

P: 14JUL2020 125682    21.0S  178.0W 4.0-5.7 CAAAA  Tonga Islands              

 

STRONG SEISMICITY EVADES NEW MOON; MAY YET OCCUR

 

EARTHQUAKE SUMMARY FOR JULY 20, 2020

 

While global seismicity remained at low levels today, it was the first day of the new moon. This is a period in the lunar month which often sees tidally triggered seismicity. This summary continues to contend that the situation could bring a major earthquake in the next several days especially at high latitudes or near the geomagnetic equator as noted in previous summaries:

 

"The new moon will arrive on July 20, 2020 at 17:33 UT. Areas which are sub-solar (local solar noon) at this hour center at longitude 85 West and 95 East longitudes. These include areas of Central and western South America in the west and western Indonesia and eastern Asia in the east. Tidal triggering will be most prominent in these regions. A strong earthquake is likely within the period July 17-23, most likely in this area. Tidal triggering of seismicity is also possible in many other areas and is most likely near local solar noon and local solar midnight." (July 14-17, 2020)

 

and

 

"High latitude geomagnetic field also saw unsettled conditions  with AP at 11. Active geomagnetic conditions such as these often enable stronger seismicity especially near the geomagnetic equator and at high latitudes. Moderate large quakes are expected at these latitudes in the next several days." (July 15-16. 2020)

 

The strongest earthquake in the world today was an M 5.2 at a high latitude in the South Sandwich Islands. A similar event hit this region yesterday. These are not being felt in this area. Forecast 125701 had expected today's South Sandwich Islands event was likely within about 50 km of this epicenter around July 17.

 

O: 20JUL2020 23:07:14  58.0S   25.9W Mw=5.2  EMSC   SOUTH SANDWICH ISLANDS REGION

P: 17JUL2020 125701    58.0S   25.0W 4.0-6.1 BAAAA  So. Sandwich Islands       

 

The largest earthquakes felt in the world today were a pair of M 4.9 events in eastern Xizang, China. This area saw earthquakes of slightly larger magnitude yesterday and this was noted in the previous summary as:

 

"The earthquake Xizang, China is near the point of maximum solar eclipse with the last new moon of June 21 and probably will see more of this type of event in coming days. Floods and a series of moderate earthquakes have hit many areas of China including the Three Gorges Dam area and could help promote further seismicity. Floods load the area and help lubricate faults and have been known to trigger significant earthquakes, including the Three Gorges Dam earthquake of May 12, 2008 (M 7.9). (July 20, 2020)

 

O: 21JUL2020 06:18:48  30.4N   94.9E mb=4.9  EMSC   EASTERN XIZANG

O: 21JUL2020 02:15:27  30.9N   94.9E mb=4.4  EMSC   EASTERN XIZANG

O: 20JUL2020 19:21:39  30.4N   95.0E mb=4.9  EMSC   EASTERN XIZANG               

O: 21JUL2020 01:33:57  35.6N   82.5E mb=4.1  EMSC   XINJIANG-XIZANG BORDER REGION

P: 17JUL2020 125587    30.0N   84.0E 3.8-5.5 BCBAA  Xizang                     

 

The strongest earthquake in the U.S. or Canada today was an M 3.8 in the area of

Southern Alaska. This was probably promoted by tidal stresses from the new moon and geomagnetic stresses as noted above. NEIC reported it was felt in Alaska at Sterling, Soldotna, Kasilof, Kenai, Anchorage, Cooper Landing.  Further activity in the region of southern Alaska is likely with the new moon in the next several days. The most active region in Alaska in recent weeks has been the Fox Islands and the Unimak Island area where a moderate to strong earthquake may be possible at this time.  The last earthquake within about 200 km of this epicenter with larger magnitude was an M 4.2 on February 15, 2020 more than five months ago. Forecast 125645 had expected today's earthquake was likely in mid-July.

 

O: 20JUL2020 07:08:48  60.8N  151.5W mb=3.9  EMSC   KENAI PENINSULA, ALASKA      

P: 17JUL2020 125645    60.8N  151.7W 3.2-4.9 BAAAA  Central Alaska             

 

An unusual earthquake of M 2.2 also occurred in Mississippi, U.S. today. This is the strongest earthquake in Mississippi within about 100 km of this epicenter since an M 2.4 on December 22, 2019 and an M 2.3 on January 12, 2019. Forecast 125560 had expected this activity to the northeast was likely around July 14.

 

O: 20JUL2020 12:45:33  34.6N   90.6W Md=2.2  EMSC   MISSISSIPPI                  

P: 14JUL2020 125560    36.3N   89.5W 2.0-4.3 CBAAA  New Madrid area            

 

TIDAL STRESSES CONTINUE TO TRIGGER EARTHQUAKES

 

EARTHQUAKE SUMMARY FOR JULY 19, 2020

 

 

It was a relatively quiet day in global seismicity with the maximum sized events in the low M 5.0 range. The strongest of these tended to occur near the longitude of tidal maximum stresses as reported in previous issues of this report:

 

"The new moon will arrive on July 20, 2020 at 17:33 UT. Areas which are sub-solar (local solar noon) at this hour center at longitude 85 West and 95 East longitudes. These include areas of Central and western South America in the west and western Indonesia and eastern Asia in the east. Tidal triggering will be most prominent in these regions. A strong earthquake is likely within the period July 17-23, most likely in this area. Tidal triggering of seismicity is also possible in many other areas and is most likely near local solar noon and local solar midnight." (July 14-17, 2020)

 

These included events of M 4.9 and 5.0 in Southern Xizang, China at 94 East longitude and an M 5.3 in northern Peru at 81 West longitude. Other events occurred with lesser magnitude in Myanmar. This pattern continues that seen in the past several days and is likely due to strong tidal stresses at these longitudes.

 

The earthquake Xizang, China is near the point of maximum solar eclipse with the last new moon of June 21 and probably will see more of this type of event in coming days. Floods and a series of moderate earthquakes have hit many areas of China including the Three Gorges Dam area and could help promote further seismicity. Floods load the area and help lubricate faults and have been known to trigger significant earthquakes, including the Three Gorges Dam earthquake of May 12, 2008 (M 7.9). At the time this summary noted in this regard:

 

"A great earthquake of M 7.9 destroyed a large portion of eastern Sichuan China near the Gansu border today leaving more than 10,000 people dead. News reports from Xinhua, AP and Reuters place the epicenter about 100 km south of the capital of Sichuan province, Chengdu. Chengdu is a major city of 11 million." (May 12, 2008)

 

"The Sichuan earthquake was most likely triggered by motion of the faults in southeastern Asia initiated a week ago by the unusual landfall of the tropical cyclone Nargis which hit the Irrawady Basin killing more than 100,000 people on May 3-5. The faults in this region are strike-slip for the  most part allowing the plastic indentation of Asia by India. The slippage occurs along several long faults generally oriented North-South. It is on one of these that the earthquake today probably occurred. While this was likely the major external trigger for today's earthquake the event was also promoted by several recent strong earthquakes. As we noted in our summary two days ago a series of unusual earthquakes were occurring at distances from the M 6.7 in Alaska on May 2, 2008. The distance between the Andreanof epicenter and the Sichuan quake is exactly 60.0 degrees, a distance (360/6 degrees) where strong triggering is expected following large earthquakes. Another earthquake which lay at a distance of 60 degrees from  the Andreanof Islands was the earthquake of M 5.2 in southern Illinois which occurred earlier this month. It also lies near distances from Guam (40-41 degrees, n=9) and Honshu, Japan (32.5 degrees, n=11) such that some triggering may have occurred from those events.

... triggering may have been associated with the filling of the Three Gorges dam about 400 miles to the east but loading associated with new dams often triggers strong region seismicity." (May 13, 2008)

 

The last earthquake of M>=5 within about 200 km of today's Xizang quake was an  M 5.5 on January 24, 2020 and prior to that an M 5.0 on August 11, 2019. One year ago on July 19, 2019 a quake about 300 km to the south in the Arunachal Pradesh area of India, within an hour of today's event. Forecast 125295 had expected earthquake in Eastern Xizang was likely in mid-July. This epicenter is at 104 degrees from the M 7.4 in the Kermadec Islands of June 18 and was probably promoted by concentrated energy from that source as were the event of Myanmar today. Other earthquakes near the longitude of maximum tidal stress today included events of M 3.2 and 3.5 along the Myanmar-India border and an M 4.9 in central Mongolia. In the west an M 5.1 shook areas of northern Peru at 80 West longitude.

 

O: 19JUL2020 22:09:38  23.2N   93.3E ML=3.2  EMSC   MYANMAR-INDIA BORDER REGION  

O: 19JUL2020 21:00:47  25.0N   94.6E ML=3.5  EMSC   MYANMAR-INDIA BORDER REGION  

P: 19JUL2020 125535    26.0N   93.0E 4.0-5.6 AABAA  Myanmar                    

 

O: 20JUL2020 00:36:49  30.3N   94.9E mb=4.5  EMSC   EASTERN XIZANG

O: 19JUL2020 23:36:38  30.4N   94.9E mb=4.9  EMSC   EASTERN XIZANG

O: 19JUL2020 10:15:47  30.4N   95.0E mb=5.0  EMSC   EASTERN XIZANG               

P: 11JUL2020 125295    26.0N   93.0E 4.0-5.6 CCBAA  Myanmar                    

 

O: 20JUL2020 01:59:41  43.7N   99.9E mb=4.9  EMSC   CENTRAL MONGOLIA             

P: 14JUL2020 125601    46.0N   96.0E 4.0-5.6 CCCAA  Mongolia                   

 

The M 5.3 off the coast of Northern Peru today was the strongest earthquake in the world today. The last earthquake of equal or larger magnitude within about 200 km of today's epicenter occurred as an M 5.5 on March 31, 2019 and prior to that an M 5.4 on November 20, 2018. Forecast 125497 had expected today's event in mid-July within about 50 km of this epicenter.

 

NEIC reported this earthquake of M 5.3 in northern Peru  was felt with intensity II-III in the area(s) of northern Peru at Trujillo and Viru, La Libertad and in Santa Rosa Lambaeque.

 

O: 20JUL2020 01:50:11   8.4S   80.0W Mw=5.3  EMSC   OFF COAST OF NORTHERN PERU   

P: 16JUL2020 125497     9.0S   80.0W 4.0-5.5 BAAAA  No. Peru                   

 

 

The area of Iceland also continued active today. Two series continued with moderate quakes of M>=4 - one north of Iceland and one in western Iceland which more widely felt and had the largest events. This area has been active for about a month and today's activity was expected in mid-July in forecast 125649. This activity is located at 144 degrees from the M 7.4 in the Kermadec Islands of June 18 and was probably promoted by energy from that source.

 

NEIC reported this earthquake of M 4.3 in  Western Iceland was felt with intensity II-III in the area(s) of Western Iceland at Keflavik, Sudumes. An M 4.5 earlier in the day was felt with intensity IV in Reykholt, Vesturland and II-III in Reykjavik, Keflavik and Njardvik.

 

O: 20JUL2020 06:23:29  63.9N   22.4W ML=4.3  EMSC   ICELAND REGION

O: 19JUL2020 23:36:14  64.1N   22.3W mb=4.5  EMSC   ICELAND

P: 14JUL2020 125649    63.0N   26.0W 3.0-4.8 CABAA  Iceland area               

 

O: 19JUL2020 17:21:50  66.3N   18.4W ML=4.0  EMSC   ICELAND REGION               

P: 16JUL2020 125649    65.0N   17.0W 3.0-4.9 BBAAA  Iceland area               

 

An earthquake also occurred at the opposite end of the Atlantic Ocean as an M 5.2 in the South Sandwich Islands. It was not felt in this remote area. Forecast 125701 had expected this activity was likely in mid-July.

 

O: 20JUL2020 03:08:02  55.0S   29.1W mb=5.2  EMSC   SOUTH SANDWICH ISLANDS REGION

P: 15JUL2020 125701    60.0S   29.0W 4.0-5.7 BCAAA  So. Sandwich Islands       

 

 

 

 

 

STRONG QUAKE SHAKES AMERICAN SAMOA

 

EARTHQUAKE SUMMARY FOR JULY 18, 2020

 

The strongest earthquake in the world today was an M 6.1 in Samoa. NEIC reported it was felt with intensity III in Apia, Apia Urban area, Samoa. This is the strongest earthquake in the American Samoa area within about 250 km of this epicenter since an M 6.8 on November 4, 2017 and prior to that an M 6.4-6.5 on March 30, 2015. Forecasts 125667 and 125662 had expected today's activity was likely in mid-July within 50-100 km of today's epicenters.

 

O: 18JUL2020 16:03:05  14.8S  173.1W mb=4.9  EMSC   SAMOA ISLANDS REGION         

O: 18JUL2020 15:32:39  15.5S  173.1W Mw=6.2  EMSC   TONGA                        

P: 13JUL2020 125667    16.0S  173.0W 4.0-5.6 BAAAA  Tonga Islands               

P: 18JUL2020 125662    15.0S  175.0W 4.0-5.7 AABAA  Samoa Islands              

 

The most unusual earthquake in the world today occurred in the ocean basin south of Sumatra. This event of M 5.3 was not reported felt. It occurred at 93 East longitude and was probably part of the tidal triggering in the region associated with the new moon which is due tomorrow. This summary had noted this in previous issues as:

 

 

"The new moon will arrive on July 20, 2020 at 17:33 UT. Areas which are sub-solar (local solar noon) at this hour center at longitude 85 West and 95 East longitudes. These include areas of Central and western South America in the west and western Indonesia and eastern Asia in the east. Tidal triggering will be most prominent in these regions. A strong earthquake is likely within the period July 17-23, most likely in this area. Tidal triggering of seismicity is also possible in many other areas and is most likely near local solar noon and local solar midnight." (July 14-17, 2020)

 

and

 

" A active geomagnetic storm is due in the next couple of days and the new moon is due July 20 when areas of Central and South America are sub-solar and Southeast Asia is anti-solar. This will probably bring about an increase in global seismicity with the possibility of one or two strong earthquakes near the geomagnetic equator and/or with lesser probability at high latitude around July 16-20." (July 12, 2020)

 

The earthquake in the South Indian Ocean of M 5.4 is the strongest within about 400 km of that epicenter in the past six years - since an M 6.4 hit on June 14, 2009. Other earthquakes of M>=5.4 in this area in the past 20 years were an M 5.4 on July 19, 2009 exactly 11 years ago and an M 5.7 on July 10, 2004 five months prior to the great earthquake in Sumatra of December 26, 2004. That M 5.7 may have been a stress indicator for the upcoming December event. When the strong quake hit the area in June, 2014, this summary noted:

 

"A strong earthquake of M 6.4-6.6 hit under the Indian Ocean south of Sumatra, Indonesia today. This is a remote area and the quake was not reported felt. A tsunami warning was issued for the Cocos Islands but was later cancelled. Australians in Cocos Island were warned to avoid beaches and coastal areas because of possible dangerous rips and currents. The warning was later cancelled when no evidence of a tsunami was observed. There were no reports of damage or casualties associated with this earthquake." (June 15, 2014)

 

 

O: 19JUL2020 02:15:17  10.9S   93.8E mb=5.4  EMSC   SOUTH INDIAN OCEAN           

 

Other earthquakes near 95 East Longitude today included an M 4.5 in Myanmar. Forecast 125535 had expected this event was likely within about 200 km of this epicenter around July 14.

 

O: 18JUL2020 18:38:22  21.8N   97.0E mb=4.5  EMSC   MYANMAR                      

P: 14JUL2020 125535    20.0N   96.0E 4.0-5.5 BBAAA  Myanmar                    

 

A near-antipodal earthquake also occurred in Nicaragua with M 4.5. It was reported lightly felt in the epicentral area and occurred near local solar noon.  NEIC reported this earthquake of M 4.5 off Nicaragua  was felt with intensity II-III in the area(s) of Choluteca, Honduras.  The region of Nicaragua south to Panama has been active in recent days with an M 5.8 in Panama on July 15. At the time this summary noted:

 

 

"The earthquake in Panama occurred north of the geomagnetic equator and was probably enhanced by tidal and geomagnetic effects. It occurred near the maximum tidal longitude as discussed above in the tidal seismicity forecast. This is the strongest earthquake in the area of Panama in more than a year - since an M 6.2 on June 26, 2019. Forecast 125480 had expected today's event within about 50 km was likely around June 14." (July 16, 2020)

 

O: 18JUL2020 16:05:55  12.8N   87.4W mb=4.5  ANSS   N of Jiquilillo Nicaragua    

P: 18JUL2020 125518    12.0N   88.0W 3.5-5.3 AAAAA  Nicaragua                  

 

O: 15JUL2020 21:39:41   7.5N   81.9W Mw=5.8  EMSC   PANAMA                       

P: 14JUL2020 125480     8.0N   82.0W 3.5-5.1 AAAAA  Costa Rica                 

 

The strongest earthquake in the U.S. or Canada today was an M 3.9 in Central  Alaska. The last earthquake in this area of central Alaska with larger magnitude was an M 4.3 on April 17, 2000.  Forecast 125646 had expected today's activity was likely to the east around July 21.

 

NEIC reported this earthquake of M 4.1 in Central Alaska  was felt with intensity II-III in the area(s) of Central Alaska at McGrath.

 

O: 19JUL2020 00:35:27  62.2N  154.9W Mw=3.9  EMSC   CENTRAL ALASKA                

O: 19JUL2020 00:35:28  62.1N  154.9W Mw=4.1  ANSS   CENTRAL ALASKA               

P: 21JUL2020 125646    62.7N  151.6W 3.2-5.0 AABAA  Central Alaska             

 

STRONG TIDALLY ENHANCED SEISMICITY AT 94-95 EAST LONGITUDE

 

EARTHQUAKE SUMMARY FOR JULY 17, 2020

 

The largest events in the world today occurred at the longitude of maximum tidal stress (95 East longitude) with the upcoming new moon as described in previous issues of this report:

 

"The new moon will arrive on July 20, 2020 at 17:33 UT. Areas which are sub-solar (local solar noon) at this hour center at longitude 85 West and 95 East longitudes. These include areas of Central and western South America in the west and western Indonesia and eastern Asia in the east. Tidal triggering will be most prominent in these regions. A strong earthquake is likely within the period July 17-23, most likely in this area. Tidal triggering of seismicity is also possible in many other areas and is most likely near local solar noon and local solar midnight." (July 14-17, 2020)

 

and

 

" A active geomagnetic storm is due in the next couple of days and the new moon is due July 20 when areas of Central and South America are sub-solar and Southeast Asia is anti-solar. This will probably bring about an increase in global seismicity with the possibility of one or two strong earthquakes near the geomagnetic equator and/or with lesser probability at high latitude around July 16-20." (July 12, 2020)

 

This activity included an M 6.1 in the Andaman Islands and an M 5.3 in Myanmar.

The strongest earthquake in the world today occurred as an M 6.1 in the Andaman Islands, India. NEIC reported it was felt with intensity I-II in Port Blair and Bombuflat, Andaman and Nicobar Islands, India. The M 6.1 was accompanied by a series of moderate foreshocks and aftershocks including events of M 4.8 and  M 5.6 near local solar midnight, a prime time for tidal triggering. The Andaman Islands are capable of great earthquakes but the last of M>=6.1 within about 250 km of today's epicenter was an M 6.5 more than 10 years ago  on May 31, 2010. The area was active to the north following the great tsunamigenic quake of Boxing Day (December 26, 2004) which killed upward toward a quarter million around the Indian Ocean. Strong quakes followed every two years after that up to 2010 when quiet conditions returned to the region.  Forecast 125506 had expected a strong quake was possible in the Andaman Islands around July 18 to the southwest of today's epicenter.

 

O: 17JUL2020 14:43:18  12.0N   94.7E mb=5.0  EMSC   ANDAMAN ISLANDS, INDIA REGION

O: 17JUL2020 14:03:50  12.0N   94.9E Mw=6.1  EMSC   ANDAMAN ISLANDS, INDIA REGION

O: 17JUL2020 17:45:23  12.0N   95.1E mb=4.8  EMSC   ANDAMAN ISLANDS, INDIA REGION

O: 17JUL2020 18:32:59  12.1N   95.0E mb=5.6  EMSC   ANDAMAN ISLANDS, INDIA REGION

O: 17JUL2020 13:29:05  11.9N   95.0E Mw=5.1  EMSC   ANDAMAN ISLANDS, INDIA REGION

P: 18JUL2020 125506    11.0N   92.0E 4.0-5.8 AACAA  Andaman Islands            

 

The event of M 5.3 in Myanmar-India border is the strongest in that region since the solar eclipse of June 21 which was accompanied by a series of regional moderate quakes. including an M 5.6 with the solar eclipse on June 21, 2020. Two other such events have hit the area in the past year - an M 5.9 on April 16, 2020 and an M 5.5 on August 31, 2019. Forecast 125535 had expected today's activity within about 150 km was likely around July 19 with the coming new moon.

 

NEIC reported this earthquake of M 5.3 in the Myanmar-India border region  was felt with intensity II-III in the area(s) of the Myanmar-India border region in Serchhip and Lunglei, Mizoram.

 

O: 17JUL2020 10:26:42  23.2N   93.3E mb=4.3  EMSC   MYANMAR-INDIA BORDER REGION   

O: 17JUL2020 16:33:52  23.3N   93.4E Mw=5.3  EMSC   MYANMAR-INDIA BORDER REGION  

O: 17JUL2020 22:55:41  24.7N   92.6E ML=4.0  EMSC   INDIA-BANGLADESH BORDER REGION

P: 19JUL2020 125535    26.0N   93.0E 4.0-5.6 ABAAA  Myanmar                    

 

A moderately strong earthquake of M 5.8 also occurred today in the Solomon Islands. It was not reported felt. It was probably promoted by strong tidal effects as it occurred within minutes of local solar noon, a time when tidal stresses are maximized. Earthquakes of M 6.0 and 6.3 hit this area on January 29 and January 27, 2020, the first such activity since November 16, 2018. Today's event is probably an aftershock of the event in late January. Forecast 125661 had expected today's activity within about 100 km of the epicenter was likely around July 21.

 

O: 18JUL2020 01:37:16  10.3S  161.3E Mw=5.8  EMSC   SOLOMON ISLANDS              

P: 21JUL2020 125661    10.0S  162.0E 4.0-5.4 BAAAA  No. of Santa Cruz Islands  

 

The strongest activity in the U.S. or Canada today was a pair of events of M 4.3 in Alaska. These included an M 4.3 in the Fox Islands and an M 4.3 in Southern Alaska. NEIC reported this earthquake of M 3.9-4.3 in Southern Alaska was felt with intensity II-III in the area(s) of Southern Alaska at Ninilchik, Homer, Soldotna, Kenai and Eagle River. The earthquake in Southern Alaska is the strongest within about 200 km of that epicenter since an M 4.4 on February 12, 2020 and prior to that an M 4.5 on December 1, 2019. Forecast 125645 had expected this activity within about 25 km was likely around July 20.

 

 

O: 17JUL2020 18:06:40  60.0N  152.9W mb=4.3  EMSC   SOUTHERN ALASKA              

O: 17JUL2020 19:43:10  60.3N  153.1W ML=3.3  EMSC   SOUTHERN ALASKA              

P: 20JUL2020 125645    60.1N  153.4W 3.2-5.2 BAAAA  Central Alaska             

 

The last event within about 150 km of the M 4.3 in the Fox Islands  with equal or larger magnitude was an M 4.5 on June 15, 2020 and an M 4.8 on March 30, 2020, the only two such events in the area during the current year.

Forecast 125631 had expected today's event was likely within about 50 km around July 20. Today's earthquake was not reported felt in this remote epicentral area.

 

O: 18JUL2020 02:27:03  53.1N  166.6W mb=4.3  EMSC   FOX ISLANDS, ALEUTIAN ISLANDS

P: 20JUL2020 125631    53.6N  166.1W 3.5-5.1 AAAAA  Fox Islands, Aleutians     

 

MAJOR EARTHQUAKES STRIKE NEAR GEOMAGNETIC EQUATOR

 

EARTHQUAKE SUMMARY FOR JULY 16, 2020

 

A major earthquake of M 7.0 hit the region of eastern New Guinea, PNG today.

This is the strongest earthquake in the world since the M 7.5 in Oaxaca, Mexico of July 23, 2020. It was probably triggered by the recent geomagnetic storm as it occurred within minutes of local solar noon near the geomagnetic equator. This had been expected in previous issues of this summary as:

 

"High latitude geomagnetic field also saw unsettled conditions  with AP at 11. Active geomagnetic conditions such as these often enable stronger seismicity especially near the geomagnetic equator and at high latitudes. Moderate large quakes are expected at these latitudes in the next several days." (July 15-16. 2020)

 

The earthquake in eastern New Guinea was felt with maximum intensity VI in Pap;ua New Guinea at Popondetta Oro; V in Lae Morobe, Kainantu; IV in Port Moresby and II-III at Goroka, Daru, Fly River and Lilibu. The earthquake in New Guinea was joined several hours later by a strong M 5.9-6.0 in northern Chile in the Tarapaca area. It occurred near the geomagnetic equator like the M 7.0 in New Guinea and was likely affected by geomagnetic effects. This is also near the longitude of maximum tidal stresses with the upcoming new moon and was probably promoted at this time by tidal effects. This summary had expected this in previous issues in the tidal seismicity statement with this new moon as:

 

"The new moon will arrive on July 20, 2020 at 17:33 UT. Areas which are sub-solar (local solar noon) at this hour center at longitude 85 West and 95 East longitudes. These include areas of Central and western South America in the west and western Indonesia and eastern Asia in the east. Tidal triggering will be most prominent in these regions. A strong earthquake is likely within the period July 17-23, most likely in this area. Tidal triggering of seismicity is also possible in many other areas and is most likely near local solar noon and local solar midnight." (July 15-17, 2020)

 

Since today's New Guinea earthquake occurred under land, a tsunami is unlikely and was not reported. Areas where far-field triggering may occur include at 144 degrees, Spain, Puerto Rico, Northern Venezuela and the Central Atlantic and near 103 degrees in the Central U.S. and western Mexico, Mayotte, the Red Sea, eastern Turkey, among others but at M 7.0 strong triggering at a distance from New Guinea is not likely. The last earthquake within about 250 km of today's epicenter with M>=7 occurred on  May 6, 2019 (M 7.2) and prior to that on December 14, 2011 with M 7.1. Forecast 125495 had expected today's epicenter would be active within about 100 km around July 18.

 

O: 17JUL2020 02:50:23   7.8S  147.7E Mw=7.0  EMSC   EASTERN NEW GUINEA REG., P.N.G

P: 18JUL2020 125495     7.0S  147.0E 4.0-5.4 AAAAA  New Ireland                

 

An earthquake of M 5.9-6.0 also shook northern Chile today.

 

NEIC reported today's event in the Tarapaca area of northern Chile was felt with intensity VI in Iquique, Tarapaca and III in Arica. GUC reported this earthquake was felt with intensity  VI in  Tarapaca at Alto Hospicio, El Loa, Iquique,La Tirana, Pozo Almonte; V in Pisagua III in Ujina and II in Cancosa; in Arica with IV in Arica, Cuya, Pocon Chile and III in Chapiquina and San Miguel and in Antofagasta with V in Quillagua and IV in Calama, Maria Elena, Sierra Gorda and Tocopilla and III in Ollague, Chile. An M 6.0 was also recorded about 200 km northwest of this on December 3, 2019 after an M 5.4 foreshock 45 minutes earlier near today's epicenter. But the last event of significantly larger magnitude in this area was an M 6.2 on November 1, 2018 and prior to that an M .1 on July 13, 2014. Forecast 125681 had expected today's event in this region was likely around July 18, 2020.

 

O: 17JUL2020 05:40:35  20.2S   70.1W Mw=5.9  EMSC   TARAPACA, CHILE              

O: 17JUL2020 05:40     20.2S   70.1W mb=5.9  GUC    Tarapaca at Alto Hospicio, El

P: 18JUL2020 125681    20.0S   71.0W 4.0-5.5 AAAAA  So. Peru/Bolivia           

 

An unusual earthquake of M 4.2 was widely felt in the area of Slovenia today. NEIC reported it was felt in northern Italy at Tarvisio, ad Gondia and in Slovenia with II-III in Kobarid, Tolmin, Kranjska, Nova Gorica, Bled Gorenjska, in Finkenstein, Austria and in Italy at Udine, Resia, and Gorizia. The last earthquake within about 150 km of this event in Slovenia was recorded on August 11, 2018 with M 4.2.  Forecast 125590 had expected today's event in this area was likely around July 16.

 

O: 17JUL2020 02:50:57  46.3N   13.5E ML=4.2  EMSC   SLOVENIA                     

P: 16JUL2020 125590    45.0N   12.0E 3.0-5.3 ABAAA  Austria                    

 

The strongest activity in the U.S. or Canada today occurred with three events of M 3.5 in Southeastern Alaska near Juneau, Alaska. These were not reported felt in the epicentral area. The last events of M>=3.5 within about 200 km of today's epicenters occurred on May 25, 2009 with M 3.6. Forecast 125629 had expected today's activity was likely within about 10 km around July 16.

 

O: 16JUL2020 18:29:17  58.3N  133.5W MB=3.5  ECAN Juneau, Alaska, USA   

O: 16JUL2020 06:31:22  58.3N  133.5W MB=3.5  ECAN Juneau, Alaska, USA   

O: 16JUL2020 03:42:28  58.4N  133.5W MB=3.5  ECAN Juneau, Alaska, USA    

O: 16JUL2020 18:29:17  58.3N  133.5W ML=3.5  EMSC   SOUTHEASTERN ALASKA          

O: 17JUL2020 00:21:12  58.4N  133.5W ML=3.0  EMSC   SOUTHEASTERN ALASKA          

P: 16JUL2020 125629    58.3N  133.5W 3.0-5.3 AAAAA  British Colombia           

 

MODERATELY STRONG QUAKE SHAKES PANAMA

 

EARTHQUAKE SUMMARY FOR JULY 15, 2020

 

The strongest earthquake in the world today was an M 5.8 south of Panama. It was reported with maximum intensity IV n Panama at El Cope and Rio Hato and II-III in El Uvito, Divala, Santa Fe, Malmira, Boquite, Penonome, Llano Mann, and Anton, Cocle. It was probably promoted by stresses associated with the current geomagnetic storm and the upcoming new moon as outlined in this summary:

 

"The geomagnetic field saw  unsettled conditions today. The AP level was 11.  High latitude geomagnetic field also saw unsettled conditions  with AP at 18. Active geomagnetic conditions such as these often enable stronger seismicity especially near the geomagnetic equator and at high latitudes. Moderate large quakes are expected at these latitudes in the next several days." (July 14-16, 2020)

 

and on July 12:

 

"The strongest earthquake in the world today continued in ocean ridges. This continues the seismic pattern of the past week with low levels of seismicity mostly confined to ocean ridges. This may about to change. A active geomagnetic storm is due in the next couple of days and the new moon is due July 20 when areas of Central and South America are sub-solar and Southeast Asia is anti-solar. This will probably bring about an increase in global seismicity with the possibility of one or two strong earthquakes near the geomagnetic equator and/or with lesser probability at high latitude around July 16-20." (July 12, 2020)

 

"The new moon will arrive on July 20, 2020 at 17:33 UT. Areas which are sub-solar (local solar noon) at this hour center at longitude 85 West and 95 East longitudes. These include areas of Central and western South America in the west and western Indonesia and eastern Asia in the east. Tidal triggering will be most prominent in these regions. A strong earthquake is likely within the period July 17-23, most likely in this area. Tidal triggering of seismicity is also possible in many other areas and is most likely near local solar noon and local solar midnight." (July 14-16, 2020)

 

The earthquake in Panama occurred north of the geomagnetic equator and was probably enhanced by tidal and geomagnetic effects. It occurred near the maximum tidal longitude as discussed above in the tidal seismicity forecast. This is the strongest earthquake in the area of Panama in more than a year - since an M 6.2 on June 26, 2019. Forecast 125480 had expected today's event within about 50 km was likely around June 14.

 

O: 15JUL2020 21:39:41   7.5N   81.9W Mw=5.8  EMSC   PANAMA                       

P: 14JUL2020 125480     8.0N   82.0W 3.5-5.1 AAAAA  Costa Rica                 

 

 

The strongest earthquake in the U.S. or Canada today was an M 5.3-5.4 event in the central Andreanof Islands which was lightly felt with intensity IV at Adak, Alaska. This is the strongest earthquake within about 200 km of this epicenter since an M 6.2 on January 23, 2020 and prior to that an M 6.0 on December 2, 2019. Other earthquakes of M>=5.3 in the U.S. and Canada in the past three months occurred in the Ridgecrest aftershock zone of California; in Unimak area of Alaska (M 5.5 on July 5) and off the coast of Oregon (M 5.5, May 18). Forecast 125627 had expected today's event was likely in this area of the Andreanof Islands around July 15.

 

 

O: 15JUL2020 08:59:55  52.0N  177.3W Mw=5.3  EMSC   ANDREANOF ISLANDS, ALEUTIAN IS

P: 15JUL2020 125627    51.7N  175.3W 3.5-5.1 AABAA  Andreanoff Isls, Aleutians 

 

GEOMAGNETIC ACTIVITY ASSOCIATED WITH ENHANCED SEISMICITY IN ALASKA; INDONESIA

 

EARTHQUAKE SUMMARY FOR JULY 14, 2020

 

A moderate geomagnetic storm was recorded today and noted in this summary as:

 

"The geomagnetic field saw  unsettled conditions today. The AP level was 11.  High latitude geomagnetic field also saw unsettled conditions  with AP at 18. Active geomagnetic conditions such as these often enable stronger seismicity especially near the geomagnetic equator and at high latitudes. Moderate large quakes are expected at these latitudes in the next several days." (July 14-15, 2020)

 

In the previous issues of this summary this activity was expected to accompany an increase in seismicity at high and low latitudes as:

 

"Global seismicity remained at quiet levels today. The strongest activity was at high latitudes in Iceland and the Balleny Islands. This appears to have begun as the anticipated geomagnetic active period was getting underway and may have been triggered by geomagnetic effects" (July 13-14, 2020)

 

Today's activity was consistent with this interpretation. The largest earthquake of the day was an M 5.7 in the Flores Island area of Indonesia near the geomagnetic equator but an unusual M 5.3 in the Central Andreanof Islands of Alaska also occurred at high latitudes.

 

The earthquake of M 5.5-5.8 that hit the Flores area of Indonesia was reported by BMG to have been felt with intensity II in Denpasar and Waingapu, Indonesia.

This epicenter is located at 144 degrees from the M 7.5 in Oaxaca, Mexico of  June 23 and was probably enhanced concentrated energy from that source. This is the strongest earthquake in the world in the past nine days - since an M 6.6 associated with the last geomagnetic storm on July 6 in the region of Java. The last event in the Flores area within about 250 km of today's epicenter with M>=5.7 occurred on August 17, 2018 with M 6.5 and prior to that on July 28, 2018 with M 6.0. Forecast 125491 had expected today's event near the geomagnetic equator in the Flores area within about 50 km of today's epicenter.

 

O: 14JUL2020 23:33:58   7.2S  120.5E Mw=5.7  EMSC   FLORES SEA                   

P: 14JUL2020 125491     7.0S  121.0E 4.0-5.6 AAAAA  Flores Island area         

 

The strongest earthquake in the U.S. or Canada today was an M 5.3-5.4 event in the central Andreanof Islands which was lightly felt at Adak, Alaska. This is the strongest earthquake within about 200 km of this epicenter since an M 6.2 on January 23, 2020 and prior to that an M 6.0 on December 2, 2019. Other earthquakes of M>=5.3 in the U.S. and Canada in the past three months occurred in the Ridgecrest aftershock zone of California; in Unimak area of Alaska (M 5.5 on July 5) and off the coast of Oregon (M 5.5, May 18). Forecast 125627 had expected today's event was likely in this area of the Andreanof Islands around July 15.

 

O: 15JUL2020 08:59:55  51.9N  177.4W Mw=5.3  EMSC   ANDREANOF ISLANDS, ALEUTIAN IS

P: 15JUL2020 125627    51.7N  175.3W 3.5-5.1 AABAA  Andreanoff Isls, Aleutians 

 

 

 

HIGH LATITUDE ANTIPODAL PAIR IN ICELAND AND BALLENY ISLANDS

 

EARTHQUAKE SUMMARY FOR JULY 13, 2020

 

Global seismicity remained at quiet levels today. The strongest activity was at high latitudes in Iceland and the Balleny Islands. This appears to have begun as the anticipated geomagnetic active period was getting underway and may have been triggered by geomagnetic effects. A pair of events in the Central Vanuatu Islands (M 5.0, 5.1) and the M 5.2 in the Balleny Islands were located near 103 degrees from the M 7.5 in Oaxaca, Mexico of June 23 and may have been promoted by concentrated energy from that source.

 

A near-antipodal pair of earthquakes occurred today in the regions of Iceland and the Balleny Islands. These epicenters with M 4.4 and 5.2 respectively included the largest earthquake of the day and were within about 250 km of being exact antipodes. They were probably tidally promoted as they occurred within about 30 minutes of local solar midnight in Iceland and 46 minutes later near local solar noon in the Balleny Islands south of New Zealand. ScS waves return the antipodal region at this time and may have helped promote the Balleny Islands earthquake. Neither was reported felt in their respective epicentral area. The M 4.4 in Iceland is the strongest within about 200 km of that epicenter since an M 4.8 on April 20, 2020 and an M 5.0 on January 5, 2020, the only such events in that region in the past year. The series on June 20 and 21, 2020 occurred about 250 km northwest of today's event. Forecasts 125649 had expected today's epicenter would be active around July 16.

 

 

O: 13JUL2020 23:41:39  64.6N   17.4W ML=3.0  EMSC   ICELAND

O: 14JUL2020 00:56:19  64.6N   17.6W mb=4.4  EMSC   ICELAND                      

P: 16JUL2020 125649    65.0N   17.0W 3.0-4.9 AAAAA  Iceland area               

 

The M 5.2 in the Balleny Islands south of New Zealand today is the strongest within about 250 km of that epicenter since an M 5.5 on August 10, 2018. It was not reported felt in this remote epicentral area. This summary still maintains that the upcoming geomagnetic activity is likely to bring on renewed moderately large to large earthquakes near the geomagnetic equator especially in Indonesia and other possible seismicity at high latitudes in the next several days.

 

O: 14JUL2020 01:42:04  62.2S  165.2E Mw=5.2  EMSC   BALLENY ISLANDS REGION       

 

The strongest earthquake in the U.S. or Canada today was a high-latitude M 4.1 in the Rat Islands, Aleutians, Canada. This may be an aftershock of an M 4.2 that hit the region on July 10, 2020. At the time this summary noted in this regard:

 

 

"The strongest earthquake in the U.S. or Canada today was an unfelt event of M 4.2 in the Rat Islands, Aleutians, Alaska. The last earthquake of larger magnitude in the Rat Islands was an M 4.8 on April 17, 2020 about 50 km east of today's epicenter. Forecast 125407 had expected today's event within about 25 km was likely around July 8." (July 10-11, 2020)

 

O: 13JUL2020 07:48:00  50.6N  178.6E mb=4.1  EMSC   RAT ISLANDS, ALEUTIAN ISLANDS

P:  8JUL2020 125407    52.0N  179.0E 4.0-5.6 BBAAA  Rat Islands                

 

 

 

MODERATE QUAKE IN NORTHERN HONSHU; VENEZUELA AND NICARAGUA

 

EARTHQUAKE SUMMARY FOR JULY 12, 2020

 

The strongest earthquakes in the world today occurred in Central and northern South America with an M 5.1 in Venezuela and an M 5.1-5.3 in Nicaragua. Similar events of M 4.9 and 5.0 also shook areas of northern Honshu and Hokkaido, Japan and Yap, Micronesia (M 5.2). This continues the quiet seismicity of the past two weeks. This level of seismicity is not sustainable over the long term and will probably end with active geomagnetic conditions which are expected by SWPC over the next several days. The earthquake in northern Venezuela of M 5.1 is the largest within about 200 km of that epicenter since an M 5.4 more than a year-and-a-half ago on December 27, 2018 and prior to that events of M 5.2 on November 24, 2019 and November 22, 2015. Forecast 125237 had expected this event was likely within about 50 km of this epicenter around July 8.

 

NEIC reported this earthquake of M 5.1 in Northern Venezuela  was felt with intensity IV-V in the area(s) of Venezuela  at Barquisimento, Cabudare, Los Rastrojos, Banencia, Lara; and II-III in Araure, Valera, Ejido, Tinaquillo, Tacarigua and Maracaibo.

 

O: 12JUL2020 15:08:49   9.5N   69.8W Mw=5.1  EMSC   LARA, VENEZUELA               

P:  8JUL2020 125237     9.0N   70.0W 4.0-5.7 BAAAA  Venezuela                  

 

The earthquake in Nicaragua was the strongest within about 150 km of that  epicenter since an M 5.3 on June 21, 2020. The last of larger magntiude was an M 5.5 on January 3, 2020 more than half a year ago.  NEIC reported this earthquake of M 5.4 in Nicaragua  was felt with intensity II-III in the area(s) of Nicaragua at Leon, Chichigalpa, San Juan de Sur and Sardinal, Costa Rica.

Forecast 125277 had expected this event to the west was likely in Nicaragua around July 10.

 

O: 12JUL2020 22:38:43  12.0N   86.3W mb=5.1  EMSC   NICARAGUA                    

O: 12JUL2020 22:38:43  12.0N   86.4W mb=5.3  ANSS   NICARAGUA                    

P: 10JUL2020 125277    12.0N   88.0W 3.5-5.5 AABAA  Nicaragua                  

 

NEIC reported the earthquake of M 4.9 in  Hokkaido, Japan was felt with intensity II-III in the area(s) of Hokkaido, Japan at Misawa, Japan.  The earthquakes in Hokkaido, Japan are the strongest within about 150 km of those epicenters since an M 5.6 on May 30, 2020. Two other such events of M 5.2 have occurred during the current year - an M 5.2 on April 30 and M 5.2 on April 23, 2020. Forecast  125350 had expected this activity around July 10.

 

O: 12JUL2020 09:32:25  41.0N  143.1E Mw=4.9  EMSC   OFF EAST COAST OF HONSHU, JAPA

O: 13JUL2020 01:42:48  41.2N  142.7E mb=5.0  EMSC   HOKKAIDO, JAPAN REGION       

P: 10JUL2020 125350    39.0N  143.0E 4.0-5.4 CCAAA  So. of Honshu              

 

O: 13JUL2020 06:22:31  12.1N  140.2E Mw=5.2  EMSC   STATE OF YAP, MICRONESIA     

P:  7JUL2020 125284    11.0N  140.0E 4.0-5.4 CBAAA  So. Marianas/Guam          

 

The strongest earthquake in the U.S. or Canada was an M 3.7 in the Fox Islands, Alaska. This is an aftershock of an M 4.7 in the area yesterday. This summary had noted that event as:

 

"The largest earthquake in the U.S. or Canada today was an M 4.7 in the Fox Islands, Aleutians, Alaska. It was not reported felt in this remote area. Earthquakes of M 4.8 hit within about 200 km of this epicenter on May 17 and March 1, 2020 but the only event this year of significantly larger magnitude was an M 5.0 on January 13, 2020 and an M 5.8 on October 26, 2019. Forecast 125400 expected today's event was likely within about 50 km of this epicenter in early July." (July 12, 2020)

 

O: 12JUL2020 21:00:50  51.2N  169.1W mb=3.7  EMSC   FOX ISLANDS, ALEUTIAN ISLANDS

P:  6JUL2020 125400    51.9N  169.2W 3.5-5.3 CAAAA  Fox Islands, Aleutians     

 

 

 

SEISMIC PATTERN CONTINUES AT MODERATE LEVELS

 

EARTHQUAKE SUMMARY FOR JULY 11, 2020

 

The strongest earthquake in the world today continued in ocean ridges. This continues the seismic pattern of the past week with low levels of seismicity mostly confined to ocean ridges. This may be about to change. An active geomagnetic storm is due in the next couple of days and the new moon is due July 20 when areas of Central and South America are sub-solar and Southeast Asia is anti-solar. This will probably bring about an increase in global seismicity with the possibility of one or two strong earthquakes near the geomagnetic equator and/or with lesser probability at high latitude around July 16-20.  The largest earthquake today was an M 5.3 in the South Sandwich Islands. It was not reported felt in this remote area. The last earthquake of M>=5.3 in the South Sandwich Islands was an M 5.3 on June 6, 2020 and prior to than an M 5.6 on May 8. Forecast 125472 had expected today's event was likely around July 9 within about 100 km of today's epicenter.

 

O: 11JUL2020 18:58:06  59.0S   25.8W mb=5.3  EMSC   SOUTH SANDWICH ISLANDS REGION

P:  9JUL2020 125472    58.0S   26.0W 4.0-6.0 AAAAA  So. Sandwich Islands       

 

An earthquake of M 5.4 also shook the region of New Guinea today. An M 6.3 hit south of this on April 25, 2020 and was followed by an M 6.1 on May 7, 2020. Today's event is probably an aftershock of this. Forecast 125246 had expected today's event to the south around July 9.

 

O: 11JUL2020 21:53:01   5.6S  154.2E Mw=5.4  EMSC   BOUGAINVILLE REGION, P.N.G.  

P:  9JUL2020 125246     7.0S  154.0E 4.0-5.4 ABAAA  New Britain                

 

An unusual earthquake of M 4.9 in the southeast Indian Ridge. The antipode of this epicenter is at 50N 68W in Quebec. This is an active area and may see some minor enhancements in seismicity in the next several day. Tropical Storm Fay passed near this epicenter two days ago with energy that may have helped promote the event in the Indian Ridge. A similar M 4.9 hit northeast of today's epicenter on July 8, 2020, the first within about 200 km of this epicenter since an M 5.0 on May 14, 2017.

 

O: 11JUL2020 10:37:48  50.3S  112.5E mb=4.9  EMSC   SOUTHEAST INDIAN RIDGE       

 

An earthquake of M 4.7 also occurred in northeastern China near Beijing today.

NEIC reported this earthquake of M 4.7 in Northeastern China was felt with intensity V-VI in the area(s) of Northeastern China in Hebei at Tangjiazhuang, Tangshan; IV in Tianjin, Chengde and II-III at Tanggu, Gangdong, Tongzhou, Shunyi, Beijing, and Chaoyang, Liaoning. The only event in the area within about 200 km of this epicenter with M>=5 in the past 30 years was an M 5.0 on October 5, 1995. The last event in the area with M>=4.7 was an M 4.7 on December 5, 2019 and an M 4.8 on May 22, 2016.  A great earthquake in late  July, 1976 leveled most of this area and killed 200,000-600,000 persons.

 

O: 11JUL2020 22:38:24  39.8N  118.5E mb=4.7  EMSC   HEBEI, CHINA                 

 

The largest earthquake in the U.S. or Canada today was an M 4.7 in the Fox Islands, Aleutians, Alaska. It was not reported felt in this remote area. Earthquakes of M 4.8 hit within about 200 km of this epicenter on May 17 and March 1, 2020 but the only event this year of significantly larger magnitude was an M 5.0 on January 13, 2020 and an M 5.8 on October 26, 2019. Forecast 125400 expected today's event was likely within about 50 km of this epicenter in early July.

 

O: 12JUL2020 04:20:25  52.1N  169.5W mb=4.7  EMSC   FOX ISLANDS, ALEUTIAN ISLANDS

P:  6JUL2020 125400    51.9N  169.2W 3.5-5.3 CAAAA  Fox Islands, Aleutians     

 

MODERATE QUAKE IN PACIFIC-ANTARCTIC RIDGE ON QUIET DAY

 

EARTHQUAKE SUMMARY FOR JULY 10, 2020

 

Global seismicity remained at quiet levels today. No earthquakes of M>5 were reported. The strongest earthquake in the world was another on an ocean ridge - an M 5.0 on the Pacific-Antarctic Ridge. This is the strongest earthquake on the Paciric-Antarctic Ridge within  about 300 km of this epicenter since an M 5.5 on February 14, 2020 and prior to that an M 5.9 on November 22, 2018.

 

O: 10JUL2020 22:40:26  54.9S  141.0W mb=5.0  EMSC   PACIFIC-ANTARCTIC RIDGE      

 

The strongest earthquake in the U.S. or Canada today was an unfelt event of M 4.2 in the Rat Islands, Aleutians, Alaska. The last earthquake of larger magnitude in the Rat Islands was an M 4.8 on April 17, 2020 about 50 km east of today's epicenter. Forecast 125407 had expected today's event within about 25 km was likely around July 8.

 

O: 10JUL2020 23:13:22  52.2N  179.1E mb=4.2  EMSC   RAT ISLANDS, ALEUTIAN ISLANDS

P:  8JUL2020 125407    52.0N  179.0E 4.0-5.6 AAAAA  Rat Islands                

 

A pair of M 4.0 aftershocks in the area of Southern Idaho also shook that area today. NEIC reported these earthquakes of M 4.0 in  southern Idaho was felt with intensity II-III in the area(s) of southern Idaho at Stanley, Ketchum, Idaho City, Challis, Haley, Garden City, Boise. The last event the southern Idaho aftershocks zone of M>=4.0 was an M 4.4 on July 3 and prior to that an M

4.2 on June 27, 2020. Forecast 125372 had expected today's activity was likely in early July.

 

 

O: 10JUL2020 08:15:23  44.1N  115.0W mb=4.0  EMSC   SOUTHERN IDAHO

O: 10JUL2020 08:15:05  44.1N  115.1W Mw=4.0  EMSC   SOUTHERN IDAHO               

P:  6JUL2020 125372    44.5N  115.1W 2.0-3.9 BAAAA  Montana/Idaho              

 

 

MODERATE SEISMICITY IN OCEAN RIDGE AREA

 

EARTHQUAKE SUMMARY FOR JULY 9, 2020

 

It was another quiet day in global seismicity. The largest earthquakes in the world today occurred in ocean ridges. These included an M 5.3 on the Carlsberg Ridge and an M 4.9 in the Southwest Indian Ridge. These remote earthquakes were not reported felt in these areas. The M 5.3 in the Carlsberg Ridge is the largest in that region since events of M 5.5 on November 14, 2019 and  on November 27, 2019 far to the north (500-1000 km) of today's epicenter. Today's event had been expected in forecast 125244 within about 200 km of this epicenter. 

 

O: 10JUL2020 06:29:42   2.6S   68.1E Mw=5.3  EMSC   CARLSBERG RIDGE              

P: 10JUL2020 125244     1.0S   67.0E 4.0-5.4 ABAAA  Indian Ocean               

 

The earthquake of M 4.9 in the Southwest Indian Ridge is the strongest within about 250 km of that epicenter since an M 5.9 on March 6, 2020. The only other such events in the region in the past year occurred on January 26, 2020 (M 5.1) and September 24, 2019 M 6.1 ..).  Forecast 125462 had expected activity in this area was likely around July 11. This earthquake is located near the antipode of Southern California but is probably not large enough to have significant effect on regional seismicity in this area.

 

O:  9JUL2020 16:09:08  31.7S   58.3E mb=4.9  EMSC   SOUTHWEST INDIAN RIDGE       

P: 11JUL2020 125462    34.0S   55.0E 4.0-5.5 ACCAA  So. Indian Ocean           

 

The strongest earthquake in the U.S. or Canada today was an M 3.7 in Central Alaska. NEIC reported this earthquake of M 3.6 in Central Alaska  was felt with intensity II-III in the area(s) of Central Alaska at Talkeetna, Palmer, Chugiak, Eagle River and Anchorage. The last earthquake in central Alaska within about 150 km of this epicenter with M>=3.7 occurred on April 16, 2020 with M 3.8. The last in this area with M>=4 was an M 4.2 five months ago on February 15, 2020. Forecast 125414 had expected this event was likely in this area around July 9.

 

 

O:  9JUL2020 16:44:18  62.3N  148.7W mb=3.7  EMSC   CENTRAL ALASKA               

P:  9JUL2020 125414    61.2N  147.4W 3.2-4.9 ABAAA  Central Alaska             

 

 

MODERATE QUAKE SOUTH OF AUSTRALIA

 

EARTHQUAKE SUMMARY FOR JULY 8, 2020

 

The strongest earthquake in the world today was an M 5.6 south of Australia  in the western Indian-Antarctic Ridge. It was not reported felt in this remote area. The last earthquake within about 300 km of this epicenter with M>=5.6 was an M 5.6 on August 30, 2012 and an M 5.6 on April 27, 2010. No events of M>5.6 have hit the area in the past 30 years.  Forecast 125470 had expected today's epicenter in early July was likely to the east of today's epicenter.

 

O:  8JUL2020 09:08:24  49.8S  114.3E Mw=5.6  EMSC   WESTERN INDIAN-ANTARCTIC RIDGE

P:  3JUL2020 125470    49.0S  122.0E 4.0-5.8 BACAA  So. of Australia            

 

An M 4.6 also occurred in the Falkland Islands east of Southern South America today. It was not reported felt in this area. The last earthquake in the Falkland Islands of M>=4.6 was an M 4.9 on March 20, 2020 and prior to that an M 4.8 on December 8, 2018. The last event in the region with M>=5 was an M 5.4 on November 25, 2013. Forecast 125473 had expected this activity to the southeast of this epicenter was likely around July 11.

 

O:  8JUL2020 18:08:19  54.2S   60.4W mb=4.6  EMSC   FALKLAND ISLANDS REGION      

P: 11JUL2020 125473    60.0S   44.0W 3.0-5.5 BCCAA  So. So. America            

 

The strongest earthquake felt in the world today was an M 5.1 in northern Colombia. This is the strongest event in Northern Colombia within about 200 km of this epicenter since an M 5.4 on January 24, 2019. Forecast 125228 had expected today's event within about 25 km of the epicenter was likely around July 9.

 

NEIC reported this earthquake of M 5.1 in Northern Colombia  was felt with intensity III-IV in the area(s) of Colombia at Floridablanca, Bucaramanga, Cota and Subachoque, Chia, Cajica, Cepita, Maripi, Sutatausa and Zipaquira.

 

O:  9JUL2020 03:22:48   6.8N   73.0W Mw=5.1  EMSC   NORTHERN COLOMBIA            

P:  9JUL2020 125228     7.0N   73.0W 4.0-5.6 AAAAA  Colombia                   

 

UNUSUAL QUAKES SHAKE POLAND AND SOUTH AFRICA

 

EARTHQUAKE SUMMARY FOR JULY 7, 2020

 

Although no earthquakes of M>=5.1 occurred today in the world, events of M 4.4 and 4.9 shook the unusual regions of South Africa and Poland today. Still effects from the geomagnetic storm and from the full moon tides appear to have dissipated to background stresses. The M 4.9 in Poland is the strongest within about 200 km of that epicenter in Poland since an M 4.9-5.0 on July 20, 2018. The last of larger magnitude in the area was an M 5.1 on July 23, 2008. The strongest in the region in the past 30 years was an M 5.4 on December 31, 1999.  Forecast 125405 expected today's event within about 50 km of this epicenter in Poland was likely around July 6, 2020.

 

NEIC reported this earthquake of M 4.9 in Poland  was felt with intensity V in Lubin and Polkowice Dolnoslaskie, Poland and II-III in the area(s) of Poland at Dzierzonlow. This epicenter is located at 104 degrees from the M 6.8 in northern Chile of June 3, 2020 and may have been promoted by energy from that source. An M 4.3 also shook the region of Bosnia today at this distance from northern Chile as did an M 5.1 in the Kodiak Island area of Alaska. It is also at the fourth node (90 degrees) from the M 7.5 in Oaxaca, Mexico of June 23 and was probably enhanced by energy from that epicenter.

 

O:  8JUL2020 05:18:59  51.6N   16.1E mb=4.9  EMSC   POLAND                       

O:  8JUL2020 06:18:15  51.6N   16.2E ML=3.8  EMSC   POLAND                       

P:  6JUL2020 125405    51.0N   16.0E 3.0-4.7 AAAAA  Poland                     

 

The earthquake in South Africa was also unusually large. The last earthquake within about 250 km of this epicenter with M>=4.4 occurred on March 22, 2019 with M 4.9.  Forecast 125449 expected today's event within about 50 km of this epicenter was likely around July 4.

 

NEIC reported this earthquake of M 4.4 in South Africa  was felt with intensity II-III in the area(s) of South Africa at Potchefstroom, North West.

 

O:  7JUL2020 10:44:14  26.5S   27.4E mb=4.4  EMSC   SOUTH AFRICA                 

P:  4JUL2020 125449    27.0S   27.0E 3.0-4.4 AAAAA  Rep. South Africa          

 

 

The strongest earthquake in the U. S. or Canada today was also the largest in the world today. This event of M 5.1 in the Kodiak Island area of Alaska was not reported felt in this epicentral area. It is the largest event in this area since an M 5.2-5.3 on April 17, 2020 - the only  other such event in the past 8 months. Forecast 125394 had expected today's activity to the southwest was likely around July 11.

 

 

O:  8JUL2020 01:07:03  56.2N  153.9W Mw=5.1  EMSC   KODIAK ISLAND REGION, ALASKA 

P: 11JUL2020 125394    54.7N  156.9W 3.5-5.0 BBBAA  Alaska Peninsula           

 

GEOMAGNETIC STORM PROMOTES EQUATORIAL SEISMICIY

 

EARTHQUAKE SUMMARY FOR JULY 6, 2020

 

Several strong earthquakes occurred near the geomagnetic equator today. These

included an M 6.6 in the Java Sea, Indonesia and an M 6.3 south of Guam in the Yap region of Micronesia. This summary had expected an enhancement of seismicity along the geomagnetic equator in the previous issue as:

 

 

"There have been no earthquakes in the world of M>=5.5 since this quiet began.

Among factors helping to increase global seismicity at this time is the full moon of July 5 and a moderate geomagnetic storm today, the strongest since May 30, 2020 when AP reached 14. These seismic enhancement effects area likely to bring a strong earthquake near the geomagnetic equator or at high latitudes in the next several days. The effects of this  storm are summarized here as:

 

"The geomagnetic field saw slightly disturbed conditions today. The AP level was 10.  High latitude geomagnetic field also saw active conditions  with AP at 24. Geomagnetic disturbances of this level can help to promote seismicity near the geomagnetic equator and high-latitude seismicity. The M 5.5 in the region of Alaska occurred at the peak of this disturbance and may have been promoted by geomagnetic effects." (July 5-6, 2020)

 

The strongest earthquake in the world today, and the strongest in the past two weeks was an M 6.6 in the Java Sea of Indonesia. This is near the local geomagnetic equator and was probably enhanced by the geomagnetic storm today (see above). It is located in central Indonesia, an area expected to see a strong earthquake at this time due to its location with respect to the M 7.5 in Oaxaca, Mexico of June 23 as noted in previous issues of this report:

 

"... One area which is still quiet is at 144 degrees from Oaxaca - in central Indonesia, an active zone where a strong earthquake has not occurred with the current seismic enhancements." (June 27, July 6, 2020)

 

A strong earthquake of M 6.6 hit the Java Sea today. It was located at a deep focal depth of 538 km and was thus felt over a wide area including Java, Yogyakarta, Indonesia with little damage. NEIC reported maximum shaking in Surakarta, Java and Sewon, Yogyakarta of IV with II-III in Rembang, Grogol, Depok, Yogyakarta, Wonogin, Kasihan, Sewon, Bambanglipuro, and Srandakan, Indonesia. A regional aftershock of the M 6.6 in Java was reported with M 5.1. NEIC reported it was felt in Banten and Java Indonesia at Serpong, Ciputat, Pamulang, Clomas, Bogor, Depok and Jakarta. This event of M 6.6 is the strongest within about 250 km of this epicenter  since an M 6.7 on September 2, 1992 about 250 km northeast of today's epicenter. An M 7.4-7.5 also hit about 350 km west of this on August 8, 2007, the only such events in the area in the past 30 years.  Forecast 125254 had expected today's event south of Java around July 6.

 

O:  6JUL2020 22:54:49   5.6S  110.7E Mw=6.6  EMSC   JAVA SEA                     

P:  6JUL2020 125254     8.0S  108.0E 4.0-5.4 ACCAA  So. of Java                

 

The area of Yap,  Micronesia and the northern Marianas was active today. These

surround the local geomagnetic equator and were expected to see enhanced seismicity at this time (see above). The strongest of these was an M 6.2 in the State of Yap, Micronesia. This is the strongest earthquake within about 200 km of this epicenter since an M 6.3 on September 26, 1993, the only other such event  in the area in the past 30 years. Forecast 125284 had expected this earthquake within about 100 km was likely around July 7.

 

O: 06JUL2020 18:16:18  12.0N  140.3E Mw=6.2  EMSC   STATE OF YAP, MICRONESIA

O: 07JUL2020 01:20:54  12.2N  140.2E mb=4.7  EMSC   STATE OF YAP, MICRONESIA

O: 06JUL2020 21:01:09  12.6N  140.4E mb=5.1  EMSC   STATE OF YAP, MICRONESIA

O:  6JUL2020 15:30:29  11.0N  138.7E mb=5.0  EMSC   STATE OF YAP, MICRONESIA     

P:  7JUL2020 125284    11.0N  140.0E 4.0-5.4 AAAAA  So. Marianas/Guam          

 

A moderately strong earthquake of M 5.5 also occurred in the Northern Mariana/Volcano Islands region today. This is the strongest earthquake within about 200 km of this epicenter since an M 6.4 more than a year ago on June 28, 2019 and prior to that an M 5.9 on December 21, 2016. Forecast 125303 had expected today's event in this region around July 4.

 

 

O:  6JUL2020 12:58:04  21.0N  144.8E Mw=5.5  EMSC   MAUG ISLANDS REG, N. MARIANA I

P:  4JUL2020 125303    22.0N  144.0E 4.0-5.4 AAAAA  Volcano Islands            

 

 

An M 5.6 also occurred in the Izu Islands south of Honshu, Japan today.

The last earthquake in the Izu Islands within about 150 km of this epicenter with larger magnitude was an M 5.8 on April 5, 2019 and prior to that an M 5.9  on August 25, 2016. Forecast 125317 had expected this region was likely to see enhanced seismicity around July 10.

 

O:  6JUL2020 18:19:09  31.5N  138.1E Mw=5.6  EMSC   IZU ISLANDS, JAPAN REGION    

P: 10JUL2020 125317    33.0N  137.0E 3.5-4.9 BBAAA  Central/So. Honshu Japan   

 

The strongest earthquake felt in the U.S. or Canada today was an M 3.9 off the coast of Oregon. It was reported felt along the coast of Oregon with III in Lincoln City and I in Yachats, Oregon. The last earthquake of equal or larger magnitude within about 100 km of this epicenter occurred on October 2, 2019 with M 3.9. The last of significantly larger magnitude was an M 5.4 on August 16, 2019. Two event of M 4.1 hit the area during the regional activation of early July 2, 2019. Forecast 125382 had expected today's event within about 50 km was likely around July 6.

 

O:  6JUL2020 12:28:12  43.6N  129.9W mb=3.9  EMSC   OFF COAST OF OREGON          

P:  6JUL2020 125382    44.3N  129.4W 3.0-4.4 AAAAA  Off Coast of Oregon        

 

GLOBAL SEISMICITY BEGINS TO CLIMB OUT OF QUIET PERIOD

 

EARTHQUAKE SUMMARY FOR JULY 5, 2020

 

Seismicity around the world today appeared to be climbing out of the quiet period of the past 10 days. This had been announced in this summary on June 28-29, 2020, 10 days ago.

 

"Seismicity around the world today was returning to the quiet pre-Kermadec levels. It is expected that this will be the pattern of seismicity for several weeks to come. While an occasional moderately large to large quake is likely, much of the available seismic energy was dissipated in the unusually active seismic triggering following the M 7.4 in the Kermadec Islands, the M 7.5 in Oaxaca, Mexico and the annular solar eclipse across southern Asia. Most of the areas which were likely to have seen enhanced seismicity from these events have now seen it as moderately large to large earthquakes. Further moderate seismicity is likely in these areas in coming days, and the possibility of a large quake in these regions cannot be precluded at this time. One area which is still quiet is at 144 degrees from Oaxaca - in central Indonesia, an active zone where a strong earthquake has not occurred with the current seismic enhancements.  The absence of strong ocean storms, geomagnetic disturbances and/or other triggering agents for seismic enhancement at this time suggests quiet upcoming conditions." (June 29, 2020)

 

There have been no earthquakes in the world of M>=5.5 since this quiet began.

Among factors helping to increase global seismicity at this time is the full moon of July 5 and a moderate geomagnetic storm today, the strongest since May 30, 2020 when AP reached 14. These seismic enhancement effects area likely to bring a strong earthquake near the geomagnetic equator or at high latitudes in the next several days. The effects of this  storm are summarized here as:

 

"The geomagnetic field saw slightly disturbed conditions today. The AP level was 10.  High latitude geomagnetic field also saw active conditions  with AP at 24. Geomagnetic disturbances of this level can help to promote sesismicity near the geomagnetic equator and high-latitude seismicity. The M 5.5 in the region of Alaska occurred at the peak of this disturbance and may have been promoted by geomagnetic effects." (July 6, 2020)

 

The strongest earthquake in the world today was an M 5.9 in central Vanuatu. NEIC reported it was felt with intensity IV in Luganville,Sanma, Vanuatu. This epicenter is at 101 degrees from the M 7.5 in Oaxaca, Mexico of June 23 and was probably promoted by energy from that source. An event of M>=5.9 last hit the area within about 200 km of this epicenter a half year ago on December 14, 2019.

Forecast 125440 had expected today's event within about 50 km was likely around

July 7.

 

O:  5JUL2020 18:50:01  14.9S  167.4E Mw=5.9  EMSC   VANUATU                      

P:  7JUL2020 125440    15.0S  168.0E 4.0-5.6 AAAAA  Vanuatu Islands            

 

The strongest earthquake in the U.S. or Canada today was an M 5.5 in the Alaska Peninsula near Unimak Island. It was not reported felt in this remote area. This event occurred near local solar midnight and was probably enhanced by tidal stresses associated with the full moon which was nearly coincident with it (as well as with the maximum of today's geomagnetic disturbance). The tidal seismic forecast had read:

 

"The full moon arrived on July 5, 2020 at 04:44 UT. Longitudes at local midnight at this time are near 70 degrees West longitude and 110 East Longitude. These include seismic areas in Puerto Rico and the northern Caribbean and the western Coast of South and Central America in the west and western Indonesia in the east. These areas may see enhanced seismicity in the next several days. Enhanced seismicity is also possible in other areas but is not expected to be exceptional with this full moon." (July 3-6, 2020)

 

The last earthquake within about 200 km of today's earthquake south of Alaska with M>=5.5 occurred more than a year-and-a-half ago on December 31, 2018 with M 6.0. Forecast 125411 had expected today's event in this area was likely around July 4.

 

O:  5JUL2020 08:53:33  53.3N  160.4W mb=5.5  EMSC   SOUTH OF ALASKA              

O:  5JUL2020 21:45:58  53.3N  160.5W ml=3.3  EMSC   SOUTH OF ALASKA              

P:  4JUL2020 125411    54.3N  161.4W 3.5-5.1 AAAAA  Unimak Islands, Aleutians  

 

An M 4.5 aftershock also occurred today in the western Nevada aftershock zone near Tonopah, Nevada. NEIC reported it was felt with intensity IV in Gabbs, Nevada and II-III in Fallon, Glenbrook, Las Vegas, Nevada and in California at Bishop, June Lake, Yosemite, North Fork. Forecast 125310 had expected this activity was likely around July 5.

 

O: 05JUL2020 20:42:27  38.1N  118.0W ml=2.1  EMSC   NEVADA

O: 05JUL2020 21:27:56  38.1N  118.0W ml=2.4  EMSC   NEVADA

O: 05JUL2020 23:06:20  38.1N  118.0W ml=2.0  EMSC   NEVADA

O: 05JUL2020 18:01:05  38.2N  118.0W ML=2.8  EMSC   NEVADA

O: 05JUL2020 21:26:43  38.2N  118.0W ML=2.5  EMSC   NEVADA

O: 05JUL2020 22:04:34  38.2N  118.0W ML=2.3  EMSC   NEVADA

O: 05JUL2020 23:12:29  38.2N  118.1W ml=2.3  EMSC   NEVADA

O: 06JUL2020 06:10:37  38.2N  117.9W ml=3.4  EMSC   NEVADA

O:  6JUL2020 06:12:54  38.2N  117.9W mb=4.1  EMSC   NEVADA

O:  6JUL2020 06:12:54  38.2N  117.9W mb=4.5  ANSS   NEVADA                       

P:  5JUL2020 125310    38.0N  118.0W 2.5-4.5 AAAAA  California/Nevada area     

 

MODERATE QUAKE SHAKES NORTHERN ALGERIA

 

EARTHQUAKE SUMMARY FOR JULY 4, 2020

 

It was another in a series of quiet days in global seismicity. The most unusual

earthquake felt today was an M 4.6 in Northern Algeria.  NEIC reported this earthquake of M 4.5 in northern Algeria  was felt with intensity II-III in the area(s) of northern Algeria with V in Batna, Algeria.  An earthquake of M 5.0 hit west of this in Northern Algeria on March 26, 2020. The only other such event within about 200 km within the past year was an M 4.9 about 150 km to the north on January 24, 2020. Forecast 125324 had expected this activity was likely around July 4. This epicenter is near the antipode of the M 7.4 in the Kermadec Islands of June 18 and was probably promoted by focused energy from that event.

 

O:  4JUL2020 07:59:39  35.6N    6.3E mb=4.6  EMSC   NORTHERN ALGERIA             

P:  4JUL2020 125324    37.0N    5.0E 3.5-4.9 ABAAA  Algeria/Spain              

 

The strongest earthquake in the world today was an M 5.5 in Tajikistan. This  quake occurred near local solar noon and may have been enhanced by seismic energy from the full moon of July 5. The seismic forecast for that full moon has been published in this summary in previous issues as:

 

"The full moon arrived on July 5, 2020 at 04:44 UT. Longitudes at local midnight at this time are near 70 degrees West longitude and 110 East Longitude. These include seismic areas in Puerto Rico and the northern Caribbean and the western Coast of South and Central America in the west and western Indonesia in the east. These areas may see enhanced seismicity in the next several days. Enhanced seismicity is also possible in other areas but is not expected to be exceptional with this full moon." (July 3-5, 2020)

 

This epicenter is also near the path of the total solar eclipse of June 21 and may have been influenced by tidal effects associated with that event. Forecast 125047 had expected this event within about 100 km was likely at the end of June. The last earthquake within about 150 km of this epicenter with M>=5.5 occurred on January 24, 2020 with M 5.5. The last with larger magnitude was an M 5.8 on May 5, 2017.

 

O:  4JUL2020 09:53:00  39.1N   71.0E mb=5.5  EMSC   TAJIKISTAN                   

P: 28JUN2020 125047    39.0N   72.0E 3.8-5.3 CAAAA  Hindu Kush/Pakistan        

 

The strongest earthquake in the U.S or Canada today was an M 3.7 in the western Andreanof Islands, Aleutians, Alaska. It was not reported felt in this remote area. The last earthquake in this region within about 150 km of today's epicenter with M>=3.7 occurred on June 22, 2020 when an M 3.8 aftershock of an M 5.2 on June 19 occurred. Forecast 125397 had expected today's event was likely in this area around July 6.

 

O:  4JUL2020 15:55:46  51.3N  178.1W ml=3.7  EMSC   ANDREANOF ISLANDS, ALEUTIAN IS

P:  6JUL2020 125397    51.7N  179.7W 3.5-5.0 AAAAA  Andreanoff Isls, Aleutians 

 

 

 

SUBSOLAR HAWAII; PUERTO RICO SHAKE

 

EARTHQUAKE SUMMARY FOR JULY 3, 2020

 

The areas of Hawaii and Puerto Rico saw significantly enhanced seismicity today.

These areas are at 18-19 North latitude and are subsolar at this time when the sun reaches its zenith while passing over and is directly overhead at local solar noon in these two regions. In addition the full moon of July 5, 2020 is at its maximum while over Puerto Rico as noted in this summary:

 

"The full moon will arrive on July 5, 2020 at 04:44 UT. Longitudes at local midnight at this time are near 70 degrees West longitude and 110 East Longitude. These include seismic areas in Puerto Rico and the northern Caribbean and the western Coast of South and Central America in the west and western Indonesia in the east. These areas may see enhanced seismicity in the next several days. Enhanced seismicity is also possible in other areas but is not expected to be exceptional with this full moon." (July 4, 2020)

 

The strongest felt earthquake of the day in the world was an M 5.3 aftershock in the southern Puerto Rico aftershock zone. It was felt with some damage with intensity VI in Ensenada and V in Lajas, Guanica, Sabana Grande, Cabo Rojo, San German, Yauco, Guayanilla and IV in Hormigueros and Maricao, Puerto Rico among others. It was preceded by, among other events, an M 4.9-5.1 which was also widely felt in this area of Puerto Rico. A number of light to moderate aftershocks were also felt. The area has been active in the previous week as noted in the June 28 issue of this summary:

 

"A series of moderate earthquakes in the north Atlantic Ocean today culminated

with a pair of strongly felt earthquakes in southern Puerto Rico. This pair of moderate earthquakes of M 4.7 and 4.9 shook the southern Puerto Rico aftershock zone near Ponce today. NEIC reported these were felt with maximum intensity V in Puerto Rico at Ensenada, Guanica, Sabana Grande, Guayanilla, San German  and Ponce and IV in Lajas, Yauco, Cabo Rojo, Penuelas and Hormigueros. The M 4.9 is the strongest aftershock in southern Puerto Rico in the vicinity of The M 6.5 of January 7, 2020 since an M 5.4 on May 2, 2020 and an M 5.0 on  February 4, 2020. Forecast 125004 had expected today's activity was likely around June 27." (June 27-28, 2020)

 

The first of today's moderate quakes in Puerto Rico occurred near local solar noon and was probably enhanced by tidal effects from the full moon of July 5 which maximizes over Puerto Rico. Other earthquakes of M>=4 today in  Puerto Rico included the M 5.3 aftershock as well as events of M 4.2, 4.3 and 4.4 Forecast 125282 had expected today's activity within about 10 km of these epicenter was likely around July 5.

 

O: 03JUL2020 13:54:50  17.9N   67.0W Mw=5.1  EMSC   PUERTO RICO REGION

O: 03JUL2020 21:17:38  17.9N   67.0W mb=4.2  EMSC   PUERTO RICO REGION

O: 03JUL2020 20:58:19  17.9N   67.0W mb=4.3  EMSC   PUERTO RICO

O: 03JUL2020 21:00:07  17.9N   67.0W mb=4.4  EMSC   PUERTO RICO REGION

O: 03JUL2020 20:49:46  17.9N   67.0W mb=5.3  EMSC   PUERTO RICO REGION

P:  5JUL2020 125282    18.0N   67.0W 3.4-4.9 AAAAA  Puerto Rico                

 

 

The strongest earthquake in the U.S. or Canada today occurred in Hawaii with M 4.7. NEIC reported it was felt with intensity IV in Hawaii at Hakalau, Pahoa, Volcano,Mountain View, Hawaii National Park, Kuritstown, Keaau, Hilo, Pahala, Papaikou and Pepeekeo. An M 4.5 aftershock was felt in a similar area later in the day. This activity occurred within about an hour of local solar midnight, a time when tidal stresses are maximized at full moon and was probably promoted by strong tidal effects. An M 4.3 hit the area on June 21 but the last of larger magnitude in Hawaii was an M 4.9 on November 11, 2019. Forecast 124988 had expected activity within about 15 km of this epicenter was likely at the end of June.

 

O:  4JUL2020 00:18:49  19.3N  155.1W mb=4.5  EMSC   ISLAND OF HAWAII, HAWAII     

O:  3JUL2020 09:20:01  19.3N  155.1W mb=4.7  EMSC   ISLAND OF HAWAII, HAWAII     

P: 25JUN2020 124988    19.2N  155.2W 3.0-4.4 CAAAA  Hawaii                      

 

Aftershocks of M 3.8 and 3.9-4.4 also shook the southern Idaho aftershocks zone today. NEIC reported they were felt with intensity II-III in southern Idaho at Stanley, Lowman, Ketchum, Boise, May. Earthquakes of M 4.6 and 4.7 hit that area of Idaho on June 25 and June 14, the last such aftershocks of M>=4.4 in the area of the M 6.5 of March 31, 2020. Forecasts 125372 had expected today's activity was likely within about 10 km  of these epicenters around July 6.

 

O: 03JUL2020 07:52:33  44.4N  115.2W Ml=2.0  EMSC   SOUTHERN IDAHO

O: 03JUL2020 08:05:31  44.4N  115.2W Ml=2.1  EMSC   SOUTHERN IDAHO

O: 03JUL2020 13:50:29  44.4N  115.2W Ml=4.4  EMSC   SOUTHERN IDAHO

O: 03JUL2020 15:24:01  44.5N  115.2W ML=3.0  EMSC   SOUTHERN IDAHO

O:  4JUL2020 02:57:22  44.3N  115.2W ML=3.3  EMSC   SOUTHERN IDAHO               

P:  6JUL2020 125372    44.5N  115.1W 2.0-3.9 AAAAA  Montana/Idaho              

 

A light M 2.1 was recorded in southwestern Maine today. It was not reported felt in this area. The last earthquake of M>=2.1 within about 100 km of this epicente occurred September 7, 2019 with M 2.3 and with M 2.1 on April 11, 2020. Forecast 125369 had expected this activity was likely around July 4. This event occurred near local solar midnight at a longitude of maximum tidal stress with the full moon and may have been promoted by tidal effects from that alignment.

 

O:  4JUL2020 06:23:27  44.2N   70.7W ML=2.1  EMSC   MAINE                        

P:  4JUL2020 125369    44.0N   70.0W 2.0-3.9 AAAAA  Maine                       

 

The largest earthquake of the past week in the world occurred today as an M 5.4 in the Solomon Islands. An M 5.6 was recorded in the Ascension Island area on June 29 but the last earthquake in the world of significantly larger magnitude was an M 6.3 on June 25, 2020 in southern China. The earthquake in China occurred near the area of maximum solar eclipse of June 21 and was probably promoted by that tidal alignment. Today's M 5.4 and 5.2 in the D'Entrecasteaux Islands south of the Solomon Islands occurred within minutes of local solar noon and was probably promoted by high tidal stresses which maximize at this hour. Forecast 125167 had expected seismicity to the west was likely around June 29. The last earthquake of M 5.4 or greater within about 200 km of this epicenter in  the D'Entrecasteaux Islands was an M 5.6 on November 17, 2014. An earthquake of M 6.1 hit the area about 300 km to the southwest of this on March 10, 2019, the only other such event in the area in the past five years.

 

O:  4JUL2020 01:34:44   9.7S  154.8E mb=5.4  EMSC   D'ENTRECASTEAUX ISLANDS REGION

O:  4JUL2020 01:49:58   9.8S  154.9E mb=5.2  EMSC   D'ENTRECASTEAUX ISLANDS REGION

P: 29JUN2020 125167    10.0S  151.0E 4.0-5.4 BACAA  New Ireland                

 

 

 

 

 

 

 

 

OCEAN RIDGES SHOW ENHANCED SEISMICITY

MODERATE EARTHQUAKES SHAKE CENTRAL MEXICO AND SOUTHERN KURIL ISLANDS, JAPAN

 

EARTHQUAKE SUMMARY FOR JULY 2, 2020

 

It was another quiet day in global seismicity. The strongest earthquake of the

day was an M 5.2 in the Kuril Islands of Japan. JMA reported it was lightly

felt in northern Japan. The only larger event within about 150 km  of this epicenter in the past year was an M  5.3 on October 14, 2019. An M 7.0 hit the area about 250 km to the northeast of this on February 13, 2020. Forecast 125089 had expected today's event within about 100 km of this epicenter was likely at the end of June, 2020. 

 

O:  2JUL2020 07:07:25  43.8N  147.9E mb=5.2  EMSC   KURIL ISLANDS                

P: 27JUN2020 125089    44.0N  147.0E 3.5-5.4 BAAAA  Hokkaido, Japan             

 

An M 5.2 also shook areas of Oaxaca, Mexico west of the aftershock zone of the M 7.5 event of June 23. Earthquakes of M 5.2-5.3 have previously hit this area within about 100 km of this epicenter on January 15,, 2020 and August 22, 2018 but the last of larger magnitude within this area was an M 5.7 on July 19, 2018. Forecasts 125280 and 125002 had expected this activity in late June or early July, 2020.

 

O:  2JUL2020 16:17:57  16.4N   97.8W ML=5.2  EMSC   OFFSHORE OAXACA, MEXICO      

P:  5JUL2020 125280    16.0N   96.0W 3.5-5.8 BAAAA  Oaxaca, Mexico             

P: 28JUN2020 125002    16.0N   96.0W 3.5-5.1 BAAAA  Oaxaca, Mexico             

 

The strongest earthquake in the U.S. or Canada today was an M 4.6 south of Alaska in the Unimak, Alaska area. This earthquake was not reported felt in this remote area. The last earthquake within about 150 km of this epicenter with M>=4.6 occurred on June 9, 2020 also with M 4.6 and prior to that on May 9 with M 4.7. The last earthquake of larger magnitude in this area was an M 5.1 on February 15, 2019.  Forecast 125143 had expected today's event in this area was likely around June 30.

 

 

O:  2JUL2020 22:24:59  53.9N  161.2W mb=4.6  EMSC   SOUTH OF ALASKA              

P: 30JUN2020 125143    54.7N  161.2W 3.5-4.9 AAAAA  Unimak Islands, Aleutians  

 

EARTHQUAKE SUMMARY FOR JULY 1, 2020

 

A series of moderate earthquakes occurred along ocean ridges today in the greatest seismicity of the day. Most of these were M 4.6-5.1. They were not reported felt in these remote epicentral areas. These events occurred with M 5.1 in the Southern East Pacific Rise and in the Western Indian-Antarctic Ridge and in the Greenland Sea north of Norway with M 4.6 and 3.4.

 

The M 5.1 in the East Pacific Rise was the strongest within about 300 km of that epicenter since an M 5.5 on September 1, 2019. 

 

Forecast 125217 had expected area would be active at the end of June.

 

O:  2JUL2020 03:35:20  49.5S  115.5W Mw=5.1  EMSC   SOUTHERN EAST PACIFIC RISE   

 

The M 5.1 in the Western Indian-Antarctic Ridge south of Australia was the strongest within about 300 km of that epicenter since an M 5.1  on July 5, 2019 and prior to that an M 5.2 on November 6, 2017.

 

O:  2JUL2020 00:16:33  49.6S  126.2E Mw=5.1  EMSC   WESTERN INDIAN-ANTARCTIC RIDGE

P: 26JUN2020 125217    49.0S  122.0E 4.0-5.7 CACAA  So. of Australia           

 

The earthquake in the Greenland Sea is the largest within about 250 km of that epicenter in the past half year. An M 4.8 occurred near this epicenter on December 18, 2019 and  prior to that an  M 4.6 on June 21, 2019. Forecast 125159 had expected activity in this area at the end of June.

 

O:  2JUL2020 06:54:36  75.6N    7.8E Mn=4.6  EMSC   GREENLAND SEA                

O:  2JUL2020 06:52:45  75.8N    8.6E Mn=3.4  EMSC   GREENLAND SEA                

P: 30JUN2020 125159    74.0N   14.0E 3.0-4.6 ABAAA  Norway                     

 

O:  1JUL2020 22:42:53   7.3S   68.0E mb=4.9  EMSC   MID-INDIAN RIDGE             

P: 27JUN2020 124960     3.0S   68.0E 4.0-5.4 BCAAA  Indian Ocean                

 

The strongest earthquake in the U.S. or Canada today was an M 3.9 in the Alaska Peninsula. It was not reported felt in this remote area. The last earthquake in the Alaska Peninsula of M>=3.9 occurred on June 12, 2020 with M 4.4 but an M 4.6 hit west of this on June 9. The largest earthquake in the Alaska Peninsula in the past half year was an M 4.9 on February 17, 2020. Forecast 125143 had expected today's activity to the southwest around June 30.

 

O:  2JUL2020 09:59:12  55.9N  158.8W ml=3.9  EMSC   ALASKA PENINSULA             

P: 30JUN2020 125143    54.7N  161.2W 3.5-4.9 ABBAA  Unimak Islands, Aleutians  

 

QUIET SEISMIC PATTERN EXPECTED

 

EARTHQUAKE SUMMARY FOR JUNE 29, 2020

 

Seismicity around the world today was returning to the quiet pre-Kermadec levels. It is expected that this will be the pattern of seismicity for several weeks to come. While an occasional moderately large to large quake is likely, much of the available seismic energy was dissipated in the unusually active seismic triggering following the M 7.4 in the Kermadec Islands, the M 7.5 in Oaxaca, Mexico and the annular solar eclipse across southern Asia. Most of the areas which were likely to have seen enhanced seismicity from these events have now seen it as moderately large to large earthquakes. Further moderate seismicity is likely in these areas in coming days, and the possibility of a large quake in these regions cannot be precluded at this time. One area which is still quiet is at 144 degrees from Oaxaca - in central Indonesia, an active zone where a strong earthquake has not occurred with the current seismic enhancements.  The absence of strong ocean storms, geomagnetic disturbances and/or other triggering agents for seismic enhancement at this time suggests quiet upcoming conditions.

 

The strongest earthquakes in the world today were a pair of M 5.4 and 4.7 events in southeastern Honshu, Japan south of Tokyo. JMA reported they were felt lightly in the epicentral areas. These are unusual epicenters with the last event of M>=5.4 within about 100 km of them occurring  as an M 5.5 on December

24, 2018 but the last event of this size in the area between 33 and 34 North Latitude was an M 5.4 on December 18, 2009 more than 10 years ago. Forecast 125058 had expected this activity within about 25 km of the epicenters was likely around June 28. Like other recent moderately large quakes in Honshu, Japan this occurred at 105-106 degrees from the M 7.5 in Oaxaca, Mexico of June 23 and was probably promoted by energy from that source.

 

O: 29JUN2020 19:37:08  33.8N  141.9E mb=4.7  EMSC   OFF EAST COAST OF HONSHU, JAPA

O: 29JUN2020 09:52:49  33.9N  141.6E Mw=5.4  EMSC   OFF EAST COAST OF HONSHU, JAPA

P: 28JUN2020 125058    34.0N  142.0E 4.0-5.4 AAAAA  Off East Coast Honshu      

 

An unusual earthquake of M 5.1 hit the Sabah area of Malaysia today. This epicenter is at 141 degrees from the Oaxaca, Mexico epicenter and may have been promoted from that source. An M 4.4 in Flores also occurred today at 143 degrees from Oaxaca. The last earthquake within about 300 km of the Sabah quake today with M>=5 was an M 5.2 on March 8, 2018. Today's event and the 2018 quake are probably aftershocks of an M 6.0 that hit nearby on June 4, 2015, more than five years ago. Forecasts 124945 and 124959 had expected regional seismic enhancement at the end of June.

 

O: 30JUN2020 01:58:30   6.9N  116.4E Mw=5.1  EMSC   SABAH, MALAYSIA               

P: 26JUN2020 124945     1.0N  123.0E 4.0-5.6 BCCAA  Mindanao, Philippines      

 

O: 30JUN2020 06:27:10   8.4S  121.4E Mw=4.9  EMSC   FLORES REGION, INDONESIA     

P: 29JUN2020 124959     7.0S  120.0E 4.0-5.4 ABBAA  Flores Island area          

 

The swarm of light earthquakes on the Texas-New Mexico border continued today for the third day. This summary noted these in the previous issue as:

 

"The series of earthquakes in New Mexico near the Texas border also continued at an active level today including 10 minor quakes in the past day. This series of light earthquakes has been felt in the past two days in New Mexico and western Texas. The largest today was an M 3.1. NEIC reported this earthquake of M 3.1 in New Mexico  was felt with intensity II-III in the area(s) of Midland, Texas.  Forecast 125060 had expected this activity to the south was likely around  June 23." (June 28-29, 2020)

 

These events are located at the maximum longitude of tidal stresses with the past new moon (103 degrees) and may have been promoted by tidal stresses.

 

O: 29JUN2020 10:04:51  32.8N  103.4W mb=2.7  EMSC   NEW MEXICO

O: 29JUN2020 15:19:37  32.8N  103.5W ML=3.1  EMSC   NEW MEXICO

O: 30JUN2020 02:14:38  32.8N  103.5W ML=2.6  EMSC   NEW MEXICO

O: 29JUN2020 09:07:57  32.8N  103.5W mb=2.5  EMSC   NEW MEXICO                   

P: 23JUN2020 125060    31.4N  103.8W 2.0-4.0 CBAAA  SW U.S.A                   

 

A moderately strong earthquake of M 5.6 also occurred in the South Mid-Atlantic Ridge near Ascension Island today. The last earthquake within about 250 km of this epicenter in the Ascension Island area was an M 5.9 on January 27, 2020. Forecast 125171 had expected today's activity about 250 km south of today's epicenter was likely around June 25.

 

O: 29JUN2020 19:40:12  11.7S   13.4W Mw=5.6  EMSC   ASCENSION ISLAND REGION      

P: 25JUN2020 125171    14.0S   14.0W 4.0-5.6 BCAAA  So. Mid-Atlantic Ridge     

 

ACTIVE CONDITIONS CONTINUE IN GREECE AND TURKEY

 

EARTHQUAKE SUMMARY FOR JUNE 28, 2020

 

Active seismicity continued today in the region of Greece and Turkey which has

been at enhanced seismicity levels over the past three days following the M 7.5 in Oaxaca, Mexico at 103-105 degrees distance on June 23, 2020. The strongest earthquake in the world today was an M 5.5 in the Dodecanese Islands, near the Greek-Turkish border.  The mainshock of M 5.5 was reported felt with maximum intensity VI in Koycegiz, Mugla, Turkey and V in Dalaman, Marmara, Turkey and Pastida, Rodos, Paradision, Greece with lesser shaking within about 100 km of the epicenter. An M 4.8 aftershock was reported felt with maximum intensity IV in Rodos. Greece and Nurdagi, Turkey and II-III in Marmara, Dalaman, Turkey and in Greece in the Dodecanese Islands at Kos, Simi, Mugla.  Like earthquakes in Crete, Greece and western Turkey of the past several days, this epicenter is located at 105 degrees from the M 7.5 in Oaxaca, Mexico of June 23 and

was probably promoted by concentrated energy from that source. The last earthquake in the Dodecanese Islands of Greece within about 150 km of the M 5.5 today occurred as an M 5.8 nearly a year ago on August 8, 2019 and prior to that an M 5.7 on March 20, 2019. Forecast 125076 had expected today's events were likely about 150 km northeast of today's epicenter most likely around June 28.

 

O: 29JUN2020 04:06:24  36.7N   28.2E mb=4.7  EMSC   DODECANESE IS.-TURKEY BORDER R

O: 28JUN2020 17:43:29  36.7N   28.3E Mw=5.5  EMSC   DODECANESE IS.-TURKEY BORDER R

P: 28JUN2020 125076    38.0N   29.0E 3.5-5.1 ABAAA  Turkey                     

 

Earthquakes also continued in Crete today. The largest of these was an M 4.4 in Crete which was lightly felt in the epicentral area. These had been expected around June 25-29 in Crete and the Aegean Sea within this epicentral area. They appear to be aftershocks of the M 4.8 on June 26, 2020. When the event occurred in Crete on June this summary noted in this regard:

 

 

"A series of moderate earthquakes also occurred in the area of Crete, Greece today. The M 4.8 in Crete was reported by NEIC with maximum intensity V in Karpathos, Dodecanese Islands, Greece. These are located at 105 degrees from the epicenter of the Oaxaca, Mexico earthquake of M 7.7 on June 23  and were probably promoted by energy from that event as expected in previous issues of this summary:

 

 

"Far-field triggering is likely with this earthquake. Areas near 144 degrees include Minahasa, Indonesia where an M 5.9-6.1 occurred earlier today; India, Myanmar, Mayotte. The antipode at 16S 84E is in the Indian Ocean and is not seismic. Areas at 103 degrees from the Oaxaca epicenter include the east coast of Honshu, Japan and Guam as well as western Turkey and Greece and New Zealand from Cook Strait through South Island; the Vanuatu Islands. The fourth node at 90 degrees is prominent in the area south of the Kermadec Islands, the Kuril Islands, the French-Swiss Alps where an M 3.8 occurred earlier in the day.  A lack of moderate seismicity in the region of Honshu, Japan today is unsettling and may suggest a seismic quiescence following the Mexico M 7.4, a quiet which is likely to be broken soon." (June 23-24, 27, 2020)

 

O: 28JUN2020 23:45:24  35.5N   26.7E ML=3.2  EMSC   CRETE, GREECE

O: 28JUN2020 13:42:14  35.5N   26.7E ML=3.3  EMSC   CRETE, GREECE

O: 28JUN2020 11:18:35  35.5N   26.7E mb=4.4  EMSC   CRETE, GREECE                

P: 25JUN2020 125045    34.0N   27.0E 3.0-4.6 BBAAA  Crete                      

P: 29JUN2020 125027    36.0N   24.0E 3.0-4.8 AABAA  Aegean Sea                 

 

Other activity near 103 degrees from Oaxaca, Mexico continued in southeastern Honshu, Japan (M 4.7).

 

Moderate aftershocks also continued today in the region of Southern Puerto Rico. The strongest today was an M 4.6 and M 4.2. NEIC reported it was felt with maximum intensity V in Puerto Rico at Guanica, Guayanilla, San German and Ponce with IV in Lajas, Sabana Grande, Yauco, Cabo Rojo, Penuelas and Hormigueros. These followed earthquakes of M 4.7 and 4.9 in the area yesterday. This summary had noted these in the previous issue as:

 

 

"A series of moderate earthquakes in the north Atlantic Ocean today culminated with a pair of strongly felt earthquakes in southern Puerto Rico. This pair of moderate earthquakes of M 4.7 and 4.9 shook the southern Puerto Rico aftershock zone near Ponce today. NEIC reported these were felt with maximum intensity V in Puerto Rico at Ensenada, Guanica, Sabana Grande, Guayanilla, San German  and Ponce and IV in Lajas, Yauco, Cabo Rojo, Penuelas and Hormigueros. The M 4.9 is the strongest aftershock in southern Puerto Rico in the vicinity of The M 6.5 of January 7, 2020 since an M 5.4 on May 2, 2020 and an M 5.0 on  February 4, 2020. Forecast 125004 had expected today's activity was likely around June 27." (June 27-28, 2020)

 

O: 28JUN2020 23:12:46  17.8N   67.0W ML=4.0  EMSC   PUERTO RICO REGION

O: 28JUN2020 18:19:14  17.9N   66.8W Md=3.0  EMSC   PUERTO RICO REGION

O: 28JUN2020 07:15:17  17.9N   66.9W ML=3.0  EMSC   PUERTO RICO REGION

O: 29JUN2020 03:56:39  17.9N   66.9W ML=3.2  EMSC   PUERTO RICO REGION

O: 28JUN2020 11:52:35  17.9N   66.9W ML=3.5  EMSC   PUERTO RICO REGION

O: 28JUN2020 11:49:22  17.9N   66.9W ML=3.6  EMSC   PUERTO RICO REGION

O: 28JUN2020 07:56:44  17.9N   66.9W Md=3.1  EMSC   PUERTO RICO

O: 28JUN2020 22:34:16  17.9N   67.0W ML=3.0  EMSC   PUERTO RICO REGION

O: 28JUN2020 21:43:57  17.9N   67.0W Mw=3.9  EMSC   PUERTO RICO REGION

O: 28JUN2020 06:54:23  18.0N   66.9W ML=3.0  EMSC   PUERTO RICO

O: 28JUN2020 07:58:53  18.0N   66.9W ML=3.5  EMSC   PUERTO RICO

O: 28JUN2020 11:54:21  18.0N   66.9W ML=3.7  EMSC   PUERTO RICO

O: 28JUN2020 22:48:48  18.0N   66.9W Mw=4.4  EMSC   PUERTO RICO

O: 28JUN2020 08:15:55  18.0N   67.0W ML=3.1  EMSC   PUERTO RICO

O: 28JUN2020 22:10:45  17.8N   66.9W ML=3.5  EMSC   PUERTO RICO REGION           

P: 27JUN2020 125004    18.0N   66.0W 3.4-5.2 AAAAA  Puerto Rico                

 

The strongest earthquake in the U.S. or Canada today was an M 3.7 in the Fox Islands, Aleutians, Alaska. NEIC reported this earthquake of M 3.7 in  the Fox Islands, Alaska was felt with intensity II-III in the area(s) of Unalaska, Alaska. This area has been active in June with an M 4.8 on June 13 and an M 4.5 on June 15. The last event of M>=3.7 in the Fox Islands within about 150 km of today's epicenter occurred June 19, 2020 with M 3.7. Forecast 125128 had expected today's event was likely within about 50 km of this epicenter around June 29.

 

O: 29JUN2020 02:02:36  53.8N  166.8W mb=3.7  EMSC   FOX ISLANDS, ALEUTIAN ISLANDS

P: 29JUN2020 125128    53.6N  166.1W 3.5-4.9 AAAAA  Fox Islands, Aleutians     

 

The series of earthquakes in New Mexico near the Texas border also continued at an active level today including 10 minor quakes in the past day. This series of light earthquakes has been felt in the past two days in New Mexico and western Texas. The largest today was an M 3.1. NEIC reported this earthquake of M 3.1 in New Mexico  was felt with intensity II-III in the area(s) of Midland, Texas.  Forecast 125060 had expected this activity to the south was likely around  June 23.

 

O: 28JUN2020 14:05:40  32.8N  103.5W ML=2.5  EMSC   NEW MEXICO

O: 28JUN2020 17:09:25  32.8N  103.5W ML=3.1  EMSC   NEW MEXICO

O: 28JUN2020 09:30:32  32.8N  103.5W mb=2.4  EMSC   NEW MEXICO

O: 28JUN2020 10:10:41  32.8N  103.5W mb=2.5  EMSC   NEW MEXICO

O: 28JUN2020 08:14:44  32.8N  103.5W mb=2.6  EMSC   NEW MEXICO

O: 28JUN2020 08:19:06  32.8N  103.5W mb=2.6  EMSC   NEW MEXICO

O: 28JUN2020 12:51:49  32.8N  103.5W mb=2.6  EMSC   NEW MEXICO

O: 28JUN2020 07:26:43  32.8N  103.5W mb=2.8  EMSC   NEW MEXICO

O: 28JUN2020 11:13:14  32.7N  103.4W mb=2.7  EMSC   NEW MEXICO                   

P: 23JUN2020 125060    31.4N  103.8W 2.0-4.0 BBAAA  SW U.S.A                   

 

NORTH ATLANTIC SEES ENHANCED SEISMICITY;  QUAKES IN SOUTHERN PUERTO RICO

 

EARTHQUAKE SUMMARY FOR JUNE 27, 2020

 

A series of moderate earthquakes in the North Atlantic Ocean today culminated with a pair of strongly felt earthquakes in southern Puerto Rico. This pair of moderate earthquakes of M 4.7 and 4.9 shook the southern Puerto Rico aftershock zone near Ponce today. NEIC reported these were felt with maximum intensity V in Puerto Rico at Ensenada, Guanica, Sabana Grande, Guayanilla, San German  and Ponce and IV in Lajas, Yauco, Cabo Rojo, Penuelas and Hormigueros.  The M 4.9 is the strongest aftershock in southern Puerto Rico in the vicinity of The M 6.5 of January 7, 2020 since an M 5.4 on May 2, 2020 and an M 5.0 on  February 4, 2020. Forecast 125004 had expected today's activity was likely around June 27.

 

O: 28JUN2020 07:15:17  17.9N   66.9W ML=3.0  EMSC   PUERTO RICO REGION

O: 28JUN2020 06:45:05  17.9N   66.9W mb=4.7  EMSC   PUERTO RICO REGION

O: 27JUN2020 14:04:05  18.0N   66.8W Md=3.0  EMSC   PUERTO RICO REGION

O: 28JUN2020 06:54:23  18.0N   66.9W ML=3.0  EMSC   PUERTO RICO

O: 28JUN2020 07:58:53  18.0N   66.9W ML=3.5  EMSC   PUERTO RICO

O: 28JUN2020 07:30:39  18.0N   66.9W ML=3.6  EMSC   PUERTO RICO

O: 28JUN2020 06:42:41  17.8N   66.9W Mw=4.9  EMSC   PUERTO RICO REGION           

P: 27JUN2020 125004    18.0N   66.0W 3.4-5.2 AAAAA  Puerto Rico                

 

The moderate earthquakes in the North Atlantic today included at least four of M 4.3-4.5. These occurred off the west coast of Portugal (M 4.4); north of this in the Cape St. Vincent Ridge (M 4.3); about 200 km north of these with M 4.4 and in the North Atlantic west of France with M 4.5. These are generally antipodal to recent strong activity in New Zealand - especially the M 6.0 in South Island two days ago and the M 4.5 today in the North Atlantic. The series is reminiscent of a similar series in the area of that followed an unusual M 4.9 off the west coast of North Island on June 13 and was noted in this summary at the time:

 

"The earthquake in South Island, New Zealand today was accompanied by an unusual earthquake west of North Island, New Zealand of M 4.7. The epicenter of this event is quite unusual. No earthquakes of M>=4.0 have occurred in this region northwest of New Zealand within about 300 km in at least 30 years. The only events within this area on record of M>=4.7 occurred on December 28, 1976 and December 26, 1946 (both M 5.4) and on January 27, 1945 (M 5.1). An M 7.1 hit in the Loyalty Islands on February 1, 1945; an M 6.5 in the Kermadec Islands on December 30, 1946.  A series of great earthquakes in Central Honshu and the Kuril Islands of M 7.9 and 8.4 occurred on December 20 and 21, 1946 and may have helped trigger the New Zealand event of December 26, 1946. And an M 6.3 in northern Chile on December 28, 1976 but none were associated with a subsequent major or great earthquake in the several days following." (June 13, 2020)

 

and

 

 

"Near the antipode of the event west of North Island an M 4.9 occurred later in the day off the west coast of Spain. This is within about 300 km of the exact antipode of the New Zealand event (39N 13W). The combination of these unusual near-antipodal quake suggests something may be brewing in global seismicity. Today's earthquake off Spain is the largest within about 250 km of that epicenter since an M 5.5 on December 17, 2009 more than 10 year ago.  Forecast 124784 had expected today's event was likely within about 100 km of this epicenter around June 13. After the event in New Zealand and an M 5.1 in Tonga, this is the third largest event in the world today. There is no history of unusual major global events following the rare events of M>=4.9 in this region off Spain in the past 30 years. Antipodal earthquake pairs, especially those at rare epicenters, can precede changes in  global seismicity but how that might play out in this case is uncertain." (June 13, 2020)

 

Forecasts 125050 had expected today's activity off the coast of Spain was  likely around June 27. Forecast 124996 had expected the event in the Northern  Mid-Atlantic Ridge around June 30 as reported in earlier issues of this summary as below. Much of this activity in the North Atlantic is at the fifth node (72 degrees) from the M 7.5 in Oaxaca, Mexico of June 23 and may have been promoted by energy from that source.

 

"On the first day of summer in the northern hemisphere, the sun reaches its zenith at about 23 degree North latitude due to the tilt of the earth's axis. ...  The only seismic areas at this latitude in the western hemisphere are in the Gulf California and the north mid-Atlantic Ridge. (June 22, 2020)

 

O: 28JUN2020 07:32:57  17.6N   46.5W ML=4.6  EMSC   NORTHERN MID-ATLANTIC RIDGE  

P: 30JUN2020 124996    17.0N   47.0W 4.0-5.4 AAAAA  Mid-Atlantic Ridge         

 

O: 27JUN2020 17:32:17  32.9N   12.3W mb=4.4  EMSC   MADEIRA ISLANDS, PORTUGAL REGI

O: 28JUN2020 07:21:58  35.1N   14.7W mb=4.3  EMSC   AZORES-CAPE ST. VINCENT RIDGE

P: 27JUN2020 125050    37.0N   11.0W 3.5-5.2 ABBAA  Morocco/Spain              

 

O: 27JUN2020 20:18:54  36.7N   11.2W ML=2.7  EMSC   AZORES-CAPE ST. VINCENT RIDGE

O: 27JUN2020 14:14:59  37.3N   12.7W mb=4.4  EMSC   AZORES-CAPE ST. VINCENT RIDGE

P: 27JUN2020 125050    37.0N   11.0W 3.5-5.2 AAAAA  Morocco/Spain              

 

O: 27JUN2020 10:59:25  47.5N    5.4W ML=4.5  EMSC   NORTH ATLANTIC OCEAN         

 

 

The strongest earthquake in the U.S. or Canada today was an M 3.9 in the Rat Islands, Aleutians, Alaska. This is the strongest earthquake in the Rat Islands in two months - since an M 4.1 on April 26, 2020. It was not reported felt in this remote area. Forecast 125136 had expected this event within about 100 km was likely around June 21.

 

O: 27JUN2020 21:35:55  51.6N  178.0E mb=3.9  EMSC   RAT ISLANDS, ALEUTIAN ISLANDS

P: 21JUN2020 125136    51.0N  179.0E 4.0-5.8 CAAAA  Rat Islands                

 

FAR-FIELD TRIGGERING CONTINUES FOLLOWING OAXACA, MEXICO M 7.5-7.7

 

EARTHQUAKE SUMMARY FOR JUNE 26, 2020

 

Seismicity at 103 degrees from the M 7.7 in Oaxaca, Mexico of June 23, 2020 continued today. Several moderate earthquakes were felt in western Turkey and Crete, Greece. The M 4.8 in Crete was reported by NEIC with maximum intensity V in Karpathos, Dodecanese Islands, Greece. Moderate quakes at 103 degrees from Oaxaca also shook areas near Tokyo, Japan (M 4.5); and South Island, New Zealand today (M 4.1, 4.1).

 

The largest earthquake recorded today was an M 5.4 in northern Philippines at the eastern terminix of the solar eclipse of June 21, 2020. NEIC reported it was felt with maximum intensity IV in Vintar, Ilocos and III in Laoag and Aparri Cagayan Valley and Balibago, Central Luzon, Philippines. A series of moderate earthquakes also continued to the west along the path of the solar eclipse of June 21. The events in Taiwan and the northern Philippines had been an expected consequence of the eclipse as noted in previous issues of this report. The M 5.4 today was the largest in the area of the northern Philippines in more than a year - since a similar M 5.4 on May 12, 2019. The last event of significantly larger magnitude in the area was an M 5.8 on February 17, 2014. Forecast 124765 had expected a moderate quake in the area was likely in mid-June.

 

O: 26JUN2020 11:54:57  19.1N  121.1E Mw=5.4  EMSC   BABUYAN ISL REGION, PHILIPPINE

P: 16JUN2020 124765    20.0N  121.0E 4.0-5.4 CAAAA  Taiwan                      

 

 

A moderately strong earthquake of M 5.6 (later downgraded to M 5.2) hit Western Turkey today and was widely felt. EMSC reported intensities up to V in Turkey at Ahmetli, Akhisar, Manisa, Salihli, Muradiye, Kemalpasa, Soma, and other areas within about 300 km of the epicenter. NEIC reported intensity VII in Manisa, Turkey at Golmarmara; V in Foca, Izmir, IV in Manisa, Izmir, Tire, Balikesir, and II-III in Torbali, Aydin, Milas, Mugla and Bursa, Turkey. This event is at 103-104 degrees from the epicenter in Oaxaca, Mexico and is the third moderately strong to strong event at that distance from Oaxaca in the two days following that M 7.7 event - including events of M 6.0 and 6.2 in South Island, New Zealand an Southeastern Honshu, Japan yesterday. The last event within about 200 km of this epicenter with M>=5.2 was recorded as occurring on January 22, 2020  with M 5.6 and September 26, 2019 in the Istanbul, Turkey area with M 5.7. Forecast 125076 had expected today's event within this area was likely around June 28.

 

O: 25JUN2020 21:50:32  39.0N   27.8E ML=2.5  EMSC   WESTERN TURKEY

O: 26JUN2020 07:21:11  38.7N   27.8E mb=5.6  EMSC   WESTERN TURKEY               

O: 26JUN2020 07:21:11  38.7N   27.8E mb=5.2  ANSS   WESTERN TURKEY               

P: 28JUN2020 125076    38.0N   29.0E 3.5-5.1 AAAAA  Turkey                     

 

A series of moderate earthquakes also occurred in the area of Crete, Greece today. The M 4.8 in Crete was reported by NEIC with maximum intensity V in Karpathos, Dodecanese Islands, Greece. These are located at 105 degrees from the epicenter of the Oaxaca, Mexico earthquake of M 7.7 on June 23  and were probably promoted by energy from that event as expected in previous issues of this summary:

 

 

 

"Far-field triggering is likely with this earthquake. Areas near 144 degrees include Minahasa, Indonesia where an M 5.9-6.1 occurred earlier today; India, Myanmar, Mayotte. The antipode at 16S 84E is in the Indian Ocean and is not seismic. Areas at 103 degrees from the Oaxaca epicenter include the east coast of Honshu, Japan and Guam as well as western Turkey and Greece and New Zealand from Cook Strait through South Island; the Vanuatu Islands. The fourth node at 90 degrees is prominent in the area south of the Kermadec Islands, the Kuril Islands, the French-Swiss Alps where an M 3.8 occurred earlier in the day.  A lack of moderate seismicity in the region of Honshu, Japan today is unsettling and may suggest a seismic quiescence following the Mexico M 7.4, a quiet which is likely to be broken soon." (June 23-24, 2020)

 

A strong M6.6 hit the region of Crete about 200 km southwest of this on May 2 but the last event in Crete within about 100 km of today's epicenter was an  M 4.8  on February 14, 2020 - the last of larger magnitude in this area was an M 5.4 on December 10, 2019. Forecast 125045 had expected today's activity was likely around June 25.

 

O: 26JUN2020 12:56:01  35.4N   26.7E ML=4.0  EMSC   CRETE, GREECE

O: 26JUN2020 18:49:19  35.5N   26.7E ML=2.6  EMSC   CRETE, GREECE

O: 27JUN2020 00:58:39  35.5N   26.7E ML=3.0  EMSC   CRETE, GREECE

O: 26JUN2020 20:40:56  35.5N   26.7E ML=3.5  EMSC   CRETE, GREECE

O: 26JUN2020 15:14:58  35.5N   26.7E ML=3.7  EMSC   CRETE, GREECE

O: 26JUN2020 22:15:15  35.5N   26.7E ML=3.7  EMSC   CRETE, GREECE

O: 26JUN2020 23:44:07  35.5N   26.7E ML=3.7  EMSC   CRETE, GREECE

O: 26JUN2020 23:10:29  35.6N   26.7E ML=3.6  EMSC   CRETE, GREECE

O: 26JUN2020 22:08:08  35.6N   26.7E ML=3.7  EMSC   CRETE, GREECE

O: 26JUN2020 19:36:36  35.4N   26.6E Mw=4.8  EMSC   CRETE, GREECE                 

P: 25JUN2020 125045    34.0N   27.0E 3.0-4.6 ABAAA  Crete                      

 

The largest earthquake in the U.S. or Canada today was an M 4.2 in the still-active aftershock zone in southern Idaho. It was accompanied by a series of light aftershocks. These may be related to the M 4.6 in Idaho of June 25 (yesterday) This summary had noted in the previous issue in this regard:

 

 

"A moderate earthquake of M 4.6 also hit the southern Idaho aftershock zone today. NEIC reported it was felt with maximum intensity IV in Idaho at Lowman; III in Stanley, Cascade, McCall, Idaho City, Ketchum, Horseshoe Bend and Ola and II in Garden Valley, Atlanta. It was reported as far as Utah and Oregon.

This is the strongest aftershock to date of the M 6.5 mainshock of March 31, 2020 in Southern Idaho. In the past 30 years only two other events have reached this magnitude in southern Idaho - both of M 4.6-4.7 on November 10, 1993 and January 28, 1995. Forecast 125100 had expected enhanced seismicity in the area was likely around June 23. It was probably promoted by energy from the M 7.5-7.7 in Oaxaca, Mexico yesterday. It is at the exact 11th node (32.7 degrees) from the Mexican mainshock." (June 25-26, 2020)

 

Forecast 125100 had expected today's activity in this aftershock zone around June 28.

 

NEIC reported this earthquake of M 3.7-4.2 in Southern Idaho  was felt with intensity II-III in the area(s) of Southern Idaho at Lowman, Stanley, Boise, Emmett and Caldwell.

 

O: 27JUN2020 00:35:57  44.1N  115.1W Ml=4.2  EMSC   SOUTHERN IDAHO

O: 26JUN2020 21:09:43  44.2N  115.0W ML=2.3  EMSC   SOUTHERN IDAHO

O: 26JUN2020 13:01:35  44.2N  115.0W Ml=2.3  EMSC   SOUTHERN IDAHO

O: 26JUN2020 14:20:23  44.3N  115.2W ML=2.8  EMSC   SOUTHERN IDAHO

O: 26JUN2020 13:44:06  44.3N  115.3W Ml=2.4  EMSC   SOUTHERN IDAHO

O: 26JUN2020 08:01:27  44.4N  115.2W Ml=2.3  EMSC   SOUTHERN IDAHO

O: 26JUN2020 07:33:54  44.4N  115.2W Ml=3.1  EMSC   SOUTHERN IDAHO

O: 26JUN2020 11:33:08  44.4N  115.2W Ml=3.1  EMSC   SOUTHERN IDAHO

O: 27JUN2020 00:34:47  44.1N  115.1W ML=3.7  EMSC   SOUTHERN IDAHO               

P: 28JUN2020 125100    44.6N  115.0W 2.0-4.1 AAAAA  Montana/Idaho              

 

An unusual earthquake of M 4.9 shook areas near Lake Taupo, North Island, New Zealand today. GEONET reported this earthquake was felt with moderate intensity northeast of Okahune and in southwestern North Island and northern South Island. Light to moderate intensity was reported throughout much of southern and western North Island and northern South Island. More than 2284 people reported feeling this earthquake with 1722 reports of weak intensity; 531 of light intensity; 29 with moderate intensity; 0 with strong intensity; and 0 of severe intensity and 2 of extreme shaking. NEIC reported this earthquake of M 4.9 in North Island, New Zealand  was felt with intensity II-III in the area(s) of North Island, New Zealand at Taupo, Rotorua, Tauranga, Cambridge, Whakatane, Napier, Hastings, Gisborne, Palmerston North and Kapiti. This is a somewhat unusual earthquake - the last in this hydrothermal area of M>=4.9 occurred on September 4, 2019 with M 5.0 and prior to that as an M 5.0 on September 23, 2015. It may be related to energy from Oaxaca, Mexico as it occurred at about 99 degrees from that epicenter. Forecast 125206 had expected a moderate event in the Taupo are was likely within about 50 km of this epicenter around June 22.

 

O: 26JUN2020 20:41:32  38.5S  176.2E mb=4.9  EMSC   NORTH ISLAND OF NEW ZEALAND  

O: 26JUN2020 20:41:34  38.4S  176.2E ML=4.9  GEONET Felt with moderate intensity

P: 22JUN2020 125206    38.0S  176.0E 3.0-4.6 BAAAA  North Island, N.Z.         

 

STRO

STRONG EARTHQUAKE IN SOUTHERN CHINA PROMOTED BY SOLAR ECLIPSE

 

 

 

RTHQUAKE SUMMARY FOR JUNE 1, 2020

 

A strong M 6.4 earthquake hit the region near the border of Xinjiang and Xizang China today. There were no immediate reports of damages or casualties. But the quake was a shallow focus event and local damage is likely. This epicenter is slightly north of the maximum annular solar eclipse of June 21, 2020 as noted in previous issues of this report. A moderately strong M 5.6 also shook area of western Turkey early on June 26 with an epicenter at 103-104 degrees from the M 7.7 in Oaxaca, Mexico two days ago. The event in China is also near the exact opposite longitude (83 East) of the M 7.7 in Oaxaca, Mexico (96 West) which was at the exact opposite longitude of the maximum eclipse two days before. Solid earth tidal forces are  maximized at the longitude of the maximum eclipse as well as at the opposite longitude on the earth and probably led to both the earthquake in Oaxaca, Mexico and today's event in Xinjinag and Xizang, Chile. The maximum solar eclipse occurred at 32N 80E - today's earthquake was at 35N 82E. This report had expected a strong earthquake in southern China at this time as:

 

 

"Some enhanced activity in northern India and Myanmar is anticipated with the new moon today but the strongest of this may be delayed as noted in the tidal seismic forecast with today's solar eclipse:

 

and

 

 

"The new moon arrived June 21 at 06:41 UT. This involved an annular solar eclipse visible in the areas of Central Africa, Southern Asia, China and the Pacific with maximum at 06:41 UT. Maximum eclipse occurs over northern India, Nepal, Hindu Kush and Pakistan, an area which has seen enhanced seismicity in recent days including some unusual events at Gujarat, India and others. The eclipse will pass over Taiwan and the southern Ryukyu Islands as well as southern Iran and Pakistan and southern China. Most of these areas will probably see enhanced seismicity with this eclipse with a moderate chance of a major earthquake within a week of the eclipse in southern Asia. Longitudes which are sub-solar at this time are near 77 East and 103 West. These include areas of central Asia including Hindu Kush, India and Tajikistan in the east and the central and western U.S. and western Mexico in the west. These will experience the maximum tidal stresses and are most likely to see tidally triggered seismicity at this time. Many areas, especially those where fluids are important modulators of seismicity, can experience tidal enhancement of seismicity, and several large earthquakes are likely in the next eight days. Tidal triggering often occurs near local solar midnight and noon when alignment is most linear." (June 18-24, 2020)

 

"There have been reports and video of strange animal behavior in several areas of China. Local lore is that such behavior often preceded major earthquakes. Many of these odd occurrences include fish jumping out of water in Yunnan and other areas of southern China where the eclipse was visible on June 21. These observations appear to have been located in time near the time of the M 7.4 in the Kermadec Islands, New Zealand of June 18 and ground motions near 103 degrees in China at that time may have affected the fish. Literature over decades has documented odd animal behavior prior to major earthquakes, so this is an observation worth noting especially with the enhanced global seismicity of the past week and the eclipse. The largest earthquake along the path of the total eclipse of June 21 today occurred in Southern Sichuan, China in the neighborhood of these unusual animal behavior. This area is subject to major earthquakes. Recent extensive flooding in the area may also contribute to the possibiliy of a strong regional earthquake in the near term." (June 23-24, 2020)

 

 

Far-field expected seismicity following the Kermadec Islands had been expected at:

 

"Areas near 103 and 144 degrees from the M 7.4 south of the Kermadec Islands of June 18 which are seismic are few, so far-field triggering from that event may be limited. Among the most likely to see significantly enhanced seismicity in the next week are Iceland and eastern Turkey at 144 degrees and the central U.S. including Oklahoma, Missouri, Wyoming, Montana, northern Alaska, areas near western Cuba, Colombia, the South Mid-Atlantic and Bangladesh, India, Myanmar and southern China near 103 degrees from the Kermadec event. Southern Spain and Morocco are near the antipode of the Kermadec Islands. One or more of these areas is likely to see a significant earthquake, especially with the new moon." (June 20, 2020)

 

A foreshock of M 4.7 preceded the event in China about half an hour before the mainshock.

 

Far-Field triggering following Oaxaca, Mexico was expected as:

 

"Far-field triggering is likely with this earthquake. Areas near 144 degrees include Minahasa, Indonesia where an M 5.9-6.1 occurred earlier today; India, Myanmar, Mayotte. The antipode at 16S 84E is in the Indian Ocean and is not seismic. Areas at 103 degrees from the Oaxaca epicenter include the east coast of Honshu, Japan and Guam as well as western Turkey and Greece and New Zealand from Cook Strait through South Island; the Vanuatu Islands. The fourth node at 90 degrees is prominent in the area south of the Kermadec Islands, the Kuril Islands, the French-Swiss Alps where an M 3.8 occurred earlier in the day.  A lack of moderate seismicity in the region of Honshu, Japan today is unsettling and may suggest a seismic quiescence following the Mexico M 7.4, a quiet which is likely to be broken soon." (June 23-24, 2020)

 

At M 6.3-6.4 this is the strongest earthquake on the Xinjiang-Xizang border of

China within about 250 km since an M 6.9 near today's epicenter more than 6 years ago on February 12, 2014.  These may be aftershocks of an M 7.1-7.2 that shook the area on Mar 20, 2008. The only other such event in the area in the past 30 years was an M 6.3 on August 12, 2012. Forecasts 125081 and 125082 had expected regional seismic enhanced in Xizang around June 23-25 in connection with the solar eclipse.

 

O: 25JUN2020 20:29:39  35.6N   82.4E mb=4.7  EMSC   XINJIANG-XIZANG BORDER REGION

O: 26JUN2020 01:30:58  35.6N   82.4E mb=4.7  EMSC   XINJIANG-XIZANG BORDER REGION

O: 25JUN2020 21:05:18  35.6N   82.5E Mw=6.3  EMSC   XINJIANG-XIZANG BORDER REGION

O: 25JUN2020 21:05:18  35.6N   82.4E Mw=6.4  ANSS   XINJIANG-XIZANG BORDER REGION

O: 25JUN2020 21:05:18  35.6N   82.5E Mw=6.4  CENC   XINJIANG-XIZANG BORDER REGION

O: 25JUN2020 21:17:04  35.7N   82.4E mb=5.0  EMSC   XINJIANG-XIZANG BORDER REGION

O: 25JUN2020 23:07:53  35.7N   82.5E mb=4.3  EMSC   XINJIANG-XIZANG BORDER REGION

O: 25JUN2020 22:51:45  35.6N   82.4E mb=4.3  EMSC   XINJIANG-XIZANG BORDER REGION

P: 23JUN2020 125081    30.0N   82.0E 3.8-5.4 ACAAA  Xizang                     

P: 25JUN2020 125082    34.0N   89.0E 3.8-5.3 ABCAA  Xizang                     

 

A moderately strong earthquake of M 5.6 (later downgraded to M 5.2) hit Western Turkey today and was widely felt. EMSC reported intensities up to V in Turkey at Ahmetli, Akhisar, Manisa, Salihli, Muradiye, Kemalpasa, Soma, and other areas within about 300 km of the epicenter. NEIC reported intensity IV in Izmir, Turkey. This event is at 103-104 degrees from the epicenter in Oaxaca, Mexico and is the third moderately strong to strong event at that distance from Oaxaca in the two days following that M 7.7 event - including events of M 6.0 and 6.2 in South Island, New Zealand an Southeastern Honshu, Japan yesterday. The last event within about 200 km of this epicenter with M>=5.2 was recorded as occurring on January 22, 2020 with M 5.6 and September 26, 2019 in the Istanbul, Turkey area with M 5.7. Forecast 125076 had expected today's event within this area was likely around June 28.

 

O: 25JUN2020 21:50:32  39.0N   27.8E ML=2.5  EMSC   WESTERN TURKEY

O: 26JUN2020 07:21:11  38.7N   27.8E mb=5.6  EMSC   WESTERN TURKEY               

O: 26JUN2020 07:21:11  38.7N   27.8E mb=5.2  ANSS   WESTERN TURKEY               

P: 28JUN2020 125076    38.0N   29.0E 3.5-5.1 AAAAA  Turkey                     

 

An earthquake of M 5.4 was also located in eastern Turkey today. EMSC reported it was felt with intensity up to IV in Turkey at Van, Ipekyolu, Edremit, Hakkari and in Itan at Khowy, Khvoy, Salmas, and other communities within about 200 km of the epicenter. NEIC reported intensity V in Turkey at Van and in Orumiyeh, Iran and II-III in Tebriz, Iran and in Kurtalan and Erzurum, Turkey. The last earthquake within about 200 km of this epicenter in eastern Turkey with M>=5.4 was an M 6.0 on February 23, 2020. This appears to be an aftershock of the February event. Forecast 125085 had expected today's activity in this area was likely around June 23.

 

O: 25JUN2020 10:03:29  38.5N   44.1E Mw=5.4  EMSC   TURKEY-IRAN BORDER REGION    

P: 23JUN2020 125085    40.0N   44.0E 3.5-5.0 ABAAA  Caucasus/Caspian Sea       

 

An unusual shallow focus earthquake of M 4.5 was located in Romania today. EMSC reported it was felt with moderate intensity in Romania at Orsova, Baile Herculane, Gura Vaii, Drobeta-Turni Severin, Brebu Nou, Resita, Bocsa, Cariova, and other communities within about 200 km of the epicenter. NEIC reported intensity II in Breznita Ocol Mehesinti, Romania.  It was preceded by an M 3.3 which was lightly felt in the epicentral area. The last earthquake of M>=4.3 in Romania within about 200 km of this epicenter occurred  as an M 4.7 on September 8, 2013. An M 4.3 on June 9, 2016 occurred west of today's epicenter in Romania. Forecast 125083 had expected today's activity to the west was likely around  June 25. This epicenter is at 98 degrees from the Oaxaca, Mexico quake of June 23 and may have been enhanced by energy from that source.

 

O: 25JUN2020 17:36:07  44.7N   22.4E ML=3.0  EMSC   ROMANIA

O: 25JUN2020 14:20:52  44.7N   22.4E ML=3.3  EMSC   ROMANIA

O: 25JUN2020 17:30:16  44.7N   22.4E ML=4.3  EMSC   ROMANIA                      

O: 25JUN2020 17:30:16  44.7N   22.4E ML=4.5  ANSS   ROMANIA                      

P: 25JUN2020 125083    45.0N   18.0E 3.0-5.2 AACAA  Adriatic Sea               

 

The strongest earthquake in the U.S. or Canada today was an M 5.0 in the Fox Islands, Aleutians, Alaska. It was not reported felt in this epicentral area. The last event with M>=5 within about 200 km of this epicenter occurred on January 13, 2020 with M 5.0. The last of larger magnitude was an M 5.8 on October 26, 2019 and an M 5.9 on August 25, 2018. It is near the fifth node (72 degrees) from the Oaxaca, Mexico quake of June 23 and may have been enhanced by energy from that source. Forecast 125125 had expected today's event within about 25 km likely to occur around June 27.

 

O: 25JUN2020 09:24:22  52.0N  171.6W mb=5.0  EMSC   FOX ISLANDS, ALEUTIAN ISLANDS

P: 27JUN2020 125125    52.1N  171.3W 3.5-5.1 AAAAA  Andreanoff Isls, Aleutians 

 

NG FAR-FIELD SEISMIC TRIGGERING FOLLOWS OAXACA, MEXICO M 7.5-7.7

 

EARTHQUAKE SUMMARY FOR JUNE 24, 2020

 

The magnitude of the earthquake in Oaxaca, Mexico, initially given as M 7.4 has been upgraded to M 7.5 and M 7.7 by many teleseismic reporters making it possibly the strongest global earthquake this year. It was followed today by a series of large and unusual earthquakes including an M 5.7-5.8 in the Lone Pine area of eastern California; an M 4.6 in Southern Idaho; an M 5.9-6.3 near Tokyo, Eastern Honshu, Japan and an M 5.5-6.0 in South Island, New Zealand. Yesterday this summary had published a listing of expected far-field seismic enhancement as:

 

 

"Far-field triggering is likely with this earthquake. Areas near 144 degrees include Minahasa, Indonesia where an M 5.9-6.1 occurred earlier today; India, Myanmar, Mayotte. The antipode at 16S 84E is in the Indian Ocean and is not seismic. Areas at 103 degrees from the Oaxaca epicenter include the east coast of Honshu, Japan and Guam as well as western Turkey and Greece and New Zealand from Cook Strait through South Island; the Vanuatu Islands. The fourth node at 90 degrees is prominent in the area south of the Kermadec Islands, the Kuril Islands, the French-Swiss Alps where an M 3.8 occurred earlier in the day.  A lack of moderate seismicity in the region of Honshu, Japan today is unsettling and may suggest a seismic quiescence following the Mexico M 7.4, a quiet which is likely to be broken soon." (June 23-24, 2020)

 

The strongest earthquake in the world today was an M 5.9-6.2 off the east coast of Honshu, Japan. According to NEIC it was widely felt with intensity V in Chiba, Tokyo, Saitama, Kanagawa, with lesser intensity in Tochigi, Gunma, Nagano,  Kanagawa, Gifu and Miyagi Prefectures. JMA reported this earthquake at M 6.2 was felt with intensity V in Chiba; IV in Ibaraki, and III in Ibaraki, Tochigi, Saitama, Tokyo, and Yamanashi Prefectures. The local magnitude is preferred as the area has geology which can confuse teleseismic magnitude determinations. A tsunami warning was not issued by JMA for this event. This epicenter is at 105 degrees from the M 7.5-7.7 in Oaxaca, Mexico yesterday and was likely promoted by concentrated energy from that source as was expected in the previous issue of this report (see above).

 

The last earthquake in the Tokyo area of Honshu, Japan with M>=5.9 occurred  on July 7, 2018 and December 28, 2016 both with M 5.9. The last with larger magnitude than M 6.2 was an M 6.4 on July 30, 2011 but an M 6.2 also occurred July 23, 2016. Forecast 125058 had expected this activity was likely within about 100 km around June 21.

 

O: 24JUN2020 19:47:46  35.5N  141.2E Mw=6.2  JMA    NEAR EAST COAST OF HONSHU, JAP

O: 24JUN2020 19:47:46  35.5N  141.0E Mw=5.9  EMSC   NEAR EAST COAST OF HONSHU, JAP

P: 21JUN2020 125058    35.0N  140.0E 4.0-5.9 BAAAA  Off East Coast Honshu      

 

An earthquake of M 5.5-6.0 shook the area of southwestern South Island, New Zealand today. NEIC reported maximum shaking IV in Te Anau and II-III in Queenstown, Wanaka, Riverton, Invercargil, Southland and Dunedin, Otago, New Zealand. GEONET reported 3737 people felt this quake with 1892 with weak intensity; 1483 with light intensity and 328 with moderate intensity. 24 reported strong shaking, 4 with severe intensity and 6 extreme intensity.

GeoNet reported M 5.9-6.0 for this event the preferred magnitude from the local network. The epicenter is at 104 degrees from the epicenter of the M 7.5-7.7 in Oaxaca, Mexico yesterday and was likely promoted by concentrated energy from that source is expected in previous issues of this report (see above).

 

The last earthquake in South Island, New Zealand with M>=6 within about 200 km  of today's epicenter occurred on August 5, 2009 with M 6.1 following a mainshock of M 7.7 on July 15, 2009.  Forecast 125215 had expected today's activity in the area in this region was likely around June 24. This epicenter is at 104-105 degrees from the M 7.7 earthquake in Oaxaca, Mexico yesterday and was probably promoted by concentrated energy from that source.

 

O: 25JUN2020 04:30:29  44.7S  167.5E ML=4.2  EMSC   SOUTH ISLAND OF NEW ZEALAND  

O: 24JUN2020 22:20:01  44.6S  167.5E ML=6.0  GEONET reported 3737 people felt this quake

O: 24JUN2020 22:20:02  44.7S  167.5E Mw=5.5  EMSC   SOUTH ISLAND OF NEW ZEALAND

O: 24JUN2020 22:25:14  44.7S  167.6E ML=4.2  EMSC   SOUTH ISLAND OF NEW ZEALAND

P: 24JUN2020 125215    44.0S  169.0E 3.0-5.1 AAAAA  So. Island, N.Z.           

 

The strongest earthquake in the U.S. or Canada today was an M 5.8 in the Lone Pine region of California midway between the Ridgecrest aftershock zone and the Tonopah, Nevada aftershock zone. It appears to be the mainshock in the current series. NEIC reported maximum intensity VI in Independence and Lone Pine and IV in California at East Porterville, Porterville, Strathmore, Big Pine, Searles Valley, Lindsay, Woodlake, Ridgecrest, Farmersville and Exeter and II-III within about 150 km of the epicenter. As reported in the previous issue of this summary, this activity is located, along with that in Oaxaca, Mexico at the fourth node (90 degrees) from the M 7.4 south of the Kermadec Islands of June 18 and was probably promoted be energy from that source along with energy from Mexico which is at the 13th node from this series (28.2 degrees).

 

 

"This epicenter (in  Oaxaca, Mexico)  is located at the fourth node (90 degrees) from the M 7.4 earthquake in the Kermadec Islands and the M 7.7 in the northern Kurils of March 25, 2020  and was probably promoted by energy from that source. An unusual  earthquake earlier in Lone Pine, California was similarly located from the Kermadec Islands and commented on in the previous issue of this report" (June 23, 2020)

 

Following is a listing of events of M>=3 in the Lone Pine area of California today. A listing of events of M>=2 can be found in the "CALIFORNIA" regional section below.

 

O: 25JUN2020 00:09:30  36.5N  118.0W ML=3.2  EMSC   CENTRAL CALIFORNIA

O: 24JUN2020 21:12:48  36.5N  118.0W ML=3.6  EMSC   CENTRAL CALIFORNIA

O: 24JUN2020 19:02:17  36.5N  117.9W ML=3.1  EMSC   CENTRAL CALIFORNIA

O: 24JUN2020 19:02:17  36.5N  117.9W ML=3.1  EMSC   CENTRAL CALIFORNIA

O: 24JUN2020 18:20:37  36.5N  118.0W ML=3.5  EMSC   CENTRAL CALIFORNIA

O: 24JUN2020 17:59:19  36.5N  117.9W Mw=4.6  EMSC   CENTRAL CALIFORNIA

O: 24JUN2020 17:47:04  36.5N  117.9W ML=3.4  EMSC   CENTRAL CALIFORNIA

O: 24JUN2020 17:45:00  36.5N  117.9W ML=3.5  EMSC   CENTRAL CALIFORNIA

O: 24JUN2020 17:40:48  36.5N  118.0W Mw=5.8  EMSC   CENTRAL CALIFORNIA

P: 24JUN2020 125029    36.2N  117.9W 2.5-4.5 AAAAA  California/Nevada area     

P: 25JUN2020 125030    36.9N  117.4W 2.5-4.6 AAAAA  California/Nevada area     

 

 

A moderate earthquake of M 4.6 also hit the southern Idaho aftershock zone today. NEIC reported it was felt with maximum intensity IV in Idaho at Lowman; III in Stanley, Cascade, McCall, Idaho City, Ketchum, Horseshoe Bend and Ola and II in Garden Valley, Atlanta. It was reported as far as Utah and Oregon. This is the strongest aftershock to date of the M 6.5 mainshock of March 31, 2020 in Southern Idaho. In teh past 30 years only two other events have reached this magnitude in southern Idaho - both of M 4.6-4.7 on November 10, 1993 and January 28, 1995. Forecast 125100 had expected enhanced seismicity in the area was likely around June 23. It was probably promoted by energy from the M 7.5-7.7 in Oaxaca, Mexico yesterday. It is at the exact 11th node (32.7 degrees) from the Mexican mainshock.

 

O: 25JUN2020 05:21:01  44.4N  115.2W Mw=4.6  EMSC   SOUTHERN IDAHO

P: 23JUN2020 125100    44.5N  115.2W 2.0-4.1 AAAAA  Montana/Idaho              

 

The most unusual earthquake in the world today was an M 4.0 in southern and eastern Ghana. NEIC reported it was felt with intensity IV in the Accra area as Ashiaman, Gbawe, Oduponkpehe, Accra, Madina, Teshie, Aburi, Nungua and II-III in Dome, Aburi and Tema, Ghana. The solar eclipse of June 21 was first visible near this epicenter in Ghana at about 06:00 on June 21 although the total eclipse was visible over the Congo. It is likely this event which occurred near local solar midnight was promoted by tidal stresses associated with the eclipse. The epicenter is slightly less than 100 degrees from the M 7.7 in Mexico and was probably also excited by energy from that source. This is the strongest earthquake in Ghana within about 500 km of this epicenter since an M M 4.4 about 300 km to the northeast on September 1, 2009 and of M 4.4 on March 6, 1997 near today's epicenter. No other such events have been recorded in the region in the past 30 years.

 

O: 24JUN2020 22:53:52   5.6N    0.4W mb=4.0  EMSC   GHANA                        

 

Aftershocks also continued in the region off the coast of Oaxaca, Mexico. Following is a listing of events of M>=4 since last report. Several sets of parameters for the mainshock are also included below.

 

O: 24JUN2020 19:32:17  15.3N   96.2W ML=4.3  EMSC   OFFSHORE OAXACA, MEXICO

O: 25JUN2020 04:54:39  15.4N   95.8W ML=4.1  EMSC   OFFSHORE OAXACA, MEXICO

O: 24JUN2020 19:01:55  15.5N   96.1W ML=4.1  EMSC   OFFSHORE OAXACA, MEXICO

O: 24JUN2020 21:07:00  15.5N   96.1W ML=4.2  EMSC   OFFSHORE OAXACA, MEXICO

O: 24JUN2020 19:23:14  15.5N   96.3W ML=4.0  EMSC   OFFSHORE OAXACA, MEXICO

O: 24JUN2020 20:06:17  15.5N   96.7W ML=4.8  EMSC   OFFSHORE OAXACA, MEXICO

O: 25JUN2020 05:35:36  15.5N   96.8W ML=4.1  EMSC   OFFSHORE OAXACA, MEXICO

O: 25JUN2020 03:00:45  15.6N   96.0W ML=4.0  EMSC   OFFSHORE OAXACA, MEXICO

O: 24JUN2020 18:01:07  15.6N   96.1W ML=4.4  EMSC   OFFSHORE OAXACA, MEXICO

O: 24JUN2020 07:24:10  15.6N   96.3W ML=4.3  EMSC   OFFSHORE OAXACA, MEXICO

O: 24JUN2020 08:36:43  15.6N   96.5W ML=4.1  EMSC   OFFSHORE OAXACA, MEXICO

O: 24JUN2020 09:47:28  15.7N   96.2W ML=4.0  EMSC   OFFSHORE OAXACA, MEXICO

O: 24JUN2020 11:54:19  15.7N   96.5W ML=4.1  EMSC   OAXACA, MEXICO

O: 24JUN2020 18:49:51  15.8N   96.3W ML=4.1  EMSC   OAXACA, MEXICO

O: 24JUN2020 16:02:28  15.9N   95.9W ML=4.0  EMSC   OAXACA, MEXICO

O: 24JUN2020 13:43:53  16.0N   95.8W ML=4.0  EMSC   OAXACA, MEXICO

O: 24JUN2020 08:26:38  16.2N   95.9W ML=4.0  EMSC   OAXACA, MEXICO

O: 25JUN2020 04:15:36  15.3N   96.2W ML=4.1  EMSC   OFFSHORE OAXACA, MEXICO      

O: 23JUN2020 15:29:05  16.1N   95.8W ML=7.7  MOS    OAXACA, MEXICO

O: 23JUN2020 15:29:05  16.2N   95.7W ML=7.7  PTWC   OAXACA, MEXICO

O: 23JUN2020 15:29:05  16.1N   95.8W ML=7.5  EMSC   OAXACA, MEXICO

P: 28JUN2020 125002    16.0N   96.0W 3.5-5.1 AAAAA  Oaxaca, Mexico             

 

MAJOR EARTHQUAKE STRIKES OAXACA, MEXICO

 

PRELIMINARY EARTHQUAKE SUMMARY FOR JUNE 23, 2020

 

A major M 7.4-7.7 earthquake off the coast of Oaxaca, Mexico caused considerable damage in that region today. UNAM reported it was felt with moderate to extreme intensity in Mexico in the States of  Oaxaca, Guerrero, Chiapas, Michoacan, Jalisco, Queretaro, Morelos, Tabasco, Veracruz, Puebla and in the State of Mexico and in Mexico City. Their epicenter at M 7.5 is well south of that of teleseismic reporters and is typical for events in this area where local geology confuses travel time data for teleseismic stations. The local epicenter is to be preferred. A tsunami warning had been issued for possible waves up to 10 feet in height. Several centimeter sized tsunamis were identified but no major waves are known to have been generated by the mainshock. A minor tsunami was caught on camera and shown on YouTube. Pictures on the web showed considerable damage with much damage to the exterior of buildings especially in Oaxaca, Mexico. It was widely felt along the coast and inland to Mexico City. Several buildings collapsed and at least six people were killed. Many buildings and homes saw wide cracks. In La Crucecita about 200 buildings were damaged including 30 with little hope of repair. Landslides were common in the surrounding hills and mountains.  Power was knocked out in some areas. The epicenter is located near the longitude of maximum tidal stress with the new moon of June 21 as noted in previous issues of this report in the tidal seismicity forecast:

 

"The new moon arrived June 21 at 06:41 UT. ...  Longitudes which are sub-solar at this time are near 77 East and 103 West. These include areas of central Asia including Hindu Kush, India and Tajikistan in the east and the central and western U.S. and western Mexico in the west. These will experience the maximum tidal stresses and are most likely to see tidally triggered seismicity at this time. Many area, especially those where fluids are important modulators of seismicity, can experience tidal enhancement of seismicity, and several large earthquakes are likely in the next eight days. Tidal triggering often occurs near local solar midnight and noon when alignment is most linear." (June 18-22, 2020)

 

The last major event in eastern or central Mexico of M>=7.4 on September 8, 2017, while primarily triggered by a strong geomagnetic excursion, occurred two days after the full moon, much as occurred in the current situation. Previous major quakes in the area have also coincided with full and new moons suggesting strong tidal triggering in the region as detailed below:

 

"The full moon will arrive on September 6 (2017) at 07:03 UT. Longitudes which are antisolar at this time (local solar midnight) are near 110 West while those which are subsolar (local solar noon) are near 70 East longitude. These include areas of the Rocky Mountains and western Mexico in the west and central Asia in the east. It is in these regions where the highest probability of tidal triggering exists for the next week." (September 8, 2017)

 

Likewise the event of March 30, 2012 of M 7.4 to the west of today's epicenter was also associated with the new moon. At the time this summary noted this as:

 

"This could have been finalized by the tidal effects of the new moon alignment which is complete tomorrow.  Activity near Tokyo, Japan is at exactly 103 degrees from the Oaxaca epicenter. This area may see enhanced seismicity in the coming days due to this relation. The Oaxaca event is also at 103-104 degrees from an M 5.6 in South Island, New Zealand which occurred several hours earlier and at 104 degrees from Crete" (March 20, 2012)

Likewise an M 7.2 on February 16, 2018, the last such quake in central Mexico of M>=7 occurred, the new moon was complete the day before as noted in this summary at the time:

 

"The new moon arrived on February 15 (2018) at 21:05 UT." (February  16-17. 2018)

 

Because of its location near the Tropic of Capricorn, Mexico is no stranger to major earthquakes near the summer solstice when the sun is directly overhead. Such events occurred in 1897 (M 7.0); 1916 (M 7.1); 1928 (M 8.0) and  1982 (M 7.2) among others. This relation had been noted in the previous issues of this report as:

 

"On the first day of summer in the northern hemisphere, the sun reaches its zenith at about 23 degree North latitude due to the tilt of the earth's axis. Vertical tidal triggering is therefore maximized near 23 North latitude at this time of year. Seismicity can be seen to increase at this latitude as well as evidenced by today's India earthquake at 23 North latitude ...  at 22-24 degrees north latitude. The only seismic areas at this latitude in the western hemisphere are in the Gulf California and the north mid-Atlantic Ridge. (June 22, 2020)

 

This epicenter is located at the fourth node (90 degrees) from the M 7.4 earthquake in the Kermadec Islands and the M 7.7 in the northern Kurils of March 25, 2020  and was probably promoted by energy from that source. An unusual earthquake earlier in Lone Pine, California was similarly located from the Kermadec Islands and commented on in the previous issue of this report:

 

"South of Kermadec to Central Chile, Oaxaca, Mexico, Lone Pine, Ridgecrest, California, Western Nevada, Sumatra," (June 21-22, 2020) 

 

Note that Sumatra is among areas at this distance from the Kermadec Islands.

 

A foreshock occurred yesterday with M 4.9 in Oaxaca Mexico.  NEIC reported this earthquake of M 4.9 in Oaxaca, Mexico  was felt with intensity IV-V   in the area(s) of Oaxaca, Mexico at Xadani and Huafulco and II-III in Pochutla, Mitia, Tlacolula, and Puerto Escondido and possibly as far as Mexico City.  It was the strongest event of the day in North or South America. NEIC reported this earthquake of M 4.9 in Oaxaca, Mexico  was felt with intensity IV-V   in the area(s) of Oaxaca, Mexico at Xadani and Huafulco and II-III in Pochutla, Mitia, Tlacolula, and Puerto Escondido and possibly as far as Mexico City. The last earthquake of M>=7.4 in the area of Oaxaca within about 250 km of this epicenter was an M 7.4 on March 20, 2012. The only such event of greater magnitude in the area in the past 30 years was an M 7.4-7.5 on September 30, 1999. Forecast 124982 had expected this activity was likely around June 24.

 

NEIC reported the M 7.4 today was felt with maximum intensity IX (major damage)

in Huatulco, Oaxaca; VIII in Comitancillo; VI in Pochutla; V in Ocotian, and Mixtequilla and IV in Xadani, Puerto Escondido, Teotitlan, Tlalixtac and Santa Lucia del Camino, Oaxaca among others. An aftershock of M 5.0 was felt with intensity II in Mexico City and Tlalnepantla, Mexico. In their special report on this earthquake, UNAM reported more than 1200 aftershocks at this writing (www.sismologico.unam.mx). There was no information on possible tsunami waves in this report.

 

A series of forecasts had expected seismic enhancement in Oaxaca at this time.

 

O: 22JUN2020 18:34:26  16.2N   95.3W ML=4.1  EMSC   OAXACA, MEXICO               

O: 23JUN2020 01:17:18  16.2N   95.7W mb=4.9  EMSC   OAXACA, MEXICO               

O: 23JUN2020 15:29:04  16.1N   95.9W mb=7.4  EMSC   OAXACA, MEXICO               

O: 23JUN2020 15:29:04  15.6N   96.1W mb=7.5  UNAM   OAXACA, MEXICO               

O: 23JUN2020 21:42:55  15.5N   96.5W ML=4.0  EMSC   OFFSHORE OAXACA, MEXICO

O: 23JUN2020 18:04:56  15.5N   96.5W ML=4.3  EMSC   OFFSHORE OAXACA, MEXICO

O: 23JUN2020 20:19:02  15.5N   96.5W ML=4.3  EMSC   OFFSHORE OAXACA, MEXICO

O: 24JUN2020 03:27:00  15.5N   96.5W ML=4.5  EMSC   OFFSHORE OAXACA, MEXICO

O: 24JUN2020 02:25:53  15.5N   96.6W ML=4.1  EMSC   OFFSHORE OAXACA, MEXICO

O: 24JUN2020 03:44:37  15.5N   96.6W ML=4.4  EMSC   OFFSHORE OAXACA, MEXICO

O: 23JUN2020 16:59:17  15.6N   95.9W ML=4.1  EMSC   OFFSHORE OAXACA, MEXICO

O: 23JUN2020 17:29:16  15.6N   95.9W ML=4.1  EMSC   OFFSHORE OAXACA, MEXICO

O: 23JUN2020 18:03:35  15.6N   95.9W ML=4.2  EMSC   OFFSHORE OAXACA, MEXICO

O: 24JUN2020 05:25:05  15.6N   96.1W ML=4.1  EMSC   OFFSHORE OAXACA, MEXICO

O: 24JUN2020 07:24:10  15.6N   96.3W ML=4.3  EMSC   OFFSHORE OAXACA, MEXICO

O: 23JUN2020 21:27:44  15.6N   96.7W ML=4.4  EMSC   OFFSHORE OAXACA, MEXICO

O: 23JUN2020 17:32:28  15.7N   96.0W ML=4.2  EMSC   OFFSHORE OAXACA, MEXICO

O: 23JUN2020 17:34:34  15.7N   96.1W ML=4.0  EMSC   OFFSHORE OAXACA, MEXICO

O: 23JUN2020 20:16:38  15.7N   96.1W ML=4.0  EMSC   OFFSHORE OAXACA, MEXICO

O: 23JUN2020 23:20:58  15.7N   96.1W ML=4.2  EMSC   OFFSHORE OAXACA, MEXICO

O: 23JUN2020 16:20:24  15.7N   96.1W ML=4.3  EMSC   OFFSHORE OAXACA, MEXICO

O: 24JUN2020 03:11:18  15.7N   96.1W mb=4.5  EMSC   OFFSHORE OAXACA, MEXICO

O: 24JUN2020 02:33:21  15.8N   96.4W Mw=5.4  EMSC   OAXACA, MEXICO

O: 23JUN2020 18:27:11  15.9N   95.8W mb=5.0  EMSC   OFFSHORE OAXACA, MEXICO

O: 23JUN2020 16:31:08  16.0N   95.7W mb=4.6  EMSC   OAXACA, MEXICO

O: 23JUN2020 17:45:23  16.0N   95.9W mb=4.1  EMSC   OAXACA, MEXICO

O: 23JUN2020 20:54:36  16.0N   95.9W mb=4.6  EMSC   OAXACA, MEXICO

O: 24JUN2020 03:05:33  16.2N   96.0W ML=4.2  EMSC   OAXACA, MEXICO

O: 23JUN2020 11:57:44  16.5N   95.1W ML=4.1  EMSC   OAXACA, MEXICO

O: 23JUN2020 17:52:20  15.4N   96.5W ML=4.3  EMSC   OFFSHORE OAXACA, MEXICO      

P: 19JUN2020 124752    16.0N   96.0W 3.5-5.1 BAAAA  Oaxaca, Mexico             

P: 24JUN2020 124982    15.0N   95.0W 3.5-5.2 AAAAA  Chiapas, Mexico            

P: 28JUN2020 125002    16.0N   96.0W 3.5-5.1 BAAAA  Oaxaca, Mexico             

P: 24JUN2020 124982    15.0N   95.0W 3.5-5.2 ABAAA  Chiapas, Mexico            

 

 

Far-field triggering is likely with this earthquake. Areas near 144 degrees include Minahasa, Indonesia where an M 5.9-6.3 occurred earlier today; India, Myanmar, Mayotte. The antipode at 16S 84E is in the Indian Ocean and is not seismic. Areas at 103 degrees from the Oaxaca epicenter include the east coast of Honshu, Japan and Guam as well as western Turkey and Greece and New Zealand from Cook Strait through South Island; the Vanuatu Islands. The fourth node at 90 degrees is prominent in the area south of the Kermadec Islands, the Kuril Islands, the French-Swiss Alps where an M 3.8 occurred earlier in the day.  A lack of moderate seismicity in the region of Honshu, Japan today is unsettling and may suggest a seismic quiescence following the Mexico M 7.4, a quiet which is likely to be broken soon.

 

An earthquake of M 5.9=6.0 shook areas of Guam today after the far-field forecast was published. NEIC reported it was felt with intensity IV in Guam at Yigo, Mongmong, Santa Rita and Tinia, Marianas and II-II in Guam at Talofofo, Hagatna Hts. Hagatna, Mangilao, Tamuning and Dededo. The last earthquakes of M>=5.9 within about 200 km of this epicenter in Guam occurred on February 11, 2018 and prior to that as an M 5.9 on October 6, 2014. The last of significantly larger magnitude was an M 6.7 on September 17, 2014.

 

O: 23JUN2020 17:50:25  14.0N  145.6E mb=5.9  EMSC   ROTA REGION, N. MARIANA ISLAND

P: 29JUN2020 125007    13.0N  143.0E 4.0-5.4 CABAA  So. Marianas/Guam          

 

An earthquake of M 4.5 occurred in the Gulf of Aden today. The annular solar eclipse of June 21 passed to the north of this epicenter but close enough to have had an impact on local seismicity. NASA shows the total eclipse was visible about 0-5 degrees to the east and north of this epicenter around 05:15 UT on June 21 and would have been nearly total at this epicenter.

 

O: 23JUN2020 16:31:57  13.7N   51.6E mb=4.7  EMSC   GULF OF ADEN                 

P: 29JUN2020 124987    13.0N   51.0E 3.5-5.0 CAAAA  Gulf of Aden               

 

There have been reports and video of strange animal behavior in several areas of

China. Local lore is that such behavior often preceded major earthquakes. Many of these odd occurrences include fish jumping out of water in Yunnan and other areas of southern China where the eclipse was visible on June 21. These observations appear to have been located in time near the time of the M 7.4 in the Kermadec Islands, New Zealand of June 18 and ground motions near 103 degrees in China at that time may have affected the fish. Literature over decades has documented odd animal behavior prior to major earthquakes, so this is an observation worth noting especially with the enhanced global seismicity of the past week and the eclipse. The largest earthquake along the path of the total eclipse of June 21 today occurred in Southern Sichuan, China in the neighborhood of these unusual animal behavior. This area is subject to major earthquakes. Recent extensive flooding in the area may also contribute to the possibiliy of a strong regional earthquake in the near term.

 

The event in southern China in eastern Sichuan was in the same area as an M 4.6

on May 21 and an M 4.7 on June 12. Forecast 125020 had expected this activity around June 27.

 

O: 23JUN2020 14:12:23  28.3N  104.8E mb=4.5  EMSC   EASTERN SICHUAN, CHINA       

P: 27JUN2020 125020    27.0N  104.0E 4.0-5.6 BBAAA  Myanmar                     

 

Seismicity also continued today in the region of eastern India and Myanmar following the M 5.8 in that area two days ago.

 

O: 23JUN2020 11:58:07  19.5N   77.1E ML=3.3  EMSC   MAHARASHTRA, INDIA           

P: 25JUN2020 124979    17.0N   74.0E 3.5-4.9 ACBAA  Arabian Sea                

 

O: 23JUN2020 13:47:32  23.9N   93.0E mb=3.6  EMSC   MYANMAR-INDIA BORDER REGION  

P: 29JUN2020 125019    26.0N   93.0E 4.0-5.5 CBAAA  Myanmar                    

 

O: 24JUN2020 07:28:13  28.8N   76.8E ML=2.8  EMSC   HARYANA - DELHI REGION, INDIA P: 13JUN2020 124796    34.0N   70.0E 3.8-5.2 AAAAA  Pakistan                   

P: 23JUN2020 125081    30.0N   82.0E 3.8-5.4 ABCAA  Xizang                     

 

The strongest earthquake in the U.S. or Canada today was an M 3.9 in Wyoming in the Grand Teton area.  NEIC reported this earthquake of M 3.6-3.9 in  Wyoming was felt with intensity II-III in the area(s) of Wyoming at Kelly, Jackson, Moran, Wilson, Alta, and in Driggs and Tetonia, Idaho.  This is the largest earthquake in this area of Wyoming within about 50 km of this epicenter since an M 4.8 on August 27, 2016 nearly four years ago. Forecast 125121 had expected today's event was likely around June 24.

 

O: 23JUN2020 14:02:39  43.6N  110.4W Ml=3.9  EMSC   WYOMING                       

P: 24JUN2020 125121    43.2N  111.0W 2.0-4.1 AAAAA  Yellowstone/Wyoming        

 

 

An M 5.9-6.3 in Sulawesi, Indonesia also occurred on June 23.  BMG reported it was felt with intensity IV at Bone Bolango, Bolaan, Uki dan Luwuk; III-IV in Gorontalo, Lokak, Ampana, Tutuyan; III in Soroako, Malili, Bitung, Kotamobagu and II in Palu, Manado, Toli-Toli and Masamba. The strongest earthquakes in the world today occurred in the Minahassa area of Indonesia with M 5.9-6.2 and in northern Philippines with M 5.1. This epicenter is near the terminix of the solar eclipse of June 21 and was probably promoted by tidal stresses associated with that event. The last earthquake within about 200 km of this epicenter in Sulawesi with M>=5.9 occurred on January 19, 2020 with M 6.1. An M 6.8 hit south of this on April 12, 2019, the only other event of M>5.9 since December, 2012.  Forecast 124945 had expected today's event within about 100 km was likely around June 26.

 

O: 23JUN2020 07:43:28   0.1N  123.8E ML=6.2  EMSC   MINAHASA, SULAWESI, INDONESIA

O: 23JUN2020 07:43:28   0.0N  123.8E ML=6.3  BMG    MINAHASA, SULAWESI, INDONESIA

O: 23JUN2020 07:43:27   0.2N  123.7E Mw=5.9  EMSC   MINAHASA, SULAWESI, INDONESIA

P: 26JUN2020 124945     1.0N  123.0E 4.0-5.6 BAAAA  Mindanao, Philippines      

P: 26JUN2020 124945     1.0N  123.0E 4.0-5.6 BAAAA  Mindanao, Philippines      

 

An earthquake of M 4.6-4.9 followed the Mexican M 7.4 in the Puerto Rico Trench north of the Island.  NEIC reported maximum shaking V in Puerto Rico at Hatillo and IV in Aguadilla, Manati and Las Marias and II-III in Isabela, Moca, Aguada, Arecibo, Rincon, San Sebastian. The last earthquake in the Puerto Rico Trench within about 50 km of today's epicenter occurred on November 29, 2019 more than half a year ago. Today's event was probably triggered by energy from Mexico. Forecast 125005 had expected today's event around June 22.

 

O: 23JUN2020 23:06:54  19.2N   67.0W Md=3.4  EMSC   PUERTO RICO REGION

O: 23JUN2020 20:34:01  19.2N   67.1W mb=4.6  EMSC   PUERTO RICO REGION

O: 23JUN2020 17:03:16  19.1N   67.0W Md=3.1  EMSC   PUERTO RICO REGION           

P: 22JUN2020 125005    19.0N   66.0W 3.4-5.2 AAAAA  Puerto Rico                

 

STRONG QUAKES AT ECLIPSE TERMINAL LONGITUDE

 

EARTHQUAKE SUMMARY FOR JUNE 22, 2020

 

The strongest earthquakes in the world today occurred in the Minahassa area of Indonesia with M 5.9-6.2 and in northern Philippines with M 5.1. These epicenters are near the terminix of the solar eclipse of June 21 and were probably promoted by tidal stresses associated with that event. The last earthquake within about 200 km of this epicenter in Sulawesi with M>=5.9 occurred on January 19, 2020 with M 6.1. An M 6.8 hit south of this on April 12, 2019, the only other event of M>5.9 since December, 2012.  Forecast 124945 had expected today's event within about 100 km was likely around June 26.

 

O: 23JUN2020 07:43:28   0.1N  123.8E ML=6.2  EMSC   MINAHASA, SULAWESI, INDONESIA

P: 26JUN2020 124945     1.0N  123.0E 4.0-5.6 BAAAA  Mindanao, Philippines      

 

The earthquake in the northern Philippines of M 5.1 was widely felt in this area.  NEIC reported this earthquake of M 5.1 in the Northern Philippines was felt with intensity II-III in the area(s) of the Northern Philippines at Paringao, Ilocos and Baguio, Cordillera.  PHIVOLCS reported intensity IV in Candon City, Ilocos Sur; III in Vigan City, Sinait, Santa and Magsingal, Sta. Lucia, Santa Maria, Sta, Cruz, San Esteban, Ilocos Sur; Luna, Bangar, Bacnota, San Juan, Bauang, and San Fernando City, La Union and II in Cabugao, San Juan, Bantay, San Ildefonse, Narvacan, Nagbukel, Tagudin, Burgos, Santiag, Sigay, Suyo, Ilocos Sur, Banna, Bacarra, Laoag City and Batac Ilocos Norte. While an M 5.1 hit about 100 km southeast of today's epicenter on May 28, 2020, the last event of larger magnitude within about 150 km was an M 5.7 on October 2, 2016.

Forecast 124991 had expected regional activity around June 25 and a moderate quake in northern Philippines had been anticipated with the solar eclipse.

 

O: 22JUN2020 08:02:44  17.1N  120.0E Mw=5.1  EMSC   PHILIPPINE ISLANDS REGION    

P: 25JUN2020 124991    12.0N  121.0E 3.5-4.9 BCAAA  Luzon, Philippines         

 

As occurred with the eclipse itself, a series of moderate earthquakes continued today along the eclipse path using up residual tidal energy from the alignment.

The strongest events in the Western Hemisphere outside the Kermadec Islands aftershock zone occurred in the East Pacific Rise at 23S 112E. This is near-antipodal to the maximum eclipse site in India-Nepal and Gujarat, India and was not unexpected on this account. The forecast for seismicity associated with the eclipse/new moon had read:

 

"The new moon arrived June 21 at 06:41 UT. This involved an annular solar eclipse visible in the areas of Central Africa, Southern Asia, China and the Pacific with maximum at 06:41 UT. Maximum eclipse occurs over northern India, Nepal, Hindu Kush and Pakistan, an area which has seen enhanced seismicity in recent days including some unusual events at Gujarat, India and others. The eclipse will pass over Taiwan and the southern Ryukyu Islands as well as southern Iran and Pakistan and southern China. Most of these areas will probably see enhanced seismicity with this eclipse with a moderate chance of a major earthquake within a week of the eclipse in southern Asia. Longitudes which are sub-solar at this time are near 77 East and 103 West. These include areas of central Asia including Hindu Kush, India and Tajikistan in the east and the central and western U.S. and western Mexico in the west. These will experience the maximum tidal stresses and are most likely to see tidally triggered seismicity at this time. Many area, especially those where fluids are important modulators of seismicity, can experience tidal enhancement of seismicity, and several large earthquakes are likely in the next eight days. Tidal triggering often occurs near local solar midnight and noon when alignment is most linear." (June 18-22, 2020)

 

and

 

"solar eclipse of June 21. The strongest tidal stresses with a solar eclipse occur near the path of totality. The path of that annular eclipse passes from southern Iran to Pakistan, Afghanistan, India, Nepal, Southern China, Taiwan and the Southern Ryukyu Islands of Japan. Some increases in seismicity may occur in these regions and near the  antipode which crosses South America near northern Chile where an M 6.8 occurred on June 3, 2020. A strong aftershock is possible in that area at this time” (June 20, 2020)

 

A major earthquake occurred on June 23, 2001 in southern Peru about two days after a solar eclipse was observed in the area. The HISTORY section of his report details that event as:

 

 6 23 20 33 14 2001 -16.265  -73.641  33 8.4   Near the coast of Peru          

 

The earthquake killed at least 75 including at least 26 by a tsunami.  Nearly 18,000 homes were destroyed and more than 35,000 damaged in Arequipa, Camana and Tacna while injuring nearly 2700. Besides the 26 killed by the tsunami an additional 64 were missing. Many historic buildings were damaged or destroyed at Arequipa. Landslides blocked many highways. The earthquake followed by several days a total eclipse of the sun in the area. A tsunami was generated with maximum height to 7 meters and inundated up to 1 km inland.

 

 

The earthquakes of M 4.9 and 5.0 are the strongest within about 150 km of those  events in the Easter Island region of the East Pacific since a series on May 2, 2018 which included an event of M 6.0 and several others of M>=5. Forecast 125190 had expected today's event near the antipode of the solar eclise in India and Nepal was likely around June 27 in the East Pacific.

 

O: 22JUN2020 14:30:46  22.9S  112.3W mb=4.9  EMSC   EASTER ISLAND REGION         

O: 22JUN2020 13:23:44  23.0S  112.5W mb=5.0  EMSC   EASTER ISLAND REGION         

P: 27JUN2020 125190    25.0S  112.0W 4.0-5.4 BBAAA  So. East Pacific Rise      

 

O: 22JUN2020 11:09:58  19.5N   83.1E ML=3.6  EMSC   ORISSA, INDIA                

 

O: 22JUN2020 13:37:16  38.6N   70.7E mb=4.8  EMSC   TAJIKISTAN                   

P: 28JUN2020 125046    37.0N   70.0E 3.8-5.2 CBAAA  Hindu Kush/Pakistan        

P: 28JUN2020 125047    39.0N   72.0E 3.8-5.3 CBAAA  Hindu Kush/Pakistan        

 

O: 22JUN2020 10:38:13  44.1N   86.7E mb=4.4  EMSC   NORTHERN XINJIANG, CHINA     

P: 16JUN2020 124826    44.0N   82.0E 4.0-5.6 CACAA  Kirgizstan/Xinjiang        

 

O: 22JUN2020 13:29:13  24.3N  122.9E mb=4.4  EMSC   TAIWAN REGION                

P: 24JUN2020 125022    25.0N  123.0E 4.0-6.2 AAAAA  Ryukyu Islands             

 

O: 22JUN2020 07:10:24  25.8N   94.5E ML=2.8  EMSC   MYANMAR-INDIA BORDER REGION  

P: 29JUN2020 125019    26.0N   93.0E 4.0-5.5 CABAA  Myanmar                    

 

 

The strongest earthquake in the U.S. or Canada today was an M 4.6 in the Lone Pine area of California near the Nevada border. This is not an aftershock of the Ridgecrest group north of the Tonopah, Nevada earthquakes of M 7.1 and 6.5 and represents a new regional mainshock. Like the Ridgecrest event of July 4, 2019 which started this group of earthquakes, today's event occurred two days

after a solar eclipse. NEIC reported maximum intensity IV in Independence and Lone Pine and II-III in California at Springville, Three Rivers, Sequoia National Park, Kings Canyon, Big Pine, Porterville, Ridgecrest and Lake Isabella among others. An aftershock of M 3.8 was felt in the Lone Pine, California area with intensity III and II in Three Rivers, California. The quake occurred near local solar noon and was probably promoted by high tidal stresses associated with the new moon/eclipse of June 21. The last earthquake within about 50 km of today's epicenter with M>=4.6 occurred on May 3, 2011 with M 4.5. Two earthquakes about 50 km southeast of this epicenter accompanied the Ridgecrest aftershocks on July 11 and July 18, 2019. The last major series of earthquakes in the area of today's epicenter occurred in early October (1 and 3), 2009 reaching maximum size of M 5.2. Today's event is at the fourth node (90 degrees) from the M 7.4 in the Kermadec Islands of June 18 and also from the M 6.7 in the Ryukyu Islands of June 13, 2020 and was probably promoted by energy from those sources. Forecast 125029 had expected today's activity within about 25 km of this epicenter was likely around June 24.

 

O: 23JUN2020 03:07:55  36.5N  118.0W Ml=2.2  EMSC   CENTRAL CALIFORNIA

O: 23JUN2020 02:51:58  36.5N  118.0W Mw=3.8  EMSC   CENTRAL CALIFORNIA

O: 23JUN2020 02:51:58  36.5N  118.0W Mw=3.8  EMSC   CENTRAL CALIFORNIA

O: 23JUN2020 02:38:35  36.5N  118.0W ML=2.3  EMSC   CENTRAL CALIFORNIA

O: 23JUN2020 02:01:40  36.5N  118.0W ML=2.3  EMSC   CENTRAL CALIFORNIA

O: 23JUN2020 02:01:40  36.5N  118.0W ML=2.3  EMSC   CENTRAL CALIFORNIA

O: 23JUN2020 06:48:10  36.5N  118.0W Ml=3.1  EMSC   CENTRAL CALIFORNIA

O: 23JUN2020 01:46:07  36.5N  118.0W ML=2.6  EMSC   CENTRAL CALIFORNIA

O: 23JUN2020 01:39:49  36.5N  118.0W ML=2.5  EMSC   CENTRAL CALIFORNIA

O: 23JUN2020 00:44:29  36.4N  118.0W ML=2.2  EMSC   CENTRAL CALIFORNIA

O: 23JUN2020 00:36:59  36.5N  118.0W ML=2.2  EMSC   CENTRAL CALIFORNIA

O: 23JUN2020 00:33:56  36.4N  118.0W ML=2.8  EMSC   CENTRAL CALIFORNIA

O: 23JUN2020 00:30:52  36.5N  118.0W ML=3.7  EMSC   CENTRAL CALIFORNIA

O: 23JUN2020 00:26:46  36.5N  118.0W ML=3.3  EMSC   CENTRAL CALIFORNIA

O: 23JUN2020 00:25:44  36.5N  118.0W mb=4.5  EMSC   CENTRAL CALIFORNIA

O: 23JUN2020 00:25:46  36.4N  117.9W mb=4.6  ANSS   CENTRAL CALIFORNIA

O: 22JUN2020 14:08:09  36.5N  118.0W ML=2.3  EMSC   CENTRAL CALIFORNIA

O: 22JUN2020 14:08:09  36.5N  118.0W ML=2.3  EMSC   CENTRAL CALIFORNIA           

P: 24JUN2020 125029    36.2N  117.9W 2.5-4.5 AAAAA  California/Nevada area     

 

The strong swarm of earthquakes in Iceland largely dissipated today. The strongest of today's events was an M 4.0 which went unfelt. An M 3.1 occurred at a new epicenter southwest of the larger recent quakes. Forecasts 125152 had expected today's activity around June 22-25.

 

O: 23JUN2020 03:35:15  63.2N   24.1W ML=3.1  EMSC   ICELAND REGION               

P: 25JUN2020 125152    62.0N   27.0W 4.0-5.8 ABBAA  Iceland area               

 

O: 22JUN2020 11:30:13  66.2N   18.5W ML=3.2  EMSC   ICELAND REGION

O: 22JUN2020 11:10:26  66.4N   18.7W ML=3.0  EMSC   ICELAND REGION

O: 22JUN2020 12:17:39  66.4N   18.7W ML=4.0  EMSC   ICELAND REGION

O: 22JUN2020 07:42:26  66.5N   18.7W ML=3.1  EMSC   ICELAND REGION

O: 22JUN2020 20:47:27  66.2N   18.5W ML=3.0  EMSC   ICELAND REGION               

P: 22JUN2020 125152    64.0N   18.0W 4.0-5.6 ABAAA  Iceland area               

 

An unusual earthquake of M 3.8 was also felt in eastern France today.  EMSC reported it was felt with loud thunderous noises in the area of France near Vallorcine, Chamonix-Mont-Blanc, Servoz, Les Houches, and in  Charrat, Fully, Champery, Orsieres, Martigny-ville,  Martigny-Combe, Switzerland, and up to 70 km from the epicenter in Blecherette, Switzerland. The last earthquake with M>=3.8 in this area of the French-Swiss Alps occurred on July 1, 2017 with M 4.1.  Forecast 125091 had expected today's activity to the south was likely around June 26.

 

O: 23JUN2020 06:25:42  46.0N    7.0E ML=3.8  EMSC   FRANCE                       

P: 26JUN2020 125091    44.0N    7.0E 3.0-5.2 BBAAA  Italy                      

 

 

NEIC reported an earthquake of M 4.9 in Oaxaca, Mexico  was felt with intensity IV-V   in the area(s) of Oaxaca, Mexico at Xadani and Huafulco and II-III in Pochutla, Mitia, Tlacolula, and Puerto Escondido and possibly as far as Mexico City. This earthquake is located at the fourth node (90 degrees) from the Kermadec M 7.4 and near the longitude of maximum tidal stresses with the new moon as noted above and in previous issues of this summary. The M 4.9 is the strongest in the America's today. Further seismicity in this area is expected in the next several days. Forecat 124982 had expected a moderate earthquake in this area around June 24.

 

 

O: 22JUN2020 18:34:26  16.2N   95.3W ML=4.1  EMSC   OAXACA, MEXICO               

O: 23JUN2020 01:17:18  16.2N   95.7W mb=4.9  EMSC   OAXACA, MEXICO               

P: 24JUN2020 124982    15.0N   95.0W 3.5-5.2 ABAAA  Chiapas, Mexico            

 

SOLAR ECLIPSE; KERMADEC ISLANDS M 7.4 CONTROL MAJOR GLOBAL SEISMICITY

 

EARTHQUAKE SUMMARY FOR JUNE 21, 2020

 

As expected in previous issues of this summary, most of the major global seismicity today occurred at locations where it appears to have been triggered by effects from the M 7.4 in the Kermadec Islands of June 18 or by tidal effects from the new moon and solar eclipse today or a combination of both. The largest earthquake in the world today was an M 6.0 in the Iceland swarm of the past two days. This epicenter is at 144 degrees from the Kermadec Islands. A moderately strong earthquake also occurred with M 5.7-5.8 today in the region of Mizoram, India near Bangladesh and Myanmar. This is at 103 degrees from the Kermadec epicenter. The area had just experienced an annular solar eclipse several hours earlier and an M 5.1 foreshock with that eclipse. Seismic energy from large earthquakes reflects and refracts off the inner core- outer core boundary and is returned to the surface in this distance range, often with a high concentration of energy. It is likely that it helps trigger additional seismicity at this distance in the days following large earthquakes. Likewise, energy reflected and refracted off the core-mantle boundary is returned to the surface near 103 degrees from the epicenter of the origin of the energy and can also help trigger seismic activity at this distance in the days following major surface events on the earth.  In previous issues of this summary it had been noted that both the eclipse and the energy from the Kermadec Islands would likely promote seismicity at this time as:

 

 

"At least one area has shown signs of increased seismicity following the event in the Kermadec Islands. An M 4.1 in Iceland occurred 20 minutes after the event of M 7.4 in the Kermadec Islands. This is the time it takes for a reflected P-wave off the core-mantle boundary takes to travel the 144 degrees from the Kermadec Islands to Iceland, and it is highly likely this event in Iceland was a reaction to that seismic energy. A strong cusp of energy occurs at 144 degrees from large surface events and often is associated with significant increases in seismicity at this distance. More such activity is likely in coming days, including a possible volcanic event in Iceland. This summary had expected active seismicity in Iceland around June 17 within  about 100 km of this in forecast 124879." (June 20, 2020)

 

and

 

"Areas near 103 and 144 degrees from the M 7.4 south of the Kermadec Islands of June 18 which are seismic are few, so far-field triggering from that event may be limited. Among the most likely to see significantly enhanced seismicity in the next week are Iceland and eastern Turkey at 144 degrees and the central U.S. including Oklahoma, Missouri, Wyoming, Montana, northern Alaska, areas near western Cuba, Colombia, the South Mid-Atlantic and Bangladesh, India, Myanmar and southern China near 103 degrees from the Kermadec event. ... " (June 20, 2020)

 

and

 

"The new moon will arrive June 21 at 06:41 UT. This involves an annular solar eclipse visible in the areas of Central Africa, Southern Asia, China and the Pacific with maximum at 06:41 UT. Maximum eclipse occurs over northern India, Nepal, Hindu Kush and Pakistan, an area which has seen enhanced seismicity in recent days including some unusual events at Gujarat, India and others. The eclipse will pass over Taiwan and the southern Ryukyu Islands as well as southern Iran and Pakistan and southern China. Most of these areas will probably see enhanced seismicity with this eclipse with a moderate chance of a major earthquake within a week of the eclipse in southern Asia. Longitudes which are sub-solar at this time are near 77 East and 103 West. These include areas of central Asia including Hindu Kush, India and Tajikistan in the east and the central and western U.S. and western Mexico in the west. These will experience the maximum tidal stresses and are most likely to see tidally triggered seismicity at this time. Many area, especially those where fluids are important modulators of seismicity, can experience tidal enhancement of seismicity, and several large earthquakes are likely in the next eight days. Tidal triggering often occurs near local solar midnight and noon when alignment is most linear." (June 19-20, 2020)

 

The earthquake in India/Myanmar today occurred near the sub-solar point at the time of the total eclipse. The sub-solar point is the point on the earth's surface where the sun is directly overhead at local solar noon. On the first day of summer in the northern hemisphere, the sun reaches its zenith at about 23 degree North latitude due to the tilt of the earth's axis. Vertical tidal triggering is therefore maximized near 23 North latitude at this time of year. Seismicity can be seen to increase at this latitude as well as evidenced by today's India earthquake at 23 North latitude; the Gujarat, India quake of M 5.5 on June 14; the M 5.5 in Taiwan of June 13 and a series in the southern Ryukyu Islands (M 5.0-5.6) over the past five days - all at 22-24 degrees north latitude. The only seismic areas at this latitude in the western hemisphere are in the Gulf California and the north mid-Atlantic Ridge.

 

The earthquake in the India-Myanmar border region of M 5.5-5.8 was reported by NEIC to have been felt with intensity IV in Mizoram, India at Champhai, Lunglei, Aizawl, and in Manipur and in Bangladesh at Chattagam, Jalakati and III in Comilla. The M 5.1 foreshock occurred north of this epicenter and was felt with intensity IV in Mizoram, India at Aizawl, in Manipur and in Lala, Assam and II-III in Sairang, Champhai, Silchar, Dharmanagar, Karimanj and Sihat, Bangladesh. This activity follows several shocks to the area that began with the landfall of

Tropical Cyclone Amphan in late May, 2020.  It was immediately followed by an M 4.5 in Bangladesh and an M 4.2 near the  Bangladesh-India border. Two foreshocks of M 4.7-4.8 hit the region on June 14 and 16. The landfall of TC Amphan was at 103 degrees from the subsequent M 7.4 in the Kermadec Islands, New Zealand, just as today's events are at 103 degrees from that M 7.4 in the Kermadec Islands. Forecast 125018 and 125019 had expected today's activity in Myanmar within about 200 km was likely around June 23-29. The last earthquake within about 300 km of today's mainshock with equal or greater magnitude than M 5.8 occurred on April 16, 2020 with M 5.9, the last of significantly larger magnitude was an M 6.9 on April 13, 2016.

 

O: 21JUN2020 22:40:52  23.2N   93.3E Mw=5.5  MIS    MYANMAR-INDIA BORDER REGION

O: 21JUN2020 22:40:52  23.2N   93.3E Mw=5.8  ANSS   MYANMAR-INDIA BORDER REGION

O: 21JUN2020 22:40:52  23.5N   93.3E Mw=5.7  CEIC   MYANMAR-INDIA BORDER REGION

O: 21JUN2020 10:46:23  23.9N   93.1E Mw=5.1  EMSC   MYANMAR-INDIA BORDER REGION

O: 21JUN2020 10:46:23  23.8N   92.9E Mw=5.1  MIS    MYANMAR-INDIA BORDER REGION

O: 21JUN2020 22:40:52  23.2N   93.3E Mw=5.6  EMSC   MYANMAR-INDIA BORDER REGION  

P: 23JUN2020 125018    25.0N   97.0E 4.0-5.7 ABCAA  Myanmar                    

P: 24JUN2020 125019    27.0N   92.0E 4.0-5.8 BCAAA  Myanmar                    

P: 29JUN2020 125019    26.0N   93.0E 4.0-5.5 CCAAA  Myanmar                    

 

In addition to the events in India/Myanmar today a series of moderate quakes followed the path of the eclipse. These included from west to east with the eclipse moderate events in the Congo (M 4.2); southern Iran (M 3.7, 3.7); Hindu Kush, Afghanistan (M 3.9); Tajikistan (M 4.2); Nepal/Xizang, China (M 4.6) near the point of maximum eclipse; Southern China (M 3.2) and Taiwan and the northern Philippines (M 4.0). Most of these were lightly felt and occur in or near the path of totality. This was the pattern expected with this solar eclipse in previous issues of this summary.

 

 

O: 21JUN2020 13:56:49   1.6S   28.6E mb=4.2  EMSC   LAC KIVU REGION, CONGO        

P: 25JUN2020 124961     2.0S   29.0E 3.0-4.9 BAAAA  Lake Victoria area         

 

NEIC reported this earthquake of M 4.2 in the Congo (DR)  was felt with intensity II-III in the area(s) of the Congo (DR) at Goma and Beni.

 

O: 21JUN2020 17:39:08  32.3N   85.5E Mw=4.6  MIS    NEPAL                        

O: 21JUN2020 17:39:01  32.9N   85.7E mb=4.4  EMSC   WESTERN XIZANG               

P: 19JUN2020 124816    31.0N   84.0E 3.8-5.3 ABBAA  Xizang                     

 

O: 21JUN2020 09:40:03  33.0N   99.1E Mw=2.1  CEIC   SOUTHERN CHINA               

P: 25JUN2020 125071    37.0N   95.0E 3.5-4.9 BCCAA  So. China                  

 

O: 21JUN2020 18:40:16  37.1N   71.2E Mw=4.3  MIS    TAJIKISTAN                   

P: 25JUN2020 125046    36.0N   71.0E 3.8-5.7 BBAAA  Hindu Kush/Pakistan        

 

O: 21JUN2020 18:15:57  36.0N   69.2E Mw=3.9  MIS    HINDU KUSH,AFGHANISTAN       

P: 25JUN2020 125046    37.0N   69.0E 3.8-5.4 BAAAA  Hindu Kush/Pakistan        

 

O: 21JUN2020 21:46:05  27.3N   56.7E ML=3.7  EMSC   SOUTHERN IRAN                

P: 19JUN2020 124764    27.0N   56.0E 3.5-5.1 AAAAA  So. Iran/Persian Gulf      

 

O: 21JUN2020 08:05:40  27.6N   53.4E ML=3.7  EMSC   SOUTHERN IRAN                

P: 25JUN2020 125023    28.0N   52.0E 3.5-5.6 BAAAA  So. Iran/Persian Gulf      

 

O: 22JUN2020 01:06:11  38.3N   45.1E ML=4.0  EMSC   NORTHWESTERN IRAN            

P: 23JUN2020 125085    40.0N   44.0E 3.5-5.0 ABAAA  Caucasus/Caspian Sea       

 

O: 21JUN2020 13:19:12  23.1N  120.8E ML=4.0  TAI    Hualien, Taiwan               

P: 24JUN2020 125024    23.0N  122.0E 4.0-5.8 BAAAA  Taiwan                     

 

CWB reported this earthquake was felt with intensity II in Taitung, and I in Kaohsiung, Tainan and Hualien Counties, Taiwan.

 

 

The M 6.0 in Iceland was the strongest earthquake in the world today. NEIC reported it was felt with intensity III-IV in Nordurland, Iceland at Husavik, Akureyri, and Kristnes.  This is part of series of events over the past two days which has included those of M 5.7, 5.6 and 5.4. It was followed by a number of moderate aftershocks and preceded by many foreshocks. The M 6.0 is the strongest earthquake recorded in Iceland since an M 6.2-6.3 on May 29, 2008 and an M 6.8 and M 6.5 on June 17 and 21, 2000 (exactly 20 years ago today). Forecasts 124879 and 125152 had expected today's activity in Iceland was likely around June 17-22. These events are located at 144 degrees from the M 7.4 south of the Kermadec Islands of June 18, 2020 and were probably promoted by energy from that source. Fluid motions accompanying strong tides from the new moon probably also enhanced this series at this time.

 

O: 21JUN2020 12:51:41  66.3N   18.5W ML=3.9  EMSC   ICELAND REGION

O: 21JUN2020 19:46:17  66.3N   19.0W mb=4.4  EMSC   ICELAND REGION

O: 21JUN2020 18:25:47  66.4N   18.6W ML=3.4  EMSC   ICELAND REGION

O: 21JUN2020 17:36:18  66.4N   18.7W ML=3.4  EMSC   ICELAND REGION

O: 21JUN2020 20:00:14  66.4N   18.7W ML=3.4  EMSC   ICELAND REGION

O: 22JUN2020 02:04:19  66.4N   18.7W ML=3.4  EMSC   ICELAND REGION

O: 21JUN2020 19:37:52  66.4N   18.7W ML=3.5  EMSC   ICELAND REGION

O: 21JUN2020 19:36:05  66.4N   18.7W ML=3.8  EMSC   ICELAND REGION

O: 21JUN2020 19:10:42  66.4N   18.7W ML=4.0  EMSC   ICELAND REGION

O: 21JUN2020 19:14:48  66.4N   18.7W ML=4.1  EMSC   ICELAND REGION

O: 21JUN2020 19:07:55  66.4N   18.7W Mw=6.0  EMSC   ICELAND REGION

O: 21JUN2020 19:18:37  66.4N   18.8W ML=3.7  EMSC   ICELAND REGION

O: 21JUN2020 19:29:17  66.4N   18.8W mb=4.5  EMSC   ICELAND REGION

O: 22JUN2020 03:58:19  66.5N   18.7W ML=3.4  EMSC   ICELAND REGION

O: 21JUN2020 18:20:10  66.5N   19.0W mb=4.4  EMSC   ICELAND REGION

O: 21JUN2020 23:42:26  66.6N   18.8W ML=3.6  EMSC   ICELAND REGION

O: 21JUN2020 19:57:08  66.6N   18.9W mb=4.5  EMSC   ICELAND REGION

O: 21JUN2020 20:02:49  66.6N   19.5W ML=3.4  EMSC   ICELAND REGION

O: 21JUN2020 21:26:28  66.2N   19.2W mb=4.2  EMSC   ICELAND REGION               

P: 17JUN2020 124879    65.0N   17.0W 3.0-5.0 BAAAA  Iceland area               

P: 22JUN2020 125152    64.0N   18.0W 4.0-5.6 AAAAA  Iceland area                

 

STRONG EARTHQUAKE SERIES IN NORTHERN ICELAND

 

EARTHQUAKE SUMMARY FOR JUNE 20, 2020

 

A series of moderate to moderately large earthquakes was felt in northern Iceland today. NEIC reported these events of M 5.4, 5.6 and 5.7 were felt with intensity III-IV in Iceland at Husavik and Akureyn, Nordurland and in Grenivik, Iceland with intensity III. They were also felt as far the Faroe Islands.

This summary had anticipated this activity in Iceland at this time in the previous issue as:

 

"At least one area has shown signs of increased seismicity following the event in the Kermadec Islands. An M 4.1 in Iceland occurred 20 minutes after the event of M 7.4 in the Kermadec Islands. This is the time it takes for a reflected P-wave off the core-mantle boundary takes to travel the 144 degrees from  the Kermadec Islands to Iceland, and it is highly likely this event in Iceland was a reaction to that seismic energy. A strong cusp of energy occurs at 144 degrees from large surface events and often is associated with significant increases in seismicity at this distance. More such activity is likely in coming days, including a possible volcanic event in Iceland. This summary had expected active seismicity in Iceland around June 17 within  about 100 km of this in forecast 124879." (June 20, 2020)

 

and

 

"Areas near 103 and 144 degrees from the M 7.4 south of the Kermadec Islands of June 18 which are seismic are few, so far-field triggering from that event may be limited. Among the most likely to see significantly enhanced seismicity in the next week are Iceland and eastern Turkey at 144 degrees and the central U.S. including Oklahoma, Missouri, Wyoming, Montana, northern Alaska, areas near western Cuba, Colombia, the South Mid-Atlantic and Bangladesh, India, Myanmar and southern China near 103 degrees from the Kermadec event. Southern Spain and Morocco are near the antipode of the Kermadec Islands. One or more of these areas is likely to see a significant earthquake, especially with the new moon." (June 20, 2020)

 

Today's activity began with an M 5.4 near local solar noon and continued throughout the day. It may have been promoted by the new moon which arrives today. The M 5.7 is the strongest event located in Iceland since a similar M 5.7 on August 26, 2014 and an M 5.7-5.8 on September 16, 2002, the only two such events within Iceland within about 250 km of today's epicenter in the past 30 years. Forecast 124879 had expected today's Iceland activity was likely around June 17. This activity is located at 144-145 degrees from the M 7.4 south of the Kermadec Islands of June 18 and was probably promoted by energy from that source.

 

O: 21JUN2020 02:50:46  66.2N   18.7W mb=4.2  EMSC   ICELAND REGION

O: 20JUN2020 19:38:46  66.3N   18.4W ML=4.1  EMSC   ICELAND REGION

O: 20JUN2020 15:05:10  66.3N   18.4W mb=5.4  EMSC   ICELAND REGION

O: 20JUN2020 15:42:03  66.3N   18.5W ML=3.5  EMSC   ICELAND REGION

O: 21JUN2020 00:22:13  66.3N   18.5W ML=3.6  EMSC   ICELAND REGION

O: 20JUN2020 16:39:33  66.3N   18.5W ML=4.1  EMSC   ICELAND REGION

O: 20JUN2020 19:35:36  66.3N   18.6W ML=3.8  EMSC   ICELAND REGION

O: 20JUN2020 19:26:23  66.3N   18.6W Mw=5.7  EMSC   ICELAND REGION

O: 20JUN2020 20:11:18  66.3N   18.8W mb=4.5  EMSC   ICELAND REGION

O: 20JUN2020 15:08:09  66.4N   18.5W ML=3.7  EMSC   ICELAND REGION

O: 20JUN2020 15:22:50  66.4N   18.9W ML=3.8  EMSC   ICELAND REGION

O: 20JUN2020 19:49:07  66.1N   17.9W ML=3.7  EMSC   ICELAND REGION               

P: 17JUN2020 124879    65.0N   17.0W 3.0-5.0 BBAAA  Iceland area               

 

O: 20JUN2020 22:23:57  63.8N   22.1W ML=3.6  EMSC   ICELAND REGION               

O: 20JUN2020 19:26:54  64.2N   20.1W ML=5.6  EMSC   ICELAND                      

P: 17JUN2020 124879    65.0N   17.0W 3.0-5.0 BABAA  Iceland area               

P: 22JUN2020 125152    64.0N   18.0W 4.0-5.6 AAAAA  Iceland area               

 

 

A moderate earthquake of M 4.2 occurred today in northern Oklahoma. It was  reported by NEIC to have been felt with intensity IV n Perry, Stillwater and Billings, Oklahoma and II-III in Much of northern Oklahoma and southern Kansas including in Oklahoma at Lucien, Covington, Garber, Morrison, Marshall, and in Kansas within about 300 km of the epicenter and in Missouri within about 400 km of the epicenter with intensity up to IV. Seismicity is often elevated in Oklahoma and Kansas at times of new moons. Tidal stresses probably promote movement of groundwater lubricating local small faults. The last earthquake of M>=4.2 in Oklahoma or Kansas was an M 4.5 on January 19, 2020. The only other such event in the past year was an M 4.2 on August 16, 2019, an event associated with the full moon. Forecasts 124809 and 125075 had expected today's activity around June 18-21. This epicenter is at 103 degrees from the Kermadec Islands quake of M 7.4 of June 18, and was likely promoted by concentrated energy from that source as well.

 

O: 21JUN2020 03:15:41  36.3N   97.4W mb=4.2  EMSC   OKLAHOMA                     

P: 18JUN2020 124809    35.0N   97.0W 2.0-4.1 BBAAA  Southern Plains            

P: 21JUN2020 125075    37.0N   97.0W 2.0-4.0 AAAAA  Southern Plains            

 

Other areas near 103 degrees from the M 7.4 in the Kermadec Islands of June 18 seeing moderate quakes today included Northern Alaska  (M 3.0); Pakistan (M 2.7); Colombia and Nicaragua (M 5.3).

 

The strongest earthquake in the U.S. or Canada today was an M 4.3 in Hawaii.

NEIC reported this earthquake of M 3.6-4.2 in Hawaii  was felt with intensity II-IV in the area(s) of Hawaii at Pahala, Hawaii National Park, Naalehu, Volcano, Captain Cook, Pahoa, Mountain View, Hilo, Kurtistown and Holualoa.  The last earthquake of M>=4.3 in Hawaii occurred as an M 4.9 on November 11, 2019. The only other such event in Hawaii in the past year was an M 4.5 on August 12, 2019. That earthquake occurred in conjunction with the full moon of November 12, 2019. Like it, today's event was probably promoted by the new moon today. Forecast 124759 had expected today's activity in mid-June.

 

O: 21JUN2020 01:48:49  19.3N  155.4W mb=4.3  EMSC   ISLAND OF HAWAII, HAWAII     

P: 14JUN2020 124759    19.4N  155.1W 4.0-5.4 CAAAA  Hawaii area                

 

Some enhanced activity in northern India and Myanmar is anticipated with the new moon today but the strongest of this may be delayed as noted in the tidal seismic forecast with today's solar eclipse:

 

"The new moon will arrive June 21 at 06:41 UT. This involves an annular solar eclipse visible in the areas of Central Africa, Southern Asia, China and the Pacific with maximum at 06:41 UT. Maximum eclipse occurs over northern India, Nepal, Hindu Kush and Pakistan, an area which has seen enhanced seismicity in recent days including some unusual events at Gujarat, India and others. The eclipse will pass over Taiwan and the southern Ryukyu Islands as well as southern Iran and Pakistan and southern China. Most of these areas will probably see enhanced seismicity with this eclipse with a moderate chance of a major earthquake within a week of the eclipse in southern Asia. Longitudes which are sub-solar at this time are near 77 East and 103 West. These include areas of central Asia including Hindu Kush, India and Tajikistan in the east and the central and western U.S. and western Mexico in the west. These will experience the maximum tidal stresses and are most likely to see tidally triggered seismicity at this time. Many area, especially those where fluids are important modulators of seismicity, can experience tidal enhancement of seismicity, and several large earthquakes are likely in the next eight days. Tidal triggering often occurs near local solar midnight and noon when alignment is most linear." (June 19-20, 2020)

 

TONGA-FIJI-KERMADEC ISLAND ARC REMAINS ACTIVE

 

EARTHQUAKE SUMMARY FOR JUNE 19, 2020

 

The strongest seismicity in the world today occurred in the Tonga-Fiji-Kermadec

Islands arc. This included aftershocks in the Kermadec Islands of M 4.6 and 5.1;

an M 4.3 north of this but south of the Fiji Islands (M 4.3); an M 5.4 in Tonga near Samoa; an M 4.6 in Samoa and the strongest earthquake in the world today - an M 5.7 in Fiji. None of these events were reported felt in their epicentral areas. This continues activation of that region which appears to have begun with an unusual earthquake that shook Fiji on June 6 (M 5.8) and was followed by event of M 5.9 on June 10 and preceded by a similar event on June 3. When the event of June 6 occurred this summary noted:

 

"Despite what some may think, felt earthquakes in the Fiji Islands are rare. This group is situated midway between two active seismic zones - the Vanuatu Islands to the west and the Tonga Islands to the east and sees large deep focus earthquakes but little large-magnitude shallow focus activity.  ...  Several other moderate earthquakes also occurred today in the Southwest Pacific and the Fiji Islands group may be a catalyst for strong regional activation in the next several days." (June 7, 2020)

 

O: 19JUN2020 17:10:34  33.4S  178.6W mb=5.1  EMSC   SOUTH OF KERMADEC ISLANDS    

O: 19JUN2020 07:57:44  33.7S  178.0W mb=4.6  EMSC   SOUTH OF KERMADEC ISLANDS    

P: 14JUN2020 124928    34.0S  180.0W 4.0-5.7 BABAA  So. Kermadec Islands       

 

O: 19JUN2020 17:54:40  25.6S  179.6E mb=4.3  EMSC   SOUTH OF FIJI ISLANDS        

P: 17JUN2020 124918    23.0S  179.0E 4.0-5.4 ACAAA  Tonga/Fiji                 

 

O: 20JUN2020 01:58:09  16.0S  173.1W Mw=5.4  EMSC   TONGA                        

P: 17JUN2020 124898    15.0S  173.0W 4.0-5.9 BAAAA  Samoa Islands              

 

O: 19JUN2020 10:07:55  17.5S  178.9W Mw=5.7  EMSC   FIJI REGION                  

P: 11JUN2020 124905    17.0S  179.0W 4.0-5.6 CAAAA  Tonga Islands              

P: 17JUN2020 124905    19.0S  178.0W 4.0-5.6 ABAAA  Tonga Islands              

 

O: 20JUN2020 04:44:31  16.3S  172.6W mb=4.6  EMSC   SAMOA ISLANDS REGION         

P: 13JUN2020 124904    16.0S  173.0W 4.0-5.8 CAAAA  Tonga Islands              

P: 17JUN2020 124898    15.0S  173.0W 4.0-5.9 BBAAA  Samoa Islands              

 

The strongest earthquake in the U.S. or Canada today was an M 4.9 in the western Nevada aftershock zone. NEIC reported it was felt with maximum intensity in Nevada at Goldfield and II-III in Luning, Silverpeak, Hawthorne, Tonopah, Beatty, and Glenbrook and in California at Bishop, Lee Vining, and El Portal.

The mainshock was preceded by an M 4.3 and followed by an M 4.2 aftershock, both of which were lightly felt in the epicentral area. This epicenter is located at the fourth node (90 degrees) from the Kermadec epicenter and was probably enhanced by energy from that source. The M 4.9 is the strongest aftershock in this area in nearly a month since an M 5.3 on May 22, 2020. The mainshock of M 6.5 on May 15, 2020 was followed by an immediate aftershocks of M 5.1 23 minutes later and an M 5.0 on May 20, 2020 - the only other such aftershocks to date. Forecast 124770 had expected today's activity in the aftershock area in mid-June.

 

O: 20JUN2020 05:32:33  38.2N  117.8W ML=2.1  EMSC   NEVADA

O: 20JUN2020 03:55:26  38.2N  117.8W ML=2.9  EMSC   NEVADA

O: 20JUN2020 03:49:54  38.2N  117.8W ML=3.8  EMSC   NEVADA

O: 20JUN2020 03:49:54  38.2N  117.8W ML=4.2  ANSS   NEVADA

O: 20JUN2020 03:40:46  38.1N  118.2W ml=2.0  EMSC   NEVADA

O: 20JUN2020 03:16:55  38.2N  117.9W ML=2.1  EMSC   NEVADA

O: 20JUN2020 01:13:57  38.2N  117.8W ML=2.2  EMSC   NEVADA

O: 20JUN2020 00:06:51  38.2N  117.9W ml=2.2  EMSC   NEVADA

O: 19JUN2020 20:42:21  38.2N  117.8W ML=4.9  ANSS   NEVADA

O: 19JUN2020 16:07:08  38.1N  118.0W ML=3.0  EMSC   NEVADA

O: 19JUN2020 10:26:42  38.2N  117.7W Mw=4.1  EMSC   NEVADA

O: 19JUN2020 08:49:08  38.2N  117.9W ML=2.4  EMSC   NEVADA

O: 19JUN2020 07:40:58  38.2N  117.9W ML=2.4  EMSC   NEVADA

P: 14JUN2020 124770    38.1N  117.8W 2.5-4.4 CAAAA  California/Nevada area     

 

Areas near 103 and 144 degrees from the M 7.4 south of the Kermadec Islands of June 18 which are seismic are few, so far-field triggering from that event may be limited. Among the most likely to see significantly enhanced seismicity in the next week are Iceland and eastern Turkey at 144 degrees and the central U.S. including Oklahoma, Missouri, Wyoming, Montana, northern Alaska, areas near western Cuba, Colombia, the South Mid-Atlantic and Bangladesh, India, Myanmar and southern China near 103 degrees from the Kermadec event. Southern Spain and Morocco are near the antipode of the Kermadec Islands. One or more of these areas is likely to see a significant earthquake, especially with the new moon.

 

At least one area has shown signs of increased seismicity following the event in the Kermadec Islands. An M 4.1 in Iceland occurred 20 minutes after the event of M 7.4 in the Kermadec Islands. This is the time it takes for a reflected P-wave off the core-mantle boundary takes to travel the 144 degrees from  the Kermadec Islands to Iceland, and it is highly likely this event in  Iceland was a reaction to that seismic energy. A strong cusp of energy occurs at 144 degrees from large surface events and often is associated with significant increases in seismicity at this distance. More such activity is likely in coming days, including a possible volcanic event in Iceland. This summary had expected active seismicity in Iceland around June 17 within  about 100 km of this in forecast 124879.

 

O: 18JUN2020 13:09:20  65.8N   18.1W ML=4.1  EMSC   ICELAND                      

P: 17JUN2020 124879    65.0N   17.0W 3.0-5.0 AAAAA  Iceland area               

 

O: 20JUN2020 06:50:35  66.3N   18.5W ML=3.6  EMSC   ICELAND REGION               

P: 17JUN2020 124879    65.0N   17.0W 3.0-5.0 AAAAA  Iceland area               

 

The strongest earthquake in Alaska today was an M 4.0 in Northern Alaska.

This is part of an aftershock sequence in the area which began with an M 6.3 mainshock on August 12, 2018 and is located at 104 degrees from the Kermadec Islands epicenter. Today's is a significant regional event as the last aftershock in this series of M>4 was an M 4.3 on December 16, 2019. An M 5.3 hit the area with the eclipse of July 2, 2019 - the strongest aftershock since August, 2018 - and was part of the regional activation at that time. Forecast 124881 had expected today's event was likely within this aftershock zone around June 15.

 

O: 19JUN2020 16:58:59  69.6N  144.0W ML=4.0  EMSC   NORTHERN ALASKA              

P: 15JUN2020 124881    69.0N  144.0W 3.0-4.7 AAAAA  Northern Alaska            

 

O: 18JUN2020 12:49:53  33.4S  177.8W Mw=7.4  EMSC   SOUTH OF KERMADEC ISLANDS

 

UNPRECEDENTED MAJOR QUAKE OF M 7.4 SHAKES NORTHERN NEW ZEALAND

 

EARTHQUAKE SUMMARY FOR JUNE 18, 2020

 

A major earthquake of M 7.4 shook most of northern New Zealand today. The epicenter was south of the Kermadec Islands and north of North Island.

This is the third strongest earthquake in the world in the past year following an M 7.7 South of Cuba on January 28, 2020 and an M 7.5 on March 25, 2020 in the northern Kuril Islands. The last event of significantly larger magnitude was an M 8.0 on May 26, 2019 in northern Peru. This is the strongest earthquake within about 300 km of this epicenter ever recorded. The epicenter is considerably southeast of most activity in this region and is highly unusual. At 10 km depth it may be an outer rise earthquake preceding a major quake to the northwest in coming days. NEIC reported maximum intensity VII in Whangamata, Waikota, North Island, New Zealand and IV in Napier, Bay of Plenty with II-III shaking ini the Bay of Blenty at Te Kaha, Opotiki, Whakatane, and in Napier, Hawkes Bay (IV), Gisborne, East Opus, Northland, Auckland, Taupo and Hastings. GEONET reported this earthquake was felt by 8907 people throughout both North and South Island with weak intensity by 3732 and light intensity by 3843 persons and moderate intensity by 1793. Strong shaking was felt by 124 with 9 feeling the quake with severe and six with extreme intensity. Aftershocks of M 5.5, 5.5, 5.4 ... were not reported felt. The earthquake occurred within about an hour of local solar midnight and was probably enhanced or promoted by tidal stresses associated with the upcoming new moon and solar eclipse. The tidal seismicity forecast for the coming new moon reads:

 

"The new moon will arrive June 21 at 06:41 UT. This will involve an annular solar eclipse visible in the areas of Central Africa, Southern Asia, China and the Pacific with maximum at 06:41 UT. Maximum eclipse occurs over northern India, Nepal, Hindu Kush and Pakistan, an area which has seen enhanced seismicity in recent days including some unusual events at Gujarat, India and others. The eclipse will pass over Taiwan and the southern Ryukyu Islands as well as southern Iran and Pakistan and southern China. Most of these areas will probably see enhanced seismicity with this eclipse with a moderate chance of a major earthquake within a week of the eclipse in southern Asia. Longitudes which are sub-solar at this time are near 77 East and 103 West. These include areas of central Asia including Hindu Kush, India and Tajikistan in the east and the central and western U.S. and western Mexico in the west. These will experience the maximum tidal stresses and are most likely to see tidally triggered seismicity at this time. Many area, especially those where fluids are important modulators of seismicity, can experience tidal enhancement of seismicity, and several large earthquakes are likely in the next eight days. Tidal triggering often occurs near local solar midnight and noon when alignment is most linear." (June 18-19, 2020)

 

When an unusual earthquake occurred west of North Island on June 13, this summary warned:

 

"The earthquake in South Island, New Zealand today was accompanied by an unusual earthquake west of North Island, New Zealand of M 4.7. The epicenter of this event is quite unusual. No earthquakes of M>=4.0 have occurred in this region northwest of New Zealand within about 300 km in at least 30 years. ..." (June 13, 2020)

 

and

 

"Unusual earthquakes in the New Zealand area have been known to just precede major global events. For example, on February 25, 2010 this summary noted an unusual earthquake off the coast of northern New Zealand which was nearly identical to a similar event on May 20, 1960 as possibly being a precursor to an upcoming major global event" (June 13, 202)

 

The M 7.4 south of the Kermadec Islands today is consistent with this expected pattern but is, itself, unusual seismicity in the New Zealand area. It may be precursory to an even stronger event in the region of southern Asia within days of the solar eclipse of June 21. The strongest tidal stresses with a solar eclipse occur near the path of totality. The path of that annular eclipse passes from southern Iran to Pakistan, Afghanistan, India, Nepal, Southern China, Taiwan and the Southern Ryukyu Islands of Japan. Some increases in seismicity may occur in these regions and near the antipode which crosses South America near northern Chile where an M 6.8 occurred on June 3, 2020. A strong aftershock is possible in that area at this time as well. All these areas have shown increased seismicity in the past week. This area is highly populated and a major event in the region could lead to great property damage and/or loss of life.

 

The last solar eclipse occurred on December 26, 2019 and was accompanied by a series of earthquakes in Puerto Rico which led to the M 6.5 on January 7, 2020, a deadly and disastrous event, unique in that area. The only other solar eclipse in the past year occurred on July 2, 2019. It was followed by the series of large earthquake in the Ridgecrest, California area on July 4 (M 6.7) and July 6 (M 7.1) as well as activation of the western U.S. and Canada. This summary had noted this at the time as:

 

"Solar eclipses have been known to be associated with major events in South America in the past. For example, a total solar eclipse of June 21, 2001 which began over South America was accompanied by  an M 8.4 in Peru on June 23, 2001, a quake which devastated the area and killed thousands. The coincidence of these two events was probably not happenstance. A further example is the Izmit, Turkey event of August 1999 which coincided with the most complete solar eclipse in Europe in centuries." (July 2, 2019)

 

Forecast 124928 had expected elevated seismicity in this region of the Kermadec Islands was likely in mid-June. These epicenters are near the 103 distance from the landfall of Tropical Cyclone Amphan which made landfall in Bangladesh on May 25 and may have been promoted by energy from that source as noted at the time in this summary:

 

"A moderately strong earthquake of M 5.8 in the Northern Kermadec Islands of New Zealand today completed the set of such events in the area which followed landfall of TC Amphan last week." (May 29, 2020)

 

and

 

"A series of moderate earthquakes continued today in the Southwestern Pacific.

These included an M 5.9 in Tonga, an M 6.1 in Vanuatu and several moderate aftershocks; events in Fiji (M 4.3, 4.5) and in north and South Island, New Zealand of M 4.0 and 4.5. This activity is located at 101-104 degrees from the landfall of TC Amphan in Bangladesh late last week." (May 28-29, 2020)

 

The 103 degree distance from the Kermadec Islands passes through Myanmar and northern India as well as in the central U.S. in Oklahoma. These areas may see far-field triggering in coming days.

 

O: 19JUN2020 05:20:07  33.3S  177.6W mb=4.5  EMSC   SOUTH OF KERMADEC ISLANDS

O: 18JUN2020 15:06:15  33.3S  178.0W mb=5.5  EMSC   SOUTH OF KERMADEC ISLANDS

O: 18JUN2020 12:49:54  33.4S  177.5W ML=7.4  GEONET reported felt by 8907 people

O: 18JUN2020 12:49:53  33.4S  177.8W Mw=7.4  EMSC   SOUTH OF KERMADEC ISLANDS

O: 18JUN2020 16:11:40  33.4S  177.9W mb=5.5  EMSC   SOUTH OF KERMADEC ISLANDS

O: 18JUN2020 19:34:15  33.4S  178.4W mb=5.2  EMSC   SOUTH OF KERMADEC ISLANDS

O: 18JUN2020 19:11:52  33.5S  178.1W mb=5.4  EMSC   SOUTH OF KERMADEC ISLANDS

O: 19JUN2020 00:38:51  33.6S  178.6W Mw=5.4  EMSC   SOUTH OF KERMADEC ISLANDS

O: 18JUN2020 14:52:48  33.1S  177.8W mb=5.0  EMSC   SOUTH OF KERMADEC ISLANDS    

P: 14JUN2020 124928    34.0S  180.0W 4.0-5.7 BABAA  So. Kermadec Islands        

 

The earthquake south of the Kermadec Islands today appears to have reignited the  swarm in the southern Ryukyu Islands which had largely dissipated yesterday.

The largest of today's events, of M 5.3, 5.2 and 5.0 were reported felt in Okinawa and Taiwan. This epicenter is at the end of the path of totality for the June 21 Solar Eclipse and could see increased tidal triggering in the next several days. Forecast 124765 had expected moderate seismicity within about 100 km of these epicenters was likely in mid-June.

 

O: 18JUN2020 16:43:18  24.9N  123.3E Mw=5.3  EMSC   SOUTHWESTERN RYUKYU ISL., JAPAN

O: 19JUN2020 07:30:30  24.9N  123.4E ML=4.6  EMSC   SOUTHWESTERN RYUKYU ISL., JAPAN

O: 19JUN2020 00:26:35  24.9N  123.4E Mw=5.2  EMSC   SOUTHWESTERN RYUKYU ISL., JAPAN

O: 18JUN2020 16:42:14  24.8N  123.3E mb=5.0  EMSC   SOUTHWESTERN RYUKYU ISL., JAPA

P: 14JUN2020 124765    24.0N  123.0E 4.0-5.6 BAAAA  Taiwan                     

 

O: 18JUN2020 22:25:11  24.6N  125.2E mb=4.7  EMSC   SOUTHWESTERN RYUKYU ISL., JAPA

P: 19JUN2020 124763    25.0N  122.0E 4.0-5.4 AABAA  Ryukyu Islands             

 

The largest earthquakes in the U.S. or Canada today were an M 5.2 and 5.1 in the western Andreanof Islands, Alaska. They were not reported felt in this remote area. The last earthquake in the western Andreanof Islands to exceed M 5.1 occurred on March 2, 2020 with M 5.7. These are probably aftershocks of an M 6.1 that shook the area on January 26, 2020. Forecast 124854 had expected today's activity in the Andreanof Islands within about 50 km of these epicenters was likely in mid-June.

 

O: 19JUN2020 02:59:27  51.2N  179.1W Mw=5.1  EMSC   ANDREANOF ISLANDS, ALEUTIAN IS

O: 19JUN2020 03:08:31  51.3N  179.2W Mw=5.2  EMSC   ANDREANOF ISLANDS, ALEUTIAN IS

P: 14JUN2020 124854    51.0N  179.9W 3.5-5.1 BAAAA  Andreanoff Isls, Aleutians 

 

The strongest felt earthquake in the U.S. today was an M 4.2 in the Kenai Peninsula or Alaska. NEIC reported it was felt with maximum intensity IV in Eagle River and Anchorage and III in Girdwood, Moose Pass, and Fort Richardson. This is the largest earthquake in the Kenai Peninsula of Alaska since a similar M 4.2 on February 27, 2020. No other such events have occurred in the Kenai Peninsula in the past six months. Forecast 124876 had expected today's event was likely around June 16.

 

O: 18JUN2020 09:42:00  60.4N  151.8W ML=3.1  EMSC   KENAI PENINSULA, ALASKA      

O: 18JUN2020 20:38:42  60.9N  149.1W mb=4.3  EMSC   KENAI PENINSULA, ALASKA      

P: 16JUN2020 124876    60.5N  151.5W 3.2-5.0 AAAAA  Central Alaska             

 

 

CENTRAL ASIA; WESTERN U.S. CONTINUE ENHANCED SEISMICITY

 

EARTHQUAKE SUMMARY FOR JUNE 17, 2020

 

Global seismicity returned to relatively quiet levels today with no events of

M>=5. Enhanced seismicity, however did continue in central Asia with two events of M 4.2 in Hindu Kush and an M 4.7 in Pakistan and in the western U.S. where earthquakes of M 4.5 occurred off the northern California coast; an M 3.4 was widely felt in San Francisco, California and an aftershock of M 4.3 in southern Idaho continued active conditions in that area. These quiet conditons, however are not expected to continue for long. In addition to the new moon on June 21, an asteroid of moderate size will make a close pass on June 20, and there is still the outstanding matter of what the meaning of the unusual earthquake west of New Zealand of June 13 was - a large quake is still considered possible in that region in the next several days. 

 

The strongest earthquake in the U.S. or Canada today was an M 4.5 off the coast of northern California and Oregon. NEIC reported it was felt with intensity I-II in Brookings and Salem, Oregon and in Eureka, Orland and Santa Clara, California. No damage was reported with this earthquake. The last earthquake within about 100 km of this epicenter with M>=4.5 occurred on October 28, 2019 more than half a year ago with M 5.2. Forecast 124840 had expected today's event in this region was likely around June 19.

 

Previous issues summary had expected the area off the northwest coast of the U.S. could show enhanced seismicity at this time as:

 

"The enhanced seismicity on Ocean Ridges which saw the last in the Southern Mid-Atlantic Ridge yesterday of M 6.0 continued today with and M 5.8 in the Prince Edward Island region of the South Indian Ocean. It was not reported felt in this remote area. The antipodal area of this epicenter off the northwestern coast of the U.S. west of California an Oregon. This event is a bit small to significantly enhance seismicity in this area but some minor enhancement in the area is possible over the next several days. Most of the activity in this area off the coast of California and Oregon occurs well to the east of the antipode of today's Prince Edward Islands event." (June 12, 16, 2020)

 

O: 17JUN2020 21:08:09  41.8N  126.0W Mw=4.5  EMSC   OFF COAST OF NORTHERN CALIFORN

P: 19JUN2020 124840    41.8N  126.9W 2.5-4.6 AAAAA  Off Coast of No. Calif     

 

An earthquake of M 3.4 was widely felt in the San Francisco Bay area of California today. NEIC reported maximum intensity III in Milpitas, San Jose, Mount Hamilton, and other communities. This is the strongest earthquake in the San Francisco Bay area since an M 3.9 to the south of today's epicenter on January 2, 2020 nearly half a year ago. Forecast 124774 had expected area would be active around June 19. Today's event may have been promoted by tidal stresses as it occurred within a couple of hours of local solar noon.

 

O: 17JUN2020 17:35:02  37.4N  121.8W Mw=3.4  EMSC   SAN FRANCISCO BAY AREA, CALIF.

P: 19JUN2020 124774    37.8N  122.6W 2.5-4.4 AAAAA  Central California         

 

The aftershock zone in Southern Idaho continued at enhanced levels today. The strongest earthquake of the day was an M 4.3. This follows an M 4.7 in this zone on June 13. At the time this summary had noted:

 

"The strongest earthquake in the U.S. or Canada today was an M 4.2-4.7 in the Southern Idaho aftershock zone of the March 31, 2020 M 6.5. NEIC reported maximum intensity for this event was IV at Stanley, Idaho with II-III shaking in Idaho at Lowman, Garden Valley, Cascade, Ketchum, Fairfield, Hailey, May, Garden City and Boise. This is the first aftershock in southern Idaho of M 4.7 or greater since the mainshock of M 6.5 on March 31, 2020 and the third largest event in the area in the past 30 years - after a similar M 4.7 on January 28, 1995." (June 13, 2020)

 

Forecast 124830 had expected today's event was likely around June 17.

 

NEIC reported this earthquake of M 3.9-4.0 in Southern Idaho  was felt with intensity II-III in the area(s) of Southern Idaho at Lowman, Ketchum, Horseshoe Bend, Garden City, Boise and Meridian.

 

O: 17JUN2020 07:59:39  44.4N  115.2W Ml=4.3  EMSC   SOUTHERN IDAHO

O: 17JUN2020 09:04:48  44.4N  115.2W Ml=2.5  EMSC   SOUTHERN IDAHO

O: 17JUN2020 09:28:56  44.4N  115.2W Ml=2.2  EMSC   SOUTHERN IDAHO

O: 17JUN2020 12:03:24  44.4N  115.2W Ml=2.5  EMSC   SOUTHERN IDAHO

O: 18JUN2020 06:02:26  44.4N  115.2W ML=2.8  EMSC   SOUTHERN IDAHO

O: 17JUN2020 07:19:12  44.5N  115.3W Ml=2.1  EMSC   SOUTHERN IDAHO

O: 18JUN2020 02:31:53  44.2N  115.1W ML=2.7  EMSC   SOUTHERN IDAHO               

P: 17JUN2020 124830    44.4N  115.1W 2.0-4.1 AAAAA  Montana/Idaho              

 

An M 3.7-4.0 was widely felt in southern Puerto Rico today. NEIC reported it was felt with IV in Ponce and Guanica and II-III in San German, Cabo Rojo, Mayaguez, Arecibo, Hatillo, Anasco, Bayamon and Carolina, Puerto Rico. This is an aftershock of the M 6.5 of January 7, 2020. The last earthquake in this aftershock zone with M>=4 occurred June 13, 2020. Forecast 124754 had expected this activity around June 16.

 

O: 18JUN2020 06:38:33  17.9N   66.8W ML=4.0  EMSC   PUERTO RICO REGION

O: 17JUN2020 18:36:41  18.0N   67.0W Md=3.0  EMSC   PUERTO RICO REGION

O: 18JUN2020 02:20:38  19.1N   67.2W ML=3.2  EMSC   PUERTO RICO REGION

O: 18JUN2020 00:50:14  17.9N   66.9W ML=3.1  EMSC   PUERTO RICO                  

O: 18JUN2020 06:18:23  17.9N   67.1W ML=3.2  EMSC   PUERTO RICO REGION           

P: 16JUN2020 124754    18.0N   66.0W 3.4-5.1 AAAAA  Puerto Rico                

 

RED SEA SEES UNUSUAL M 5.4

 

EARTHQUAKE SUMMARY FOR JUNE 16, 2020

 

The strongest earthquake felt in the world today was an M 5.4 in the northern Red Sea. NEIC reported it was felt with maximum intensity II-III in Egypt at Hurghada, El Tur, South Sainai, Asyut, and Tockh and in Tabuk, Saudi Arabia, and Beirut, Lebanon. While the Red Sea is an active seismic zone, part of the spreading of the east African Rift Valley, earthquakes of M>=5.4 are not common in this area. The last such event in the Red Sea within about 250 km of today's epicenter occurred on November 23, 1995 nearly 25 years ago. This was an aftershock of an M 7.2 on November 22, 1995 and occurred about 150 km north of today's epicenter. This earthquake is at 101 degrees from the M 7.7 south of Cuba of January 24 and may have been promoted by energy from that source.

 

O: 16JUN2020 14:30:27  27.3N   34.7E Mw=5.4  EMSC   RED SEA                      

 

The strongest earthquake today was an M 5.6 in the Tonga Islands. It was lightly felt in the epicentral area. This is the largest earthquake within about 250 km of this epicenter in Tonga since an M 5.7 a month ago on May 15 and three months ago as an M 6.0 on March 17, 2020 - the only such events in the past half year.

Forecast 124904 had expected today's event to the east around June 13.

 

O: 17JUN2020 06:24:19  16.2S  175.0W Mw=5.6  EMSC   TONGA                        

P: 13JUN2020 124904    16.0S  173.0W 4.0-5.8 BABAA  Tonga Islands              

 

Active conditions continued in central Asia today following three days of enhanced seismicity in that region. Events of M 4.5 in Pakistan and an M 5.0 in Hindu Kush, Afghanistan were reported by NEIC to have been felt. The event in Hindu Kush with intensity II in Kabul, Afghanistan. The epicenter is at 70 East longitude and was probably promoted by high tidal stresses from the previous full and the upcoming new moon as noted in previous summaries as:

 

"The new moon will arrive June 21 at 06:41 UT. Longitudes which are sub-solar at this time are near 77 East and 103 West. These include areas of central Asia including Hindu Kush, India and Tajikistan in the east and the central and western U.S. and western Mexico in the west. These will experience the maximum tidal stresses and are most likely to see tidally triggered seismicity at this time. Many area, especially those where fluids are important modulators of seismicity, can experience tidal enhancement of seismicity, and several large earthquakes are likely in the next eight days. Tidal triggering often occurs near local solar midnight and noon when alignment is most linear." (June 15-16, 2020)

 

and

 

"The full moon will arrive on June 5 at 19:12 UT. Areas which are sub-solar at this time are near 110 West and those anti-solar at 70 East longitude. These include western U.S. in the west and Central Asia in the East. Some enhanced seismicity in these areas is likely during the next five days." (June 1-2, 2020)

 

The M 5.0 in Afghanistan is the first of M>=5.0 in the Hindu Kush area since an M 6.1 on December 20, 2019, six months ago. It followed the M 5.7 in Tajikistan about 200 km to the northeast by about 8 hours and may have been triggered by regional stresses from that event.

 

The earthquake of M 4.7 in southwestern Pakistan was the strongest within about 200 km of that epicenter since an M 4.7 on May 15, 2020.   It may have been promoted by the M 5.1-5.5 event in Gujarat, India two days ago. That event and several moderate quakes in southern Iran may have helped redistribute stress in the area leading to today's Pakistan quake.

 

O: 17JUN2020 06:58:19  25.2N   63.3E mb=4.7  EMSC   SOUTHWESTERN PAKISTAN        

P: 10JUN2020 124764    29.0N   58.0E 3.5-5.1 CCCAA  So. Iran/Persian Gulf      

P: 14JUN2020 124760    24.0N   70.0E 3.5-4.9 BBCAA  India                       

 

An M 4.5 was also felt on the Vietnam-Laos-China border today. NEIC reported it was felt with intensity II in Svay Rieng, Cambodia. This epicenter is near the landfall of TS Nuri several days ago. That landfall was followed by active conditions throughout much of southeast Asia but this is the first moderate event in the immediate landfall area since it occurred. The associated forecast with TS Nuri had read:

 

 

"The activity in Turkey and India may have been enhanced by landfall of Tropical Storm Nuri in southeastern China about the same time. A series of moderate earthquakes in southern Ryukyu Islands off eastern Taiwan also accompanied this landfall. This had been noted in the previous summary as: " (June 14-15, 2020)

 

    

"TS Nuri  (02W) continued today east of the Philippines with winds up to 35 kts. No major changes to seismicity in the region are anticipated with this storm at this time but large earthquakes in Taiwan (M 5.5) and the Ryukyu Islands (M 6.7) may have been promoted by stresses from TS Nuri today." (June 13-14, 2020)

 

O: 16JUN2020 11:15:47  19.0N   94.3E mb=4.8  EMSC   MYANMAR                      

P: 12JUN2020 124734    19.0N   96.0E 4.0-5.6 BABAA  Andaman Islands            

 

 

Several antipodal pairs were completed today. An earthquake northwest of Spain with M 4.7 occurred at 43N 14W in the Atlantic Ocean. This is antipodal within about one degree to the M 5.3-5.5 in South Island, New Zealand of June 12 at 44S 167E. Epicenters are antipodal when the latitudes are the same and in opposite hemispheres and the longitudes are in opposite hemispheres and numerically add to 180 as is the case here.

 

The last earthquake in the North Atlantic within about 250 km of today's epicenter with M>=4.2 occurred on April 29, 2017 with M 4.2. The last with larger magnitude was an M 4.5 on April 3, 2012. The largest event  in this area in the past 30 years was an M 4.9 more than 12 years ago on January 4, 2008.

The last earthquake within about 200 km of the June 12 epicenter in South Island with M>=5.3 occurred on August 12, 2019 with M 5.4 and prior to that as an M 5.4 on June 7, 2016.  It is likely this epicenter was triggered by antipodal focusing of seismic energy from the M 5.3 in South Island, New Zealand of June 13.

 

At the time of the South Island event another occurred to the north. This was also accompanied by antipodal activity in the North Atlantic as noted in this summary at the time:

 

"Near the antipode of the event west of North Island an M 4.9 occurred later in the day off the west coast of Spain. This is within about 300 km of the exact antipode of the New Zealand event (39N 13W). The combination of these unusual near-antipodal quake suggests something may be brewing in global seismicity. ... Today's earthquake off Spain is the largest within about 250 km of that epicenter since an M 5.5 on December 17, 2009 more than 10 year ago." (June 13, 2020)

 

The second antipodal pair involving the North Atlantic off Spain suggests this may be an area where a stronger quake may occur in the near-term. Great earthquakes are not unknown to occur in this region. Two such events hit the area on February 28, 1969, and May 26, 1975 with M 8.0 and M 8.1 A larger event was recorded on November 25, 1941. The great earthquake of November 1, 1755  inspired the author Voltaire to write the satire "Candide" and  triggered a tsunami which destroyed Lisbon and led to the decline of Portugal as a world power occurred in this area. The tsunami was one of the only such events which reached North America reaching wave heights up to 20 feet in the Caribbean. All of these events, however were located well to the south of the current activity and there seems little danger of such an event in today's epicentral area. The largest quake recorded near today's epicenter was an M 6.0 on March 8, 1906, a month before the great San Francisco, California earthquake of April, 1906.

 

The earthquake today in the North Atlantic is at 101 degrees from the M 6.7 in the northern Ryukyu Islands of June 13 and may have been promoted by concentrated energy from that source.

 

O: 17JUN2020 04:59:23  43.3N   14.4W mb=4.2  EMSC   NORTH ATLANTIC OCEAN         

 

O: 12JUN2020 07:29:17  44.4S  167.8E ML=5.3  GEONET reported 1737 people felt this quake

 

A series of moderate earthquakes also hit the area of Sumbawa, Indonesia on June 13 at 9S 118E. These were followed today by an M 4.4 today in the Gulf of Paria, Trinidad and Tobago within about one degree of exactly antipodal.  NEIC reported this earthquake of M 4.4 in Trinidad and Tobago  was felt with intensity II-III in the area(s) of Trinidad and Tobago at Scarborough.  The event of M 5.0 in Sumbawa was the strongest in that area in the past three months. Quakes of M 5.1 and 5.2 hit the area on March 15, and January 6, 2020, the only such activity in the region in the past half year. The last event of M>=4.4 in the Gulf of Paria, Venezuela was an M 4.7 on March 16. The only other such event in the past six months in this area was an M 4.8 on January 28, 2020. Antipodal epicenters often occur during global geomagnetic disturbance or when one event is very large. The  cause of today's antipodal events is under investigation.

 

 

O: 16JUN2020 09:56:44  10.1N   62.0W mb=4.4  EMSC   GULF OF PARIA, TRINIDAD-TOBAGO

 

O: 13JUN2020 09:15:46   8.9S  117.8E Mw 5.0  EMSC   SUMBAWA REGION, INDONESIA    

O: 13JUN2020 12:12:22   9.0S  117.9E ML 4.7  EMSC   SUMBAWA REGION, INDONESIA    

 

The strongest earthquake in California today was an M 3.8 in the northern Ridgecrest, California aftershock zone. Forecast 124805 had expected today's activity within about 10 km was likely around June 18. The area has seen a series of events around M 3.8 in recent months. The last of these was an M 4.2 on June 4 and an M 3.8 on May 24, 2020. The only other such event in the northern aftershock zone in the past half year was an M 3.8 on March 8, 2020. An M 5.5 aftershock about 50 km southeast of this occurred on June 4, 2020 and may have led to the current spike in regional activity.

 

O: 16JUN2020 09:55:16  35.9N  117.7W Ml=2.4  EMSC   CENTRAL CALIFORNIA

O: 16JUN2020 05:58:22  36.0N  117.8W Mw=3.8  EMSC   CENTRAL CALIFORNIA           

P: 18JUN2020 124805    35.9N  117.7W 2.5-4.6 AAAAA  So. California