COMMEMORATING 25 YEARS SINCE LANDERS, CALIFORNIA EARTHQUAKE (M 7.8)

 

EARTHQUAKE SUMMARY FOR JUNE 27, 2017

 

It was a very quiet date in global seismicity today. The largest events of M 4.9 each were located in Hindu Kush, Afghanistan and in Halmahera, Indonesia. Neither of these was damaging and both were felt with light intensity. As often happens in mid-summer seismicity was on the increase in the central U.S. where light earthquakes of M 2.0-2.1 occurred in Illinois and Arkansas as well as the ongoing seismicity in Oklahoma and Kansas. The minor swarm in the Truckee area of Northern California continued at a reduced level. A second minor swarm including an M 2.5 occurred near Landers, California marking 25 years since an M 7.8 at that epicenter.

 

June 28, 2017 is the 25th anniversary of an earthquake of M 7.8 in Southern California which occurred June 28, 1992. The following excerpt from the history section of this report describes that event:

 

" 6 28 11 57 35 1992  34.190 -116.540  10 7.8   So. California

 

The largest earthquake in California in 40 years, this event killed one at Yucca Valley and two others by heart attacks. More than 400 were injured.  Considerable damage occurred to buildings (bowling alley, residences, stores) in the Landers and Yucca Valley area. The maximum intensity of this earthquake was IX. It apparently triggered a second strong event several hours later in  the Big Bear area east of Los Angeles. Estimated cost was $92 million U.S. dollars. Felt in Utah, Arizona, New Mexico, Colorado, Nevada. Surface faulting was observed in the Barstow and Joshua Tree area with more than 5 meters  horizontal displacement and up to 1.0 meters vertical displacement. Seiche was observed from Washington, Colorado and Texas." (June 28, 2016)

 

The author was working in Colorado at the time of this earthquake. Personal recollection of that Sunday? morning may be of interest to readers. It was a hot morning and sleep was fitful. About 6 o'clock I was awakened by the howling of a local dog (Ransom by name) who had made a stand outside my bedroom window. I couldn't get back to sleep because of the  incessant howling, barking and whining Ransom was making. He had never done this before in the years we had been neighbors. So eventually I got up and tried to calm him down, which seemed to work. Because of the heat and disruption I couldn't get back to sleep so I turned on the television and caught the first reports of a major earthquake in southern California. Surface waves from this event would have arrived about the time Ransom started his outburst and major seiche was observed in the area where I was living. I speculate Ransom felt the local effects and was frightened having not felt this before, and needed to tell the world about it, and my bedroom was right next door. It was at the time when automatic web data was just beginning. Initial locations gave the location near Baker, California, a small hamlet in the California Desert which few had ever heard of. But at first, the quake was known as the Baker quake only later to be designated as the Landers earthquake after a somewhat larger town near the epicenter. We used to kid James Lander, founder of the National Earthquake Information Center (NEIC) that he finally had an earthquake named after him (this was not the case but the kidding was in fun anyway).

 

A minor swarm of earthquakes occurred today in the Yucca Valley/Landers area within about 10 km of the epicenter of June 28, 1992 event. The largest of these was M 2.5 within about 10 km of the epicenter of the 1992 event but was not

felt in this remote area. The area experienced a long period of quiet following the M 7.8 in 1992. The last earthquake of M>=2.5 within about 20 km of the  1992 mainshock occurred as an M 3.0 on April 7, 2017 and prior to that an M 3.5 on June 16, 2016 and an M 2.7 on August 3, 2015, the only three such earthquakes  in the past two years in the area. Statistically stronger aftershocks tend to occur about the same time of year, probably due to climate effects. The largest aftershock since 2000 was the M 3.5 in 2016. Forecast 108422 had expected this activity was likely at the end of June.

 

 

O: 27JUN2017 01:00:16  34.3N  116.4W ml=2.0  ANSS   Yucca Valley CA

O: 27JUN2017 01:24:43  34.3N  116.4W ml=2.5  ANSS   Yucca Valley CA

O: 28JUN2017 00:34:13  34.3N  116.5W ml=2.1  ANSS   Yucca Valley CA

O: 28JUN2017 00:34:13  34.3N  116.5W ML=2.1  EMSC   SOUTHERN CALIFORNIA          

P: 23JUN2017 108422    34.3N  116.5W 2.5-4.6 BAAAA  So. California             

 

The strongest earthquake in the U.S. or Canada today occurred within about 45 minutes of local solar noon in the Fox Islands, Aleutians, Alaska with M 4.0. This event was not reported felt. An M 5.8 hit near this epicenter on May 24 and this is probably an aftershock of that earthquake. Forecast 108489 had  expected today's event was likely around June 28.

 

O: 27JUN2017 23:45:26  53.2N  166.7W ML=4.0  EMSC   FOX ISLANDS, ALEUTIAN ISLANDS

P: 28JUN2017 108489    52.5N  166.5W 3.5-4.9 AAAAA  Fox Islands, Aleutians     

 

 

MODERATELY STRONG NOON QUAKE HITS FIJI

 

EARTHQUAKE SUMMARY FOR JUNE 26, 2017

 

An earthquake pair of M 5.3 and M 5.8 hit the region of Fiji today within minutes of local solar noon. These are probably tidally promoted seismicity as high tidal stresses occur at local noon and midnight. These are not aftershock of the M 6.2 in Fiji yesterday as they occurred about 500 km south of that epicenter. They were not reported felt in the remote epicentral area. The last earthquake with M>=5.8 within about 250 km of these epicenters was an M 6.1 on June 17, 2017 and these are probably aftershocks of that event. An M 6.9 occurred on February 24, 2017. Forecast 108549 had expected this activity within about 100 km of these epicenters was likely around June 27.

 

O: 27JUN2017 00:14:34  24.8S  177.3W mb=5.3  EMSC   SOUTH OF FIJI ISLANDS        

O: 27JUN2017 00:14:34  24.8S  177.3W mb=5.3  ANSS   the Fiji Islands

O: 27JUN2017 00:14:38  24.6S  177.0W Mw=5.8  EMSC   SOUTH OF FIJI ISLANDS

P: 27JUN2017 108549    25.0S  176.0W 4.0-5.7 AAAAA  Tonga Islands              

 

The strongest earthquakes in the U.S. or Canada today occurred along the northern border of California and Nevada with M 4.0 and 4.1. These were part of a strong swarm in the region which occurred within an hour of local solar midnight and may have been promoted by high tidal stresses which maximize at this hour. NEIC reported maximum intensity V in Truckee, California and IV in Norden, Dutch Flat, Glenbrook, California. Lesser shaking with intensity II-III was reported felt up to 140 km from the epicenter in Sacramento as well as in Sierraville, Soda Springs, Loyalton, Carnelian Bay, Kings Beach, Tahoe Vista, Tahoe City, Incline Village, Alta, Tahoma, Forest Hill, Nevada City, Grass Valley, Colfax, Georgetown, South Lake Tahoe, Rough and Ready, Pollock Pines, Quincy, Applegate, Meadow Vista, Garden Valley, Penn Valley, Cook, Camino, Lotus, Placerville, Newcastle, Somerset, Rescue, Pioneer, Lincoln, El Dorado Hills, Rocklin, Granite Bay, Shingle Springs, Folsom, Orangevale, Fair Oaks, Yuba City, Rancho Cordova, Chico, and in Nevada at Reno, Glenbrook, Sparks, Gardnerville.

 

No major damage was reported. The last earthquake within about 50 km of these epicenters with M>=4.1 occurred on October 27, 2011 with M 4.7-4.9 and prior to that on December 25, 2008 with M 4.5. Forecast 108391 had expected this activity was likely around June 29 about 30 km northwest of these epicenters.

 

O: 27JUN2017 09:04:47  39.5N  120.4W ML=2.9  EMSC   NORTHERN CALIFORNIA

O: 27JUN2017 09:16:28  39.5N  120.4W ML=2.9  EMSC   NORTHERN CALIFORNIA

O: 27JUN2017 09:02:01  39.5N  120.4W ML=4.0  EMSC   NORTHERN CALIFORNIA

O: 27JUN2017 09:09:21  39.5N  120.4W ML=4.1  EMSC   NORTHERN CALIFORNIA

O: 27JUN2017 09:36:29  39.5N  120.3W ML=2.1  EMSC   NORTHERN CALIFORNIA          

P: 29JUN2017 108391    39.8N  120.6W 2.5-4.4 AAAAA  Central California         

 

 

STRONG EARTHQUAKE SHAKES TONGA/FIJI

 

EARTHQUAKE SUMMARY FOR JUNE 25, 2017

 

A strong (M 6.2) earthquake hit the region of Fiji today. It was reported by  NEIC to have been felt in Tonga at Tofoa-Koloua, Tongatapu and in Central Suva, Fiji Islands. The last earthquake of larger magnitude in the Fiji region within about 250 km of today's epicenter was an M 7.0 on January 3, 2017. This is probably an aftershock of that event. Forecast 108534 had expected this event was likely between June 23 and 28. This event is a right angle quake from Guatemala occurring at the fourth node (90 degrees) from the earthquakes of M 6.8-7.0 of June 14 and 22, 2017. When a regional foreshock occurred on June 19 of M 5.8, this summary noted the relation with Guatemala as:

 

"... Fiji Islands was likely around June 19. This epicenter is at the fourth node (90 degrees) from the quake in Guatemala of June 14 and was probably promoted from that source." (June 19-20, 2017)

 

O: 25JUN2017 17:42:30  19.4S  176.6W Mw=6.1  EMSC   FIJI REGION                   

O: 25JUN2017 17:42:30  19.7S  176.5W mw=6.2  ANSS   Tonga-Fiji

P: 23JUN2017 108534    19.0S  174.0W 4.0-5.6 AABAA  Tonga Islands              

P: 28JUN2017 108534    19.0S  178.0W 4.0-5.4 BAAAA  Tonga Islands              

 

A moderate earthquake of M 5.4 in the Hindu Kush region of Afghanistan was the second largest event of the day. This is the strongest earthquake in Afghanistan during the year 2017. The last event of larger magnitude in the Hindu Kush area within about 150 km of today's epicenter was an M 5.4 one year ago on June 23, 2016. The last of larger magnitude was an M 6.6 on April 10, 2016.  NEIC reported this earthquake of M 5.4 in Hindu Kush, Afghanistan was felt with intensity IV in Kabul,  Afghanistan and II-III in the area(s) of Afghanistan at Mahmoud Raqui, Jalal Abad, Mir Bacheh Kowt and in at Islamabad, Pakistan. Forecast 108396 had expected this earthquake was likely within about 50 km of this epicenter around June 23. 

 

Like recent strong earthquakes in the Guatemala and Chiapas, Mexico area, this epicenter is located at 102-104 degrees from the Vanuatu quake of M 6.8 on May 9. Concentrated seismic energy at this distance following large earthquakes can lead to a period of enhanced seismicity at this distance. Another unusual quake today at this distance from Vanuatu was an M 4.9 in the Los Lagos region of Chile/Argentina.

 

O: 25JUN2017 23:30:39  36.5N   70.8E mb=5.4  EMSC   HINDU KUSH REGION, AFGHANISTAN

O: 25JUN2017 14:24:25  37.1N   70.1E mb=4.4  EMSC   HINDU KUSH REGION, AFGHANISTAN

P: 23JUN2017 108396    37.0N   71.0E 3.8-5.4 AAAAA  Hindu Kush/Pakistan        

 

An earthquake of M 4.4 north of Iceland today appears to have been promoted by strong tidal stresses associated with the new moon of June 24. This event is the farthest north of event in the region of Iceland with M>=4.4 since an earthquake of M 4.4 on September 1, 2015 and prior to that an M 5.0 on June 16, 2014. A strong swarm hit the region on July 15, 2013 as well. Forecast 108518 had expected this was likely within about 200 km of this epicenter around June 23. The tidally associated seismicity forecast for this period had noted that events near this longitude in the Atlantic region were especially vulnerable to enhancement by tidal stresses at this time:

 

 

"The new moon arrived on June 24 at 02:31 UT. Areas which were sub-solar at this time lie within about 20 degrees longitude of 145 East longitude while those anti-solar areas are near 35 West longitude. These include the mid-Atlantic Ocean region in the west and Japan and the western Pacific subduction zone in the east. These regions are most likely to see a strong to major earthquake during the period June 22-26 but tidal enhancement of seismicity can occur in many tectonic settings and is most likely near local solar midnight and noon at this time." (June 21-14, 2017)

 

This epicenter is at the fifth node from Guatemala (72 degrees) and was probably promoted by energy from the quakes of M 6.8-7.0 on June 14 and 22.

 

O: 26JUN2017 04:22:19  69.0N   17.0W ML=4.4  EMSC   ICELAND REGION               

P: 23JUN2017 108518    71.0N   14.0W 3.5-4.9 BBAAA  Jan Mayen Isl. area        

 

On the opposite side of the world, and probably also affected by high tidal stresses with the new moon, elevated seismicity continued in the region of Japan. An M 4.5 occurred off the coast of northern Honshu but was not reported by NEIC to have been felt. Forecast 108413 had expected this event within about 25 km of the epicenter was likely around June 23. This epicenter is at 106 degrees from the recent strong quakes of M 6.8-7.0 in Guatemala and was probably promoted from those sources.

 

O: 25JUN2017 20:16:43  38.9N  141.8E mb=4.5  EMSC   NEAR EAST COAST OF HONSHU, JAP

P: 23JUN2017 108413    39.0N  142.0E 4.0-5.6 AAAAA  Off East Coast Honshu      

 

A moderate quake of M 4.6 also occurred in Guam today. This event had been expected as a potential tropical storm moved through the area today as:

 

"A tropical storm may be forming near Guam. This system is currently located near 13.7N 145E over Guam. It could form into a stronger storm. Seismicity in the region of Guam has been high the past two days with this storm and could still see another moderate associated earthquake in the next three days." (June 24-25, 2017)

 

Forecast 108354 had expected today's event was likely around June 24 in the region of Guam.

 

O: 25JUN2017 20:29:37  12.9N  145.7E mb=4.6  EMSC   GUAM REGION                  

O: 25JUN2017 20:29:37  12.9N  145.7E mb=4.6  ANSS   Inarajan Village Guam

P: 24JUN2017 108354    13.0N  144.0E 4.0-5.8 AABAA  So. Marianas/Guam          

 

The largest earthquake in the U.S. or Canada today was an M 3.5 in the region of Southern California near Big Bear City. It was reported widely felt in the area east of Los Angeles, California.  NEIC reported this earthquake of M 3.5 in Southern California was felt with intensity II-III in the area(s) of Banning, Forest Falls, Yucaipa, Beaumont, Cabazon, Angelus Oaks, White Water, San Jacinto, Redlands, Big Bear Lake, Idyllwild, Nuevo, Morongo Valley, Big Bear City, Hemet, Homeland, Moreno Valley, Palm Springs, San Bernardino, Grand Terrace, Sun City, Riverside, and in general within about 50 km of the epicenter.  The last earthquake of M>=3.5 within about 50 km of this epicenter occurred on June 18, 2017 with M 3.5. Quakes of M 3.4-3.6 also hit the area on May 15 and March 18, 2017 but  the last of significantly larger magnitude in the region was an M 3.9 on December 28, 2016. Forecast 108422 had expected this event within about 10 km of this epicenter was likely around June 26.

 

O: 25JUN2017 13:53:24  34.0N  116.9W ML=3.5  EMSC   SOUTHERN CALIFORNIA          

P: 26JUN2017 108422    33.9N  116.9W 2.5-4.5 AAAAA  So. California             

 

TIDAL STRESSES HELP PROMOTE SEISMICITY

 

EARTHQUAKE SUMMARY FOR JUNE 24, 2017

 

A moderate earthquake was widely felt in central and eastern Honshu, Japan today. NEIC reported this earthquake was felt with maximum intensity V in Nagakute, Aichi and intensity IV in Lida and Suwa, Nagano. Intensity II-III was also reported from Matsumoto, Ueda, Nagano; Inuyama, Owariashi, Toyota, Ichinomiya, Nagoya, Okazaki, Tsushima, Toyokawa, Aichi; from Yamanashi at Kofu, Isawa, Fujiyoshida; in Gifu, Tateyama, Toyama; Fujinomiya, Shizuoka. It was also lightly felt more than 100 km from the epicenter in the Prefectures of Shiga, Mie, Toyama, Chiba, Kanagawa, Saitama, Tokyo, Kyoto, Nara, Osaka, and Hyogo more than 250 km from the epicenter. An aftershock of M 4.7 in Central Honshu, Japan was felt with intensity II-III in the area(s) of Nagoya, Aichi; Sagamihara, Kanagawa; and Tokyo, Japan. This event may have been promoted by tidal stresses associated with the New Moon of June 24. The tidal seismicity forecast with emphasis on Japan in this summary had read:

 

"The new moon arrived on June 24 at 02:31 UT. Areas which were sub-solar at

this time lie within about 20 degrees longitude of 145 East longitude while those anti-solar areas are near 35 West longitude. These include the mid-Atlantic Ocean region in the west and Japan and the western Pacific subduction zone in the east. These regions are most likely to see a strong to major earthquake during the period June 22-26 but tidal enhancement of seismicity can occur in many tectonic settings and is most likely near local solar midnight and noon at this time." (June 21-14, 2017)

 

Central Honshu has been relatively quiet in recent years. The last event of M>=5.2 in central Honshu within about 150 km of today's epicenter occurred more than  two years ago as an M 6.2 on November 22, 2014 and prior to that an M 5.7 on November 18, 2013. The last within about 100 km of this epicenter occurred as aftershocks of the March 11, 2011 M 9.3 earthquake and tsunami in Fukushima, Japan. Two weeks before that on February 26, 2011 a precursor event hit central Japan with M 5.2 near the epicenter of today's earthquake. A strong earthquake may be approaching eastern Japan if this event is a stress indicator. Forecasts 108407 and 108392 had expected today's earthquakes within about 150 km of the epicenters were likely around June 25-26.

 

O: 24JUN2017 22:02:16  35.8N  137.6E Mw=5.2  EMSC   EASTERN HONSHU, JAPAN        

O: 25JUN2017 06:17:14  35.8N  137.7E mb=4.7  EMSC   EASTERN HONSHU, JAPAN        

O: 25JUN2017 00:24:05  35.9N  137.5E mb=4.4  EMSC   EASTERN HONSHU, JAPAN        

P: 25JUN2017 108407    35.0N  136.0E 3.5-5.1 AAAAA  No. Honshu, Japan          

P: 26JUN2017 108392    34.0N  137.0E 3.5-5.1 ABAAA  Central/So. Honshu Japan   

 

The strongest earthquake in the world today was an M 5.7 (EMSC) - 6.0 (IGP) in Southern Peru. NEIC reported intensity V in Coracora, Ayacucho, Peru and II-III in Arequipa at Acari and Arequipa; in Cusco and in the San Luis area, Lima Provinces, Peru. IGP reported the mainshock of M 6.0 was felt with intensity IV-V in  Caraveli, IV Pullo, III-IV Puquio, Chuquibamba, Peru. The last earthquake within about 150 km of this epicenter with M>=5.7 was an M 6.3 on December 1, 2016 and prior to that an M 5.7 on August 25, 2014. Forecasts 108258 and 108531 had expected a moderate to large earthquake was  likely within about 100 km of this epicenter in late June.

 

O: 24JUN2017 16:09:12  15.5S   73.3W Mw=5.7  EMSC   SOUTHERN PERU                

O: 24JUN2017 09:25:21  15.8S   73.0W mb=4.2  EMSC   SOUTHERN PERU                

O: 25JUN2017 09:37     15.2S   71.8W mb=4.0  IGP    N of Madrigal-Arequipa, Peru.

O: 24JUN2017 16:09     15.7S   73.6W mb=6.0  IGP    Caraveli, IV Pullo, III-IV Puq

P: 20JUN2017 108258    16.0S   74.0W 4.0-5.4 BAAAA  So. Peru/Bolivia           

P: 29JUN2017 108531    16.0S   72.0W 4.0-5.8 BAAAA  So. Peru/Bolivia           

 

The strongest earthquake in the U.S. or Canada today outside Alaska was an M 4.0 near the coast of Northern California. This event was reported felt with intensity V in Petrolia; IV in Rio Dell and Scotia and II-III in Ferndale, Hydesville, Myers Flat, Fortuna, Redcrest, Whitethorn, Carlotta, Redway, Garberville, Loleta, Eureka, Kneeland, Samoa, Alderpoint, Bridgeville, Bayside, Arcata, McKinleyville, Trinidad, Fort Bragg, Willos, Windsor, Davis, San Francisco, and probably within about 100 km of the epicenter. This event was also probably promoted by high tidal stresses associated with the new moon as it occurred within about an hour of local solar noon. The last earthquake within about 50 km of this epicenter with M>=4.0 occurred on March 6, 2017 with M 4.0 and prior to that on December 5, 2016 (M 4.4).  Forecast 108466 had expected this event in this area was likely around June 26.

 

O: 24JUN2017 21:22:03  40.3N  124.3W Mw=4.1  EMSC   NORTHERN CALIFORNIA          

P: 26JUN2017 108466    40.6N  124.9W 2.5-4.5 AAAAA  Off Coast of No. Calif     

 

The largest event in Alaska was an M 4.7 in the eastern Andreanof Islands. It was not reported in this remote are. This is an aftershock of the M 5.4 which hit the region on January 9, 2017. The previous larger quake in the area was an M 4.9 on April 2, 2016.  Forecast 108486 had expected today's event was likely within about 50 km of this epicenter around June 24.

 

 

O: 25JUN2017 08:47:01  51.8N  170.7W mb=4.7  EMSC   FOX ISLANDS, ALEUTIAN ISLANDS

P: 24JUN2017 108486    52.3N  171.3W 3.5-5.3 AAAAA  Andreanoff Isls, Aleutians 

 

An unusual earthquake pair of M 5.2 and M 5.3 hit the mid-Indian ridge today. This epicenter is within 2 degrees of being antipodal to the unusual activity in northern Kansas which is ongoing. It is not clear what is causing this antipodal activity however. The last earthquake of M>=5.2 in the Mid-Indian Ridge within about 250 km of this epicenter occurred on May 18, 2015 with M 5.5. A strong quake of M 6.4 hit within about 100 km of this epicenter on May 31, 2008. Forecast 108561 had expected this event on the Ridge within about 500 km of  this epicenter was likely around June 27.

 

O: 24JUN2017 08:51:29  41.1S   80.7E ML=5.3  EMSC   MID-INDIAN RIDGE             

O: 24JUN2017 07:27:07  41.2S   80.7E mb=5.2  EMSC   MID-INDIAN RIDGE             

P: 27JUN2017 108561    42.0S   85.0E 4.0-5.6 BACAA  So. Indian Ocean           

P: 30JUN2017 108557    37.0S   79.0E 4.0-5.4 CCAAA  So. Indian Ocean           

 

The second strongest earthquake in the world today was also in a southern ocean ridge. This event of M 5.4 in the area southeast of Eastern Island was not reported felt in this remote area. It is the strongest earthquake in this area during 2017 and the largest within  about 250 km of the epicenter since an M 5.4 on May 1, 2014 and December 1, 2011. The last of larger magnitude in the area was an M 5.9 on May 20, 2010.  Forecast 108559 had expected this earthquake was likely around June 22 within about 50 km of this epicenter.

 

O: 25JUN2017 09:45:52  41.3S   90.4W Mw=5.4  EMSC   SOUTHEAST OF EASTER ISLAND   

P: 22JUN2017 108559    41.0S   91.0W 4.0-5.5 BAAAA  Chile Rise                  

 

NEW MOON BRING STRONG EARTHQUAKE TO MOZAMBIQUE

 

EARTHQUAKE SUMMARY FOR JUNE 23, 2017

 

A moderately strong of M 5.8 earthquake hit Mozambique today. NEIC reported it  as felt with intensity IV in Mozambique at Dondo, Beira, Sofala and in Chimoio, Manica, Mozambique and in Zimbabwe at Chimanimani and Mutare, Manicaland and in Harare at Harare and Epwoth, Zimbabwe. This earthquake appears to have been triggered by the new moon alignment of today. It is remarkable that the earthquake at 02:37 UT occurred within six minutes of the completion of the new moon at 02:31 UT as previous discussed in this report:

 

 

"The new moon will arrive on June 24 at 02:31 UT. Areas which are sub-solar at this time lie within about 20 degrees longitude of 145 East longitude while those anti-solar areas are near 35 West longitude. These include the mid-Atlantic Ocean region in the west and Japan and the western Pacific subduction zone in the east. These regions are most likely to see a strong to major earthquake during the period June 22-26 but tidal enhancement of seismicity can occur in many tectonic settings and is most likely near local solar midnight and noon at this time," (June 20-23, 2017)

 

The only event in the past 25 years of M>=5.8 in Mozambique was an M 7.0 southwest of today's epicenter on February 22, 2006. This event was near the new moon but not as today's. This summary noted that the earthquake of 2006 coincided with landfall of TS 12S and with a strong geomagnetic storm as follows:

 

 

" tropical storm (12S) hit the area over the past three days. Strong storms such as this may cause motion in plates leading to regional earthquakes associated with the storm or at a later time as in this case." (February 23, 2006)

 

and

 

"The expected geomagnetic storm hit over the past two days and was the second strongest in the past four months with high latitude AP index of 44 on Feb. 20, the strongest storm at high latitudes since mid-September, 2005." (February 23, 2006)

 

The epicenter is near the antipode of the M 5.2 and 4.5 in Hawaii of June, 2017. Forecast 108545 ad expected this event was likely as a moderate event within  about 150 km of this epicenter around June 26.

 

O: 24JUN2017 02:37:18  20.3S   34.8E Mw=5.8  EMSC   MOZAMBIQUE                   

O: 24JUN2017 02:37:15  19.4S   34.5E mb=5.8  ANSS   NW of Dondo Mozambique

P: 26JUN2017 108545    21.0S   33.0E 4.0-5.6 AABAA  So. Indian Ocean           

 

The strongest seismicity in the U.S. or Canada today continued in the aftershocks zones of the western Andreanof and eastern Rat Islands. These events of M 4.2 and 4.0 in the Andreanof Islands and of M 3.8 in the Rat Islands were not reported felt in  this remote area. Forecasts 108486, 108498 had expected this activity at the end of June.

 

O: 23JUN2017 20:08:07  50.2N  179.0W mb=4.2  EMSC   ANDREANOF ISLANDS, ALEUTIAN IS

P: 26JUN2017 108486    50.9N  179.0W 3.5-5.0 BAAAA  Andreanoff Isls, Aleutians 

 

O: 24JUN2017 02:14:40  51.2N  179.9E mb=3.8  EMSC   RAT ISLANDS, ALEUTIAN ISLANDS

P: 22JUN2017 108498    52.0N  177.0E 4.0-5.6 AABAA  Rat Islands                

 

O: 24JUN2017 05:35:24  52.6N  174.8W mb=4.0  EMSC   ANDREANOF ISLANDS, ALEUTIAN IS

P: 29JUN2017 108486    50.7N  176.2W 3.5-5.0 BBAAA  Andreanoff Isls, Aleutians 

 

An unusual earthquake of M 5.2 hit the mid-Indian ridge today. This epicenter is within 2 degrees of being antipodal to the unusual activity in northern Kansas which  is ongoing. It is not clear what is causing this antipodal activity however. The last earthquake of M>=5.2 in the Mid-Indian Ridge within about 250 km of this epicenter occurred on May 18, 2015 with M 5.5. A strong quake of M 6.4 hit within about 100 km of this epicenter on May 31, 2008.  Forecast 108561 had expected this event on the Ridge within about 500 km of  this epicenter was likely around June 27.

 

O: 24JUN2017 07:27:07  41.2S   80.6E mb=5.2  EMSC   MID-INDIAN RIDGE             

P: 27JUN2017 108561    42.0S   85.0E 4.0-5.6 BACAA  So. Indian Ocean           

 

STRONG GUATEMALA SUBDUCTION ZONE QUAKE FELT THROUGHOUT CENTRAL AMERICA

 

EARTHQUAKE SUMMARY FOR JUNE 22, 2017

 

A strong earthquake of M 6.8 hit south of Guatemala today as Tropical Storm Cindy was making landfall on the Texas-Louisiana coast directly to the north. Low pressures associated with TS Cindy probably allowed the upper crust of the subduction zone to rise, reducing the normal stress across the subduction zone and allowing this large earthquake to occur. This has been observed many times before and is a common situation when storms hit subduction areas. This summary had expected this situation in previous issues. For example in the June 19, 2017 issue it was noted:

 

"NHC is reporting a weather system north of Nicaragua which formed today is likely to reach tropical depression levels in the next two days with 80% probability. It is likely that stresses from this storm may have helped promote the M 5.4 in Nicaragua yesterday and the M 4.6 aftershock today. The storm is located over the upper plate  in the Nicaragua-Pacific subduction zone. Reducing air pressure over this region allows more movement on the underlying subduction zone faults and a higher likelihood of a moderate to large earthquake." (June 19-21, 2017)

 

This system was the precursor to Tropical Storm Cindy. NHC reported Cindy made landfall about 0400 am on June 22, this is 1000 UT. The earthquake in Guatemala occurred at 1231 UT suggesting a direct connection between the landfall event

and the quake in Guatemala.

 

The last earthquake of M>=6.8 within about 100 km of today's epicenter occurred on November 7, 2012 with M 7.4, the only other such event in the area in at least 25 years. That earthquake was the strongest in the area since the Guatemala City earthquake of February 4, 1976,  Forecasts 108086, 108336 and 108335 had expected today's activity was likely between June 17 and June 27. The event in November, 2012 had been associated with a similar tropical storm - Sandy - yes, that Sandy which later went on  to cause massive destruction along the east coast of the U.S. At the time this summary noted:

 

 

"A new hurricane - Sandy - formed over Central America over the past two days is moving north over the Caribbean Sea. Low pressures from such meteorological events, when they center over the land mass can relieve atmospheric loading on the land allowing it to rise with respect to the underlying subduction zone. This, in turn reduces friction along the subduction zone faults allowing larger earthquakes to occur. This appears to have been the case yesterday when an M 6.6 in Costa Rica occurred as the low pressure system associated with Hurricane Sandy was located over the area." (October 25, 2012)

 

The activity in Guatemala occurred at 103-104 degrees from the M 6.8 in Vanuatu of May 9, a distance at which concentrated seismic energy can help trigger subsequent activity. Other earthquakes at this distance from Vanuatu today were recorded in Kansas (M 3.7), Mexico (M 4.7), Tajikistan (M 4.5) and Afghanistan (M 4.7).

 

O: 22JUN2017 14:28:14  13.7N   91.0W mb=4.3  EMSC   OFFSHORE GUATEMALA           

O: 23JUN2017 03:08:13  13.7N   91.1W mb=4.5  EMSC   OFFSHORE GUATEMALA           

O: 22JUN2017 12:31:02  13.8N   90.9W Mw=6.8  EMSC   OFFSHORE GUATEMALA           

O: 22JUN2017 12:31:04  13.8N   90.9W mw=6.8  ANSS   SW of Puerto San

O: 22JUN2017 21:09:46  13.8N   91.0W mb=4.2  EMSC   OFFSHORE GUATEMALA           

P: 17JUN2017 108086    13.0N   90.0W 3.5-5.1 BAAAA  Guatemala                  

P: 25JUN2017 108336    14.0N   92.0W 3.5-5.5 BAAAA  Guatemala                  

P: 27JUN2017 108335    13.0N   91.0W 3.5-5.2 BAAAA  Guatemala                  

 

The epicenter of today's event is about 200 km southeast of the M 7.0 of June 14 and is not a classical aftershock of that event. It may have been affected by stress redistribution following the June 14 event however. An aftershock of M 4.3 was felt in Antigua Guatemala and in Guatemala City with intensity II-III. NEIC reported the mainshock was felt with intensity VI in Guatemala at Palin, Escuintla; San Miguel Duenas, Santa Maria de Jesus, Santa Catarina Barahona, Sacatepequez and in San Juan Cotzal, Quiche, Guatemala. Intensity V was also felt in El Salvador at Nueva San Salvador, , Sonzacate, Zaragoza, and in Guatemala at San Rafael las Flores, Santa Rosa, Santa Cruz la Laguna and San Marcos la Laguna, Solola, Mixco, El Tejar, Chimaltenango, Santiago Sacatepequez, Antigua Guatemala, Villa Nueva, Jocotenango, Barberena, Ciudad Vieja, Tiquisate, Escuintla, Taxisco, Calcaja, Quezaltenango. Lesser shaking of intensity II-IV was reported from Escuintla, at San Jose and Nueva Concepcion and with in about 100 km of the epicenter at Cotzumalguapa, San Vicente Pacaya, and Amatitlan, Guatemalas. Light to moderate shaking was also reported from Mexico City, Costa Rica, Nicaragua, Honduras, Belize, and El Salvador.

 

About 13-14 minutes after the Guatemala event, an M 3.7 was widely felt in the area of southern Kansas. NEIC reported intensity IV in Harper and Argonia, Kansas and II-III within about 100 km of the epicenter including at Belle Plaine, Wichita, Derby, and Lawrence, Kansas. It was also reported lightly felt in Drumright, Oklahoma; Papillion, Nebraska and Boyd, Texas. The distance between the Guatemala event and the subsequent event in Kansas is 25 degrees. A series of waves arrived from Guatemala in the minute before this Kansas earthquake including the main surface wave, various S-phases and a core-mantle reflection (PcS or ScP). The combined effect of these waves was to promote the Kansas earthquake. At the time of the first M 7.0 in Guatemala this summary speculated on the relation between that event and a highly unusual earthquake in  Kansas as follows:

 

"The activity in northern Kansas, the first of its kind in decades, and the sudden swarm in Yellowstone, both of which declined immediately after the Guatemala event, may have been associated with precursory effects of the Guatemala event. Earthquakes in the central plains of the U.S. often precede strong earthquakes along the western rim as previously detailed in this summary. With the emergence of wide-spread seismicity in the Central Plains in the past five years, however, this is more difficult to recognize beforehand than it was in quieter days. Two examples of this include a series of moderate quakes in South Dakota hours before the M 9.2 in Anchorage, Alaska, March 28, 1964, Also before the M 8.0 in Mexico City in  September 19, 1985 a strong unexpected series of precursory activity hit Nebraska and Kansas. Oil and water wells in the region went dry and caused much concern. Two days later when the Mexico City quake occurred these wells returned with as much as twice the capacity they had before the quake." (June 14, 2017)

 

This is the strongest earthquake in south-central Kansas since an M 4.0 on November 19, 2015. Forecast 108430 had expected this event within about 25 km of the epicenter was likely around June 26.

 

O: 22JUN2017 12:44:51  37.2N   98.0W mb=3.7  EMSC   KANSAS                       

P: 26JUN2017 108430    37.0N   98.0W 2.0-3.9 BAAAA  Southern Plains            

 

Today's triggered quake in Kansas appears to confirm this analysis. In a similar but reversed fashion the swarm in Yellowstone did not show any activity following today's Guatemala event and there were no light earthquakes today in Oklahoma. These may reflect closing of faults with effects from Guatemala or may be coincidental.

 

The largest earthquake in the U.S. or Canada today was an M 4.0 in southern Alaska. NEIC reported this earthquake of M 4.0 in Southern Alaska was felt with intensity II-III in the area(s) of Valdez and Anchorage, Alaska. The last earthquake within about 100 km of this epicenter with M>=4 occurred as an M 4.3 on August 19, 2016 and prior to that an M 4.4 on December 2, 2015. Forecast 108236 had expected this event to the north around June 18.

 

O: 22JUN2017 15:21:39  61.3N  146.9W ML=4.0  EMSC   SOUTHERN ALASKA              

P: 18JUN2017 108236    63.3N  147.5W 3.2-4.9 BBAAA  Central Alaska             

 

ODERATE EARTHQUAKE IN SOUTHERN KURIL ISLANDS TIDALLY PROMOTED

 

EARTHQUAKE SUMMARY FOR JUNE 21, 2017

 

The strongest earthquake in the world today was an M 5.4 in the region of the Kuril Islands. This event was not reported felt in the area. It occurred near local solar noon and may have been enhanced by tidal stresses which maximize near this time. The area will be under high tidal stresses with the new moon on June 24 as noted in this summary:

 

"The new moon will arrive on June 24 at 02:31 UT. Areas which are sub-solar at

this time lie within about 20 degrees longitude of 145 East longitude while those anti-solar areas are near 35 West longitude. These include the mid-Atlantic Ocean region in the west and Japan and the western Pacific subduction zone in the east. These regions are most likely to see a strong to major earthquake during the period June 22-26 but tidal enhancement of seismicity can occur in many tectonic settings and is most likely near local solar midnight and noon at this time." (June 21, 2017)

 

While normally an active zone, the Kuril Islands has been relatively quiet this year. The largest events were of M 5.4-5.5 on May 22 and April 20, 2017. The last earthquake of larger magnitude than M 5.5 in the region was an M 5.7 on July 23, 2016. The last within about 200 km of today's epicenter occurred as an M 6.2 on July 20, 2014.  Forecasts 108475 and 108450 had expected today's event within about 150 km of this epicenter was likely around June 24-25.

 

O: 22JUN2017 02:41:54  45.1N  149.8E mb=5.4  EMSC   KURIL ISLANDS                

O: 22JUN2017 02:41:55  45.1N  149.7E mb=5.4  ANSS   E of Kuril'sk Russia

P: 24JUN2017 108475    45.0N  146.0E 3.5-5.7 AACAA  So. Kurils                 

P: 25JUN2017 108450    44.0N  148.0E 3.5-5.5 BBBAA  Hokkaido, Japan            

 

The strongest earthquake in the U.S. or Canada outside Alaska today was an M 4.5 in Hawaii. NEIC reported this event was felt with intensity IV in Hawaii at Naalehu and Pahala and II-III in Captain Cook, Volcano, Holualoa, Kealakekua, Pahoa, Mountain View, Hilo, Kurtistown, Keaau, Paauilo, Kailua Kona, Papaikou, Ninole, Honomu, Kamuela, Waikoloa, Laupahoehoe, Ookala, Honokaa, Kapaau, Hawi, Kihei, Kahului, Honolulu, Kailua, and Kalaheo and in general within about 350 km of the epicenter. This event is located near Loihi Seamount, an area which had not seen moderate seismicity since an event of M 5.2 on June 5, 2013. A moderate earthquake of M 5.2 hit north of this near Kilauea on June 8, 2017 with M 5.3. This may have promoted the current activity. That earthquake occurred in association with the full moon and may have tidally promoted, not dissimilar to today's association with the new moon. At the time, this summary noted:

 

 

"Moderate earthquakes at volcanic centers, such as today's event, can change plumbing within the volcano array leading to changes in current eruptive phases either dampening or accelerating the flow of magma. In the current situation, a pair of light earthquakes occurred in the Loihi Seamount area south of Hawaii just before the mainshock. This seamount south of Hawaii was very active about a decade ago but has been quiet for  a number of years, so even light activity there, especially in association with the strange seismicity of the past several days could be notable." (June 9, 2017)

 

Forecast 108338 had expected this event within about 30 km of the epicenter was likely around June 23. This epicenter is located at the sixth node (60 degrees) from the M 7.0 in Guatemala of June 14 and may have been enhanced by energy from that event.

 

O: 21JUN2017 20:09:06  18.9N  155.5W mb=4.2  EMSC   HAWAII REGION, HAWAII        

O: 21JUN2017 20:09:06  18.9N  155.5W ml=4.5  ANSS   Hawaiian Ocean View Hawaii

P: 23JUN2017 108338    18.8N  155.2W 3.0-4.6 AAAAA  Hawaii                      

 

A light earthquake of M 3.0 was widely felt in the San Francisco Bay area, California today. NEIC reported intensity IV in Berkeley, and San Francisco. Lesser shaking was felt in an area within about 100 km of the epicenter including Rohnert Park, Menlo Park, Livermore, Fairfield, San Mateo, Burlingame, Pacifica, Castro Valley, San Ramon, South San Francisco, Danville, Walnut Creek, Benicia, Vallejo, San Leandro, Walnut Creek, Oakland, Pleasant Hill, Alameda, San Francisco, Moraga, Lafayette, Martinez, Hercules, Orinda, Richmond, Pinole, San Pablo, Emeryville, El Sobrante, Albany and El Cerrito, California.

The last earthquake of M>=3.0 within the San Francisco Bay area was an M 3.8 on April 30, 2017, the only such event during the year 2017. An M 3.0 about 70 km to the south occurred on April 5. Forecast 108129 had expected today's earthquake within about 10 km of this epicenter was likely around June 19.

 

O: 21JUN2017 19:00:20  37.9N  122.3W Mw=3.0  EMSC   SAN FRANCISCO BAY AREA, CALIF.

O: 21JUN2017 19:00:20  37.9N  122.3W mw=3.0  ANSS   ESE of El Cerrito

P: 19JUN2017 108129    38.0N  122.3W 2.5-4.4 AAAAA  Central California         

 

A light aftershock of M 3.9-4.0 was felt in southeastern Alaska today. NEIC reported this event was felt with intensity IV in Haines, Alaska and II-III in Skagway, Alaska and Whitehorse, Yukon, Canada. Earthquakes Canada noted the quake had been felt in Yukon. NEIC reported this earthquake of M 4.1 in Southern Alaska was felt with intensity II-III in the area(s) of Kodiak, Alaska. No damage was observed or expected. This is an aftershock of the strong quakes of M 6.2 on May 1, 2017. The last aftershock larger than M 3.9 in the area was an M 4.3 on May 21. Forecast 108501 had expected this activity was likely around June 25.

 

O: 22JUN2017 01:35:08  59.7N  136.6W ML=3.9  NRCA  103 km WNW of Haines          

O: 22JUN2017 01:35:05  59.7N  137.3W ML=4.0  EMSC   BRITISH COLUMBIA, CANADA     

P: 25JUN2017 108501    59.0N  136.0W 3.0-4.6 BAAAA  Southeast Alaska           

 

The strongest activity in Alaska, however, remained in the Andreanof and Rat Islands where a pair of unfelt earthquakes with M 4.9-5.0 occurred today. These events had been expected in forecasts 108208 and 108498 within about 100 km of these epicenters between June 19 and 22. The last earthquake in the Rat Islands with M>=5 was an M 5.8 on April 27 while the last of M>=4.9 in the Andreanof Islands aftershock zone occurred as aftershocks on May 8 and 10 following the mainshock of M 6.4 on May 8.

 

O: 21JUN2017 21:58:53  51.6N  178.5W ML=4.9  EMSC   ANDREANOF ISLANDS, ALEUTIAN IS

P: 19JUN2017 108208    51.8N  178.0W 3.5-5.0 AAAAA  Andreanoff Isls, Aleutians 

 

O: 21JUN2017 19:20:27  52.2N  179.4E mb=5.0  EMSC   RAT ISLANDS, ALEUTIAN ISLANDS

P: 22JUN2017 108498    52.0N  177.0E 4.0-5.6 AABAA  Rat Islands                

 

Seismicity returned to northern Texas today after a period of regional quiet.

An M 2.8 was reported felt with intensity IV in Springtown, Boyd, Fort Worth, and II-III in Azle, Weatherford, Bridgeport, Grapevine and Paris, Texas.

This earthquake was probably promoted by landfall of Tropical Storm Cindy on the border of Texas and Louisiana about the same time as the earthquake hit. This was expected seismicity related to this storm as noted in this summary  in previous issues:

 

 

"Tropical Storm Cindy formed over south of Louisiana and east of Texas today with winds up to 60 kts. It is expected to track to the north as a tropical storm making landfall on the border of Texas and Louisiana about 1 am. June 22. Some seismicity in the southeast U.S. may be promoted from this storm. The M 3.2 in Georgia (US) may have been promoted as TS Cindy hit the continental shelf east of Texas today." (June 20, 2017)

 

The only earthquake this year in Northern Texas prior to today's event was an M 2.3 on May 1, 2017. The last within about 50 km of this event in Northern Texas with M>=2.8 was an M 3.0 on December 17, 2015.  Forecast 108429 had expected regional activity around June 23.

 

O: 21JUN2017 22:52:05  32.9N   97.6W mb=2.8  EMSC   NORTHERN TEXAS               

O: 21JUN2017 22:52:05  32.9N   97.6W mb=2.8  ANSS   WSW of Reno Texas

P: 23JUN2017 108429    35.0N   98.0W 2.0-3.9 ABAAA  Southern Plains            

 

A series of earthquakes north of the landfall of TS Cindy also occurred today suggesting promotion by stresses from that storm. Small quakes in Missouri (M 1.8) and Arkansas (M 1.2) had been expected in forecasts 108143 and 108403 but the largest of M 2.7 in West Virginia had been forecast with poorer quality to occur around June 17. None of these events were reported felt.

 

O: 21JUN2017 08:21:55  36.0N   89.9W md=1.8  ANSS   SSW of Steele Missouri       

P: 19JUN2017 108143    36.3N   89.5W 2.0-3.9 AAAAA  New Madrid area            

 

O: 21JUN2017 06:21:30  36.3N   93.0W md=1.2  ANSS   NE of Harrison Arkansas      

P: 22JUN2017 108403    36.0N   93.0W 2.0-3.9 AAAAA  New Madrid area            

 

O: 21JUN2017 08:01:32  38.2N   81.4W md=2.7  ANSS   Montgomery West Virginia     

P: 17JUN2017 108137    37.2N   81.9W 2.0-4.3 BAAAA  Kentucky/Tennessee/NC      

 

QUAKES SHAKE GEORGIA (US); INDONESIA AND SOUTH SANDWICH ISLANDS

 

EARTHQUAKE SUMMARY FOR JUNE 20, 2017

 

While global seismicity was relatively quiet today, earthquakes in Georgia, U.S. (M 3.2); the South Sandwich Islands (M 5.1-5.3, 5.2-5.4) and Bengkulu, Indonesis  lightly shook the earth. An M 4.6 quake in Haiti was also regionally significant. The earthquake in Georgia was probably promoted by  a new tropical storm – Cindy which made landfall south of Louisiana about the same time as the earthquake occurred.

 

The strongest felt earthquake in the world today was an M 5.1 in Bengkulu, Indonesia. NEIC reported it was felt with intensity II-III in Bengkulu and in Lubuk Linggau, Sumatra, Indonesia. BMG reported this quake with M 5.2 was felt with intensity V in Bengkulu and Bengkulu Tengah; IV-V in Depahiang and Curup and IV in Manna, Bengkulu, Sumatra. A similar earthquake of M 5.0 hit the region on May 30 but the strongest quake in the area this year was an M 5.5 on March 7, 2017. The antipode of this epicenter is located in southern Columbia at 4N 78W and may see a promoted moderate earthquake in the next several days. Forecast 108074 had expected this event in Sumatra was likely in mid-June within about 25 km of this epicenter.

 

O: 20JUN2017 18:21:43   4.1S  102.1E mb=5.1  EMSC   SOUTHERN SUMATRA, INDONESIA  

O: 20JUN2017 18:21:42  04.2S  102.0E MS=5.2  BMG  Felt with intensity V

P: 14JUN2017 108074     4.0S  102.0E 4.0-5.4 CAAAA  So. of Sumatera            

 

The strongest unfelt earthquake today was an M 5.3-5.4 in the South Sandwich Islands. Moderate or large events in this remote area are seldom reported felt and today's events were not an exception. Earthquakes of larger magnitude most recently shook the South Sandwich Islands on May 10 (M 6.4) with aftershocks up to M 5.4 through June, 2017 within about 25 km of these epicenters. Forecasts 108569 had expected today’s activity within about 25 km of these event in late June 2017.

 

O: 20JUN2017 12:54:36  56.1S   26.5W mb=5.4  EMSC   SOUTH SANDWICH ISLANDS REGION

O: 20JUN2017 13:02:29  56.1S   27.4W mb=5.2  ANSS   the South Sandwich Islands   

O: 20JUN2017 12:54:36  56.3S   27.1W mb=5.3  ANSS   the South Sandwich Islands   

O: 20JUN2017 13:02:30  56.1S   27.5W mb=5.1  EMSC   SOUTH SANDWICH ISLANDS REGION

P: 25JUN2017 108569    55.0S   28.0W 4.0-5.9 ABAAA  So. Sandwich Islands       

P: 28JUN2017 108569    56.0S   27.0W 4.0-5.9 CAAAA  So. Sandwich Islands       

 

An earthquake of M 4.5-4.7 hit Haiti today. NEIC reported it was felt with intensity II in Camp-Perrin, South Haiti and in Guantanamo, Cuba. Damage was not reported with this earthquake. It is the largest in Haiti since an event of M 5.0 on September 30, 2016 and an M 4.6 on December 31, 2015. It is one of only six such aftershocks in Haita since 2010 when an M 7.0 hit the area  on January 12 causing up to 500,000 casualties and devastating that country's fragile economy. Forecast 108357 had expected the region to be active around June 23.

 

O: 20JUN2017 19:01:17  19.4N   74.1W mb=4.5  ANSS   N of Jeremie Haiti           

O: 20JUN2017 19:01:20  19.2N   73.7W mb=4.7  EMSC   HAITI REGION                 

P: 23JUN2017 108357    20.0N   71.0W 3.0-4.4 BABAA  Bahamas/No. Caribbean      

P: 23JUN2017 108357    20.0N   71.0W 3.0-4.4 BACAA  Bahamas/No. Caribbean      

 

An M 3.2 earthquake was widely felt in the Augusta, Georgia area today where intensity IV was reported. NEIC also reported it was felt with intensity IV in Beech Island, South Carolina; Hephzibah, Georgia; and II-III in Georgia at North Augusta, Evans, Grovetown, Blythe, Harlem, Appling, Keysville, Dearing, Waynesboro, Wrens, Stapleton, Thomson, Louisville, Lincolnton, Gibson, Warrenton, Jewell, Washington, Lexington, Greensboro, Eatonton, Athens, Lyons, Macon, Loganville, Duluth, Cumming, Griffin, Atlanta, Marietta, Lithia Springs, West Point, Valdosta, Georgia. The quake was also reported widely felt with intensity II-IV in South Carolina at Jackson, Graniteville, Aiken, New Ellenton, Trenton, Modoc, Edgefield, Johnston, Windwor, Williston, Monetta, Batesburg, Leesville, Mount Carmel, Greenwood, Kexington, Abbeville, Hodges, Chapin, Columbia and other communities within about 150 km of the epicenter. It was also reported from Tennessee, North Carolina, Alabama, Maryland and Illnois, but these are likely erroneous. Promotion of this event may have occurred from stresses related to TS Cindy as noted in this summary:

 

"Tropical Storm Cindy formed over south of Louisiana and east of Texas today with winds up to 60 kts. It is expected to track to the north as a tropical storm making landfall on the border of Texas and Louisiana about 1 am. June 22. Some seismicity in the southeast U.S. may be promoted from this storm. The M 3.2 in Georgia (US) may have been promoted as TS Cindy hit the continental shelf east of Texas today." (June 20, 2017)

 

This is the strongest earthquake within about 150 km of this epicenter since an M 3.2 on February 16, 2015 about 50 km north of this and is the largest within about 50 km of this epicenter in at least 25 years.  Forecast 108427 had expected this event was possible around June 25 in this region.

 

O: 20JUN2017 15:14:04  33.4N   82.0W ml=3.2  ANSS   SW of Augusta, Georgia       

P: 25JUN2017 108427    33.0N   80.0W 2.0-4.1 BABAA  Southeast U.S.             

 

The strongest earthquake in the U.S. or Canada today was an M 4.3 followed by an M 4.2 in the Andreanof Islands region of the Aleutians, Alaska. These events, which was not felt in this remote area, are aftershocks of the M 6.4 which hit these epicenters on May 8. Forecast 108208 had expected today's activity within  about 50 km of this was likely around June 19.

 

O: 20JUN2017 10:32:42  51.3N  178.5W mb=4.3  ANSS   Amatignak Island Alaska      

O: 20JUN2017 11:53:22  51.7N  178.5W ml=4.2  ANSS   Andreanof Islands            

P: 19JUN2017 108208    51.8N  178.0W 3.5-5.0 AAAAA  Andreanoff Isls, Aleutians 

 

SEISMICITY ACTIVE IN TONGA/FIJI

 

EARTHQUAKE SUMMARY FOR JUNE 19, 2017

 

The strongest earthquake in the world today occurred in Tonga with M 5.8. NEIC reported it was felt with intensity II-III in Tonga at Nuku'aloga, Vaini and Mu'a, Tongatapu, Tonga. A light foreshock of M 4.9 preceded the M 5.8 to the north. It was not felt in the Samoa Islands where the epicenter was located. This is probably an aftershock of the M 7.0 which hit about 150 km to the north on January 3, 2017. No earthquakes have been recorded in Fiji within about 100 km of today's epicenter since an M 5.9 on February 15, 2016. Forecast 108273 had expected a moderate to moderately large quake in this section of the Fiji Islands was likely around June 19. This epicenter is at the fourth node (90 degrees) from the quake in Guatemala of June 14 and was probably promoted from that source.

 

O: 19JUN2017 09:15:43  20.7S  176.7W Mw=5.8  EMSC   FIJI REGION                  

P: 19JUN2017 108273    20.0S  174.0W 4.0-5.8 AABAA  Tonga Islands               

 

O: 19JUN2017 07:13:08  15.1S  173.5W mb=4.9  ANSS   NNE of Hihifo Tonga          

P: 19JUN2017 108255    15.0S  173.0W 4.0-5.5 AAAAA  Samoa Islands              

 

A light earthquake of M 2.6 occurred in central Kansas today at an unusual epicenter not associated with previous activity in the current active period. NEIC reported this earthquake of M 2.6 in Kansas was felt with intensity II-III in the area(s) of Kansas at Rose Hill, Derby, Mulvane, Douglass, Udall and Augusta  An earthquake of M 2.9 in northern Kansas also continued recent activation in that location. NEIC reported it was felt with intensity III in Mankato, Kansas. The quake near Rose Hill, Kansas, the largest within about 50 km of that epicenter since an M 2.9 on December 21, 2016 had been expected in forecast 108430 to occur in late June. The strongest earthquake in this region in the past 26 years, and one of only four events of M>=2.6 in the region in this time frame occurred on July 24, 2001 with M 3.0.

 

O: 19JUN2017 15:17:31  36.1N   97.8W mb=2.6  ANSS   E of Hennessey Oklahoma      

O: 20JUN2017 03:13:31  37.5N   97.1W mb=2.6  ANSS   Rose Hill Kansas             

P: 26JUN2017 108430    37.0N   98.0W 2.0-3.9 CAAAA  Southern Plains            

 

O: 19JUN2017 12:35:21  36.2N   98.9W mb=2.7  ANSS   N of Taloga Oklahoma         

O: 19JUN2017 07:02:37  39.8N   98.3W mb=2.9  ANSS   WNW of Mankato Kansas        

P: 22JUN2017 108431    39.0N   99.0W 2.0-3.9 BAAAA  Southern Plains            

 

Analysis of the tsunami in Greenland came from Earthquakes Canada today. This analysis includes:

 

"A tsunami was reported near Uummanaq, western Greenland at 00:15 UT (June 19). It has now been confirmed by Danish military tat a rockfall, which likely triggered the tsunami, occurred in the region. the cause of the rockfall is under investigation. Analysis of the recorded waveforms shows no evidence for an earthquake of magnitude 4.1 as was initially reported. The possibility that the rockfall was triggered by a very small earthquake cannot be ruled out" (June 19, 2017, Earthquakes Canada)

 

The strongest earthquake in the U.S. or Canada today was an M 4.0-4.5 in the Vancouver Island area of British Columbia, Canada. NEIC reported it was felt, which is uncommon for earthquakes in this area, with intensity II-III in British Columbia at Gold River, Campbell River, Port MacNeill, Ucluelet, Powell River, Port Alberni, Nanaimo, Lake Cowichan, Cowichan Valley, Vancouver, Sooke, Point Roberts, White Rock, and Victoria and perhaps at Friday Harbor, Washington.

Earthquakes Canada reported this quake was lightly felt in central Vancouver.

The last earthquake in this area within about 100 km of this epicenter with M>=4.3 was an M 4.8 on January 8, 2015 and prior to that an M 6.6 on April 24, 2014. Forecast 108204 had expected a moderate regional event was likely around June 18. This epicenter is located at 104 degrees from the M 6.8 in the Celebes, Indonesia of May 29 and was probably promoted by concentrated seismic energy from that event.

 

O: 19JUN2017 17:22:00  49.7N  126.7W ML=4.5  EMSC   VANCOUVER ISLAND, CANADA REGIO

O: 19JUN2017 17:22:58  49.8N  126.7W ML=4.0  NRCA  42 km W   of Gold R.          

O: 19JUN2017 17:22:55  50.0N  126.4W Ml=4.3  ANSS   W of Campbell River          

P: 18JUN2017 108204    49.3N  129.0W 2.8-5.1 AABAA  Vancouver Island area      

 

An unusual earthquake of M 4.7 was recorded in the Sampungu area of Indonesia today north of Sumbawa. This is the strongest earthquake within about 100 km of this epicenter since an M 5.1 on July 31, 2015 and an M 5.8 on July 31, 2016,  Forecast 108312 had expected this activity to the east around June 24. This epicenter is located at the exact antipode of Tropical Storm Bret at the time of occurrence as noted in this summary:

 

"Tropical Depression Bret formed over Trinidad with winds up to 50 kts. It is expected to track to the west over the next week, first as a tropical Storm and then reducing back to a Tropical Depression around June 22-23. A moderate earthquake in northern Venezuela or Trinidad and Tobago could accompany this storm. The antipode is in the Sumbawa area and Timor area of Indonesia. A promoted earthquake in is this area is also possible at this time." (June 19-20, 2017)

 

 

O: 19JUN2017 04:39:08   7.5S  118.3E mb=4.7  ANSS   NNW of Sampungu Indonesia    

P: 24JUN2017 108312     7.0S  120.0E 4.0-5.4 BABAA  Flores Island area         

 

MODERATE EARTHQUAKE IN GREENLAND TRIGGERS DEADLY TSUNAMI

 

EARTHQUAKE SUMMARY FOR JUNE 18, 2017

 

An earthquake off the coast of Greenland today triggered a tsunami which hit the west coast of Greenland. Four people are missing after the wave swept 11 homes away in the village of Nuugaatsiaq. Major flooding hit at least three villages in Greenland. Big waves were seen from helicopter at least 25 miles off the coast. An unknown number of injuries were reported and 39 people have been evacuated from Nuugaatsiaq. This is a highly unusual event. It is likely that the moderate earthquake triggered a massive underwater landslide which, in turn, triggered the tsunami. An event of this size is incapable of directly moving the earth enough to trigger a tsunami. Tsunamis are rare in the Northern Atlantic but have occurred in the past as in the Grand Banks earthquake and tsunami of November 18, 1929. This summary noted this in previous episodes as follows:

 

"11 18 20 32  0 1929  44.500  -56.300   0 7.2   No. Mid-Atlantic Ridge

 

The Grand Banks earthquake off Newfoundland caused a submarine slide in the North Atlantic which broke at least 12 trans-Atlantic cables. A tsunami was generated which caused considerable damage at Placentia Bay, Newfoundland where 27 were killed. The tsunami was observed as far south of Charleston, South Carolina. Maximum intensity in the U.S. was in southeastern Maine where clocks stopped and items were knocked from shelves." (November 18, 2016).

 

The source of today's earthquake is not clear. An M 4.6 did occur in the Greenland Sea today but on the eastern side of Greenland and this event was recorded near local midnight in Greenland. The network which normally records earthquakes off western Greenland, NRCA or Earthquakes Canada normally does not update listings over weekends. It is possible that later on Monday, a listing for the tsunamigenic earthquake will be made by NRCA. A moderate  earthquake also occurred near Greenland in the region of Iceland with M 4.8-5.0. While not a location likely to have triggered a tsunami in western Greenland either but is closer.

 

The event in the Greenland Sea was an M 4.5-4.6. An earthquake of M 5.2 hit the same general region 10 days ago on June 9 indicating an enduring stress in the region. Forecast 108243 had expected this activity around June 21.

 

O: 19JUN2017 02:19:33  79.5N    3.9E mb=4.5  ANSS   Svalbard and Jan Mayen       

O: 19JUN2017 02:19:33  79.7N    2.8E mb=4.6  EMSC   GREENLAND SEA                

P: 21JUN2017 108243    74.0N   14.0E 3.0-4.6 ACAAA  Norway                     

 

The activity in the north Atlantic had been anticipated at this time in the previous issue of this summary as follows:

 

 

"The geomagnetic field was at disturbed conditions today.  The AP level was 15. High latitude geomagnetic field also saw disturbed conditions with AP at 17. Seismicity associated with the moderate geomagnetic storm of June 16 and 17 is expected to be moderate and concentrate at high latitude and about 10-15 degrees from the geomagnetic equator. This includes the antipodal regions of Iceland and the Macquarie/Balleny Islands area which have been active recently with geomagnetic storms. The M 6.1 in Fiji today was an example of such an event. In this regard, an earthquake in the Balleny Islands about 10 days ago has not yet been answered by antipodal activity in Iceland which was expected in this  summary:

 

"The last earthquake in the Balleny Islands region within about 250 km of this

epicenter with M>=6.0 was an M 6.2 on April 17, 2014 and prior to that on October 29, 2013 with M 6.0. As this epicenter is directly antipodal to an active seismic region of Iceland, sympathetic activity at that antipode (62N 25W) is likely in the next several days." (June 4, 2017)" (June 17-18, 2017)

 

The earthquake in Iceland of M 5.0 was the strongest within about 200 km of that epicenter since an M 5.0 on November 16, 2014. The last of M>5 in this region  occurred as an M 5.2 on May 10, 2005.  An event of M 4.9 hit northeast of this epicenter on March 2, 2017 beginning the  current upsurge in activity in Iceland. Forecast 108237 had expected a moderate earthquake in this area around June 16.

 

O: 18JUN2017 09:06:57  61.0N   27.8W mb=5.0  ANSS   Iceland region"              

O: 18JUN2017 09:06:56  61.1N   27.9W mb=4.8  EMSC   ICELAND REGION               

P: 16JUN2017 108237    62.0N   27.0W 3.0-4.6 AAAAA  Iceland area               

 

O: 18JUN2017 18:30:23  63.6N   19.1W ML=3.2  EMSC   ICELAND                      

P: 26JUN2017 108511    63.0N   18.0W 3.0-4.6 CAAAA  Iceland area               

 

An earthquake of M 3.5 in Southern California today was widely felt with intensity II-III. NEIC reported it was felt in Idyllwild, Hmet, Anza, Palm Springs, Hemet, Mountain Center, Winchester, Cathedral City, Temecula, Palm Desert, Rancho Mirage, Nuevo, Murrieta, Thousand Palms, Menifee, Sun City, Indio, Valley Center, Perris, Fallbrook, Riverside, Carlsbad, Santa Ana, and in general within about 100 km from the epicenter.

 

O: 18JUN2017 15:14:12  33.7N  116.8W ml=3.5  ANSS   SSW of Idyllwild CA          

P: 21JUN2017 108157    33.9N  116.9W 2.5-4.5 BAAAA  So. California             

 

 

AFTERSHOCKS CONTINUE IN TURKEY AND CENTRAL AMERICA

 

EARTHQUAKE SUMMARY FOR JUNE 17, 2017

 

A moderate M 5.1 aftershock in Western Turkey was widely felt in the regions of Greece, Turkey and Bulgaria today. NEIC reported maximum intensity VI in Plomarion, Lesvos, Greece and V in Mithimna, Lesvos. It was also felt in Greece with intensity II-IV in Varia, Pamfila, Parakoila, Agra, Petra, Khios, Pithagoiio, Kifisia, Aghios Dimitrios, Nea Ionia, and in Turkey at Buyukcekmece, Istanbul, Urla, Izmir, Burhaniye, Manisa, Edremit, Menderes, Kemalpasa, Kusadasi, Canakkale, Aliaga, Izmir, Ayvalik, Gomec. It was also felt in Bulgaria with intensity II-III in Dimitrovgrad, and Plovdiv. Several smaller aftershocks were also felt in the epicentral area. No major damage or tsunami was reported with this earthquake. This is the strongest aftershock to date of the M 6.3 which struck the region on June 12, triggering moderate regional damage. Forecast 108121 had expected today's earthquake was likely within about 50 km of this epicenter around June 17.

 

O: 17JUN2017 20:16:15  38.8N   26.4E ML=4.0  EMSC   NEAR THE COAST OF WESTERN TURK

O: 17JUN2017 19:50:04  38.8N   26.4E mb=5.0  EMSC   NEAR THE COAST OF WESTERN TURK

O: 17JUN2017 19:33:32  38.8N   26.5E mb=4.1  EMSC   NEAR THE COAST OF WESTERN TURK

P: 17JUN2017 108121    39.0N   26.0E 3.0-5.1 AAAAA  Aegean Sea                 

 

The strongest felt earthquake in the world today was an M 5.4 in Nicaragua. It was reported felt with intensity IV in Nicaragua at San Juan del Sur, Rivas and Santa Cruz, Guanacaste and in Managua with intensity III. This is probably a regional aftershock of the M 7.0 in Guatemala of June 14. It is the strongest earthquake located within Nicaragua since an M 5.0 on March 29, 2017, the only other such earthquake this year. Forecast 108096 had expected this earthquake within about 100 km of this epicenter was most likely to occur around June 20.

 

O: 17JUN2017 13:47:40  11.4N   86.6W mb=5.3  EMSC   NEAR COAST OF NICARAGUA      

O: 17JUN2017 13:47:38  11.3N   86.7W mw=5.4  ANSS   Nicaragua

P: 20JUN2017 108096    12.0N   86.0W 3.5-5.2 BAAAA  Nicaragua                  

 

NEIC reported an earthquake of M 4.6 in Costa Rica was felt with intensity II-III in the area(s) of Parrita, Puntarenas, Costa Rica.

 

NHC is reporting a weather system north of Nicaragua which formed today is likely to reach tropical depression levels in the next two days with 60% probability. It is likely that stresses from this storm may have helped promote the M 5.4 in Nicaragua today. The storm is located over the upper plate  in the Nicaragua-Pacific subduction zone. Reducing air pressure over this region allows more movement on the underlying subduction zone faults and a higher likelihood of a moderate to large earthquake.

 

The strongest earthquake in the world today was an M 6.1 at a deep focus south of the Fiji Islands. It occurred near local solar noon and was probably promoted by high tidal stress. The mainshock was preceded by an M 4.3 foreshock to the south. An earthquake of M 6.9 hit the area about 100 km northeast of this epicenter on February 24 and an M 6.3 was located about 50 km north of this on January 2, 2017. Forecast 108274 had expected this event within this area was likely around June 19.

 

O: 17JUN2017 22:26:02  24.1S  179.6E Mw=6.1  EMSC   SOUTH OF FIJI ISLANDS        

O: 17JUN2017 22:26:02  24.1S  179.6E mw=6.1  ANSS   South of the Fiji Islands

O: 17JUN2017 19:11:44  24.8S  179.9E mb=4.3  ANSS   the Fiji Islands

P: 19JUN2017 108274    24.0S  179.0E 4.0-5.5 AAAAA  Tonga/Fiji                 

 

The strongest earthquake in the U.S. or Canada today outside Alaska was an M 3.9 in the region of Trinidad, Colorado where it was felt with intensity III. This is the latest in a series of event which began in September, 2001. Earthquake of M>=3.9 in this series, however have been uncommon. The last such event was an M 4.0 on December 23, 2016 and prior to that on August 23, 2016 (M 3.9). The last of significantly larger magnitude than M 3.9 was the M 5.3 which occurred on August 23, 2011 on the same day as the Virginia quake which caused considerable damage in the Washington, D.C. region. These accompanied one of the strongest Gamma Ray Bursts (GRB) in recent years. Forecast 108133 had expected today's event within about 15 km of this epicenter was likely around June 12.

 

O: 17JUN2017 06:42:07  37.0N  104.9W ml=3.9  ANSS   WSW of Trinidad Colorado     

P: 12JUN2017 108133    36.9N  105.1W 2.0-4.3 BAAAA  Colorado area              

 

The strongest earthquake in Alaska today was an M 4.4-4.7 aftershock in the Near Islands, Alaska. This aftershock of the June 2 M 6.8 Near Islands quake was not felt in this remote epicentral area. It is the second strongest aftershock of that event to date - following an M 5.2 on June 2. Forecast 108216 had expected this event within about 50 km of the epicenter was likely around June 13.

 

 

O: 17JUN2017 20:19:32  53.1N  171.1E mb=4.4  EMSC   NEAR ISLANDS, ALEUTIAN ISLANDS

O: 17JUN2017 20:19:36  52.9N  171.1E mb=4.7  ANSS   Attu Station Alaska

P: 13JUN2017 108216    53.0N  170.0E 4.0-5.7 BAAAA  Near Islands               

 

The swarm in west Yellowstone which included a moderate M 4.8 earthquake appears to be winding down. Only one light quake, an M 2.7, was recorded in the area in the past day. Factors which led to promoting this swarm included the M 7.0 in Guatemala, high tidal stresses with the full moon and the current geomagnetic storm as well as its distance at the fourth node from Turkey (M 6.3). Forecast 108206 had expected activity in this region around June 17.

 

O: 18JUN2017 01:28:32  44.8N  111.0W ml=2.7  ANSS   West Yellowstone Montana     

P: 17JUN2017 108206    43.0N  111.5W 2.0-4.2 ABAAA  Yellowstone/Wyoming        

 

The geomagnetic field was at disturbed conditions today.  The AP level was 15. High latitude geomagnetic field also saw disturbed conditions with AP at 17. Seismicity associated with the moderate geomagnetic storm of June 16 and 17 is expected to be moderate and concentrate at high latitude and about 10-15 degrees from the geomagnetic equator. This includes the antipodal regions of Iceland and the Macquarie/Balleny Islands area which have been active recently with geomagnetic storms. The M 6.1 in Fiji today was an example of such an event. In this regard, an earthquake in the Balleny Islands about 10 days ago has not yet been answered by antipodal activity in Iceland which was expected in this  summary:

 

"The last earthquake in the Balleny Islands region within about 250 km of this

epicenter with M>=6.0 was an M 6.2 on April 17, 2014 and prior to that on October 29, 2013 with M 6.0. As this epicenter is directly antipodal to an active seismic region of Iceland, sympathetic activity at that antipode (62N 25W) is likely in the next several days." (June 4, 2017)

 

MODERATE EARTHQUAKE SHAKES WEST YELLOWSTONE, MONTANA

 

EARTHQUAKE SUMMARY FOR JUNE 15, 2017

 

While the earthquake swarm in Kansas appears to have dissipated following the M 7.0 in Guatemala, the swarm in Yellowstone National Park, Montana continued unabated today. The largest earthquakes in this group today were M 4.5, M 3.1 and 2.9.  Most earthquakes in the Yellowstone region are light events, even in swarms, so the activity today with the M 4.5 is quite unusual.  The mainshock of M 4.5 was the largest earthquake in the Yellowstone area since an M 4.7-4.8 on March 40, 2014 and the strongest in west Yellowstone in at least 25 years.  The M 4.5 was reported felt in Montana with intensity II-III at West Yellowstone, Gardiner, Pray, Gallatin Gateway, Ennis, Bozeman, ; in Wyoming at Casper, Yellowstone National Park and in Idaho at Saint Anthony, Soda Springs and Island Park.  The smaller of these were reported by NEIC to have been felt in west Yellowstone near Ennis, Gardiner, Montana with intensity II-III.

 

Today's activity in Yellowstone National Park was preceded by a gradually increasing swarm beginning shortly before the M 7.0 in Guatemala. This report had noted this swarm as follows:

 

"A strong swarm with maximum event of M 3.2 hit Yellowstone National Park after the mainshock in Greece-Turkey. These epicenters are 90 degrees apart at node 4. It is likely that some seismic promotion occurred from the Turkey event. Yellowstone has been inactive for months, so the coincidence of these two events with the full moon is probably significant. This is the first significant activity in Yellowstone since an M 3.1 on January 20, 2017. ...  Forecast 108206 had expected activity in the Yellowstone area around June 17." (June 12-13, 2017)

 

O: 16JUN2017 01:20:16  44.8N  111.0W ML=2.3  EMSC   YELLOWSTONE NAT. PARK, WYOMING

O: 16JUN2017 00:55:18  44.8N  111.0W ML=2.7  EMSC   YELLOWSTONE NAT. PARK, WYOMING

O: 16JUN2017 01:03:16  44.8N  111.0W ML=2.8  EMSC   YELLOWSTONE NAT. PARK, WYOMING

O: 16JUN2017 08:02:02  44.8N  111.0W ML=2.8  EMSC   YELLOWSTONE NAT. PARK, WYOMING

O: 16JUN2017 01:46:27  44.8N  111.0W ML=2.9  EMSC   YELLOWSTONE NAT. PARK, WYOMING

O: 16JUN2017 00:48:47  44.8N  111.1W mb=4.3  EMSC   YELLOWSTONE NAT. PARK, WYOMING

O: 16JUN2017 00:48:46  44.8N  111.0W ml=4.5  ANSS   West Yellowstone Montana

P: 21JUN2017 108206    44.2N  110.3W 2.0-3.9 BAAAA  Yellowstone/Wyoming        

 

 

The most unusual and widely felt earthquake in the U.S. or Canada today was an M 3.6 in Washington State. NEIC reported it was felt with intensity II-III in Washington at Quilcene, Chimacum, Port Ludlow, Port Townsend, Poulsbo, Silverdale, Hansville, Sequim, Kingston, Suquamisth, Bremerton, Seabeck, Bainbridge Island, Freeland, Greenbank, Edmonds, Clinton, Seattle, Langley, Port Orchard, Belfair, Coupeville, Lynnwood, Mukilteo, Everett, Camano Island, Bothell, Gig Harbor, Kirkland, Oak Harbor, Mercer Island, Snohomisk, Redmond, Stanwood, Woodinville, Lake Stevens, Tacoma, Renton, La Conner, Federal Way, Anacortes, University Place, Lopez Island, Monroe, Lakewood, Arlington, Friday Harbor and Olympia and in general within about 100 km of the epicenter. Also felt in Victoria and Sooke, British Columbia, Canada.

 

The last earthquake within about 100 km of this epicenter with M>=3.6 occurred as an M 4.0 on February 23, 2017. On average the area sees 1-2 quakes of this size per year.  Forecast 108205 had expected today's earthquake within about 25 km of this epicenter was likely around June 12.

 

O: 16JUN2017 03:55:26  47.8N  122.9W ML=3.6  EMSC   OLYMPIC PENINSULA, WASHINGTON

O: 16JUN2017 03:55:26  47.8N  122.9W ml=3.6  ANSS   W of Lofall Washington

P: 12JUN2017 108205    48.0N  123.0W 2.0-3.9 BAAAA  Washington state, U.S.     

 

The unusual activity in Arkansas near Lead Hill also continued today. An M 2.8 in this swarm was reported by NEIC to have been felt with intensity II-III in Lead Hill, Harrison, Omaha, Peel, Yellville, Bull Shoals, Oakland, Jasper, Flippin, Saint Joe and Mountain Home, Arkansas and in Missouri at Lampe, Bradleyville, Branson, Blue Eye, Theodosia, Ridgedale, Hollister, Kirbyville, Cedarcreek, Missouri.

 

The last earthquake within about 100 km of this epicenter in Arkansas occurred on June 11, 2017 with M 3.6 and prior to that as an M 3.1 on September 7, 2007. The event on June 11 had been considered a possible precursor to the M 7.9 in Guatemala of June 14.  Forecast 108142 had expected today's event within about 150 km to the southeast was likely around June 14.

 

O: 16JUN2017 02:28:27  36.4N   93.0W MD=2.8  EMSC   ARKANSAS                      

O: 16JUN2017 02:28:27  36.4N   93.0W md=2.8  ANSS   NNE of Harrison Arkansas

P: 14JUN2017 108142    35.0N   92.0W 2.0-4.3 ABAAA  New Madrid area            

 

An earthquake of M 3.5 was also felt in Oklahoma today. NEIC reported intensity V in Covington, Oklahoma and II-III in Enid, Oklahoma City, Norman, Minco, Tulsa, Oklahoma. Forecast 108167 had expected this event was likely within about 50 km around June 15.

 

O: 15JUN2017 14:11:25  35.9N   96.9W ML=2.7  EMSC   OKLAHOMA                      

O: 15JUN2017 07:35:15  36.3N   97.5W mb=3.5  EMSC   OKLAHOMA                     

O: 16JUN2017 04:29:08  37.0N   97.8W mb=2.3  EMSC   OKLAHOMA                     

P: 13JUN2017 108166    37.0N   97.0W 2.0-4.0 BAAAA  Southern Plains            

P: 15JUN2017 108167    36.0N   97.0W 2.0-4.1 AAAAA  Southern Plains            

 

The strongest earthquake in the world today was an M 5.8 in the Southern East Pacific Rise north of Antarctica. Like unusual quakes in the Madeira Islands an the Pribilof Islands of Alaska yesterday, this epicenter is near the fifth node (72 degrees) from the M 7.0 in Guatemala and may have been promoted from that source. It also continues the series of unusual quakes in the Pacific area which have previously been  associated by this report with high tidal stresses from the full moon of June 9. Today's event occurred in a remote area and was not felt. No tsunami was observed or expected with this ridge event. This is the strongest earthquake within about 250 km of this epicenter in the Southern Pacific since an M 5.9 on August 18, 2016 and prior to that an M 6.0 on February 16, 2016.  Forecast 108292 had expected today's earthquake about 150 km to the east of the epicenter was likely around June 12.

 

O: 15JUN2017 11:42:18  55.5S  124.7W Mw=5.8  EMSC   SOUTHERN EAST PACIFIC RISE   

P: 12JUN2017 108292    56.0S  122.0W 4.0-5.4 BABAA  Pacific-Antarctic Ridge    

 

MODERATE QUAKES IN MEXICO FOLLOW TROPICAL DEPRESSION CALVIN

 

EARTHQUAKE SUMMARY FOR JUNE 14, 2017

 

As Tropical Depression Calvin moved west and dissipated today it triggered one more fresh earthquake - an M 5.5 in Oaxaca, Mexico. NEIC reported this event was felt with intensity II-III in Huatulco, Oaxaca and in Mexico City. The epicenter was directly under the eye of Carlos when the quake occurred. This was the strongest quake northern hemisphere today. The last earthquake in this region of M>=5.5 within about 200 km of this epicenter was an M 5.7 on June 27, 2016 and May 8, 2016 (M 5.9). The last of M>=6 in the area occurred June 30, 2010 with M 6.3. The last of  Forecast 108099 had expected this event within about 50 km of the epicenter was likely around June 12.

 

O: 15JUN2017 04:43:54  15.2N   97.3W ML=4.0  UNAM  l SUROESTE de PUERTO ESCONDIDO, OA

O: 14JUN2017 23:58:53  15.3N   97.4W ML=5.0  UNAM  l SUROESTE de PUERTO ESCONDIDO, OA

O: 14JUN2017 23:58:55  15.2N   97.1W mb=5.5  EMSC   OFFSHORE OAXACA, MEXICO      

O: 14JUN2017 23:58:52  15.4N   97.1W mw=5.5  ANSS   54km S of Puerto

P: 12JUN2017 108099    16.0N   97.0W 3.5-5.5 AAAAA  Oaxaca, Mexico             

 

 

Aftershocks in the Chiapas-Guatemala area of Mexico and Guatemala today. An M 5.1 in Guatemala including an M 5.1 in Chiapas were felt with intensity I-III in Guatemala City, San Cristobal de las Casas, Chiapas and in Mexico City.

 

In the previous report this summary had expected this seismicity pattern:

 

"TD    CALVIN   2017-06-13  00:00 UT  16.2N   96.1W  040 kts  Oaxaca, Mexico

 

Tropical depression Calvin (03E) continued in the area of Oaxaca and Chiapas, Mexico with winds up to 40 kts. NHC This storm is located south of the Mexico Guatemala border at this time and is expected to dissipate over land today.

The area from Chiapas to Oaxaca could see a moderate to large earthquake

in the next three days. The area is under an earthquake watch." (June 13-14, 2017)

 

O: 14JUN2017 12:08:33  14.4N   92.0W ML=4.1  UNAM  l SURESTE de CD HIDALGO, CHIS *: 1

O: 15JUN2017 04:55:06  14.5N   92.0W ML=4.2  UNAM  l SURESTE de CD HIDALGO, CHIS *: 1

O: 14JUN2017 07:52:41  14.6N   92.0W ML=5.2  UNAM  l SURESTE de CD HIDALGO, CHIS *: 1

O: 14JUN2017 09:30:17  14.7N   92.1W ML=4.0  UNAM   NORESTE de CD HIDALGO, CHIS *: 14

O: 14JUN2017 16:00:59  14.7N   92.1W ML=4.0  UNAM  l NORESTE de CD HIDALGO, CHIS *: 1

O: 14JUN2017 08:51:38  14.6N   92.2W ML=4.0  UNAM   NOROESTE de CD HIDALGO, CHIS *: 1

O: 14JUN2017 08:21:40  14.6N   92.2W ML=4.0  UNAM   SUROESTE de CD HIDALGO, CHIS *: 1

O: 14JUN2017 07:40:48  14.7N   92.2W ML=4.0  UNAM  l NOROESTE de CD HIDALGO, CHIS *:

O: 14JUN2017 07:49:43  14.6N   92.2W ML=4.1  UNAM   SUR de CD HIDALGO, CHIS *: 14.64°

O: 14JUN2017 21:14:57  13.9N   92.4W ML=5.1  UNAM  l SUROESTE de CD HIDALGO, CHIS *:

O: 14JUN2017 16:56:33  15.0N   92.8W ML=4.1  UNAM  l SUROESTE de HUIXTLA, CHIS *: 15.

O: 15JUN2017 04:33:07  14.1N   93.3W ML=4.1  UNAM  al SUROESTE de CD HIDALGO, CHIS *:

O: 14JUN2017 21:14:58  14.0N   92.1W mb=5.1  EMSC   OFFSHORE GUATEMALA            

P: 13JUN2017 108086    14.0N   92.0W 3.5-5.3 AAAAA  Guatemala                  

 

 

The strongest earthquake in the world today was an M 5.9 in the remote Kermadec Islands, New Zealand. This event near 100 degrees from Guatemala was not reported felt in this remote area. Seismicity at this distance in New Zealand had been expected at this time. The strongest earthquake in the Kermadec Islands during 2017 was an M 5.8 on January 29 but the area has been relatively quiet since then. The last earthquake within about 200 km of this epicenter with M>=5.9 was an M 6.1 on June 6, 2016. In recent years all events of this size or larger have occurred in June or July, perhaps with a seasonal trigger. Today's earthquake occurred within an hour or local solar noon and was probably promoted by high earth tides. Forecast 108283 had expected this activity was likely around June 20 south of this epicenter in the Kermadec Islands.

 

O: 15JUN2017 00:26:22  30.5S  178.0W Mw=5.9  EMSC   KERMADEC ISLANDS, NEW ZEALAND

O: 15JUN2017 00:26:16  30.6S  178.0W mw=5.9  ANSS   NE of L'Esperance Rock

P: 20JUN2017 108283    32.0S  179.0W 4.0-5.4 BBAAA  So. Kermadec Islands       

 

The strongest earthquake in the U.S. or Canada today was an M 4.5 in the Pribilof Islands, Alaska. It was not reported felt in this remote area off the western Alaska mainland.   The epicenter is located at 72 degrees (node 5) from the M 7.0 in Guatemala hours earlier and was probably promoted by energy from that event. The last earthquake in the Pribilof Islands within about 150 km of this epicenter with M>=4.5 occurred on January 31 to February 2, 2015 when a series of events up to M 5.3 hit the region. Forecast 108213 had expected this event in the Fox Islands southeast of this  epicenter around June 12.

 

O: 14JUN2017 20:56:13  56.5N  168.4W ML=4.5  EMSC   PRIBILOF ISLANDS, ALASKA REGIO

P: 12JUN2017 108213    53.7N  167.0W 3.5-5.1 ACAAA  Fox Islands, Aleutians     

 

An unusual earthquake also hit the Madeira Islands region of Portugal today. It was not reported felt in the epicentral area. Two moderate earthquakes have hit in the Madeira Islands during 2017 to date - an M 4.3 on March 28 and an M 4.0 on May 12. The last earthquake of M>=4.5 in this region occurred more than 25 years ago. The last near this magnitude was an M 4.4 on September 26, 2008, matched in 1990, 1995, 2004 and 2005. Like the event in the Pribilof Islands, Alaska this epicenter is near the fifth node (72 degrees) from Guatemala and may have been promoted by energy from that event.  It is also in the general antipodal area of an M 5.9 in the Kermadec Islands, New Zealand, an event  that occurred several hours after this earthquake in the Atlantic.

 

O: 15JUN2017 02:14:13  32.8N   16.8W mb=4.6  EMSC   MADEIRA ISLANDS, PORTUGAL REGI

 

Another quake which appears to have been promoted by a tropical depression occurred today in the northern Philippine Islands with M 5.1 but was not felt. This summary had expected activity in this areas as TD Merbok moved through.

 

"Tropical Depression Merbok (04W) continued east of the central Philippines with winds up to 50 kts. It is expected to track to the west reversing direction after encountering the Asian mainland. It will then pass north of Taiwan around June 13-14. Increased seismicity with a moderate quake likely could occur in the central Philippines and/or in Taiwan while this storm is in the area." (June 12-13, 2017)

 

The last earthquake of M>=5.1 in the northern Philippines was an M 5.2 on December 26, 2016 and prior to that an M 5.4 on June 19, 2016.   Forecast 108118 had expected this event within about 150 km of this epicenter was likely around June 19.

 

O: 15JUN2017 03:11:07  19.8N  122.5E mb=5.1  EMSC   BABUYAN ISL REGION, PHILIPPINE

P: 19JUN2017 108118    20.0N  121.0E 4.0-5.6 BAAAA  Taiwan                      

 

MAJOR EARTHQUAKE SHAKES GUATEMALA; CHIAPAS, MEXICO; BELIZE AND EL SALVADOR

 

EARTHQUAKE SUMMARY FOR JUNE 13, 2017

 

A major earthquake, the largest in the world in more than two months, of M 6.9  (EMSC) to 7.0 (UNAM) occurred at an intermediate depth beneath Guatemala and Chiapas, Mexico near local solar midnight today. A foreshock of M 5.6 in Chiapas, Mexico preceded by about 50 minutes the earthquake in Guatemala. This is probably a tidal quake having occurred within about 15 minutes of local solar midnight. An M 5.1 aftershock of that occurred five minutes before the event in Guatemala and probably triggered it. The mainshock was felt with intensity VI in Guatemala and Chiapas, Mexico. Reports of intensity VI from NEIC came from El Tumbador, San Marcos, Coatepeque, Quezaltenango, Zunil, Huehuetenango, Champerico, Santa Catarina Barahona, and San Pedro Ayampuc, Guatemala and in Chiapas, Mexico from Comitan, Puerto Madero, Tapachula, Cacahoatan, with intensity V in Guatemala at Malacatan, Olintepeque, Mazatenango, San Pablo la Laguna, Chimaltenango, Antigua Guatemala, Santa Maria de Jesus, Santa Lucia Milpas Altas, San Lucas Sacatepequez, Mixco, Amatitlan, Villa Nueva, Santa Catarina Pinula. The earthquake was also felt with intensity II-III within at least 500 km of the epicenter in El Salvador, Belize, and 900 km away in Mexico City. The depth at  120 km created a wide cone of felt activity but also reduced the overall shaking and damage from this earthquake. The last earthquake with M>=6.9 to hit Guatemala within about 200 km from today's epicenter occurred on July 7, 2014 with M 6.9 in the subduction zone about 100 km south of Guatemala. The last within Guatemala was an M 6.9 on March 14, 1994. Other than these, the largest regional quakes in the past 25 years have registered at M 6.9-7.4 on November 7, 2012; October 21, 1995 and September 10, 1993. Today's event was more widely felt than any of these previous earthquakes. Forecasts 108083 and 108086 had expected this activity was likely around June 12-13.

 

O: 13JUN2017 21:24:11  13.8N   92.3W mb=4.9  EMSC   OFFSHORE GUATEMALA           

O: 14JUN2017 02:32:46  13.8N   92.4W mb=4.4  EMSC   OFFSHORE GUATEMALA           

O: 13JUN2017 08:43:53  14.0N   92.2W mb=4.9  EMSC   OFFSHORE GUATEMALA           

O: 14JUN2017 07:23:54  14.3N   93.1W mb=5.1  EMSC   OFFSHORE CHIAPAS, MEXICO     

O: 13JUN2017 14:03:21  13.8N   92.3W mb=4.4  EMSC   OFFSHORE GUATEMALA           

P: 13JUN2017 108083    14.0N   93.0W 3.5-5.3 AAAAA  Chiapas, Mexico            

P: 12JUN2017 108083    16.0N   93.0W 3.5-5.3 AAAAA  Chiapas, Mexico            

 

O: 14JUN2017 06:38:51  14.3N   93.1W Mw=5.6  EMSC   OFFSHORE CHIAPAS, MEXICO     

O: 14JUN2017 07:52:46  14.9N   91.6W mb=5.0  EMSC   GUATEMALA                    

O: 14JUN2017 07:52:41  14.6N   92.0W ML=5.2  UNAM  l SURESTE de CD HIDALGO, CHIS *: 1

O: 14JUN2017 02:32:48  13.6N   92.5W ML=4.4  UNAM  al SUROESTE de CD HIDALGO, CHIS *:

O: 13JUN2017 21:24:10  13.5N   92.5W ML=5.1  UNAM  al SUROESTE de CD HIDALGO, CHIS *:

O: 13JUN2017 08:43:50  13.7N   92.6W ML=4.6  UNAM  al SUROESTE de CD HIDALGO, CHIS *:

O: 14JUN2017 06:38:47  13.9N   93.3W ML=5.6  UNAM  al SUROESTE de CD HIDALGO, CHIS *:

O: 14JUN2017 07:23:53  14.2N   93.4W ML=5.0  UNAM  al SUROESTE de HUIXTLA, CHIS *: 14

O: 14JUN2017 07:29:06  15.1N   91.8W Mw=6.9  EMSC   GUATEMALA                    

O: 14JUN2017 07:29:05  15.0N   92.0W mw=6.9  ANSS   San Pablo Guatemala

O: 14JUN2017 07:29:03  14.7N   92.1W ML=7.0  UNAM  l NORESTE de CD HIDALGO, CHIS *: 1

P: 12JUN2017 108083    16.0N   93.0W 3.5-5.3 AAAAA  Chiapas, Mexico            

P: 13JUN2017 108086    14.0N   92.0W 3.5-5.3 AAAAA  Guatemala                  

 

 

This event in Guatemala is located at 101-102 degrees from the M 6.3 in Turkey which occurred yesterday. It is also at 103 degrees from a tidally triggered event of Vanuatu of M 5.8 which occurred about seven hours earlier. This is a distance at which seismic energy reflected and refracted off the core-mantle boundary returns in concentrated state to the surface. Seismicity subsequently often increases this distance range, probably due to the arriving energy. When an area is near rupture this can be precipitated by a large but non-major earthquake such as the event of M 6.3 in Turkey-Greece. Was the area of Chiapas-Guatemala ready for such a triggered event? This summary has been following an escalation of seismicity in Guatemala and Chiapas, Mexico over the past several days which began with the passage of Tropical Depression Calvin over these epicenters and was noted in the previous issue of this summary as: 

 

"Tropical depression Calvin (03E) continued in the area south of Oaxaca and Chiapas, Mexico with winds up to 40 kts. NHC This storm is located south of the Mexico-Guatemala border at this time and is expected to dissipate over land in the next two days. The area from Chiapas to Oaxaca could see a MODERATE TO LARGE EARTHQUAKE IN THE NEXT THREE DAYS. The area is under an earthquake watch." (June 12-13, 2017)

 

and

 

"The seismicity south of Chiapas, Mexico also appears to have promoted by a combination of stresses from the forming tropical depression over these epicenters and by strong tidal stresses associated with the full moon. The sequence began with an M 5.1-5.2 at 18:47 UT. Local solar noon is about 18:15 UT. Tidal stresses are high at this hour and, as in the case in Vancouver may have helped promote this earthquake at this time. The only other events within the region of Chiapas, Mexico of M>=5.1 during the year 2017 were a series on May 30 and 31, 2017 near today's epicenters. Today's activity can be considered aftershocks of those events in May. Forecast 107821 had expected this activity was likely within about  50 km of these epicenters around June 9. 

 

NEIC reported this earthquake of M 5.1 in Chiapas, Mexico was felt with intensity II-III in the area(s) of Tapachula, Chiapas, Mexico.  This activity is located at 144 degrees from the Sulawesi quake of May 29, 2017 where reflected energy from the core concentrates at the surface. It may have been promoted by some of this energy.. These epicenters are also located at 103 degrees from the M 6.8 in Vanuatu of May 9. Seismic energy, reflected from  core-mantle boundaries returns to the surface in concentrated form at this distance from large earthquakes and can help promote further seismicity" (June 11, 2017)

 

and in the previous summary:

 

"These epicenters (in Kansas and Chiapas) are 102-103 degrees from the M 6.8 of May 9, 2017 in Vanuatu and may have been promoted by concentrated surface energy from that event. Seismicity at high levels also continued at this distance from Vanuatu today in Chiapas, Mexico and Guatemala" (June 12-13, 2017)

 

The activity in northern Kansas, the first of its kind in decades, and the sudden swarm in Yellowstone, both of which declined immediately after the Guatemala event, may have been associated with precursory effects of the Guatemala event. Earthquakes in the central plains of the U.S. often precede strong earthquakes along the western rim as previously detailed in this summary. With the emergence of wide-spread seismicity in the Central Plains in the past five years, however, this is more difficult to recognize beforehand than it was in quieter days. Two examples of this include a series of moderate quakes in South Dakota hours before the M 9.2 in Anchorage, Alaska, March 28, 1964, Also before the M 8.0 in Mexico City in September 19, 1985 a strong unexpected series of precursory activity hit Nebraska and Kansas. Oil and water wells in the region went dry and caused much concern. Two days later when the Mexico City quake occurred these wells returned with as much as twice the capacity they had before the quake.

 

NEIC reported the earthquake of M 3.6 in Kansas was felt with intensity VI in Beloit, Kansas; IV in Mankato, and Jewell and II-III in the area(s) of Kansas at Randall, Burr Oak, Salina, Manhattan and Possibly Kansas City.

 

O: 13JUN2017 09:40:37  39.7N   98.2W Mw=3.6  EMSC   KANSAS                       

P: 17JUN2017 108167    38.0N   99.0W 2.0-3.9 BBAAA  Southern Plains            

 

O: 13JUN2017 14:11:35  44.8N  111.0W ML=2.1  EMSC   YELLOWSTONE NAT. PARK, WYOMING

O: 13JUN2017 15:29:39  44.8N  111.0W ML=2.1  EMSC   YELLOWSTONE NAT. PARK, WYOMING

O: 14JUN2017 06:15:06  44.8N  111.0W ML=2.5  EMSC   YELLOWSTONE NAT. PARK, WYOMING

O: 13JUN2017 07:26:50  44.8N  111.0W ML=2.7  EMSC   YELLOWSTONE NAT. PARK, WYOMING

O: 13JUN2017 11:28:39  44.8N  111.0W ML=2.7  EMSC   YELLOWSTONE NAT. PARK, WYOMING

O: 14JUN2017 03:00:29  44.8N  111.0W ML=2.9  EMSC   YELLOWSTONE NAT. PARK, WYOMING

P: 11JUN2017 107934    44.9N  113.4W 2.0-4.0 AABAA  Montana/Idaho              

 

at the end of May, 2017 it was also noted:

 

"The strongest seismicity in the western hemisphere over the past couple of days has been occurring in the region of Oaxaca and Chiapas, Mexico. Two events of M 5.3 and a series of moderate, smaller aftershocks have hit this area.  In the previous issue of this summary it was noted in this regard:" (June 1, 2017)

 

"The strongest earthquakes of the day felt outside Indonesia were a pair of events of M 5.3-5.4 south of Chiapas, Mexico. A strong weather system which can grow into a tropical storm according to NHC is in the vicinity of this seismic activity and may be promoting some of these events. The moderate activity in this region began about the same time that this storm which is stationary appeared in the region according to the NHC website.  They were reported by NEIC to have been felt with intensity II in Tuxtla Gutierrez, Chiapas, Mexico.

The only larger event in the year 2017 than M 5.3 occurred on March 31 with M 5.4. Forecast 107565 had expected today's activity was likely within about 50 km of these epicenters around May 29. These events are located at 144 degrees from the earthquake in Sulawesi yesterday. Seismic energy is concentrated at the surface after reflecting off core boundaries and often helps promote additional seismicity at this distance. A similar M 5.7 in central Chile yesterday was probably also promoted at this distance from Sulawesi." (May 31, 2017)

 

The first indications of an upcoming strong earthquake in Guatemala or Chiapas, Mexico occurred shortly after the M 6.8 in Vanuatu of May 8 and was followed in this report as:

 

"A second quake occurred at 103 degrees from the Vanuatu epicenter. This event of M 5.2 shook the region of Guatemala, Chiapas, Mexico and El Salvador.  NEIC reported this earthquake of M 5.2 in Guatemala  was felt with intensity II-III in the area(s) of Santa Catarina Pinula; Guatemala City, San Juan la Laguna, in Socoltenango, Chiapas, Mexico and Opico, El Salvador. It occurred 25 minutes after the Vanuatu quake as the S-wave from Vanuatu  was passing through the Guatemala epicenter. A series of other diffracted and reflected S- and P-phases from Vanuatu are also incident in Guatemala at this time after reflecting off the core-mantle boundary. This is an excellent example of immediate, dynamic earthquake triggering at 103 degrees from a strong earthquake - a distance often seen to include strong seismicity in days following large earthquakes. The earthquake in Guatemala was associated with a tropical storm in its own right as well.

 

TS Adrian formed today in the area south of Guatemala with winds up to 45 kts. It is expected to track to the west over the next four days turning north towards Chiapas around May 15 as a hurricane. The M 5.2 in Guatemala today was directly north of the eye of this storm and may have been promoted by stresses associated with it. As this is the first Tropical Storm of the season in this area, the effects on triggering seismicity are likely to be strong in the coming week. A seismic watch for the area from El Salvador to Chiapas, Mexico, including Guatemala is in effect through May 16. Further strong seismicity in this area is possible in the watch period.

 

Only one other earthquake has hit Guatemala with M>=5.2 during the year 2017. This was an M 5.3 on January 12, 2017. Forecast 107092 had expected today's event was likely within about 100 km of this epicenter around May 7." (May 8, 2017)

 

As noted above, the second largest event in the world today was an M 5.8 in the region of Vanuatu. This occurred within minutes of local solar noon and was probably tidally promoted. Its distance of 103 degrees from Guatemala suggests it may have promoted the subsequent M 6.9 there. The Vanuatu quake was felt with intensity IV in Vila, Shefa, Vanuatu. The last earthquake in the Southern Vanuatu Islands with M>=5.8 occurred on July 20, 2016 with M 6.1. Forecast 108265 had expected this event within about 50 km of the epicenter was likely around June 16.

 

O: 14JUN2017 00:25:37  18.3S  168.7E mb=5.8  EMSC   VANUATU                      

O: 14JUN2017 00:25:40  18.3S  168.7E mb=5.8  ANSS   SSE of Port-Vila Vanuatu

P: 16JUN2017 108265    18.0S  168.0E 4.0-5.6 AAAAA  Vanuatu Islands            

 

The strongest earthquakes in California today were of M 2.9 and M 2.7 in Central California south of San Francisco. This area has been active with light earthquakes in the past week and may be in an unstable condition. These earthquakes occurred 37 and 39 minutes after the mainshock and at a distance of 34 degrees as core reflections arrived in the area from Guatemala. Triggering is possible in this case suggesting a stronger quake could occur shortly in this area.  Forecast 108129 had expected activity in this region around June 16.

 

O: 14JUN2017 08:09:55  36.7N  121.3W MD=2.7  EMSC   CENTRAL CALIFORNIA           

O: 14JUN2017 08:06:07  36.7N  121.3W MD=2.9  EMSC   CENTRAL CALIFORNIA           

P: 16JUN2017 108129    37.3N  121.6W 2.5-4.4 AAAAA  Central California         

 

 

STRONG, TIDALLY PROMOTED QUAKE DAMAGING ON GREECE-TURKEY BORDER

 

EARTHQUAKE SUMMARY FOR JUNE 12, 2017

 

A strong earthquake near the Greece-Turkey border occurred today with M 6.3.

The mainshock caused considerable damage in Plomarion, Lesvos, Greece where it was felt with intensity IX. Intensity VI was also felt in Tire, Mimarsinan, Istanbul, Dikili, Izmir, Turkey, and VII in Canakkale, Turkey more than 125 km from the epicenter. Intensity V was also felt in Turkey at Ayvalik, Cesme, Menemen, Aftershocks up to M 4.4 were reported felt with intensity II-III in Greece at Skoutaros and in Turkey at Izmir. Intensity V was felt within about 100 km of the epicenter; IV within about 150 km and II-III as far as 500 km away in Sofia, Bulgaria.   As noted in previous issues of this summary tidal stresses apparently set this region up for this seismicity:

 

 

"Seismicity associated with high stresses related to the full moon of May 9 continued today in Turkey and eastern Europe. Turkey is especially prone to such influences as was noted when a great earthquake, the Izmit quake, of August, 1999 devastated much of the area. That quake occurred several days after the total solar eclipse was visible over the epicentral area, probably illustrating the role of tidal triggering in that event." (June 11-12, 2017)

 

"The full moon will arrive on May 9 at 21:43 UT. Longitudinal zones which are sub-solar at this time are near 145 West  longitude while those at anti-solar locations are near 35 East longitude. These include seismic areas of eastern Europe and the mid-east while those in the west are concentrated in east and central Alaska, Hawaii and the west coast of the U.S. While tidal triggering can occur in many areas including outside these zones, tidal stresses are highest in these areas and seismicity is likely to be elevated from about June 7 and June 12, 2017." (June 7-12, 2017)

 

The epicenter of today's event at 28E longitude is within the close range of 35E, and tidal promotion of this event, which occurred near local solar noon, is very likely.

 

A series of moderate earthquake have hit western Turkey about 150 km to the east of today's activity in the past several months. These too, lie on the Anatolian Fault in northern Turkey but have generally had maximum magnitude around M 5.0 - examples are events of M 5.0 on April 21 and May 27-28, 2017. The last earthquake within about 200 km of this epicenter with M>=6.3 was an M 6.5 on July 26, 2001, the only such event in the region in at least 25 years.  An event in northern Greece about 250 km from today's activity occurred on May 24, 2014. Forecasts 107864 and 108169 had expected today's activity within about 100 km of the epicenters was likely between June 9 and 13. 

 

O: 12JUN2017 12:28:38  38.9N   26.4E mw=6.3  ANSS   S of Plomarion Greece

O: 12JUN2017 12:32:54  38.8N   26.3E ML=4.0  EMSC   EAR THE COAST OF WESTERN TURKE

O: 12JUN2017 18:25:41  38.9N   26.2E ML=4.0  EMSC   EAR THE COAST OF WESTERN TURKE

O: 13JUN2017 03:19:59  38.9N   26.3E ML=4.0  EMSC   NEAR THE COAST OF WESTERN TURK

O: 12JUN2017 12:28:37  38.9N   26.3E Mw=6.3  EMSC   EAR THE COAST OF WESTERN TURKE

O: 12JUN2017 12:35:33  38.9N   26.4E ML=4.1  EMSC   EAR THE COAST OF WESTERN TURKE

O: 12JUN2017 16:30:15  38.9N   26.4E ML=4.1  EMSC   EAR THE COAST OF WESTERN TURKE

O: 12JUN2017 12:31:40  39.0N   26.2E ML=4.3  EMSC   EAR THE COAST OF WESTERN TURKE

P:  9JUN2017 107864    38.0N   27.0E 3.0-4.9 BAAAA  Aegean Sea                 

P: 13JUN2017 108169    39.0N   28.0E 3.5-5.1 AAAAA  Turkey                     

 

 

A strong swarm with maximum event of M 3.2 hit Yellowstone National Park after

the mainshock in Greece-Turkey. These epicenters are 90 degrees apart at node 4. It is likely that some seismic promotion occurred from the Turkey event. Yellowstone has been inactive for months, so the coincidence of these two events with the full moon is probably significant. This is the first significant activity in Yellowstone since an M 3.1 on January 20, 2017. The last earthquake of larger magnitude in the park occurred on January 7, 2017 with M 3.4 and prior to that a year ago on June 13 and 14, 2016 with M 4.0 each. Because of cyclic environmental conditions earthquakes often repeat on yearly cycles. Studies have shown this is a significant repetition. Forecast 108206 had expected activity in the Yellowstone area around June 17.

 

O: 12JUN2017 16:49:49  44.8N  111.0W ML=2.1  EMSC   YELLOWSTONE NAT. PARK, WYOMING

O: 13JUN2017 07:26:50  44.8N  111.0W ML=2.6  EMSC   YELLOWSTONE NAT. PARK, WYOMING

O: 12JUN2017 16:48:09  44.8N  111.0W ML=2.7  EMSC   YELLOWSTONE NAT. PARK, WYOMING

O: 13JUN2017 11:28:39  44.8N  111.0W ML=2.7  EMSC   YELLOWSTONE NAT. PARK, WYOMING

O: 12JUN2017 18:23:41  44.8N  111.0W ML=2.8  EMSC   YELLOWSTONE NAT. PARK, WYOMING

O: 12JUN2017 16:46:37  44.8N  111.0W ML=2.9  EMSC   YELLOWSTONE NAT. PARK, WYOMING

O: 12JUN2017 22:54:55  44.8N  111.0W ML=3.2  EMSC   YELLOWSTONE NAT. PARK, WYOMING

P: 17JUN2017 108206    43.0N  111.5W 2.0-4.2 BBAAA  Yellowstone/Wyoming        

 

The strongest earthquake in the U.S. or Canada today was an M 3.9 in northern Kansas. This event is part of a series at this unusual epicenter which began several months ago but has been quiet in recent weeks. It followed a foreshock of M 3.8 about a day earlier. That event was felt with intensity IV in Mankato, V in Jewel and III in Leavenworth, Kansas. NEIC reported it was felt with intensity IV in Kansas at Mankato, Jewell, Beloit and II-III in Randall and Salina. This follows an unusual M 3.5 in Arkansas yesterday. An event of M 3.4 near Lyons, Kansas about 125 km southwest of the Mankato event may have been felt in Wichita, Kansas. Oddly, the Lyons event and an M 3.2 near Mankato, Kansas occurred within about a minute of each other with the Lyons event a catalyst for the subsequent aftershocks in Mankato. This occurred earlier than the M 3.9 near Mankato, Kansas but after an M 3.2 foreshock of that event. The foreshock was felt with intensity III in Mankato, Kansas. A strong tornadic storm system passed through the area today and may have helped promote this event. It is likely that these events were promoted by stresses from the full moon of June 9 as noted in the previous summary:

 

 

"The most widely felt earthquake in the U.S. or Canada today was an M 3.6 in Arkansas ... High earth tides associated with the full moon may have helped promote this activity. Tides can move water around in faults, helping to lubricate them. This is especially true in the Central U.S. as evidenced by the strong seismicity patterns associated with water-injection wells." (June 12, 2017)

 

The M 3.9 and M 3.8 events today are the strongest in northern Kansas in the current string which often repeats early in the month. The last two such quakes occurred on April 4 and May 4 with M 3.4-3.5 each. The last earthquake within about 100 km of today's events with M>=3.9 was an M 4.0 on June 8, 1989 and an M 4.7 about 100 km east of Mankato on August 1, 1981. Four other earthquakes of M>=3.9 have been recorded in northern Kansas - in 1879, 1927, 1932 and 1933 with M 4.2 each. Forecasts 107912, 107914 and 108167 had expected this activity in early June. These epicenters are 102-103 degrees from the M 6.8 of May 9, 2017 in Vanuatu and may have been promoted by concentrated surface energy from that event. Seismicity at high levels also continued at this distance from Vanuatu today in Chiapas, Mexico and Guatemala and in Hindu Kush, Afghanistan. It is also at the sixth node (60 degrees) from the Near Islands earthquake of M 6.8 of June 2.

 

O: 12JUN2017 11:33:03  38.5N   98.0W mb=3.4  ANSS   NE of Lyons Kansas

O: 12JUN2017 11:32:07  39.7N   98.2W mb=3.2  ANSS   SSE of Mankato Kansas

O: 12JUN2017 11:33:03  38.5N   98.0W mb=3.4  EMSC   KANSAS                       

P:  6JUN2017 107912    38.0N   98.0W 2.0-4.0 CAAAA  Southern Plains            

 

O: 13JUN2017 09:40:37  39.7N   98.2W mb=3.9  EMSC   KANSAS                       

O: 12JUN2017 11:18:34  39.8N   98.1W mb=3.8  EMSC   KANSAS                       

P:  2JUN2017 107914    39.0N   99.0W 2.0-4.3 CAAAA  Southern Plains            

P: 17JUN2017 108167    38.0N   99.0W 2.0-3.9 BBAAA  Southern Plains            

 

MODERATELY LARGE QUAKE IN CHILE AND JAVA ACCOMPANY FULL MOON

 

EARTHQUAKE SUMMARY FOR JUNE 11, 2017

 

Seismicity moved from the Central Pacific into areas surrounding that ocean today. Moderately large earthquakes of M 5.6-5.7 hit the regions of Central Chile and Java today. This is probably promoted activity following the full moon of June 9. But the expected increase in activity in eastern Europe and the mid-east associated with the full moon has not arrived at this writing.

 

An earthquake of M 5.6-5.7 was widely felt in Central Chile today. NEIC reported it was felt with maximum intensity in Chile at Illapel, Vina del Mar, Valparaiso, and II-III in Ovalle, Calera, Sn Felipe, Quilpue, Coquimbo, La Serena, Lampa, Santiago and in general within about 300 km of the epicenter.

CNS reported it was felt with intensity V in  Calera, Salamanca, La Ligua, Quillota, Rinconada, Zapallar; IV Tiltil, Talagante, San Bernardo, El Monte, Villa Alemana, Valparaiso, Rio Hurtado, Ovalle, La Serena, Illapel; II-III in Coquimbo, Los vilos, Monte Patria, Cartagena, Casa Blanca, Melipilla, Puent Alto, Santiago, Las Cabras, Moctazal, Rancagua, Rengo, Chile. Felt in Coquimbo, Valparaiso and Santiago, Chile. This is the strongest earthquake in the Coquimbo area of Chile during 2017, surpassing an M 5.4 on April 13. The last event within about 100 km of this epicenter in Chile with M>=5.6 occurred April 18. 2016 with M 5.6. The last activity in the area with M>5.6 occurred as aftershocks up to September 22, 2016 of the great M 8.3 which struck the area within about 10 km of today's epicenter on September 16, 2017. Today's event is an aftershock of that mainshock. Forecast 108279 had expected this activity near the coast of Central Chile was likely around June 14. Like the continuing activity in Chiapas, Mexico this epicenter is located at 144-145 degrees  from the M 6.8 in Sulawesi of May 29 and was probably promoted by stress from that event.

 

O: 12JUN2017 02:43:27  31.5S   71.7W Mw=5.6  EMSC   OFFSHORE COQUIMBO, CHILE     

O: 12JUN2017 02:43     31.5S   71.7W mb=5.7  IGP    Calera, Salamanca, La Ligua, Q

P: 14JUN2017 108279    30.0S   70.0W 4.0-5.7 ABBAA  Coast Central Chile        

 

An earthquake of M 5.6 (EMSC) - M 6.3 (BMG) also occurred in Java, Indonesia about two hours before the event in Chile. NEIC reported it was felt with intensity II-III in Java at Cianjur, Ciomas, Bogor, Pameungpeuk, Bandung, Sawangan, Depok, Lembang, Cicalengka, Pamulang, Curug, and in Banten at Pasarkemis and Tangerang and in Jakarta. Felt within about 250 km of the epicenter.  BMG reported it was felt with intensity III in Bogor, II-III in Pelabuhan Ratu, Pengalengan, Lebak and I-II in Bekasi, Depok, Jakarta, Banjar, Bandung, Lembang, Cisarua and Padalarang, Java, Indonesia. A tsunami warning was issued but waves were probably to small to be significant. The last earthquake of M>=6.3 within about 200 km of this epicenter occurred on April 3, 2011 with M 6.8 but occurred about 100 east of today's epicenter. Today's event is the largest within about 100 km of the epicenter in at least 25 years. Forecast 108007 had expected a moderately large earthquake about 200 km south of Java was likely around June 11.

 

O: 11JUN2017 23:15:11   8.2S  106.4E Mw=5.6  EMSC   SOUTH OF JAVA, INDONESIA     

O: 11JUN2017 23:15:07  08.4S  106.2E MS=6.3  BMG  Felt with intensity III in Bogor, II-III in Pelabuhan Ratu, Pengalengan, Lebak and I-II in Bekasi, Depok, Jakarta, Banjar, Bandung, Lembang, Cisarua and Padalarang, Java, Indonesia.

P: 11JUN2017 108007    10.0S  106.0E 4.0-5.4 ABAAA  So. of Java                

 

Seismicity associated with high stresses related to the full moon of May 9 continued today in Turkey and eastern Europe. Turkey is especially prone to such influences as was noted when a great earthquake, the Izmit quake, of August, 1999 devastated much of the area. That quake occurred several days after the total solar eclipse was visible over the epicentral area, probably illustrating the role of tidal triggering in that event.

 

"The full moon will arrive on May 9 at 21:43 UT. Longitudinal zones which are sub-solar at this time are near 145 West  longitude while those at anti-solar locations are near 35 East longitude. These include seismic areas of eastern Europe and the mid-east while those in the west are concentrated in east and central Alaska, Hawaii and the west coast of the U.S. While tidal triggering can occur in many areas including outside these zones, tidal stresses are highest in these areas and seismicity is likely to be elevated from about June 7 and June 12, 2017." (June 7-12, 2017)

 

Samples of today's seismicity in eastern Europe follow:

 

O: 12JUN2017 00:30:43  38.8N   27.7E ML=2.0  EMSC   WESTERN TURKEY               

P: 13JUN2017 108169    39.0N   28.0E 3.5-5.1 AAAAA  Turkey                     

 

O: 12JUN2017 04:55:09  39.0N    5.1E mb=4.0  EMSC   WESTERN MEDITERRANEAN SEA    

P: 10JUN2017 107919    37.0N    5.0E 3.0-4.8 ABAAA  Western Mediterranean      

 

O: 11JUN2017 18:48:31  40.6N   27.6E ML=2.2  EMSC   WESTERN TURKEY               

P: 13JUN2017 108169    39.0N   28.0E 3.5-5.1 AAAAA  Turkey                     

P: 14JUN2017 108200    40.0N   28.0E 3.0-5.1 BAAAA  Romania/NW Turkey          

 

 

The most widely felt earthquake in the U.S. or Canada today was an M 3.6 in Arkansas near Lead Hill. NEIC reported it was also felt with intensity IV in Arkansas at (among others) Omaha, Peel, Everton, Yellville, Green Forest, Jasper, Mountain Home, Arkansas and Reeds Spring, Branson, Forsyth, Hollister, Ridgedale, Powersite,  Cedarcreek, Potem, Missouri. It was felt with intensity II-III in much of Arkansas and Missouri and within about 100 km of the epicenter.   The quake was also reported felt in Kansas, Oklahoma and Iowa. This is the strongest earthquake located in Arkansas during 2017. The last earthquake within about 200 km of this epicenter in Arkansas or surrounding area was an M 3.7 on August 16, 2003 but no earthquakes of this magnitude have occurred within about 150 km of this epicenter in the past 25 years. 

Forecast 108142 had expected this earthquake was likely about 150 km to the southeast around June 14. High earth tides associated with the full moon may have helped promote this activity. Tides can move water around in faults, helping to lubricate them. This is especially true in the Central U.S. as evidenced by the strong seismicity patterns associated with water-injection wells.

 

NEIC reported the aftershock of M 2.5 in Arkansas was felt with intensity II-III in the area(s) of Lead Hill and Harrison, and Little Rock, Arkansas; in Missouri at Protem, Blue Eye, Bradleyville, Forsyth, Niangua, and Isabella and in Memphis, Tennessee.

 

O: 11JUN2017 13:27:26  36.4N   93.0W MD=2.4  EMSC   ARKANSAS                     

O: 11JUN2017 12:40:25  36.4N   93.0W Mw=3.6  EMSC   ARKANSAS                     

O: 11JUN2017 19:26:46  36.4N   93.0W mb=2.6  EMSC   ARKANSAS                     

P: 14JUN2017 108142    35.0N   92.0W 2.0-4.3 BBAAA  New Madrid area            

 

The strongest earthquake in California today was an M 3.5 near the coast of northern California. NEIC reported it was felt with intensity II-III in California at McKinleyville, Trinidad, Arcata, Bayside, Eureka, Samoa, Hoopa, Will Creek, Kneeland, Fortuna, Hydesville, Ferndale, Crescent City, and within about 100 km of the epicenter. This is an unusual size for an earthquake near this epicenter. The last earthquake within about 50 km in northern California since an M 4.7 on July 21, 2016, a year ago and prior to that on August 4, 2013 (M 4.5). The activity in July, 2016 appears to have been related to stresses from the Ecuador M 7.9 of April 16, 2016. Forecast 107945 had expected this event offshore around June 7. Today's event is probably not an aftershock of the M 4.7 last year as no aftershocks of this size have previously occurred and this is somewhat removed from the epicenter of that event.

 

O: 11JUN2017 12:19:29  41.0N  124.1W Mw=3.5  EMSC   NORTHERN CALIFORNIA          

P:  7JUN2017 107945    40.6N  124.9W 2.5-4.8 BAAAA  Off Coast of No. Calif     

 

 

OCEAN STORMS PROMOTE SEISMICITY IN WESTERN NORTH AMERICA

 

EARTHQUAKE SUMMARY FOR JUNE 10, 2017

 

Two areas of the western boundary of the North American tectonic plate saw unusually  strong seismicity today. Earthquakes in Chiapas, Mexico up to M 5.1 and an M 4.8 in the Vancouver Island area of British Columbia, Canada. These events appear to have promoted by ocean storms. In Chiapas, Mexico, a new Tropical Depression (04E) was forming over these epicenter about the same time as the earthquakes occurred. This is the only tropical storm currently active in the world.  NHC reports this storm is located south of the Mexico-Guatemala border at this time and that there is a 30% chance it will expand into a tropical cyclone in the next two days. The other event - the M 4.8 in Vancouver, B.C. occurred as a strong ocean storm hit off the northeastern U.S. There is a long history of moderate increases in seismicity in the Vancouver area associated with strong nor'easters. This has been documented in this summary on multiple occasions.

 

The event in Vancouver Island was also probably promoted by high tidal stresses associated with yesterday's full moon. Not only does it lie near the longitude of high tidal stresses at the time of the full moon but it also occurred within minutes of local solar noon, a time of high earth tides.  This event was not reported felt in this remote area. The last earthquake in the Vancouver Island area of M>4.8 occurred on January 6, 2017 with M 5.1 and was followed on January 7 with an M 5.7. Forecast 107962 had expected today's event was likely within  about 50 km of this epicenter around June 11. This epicenter is located at 103 degrees from the M 6.8 in Sulawesi of May 29. Seismic energy, reflected from  core-mantle boundaries returns to the surface in concentrated form at this distance from large earthquakes and can help promote further seismicity.

 

O: 10JUN2017 20:38:18  50.7N  130.1W Mw=4.8  EMSC   VANCOUVER ISLAND, CANADA REGIO

O: 10JUN2017 20:38:19  50.8N  130.0W mw=4.8  ANSS   Port Hardy Canada

P: 11JUN2017 107962    50.9N  130.6W 3.0-5.3 AAAAA  British Colombia           

 

The seismicity south of Chiapas, Mexico also appears to have promoted by a combination of stresses from the forming tropical depression over these epicenters and by strong tidal stresses associated with the full moon. The sequence began with an M 5.1-5.2 at 18:47 UT. Local solar noon is about 18:15 UT. Tidal stresses are high at this hour and, as in the case in Vancouver may have helped promote this earthquake at this time. The only other events within the region of Chiapas, Mexico of M>=5.1 during the year 2017 were a series on May 30 and 31, 2017 near today's epicenters. Today's activity can be considered aftershocks of those events in May. Forecast 107821 had expected this activity was likely within about  50 km of these epicenters around June 9. 

 

NEIC reported this earthquake of M 5.1 in Chiapas, Mexico was felt with intensity II-III in the area(s) of Tapachula, Chiapas, Mexico.  This activity is located at 144 degrees from the Sulawesi quake of May 29, 2017 where reflected energy from the core concentrates at the surface. It may have been promoted by some of this energy.. These epicenters are also located at 103 degrees from the M 6.8 in Vanuatu of May 9. Seismic energy, reflected from  core-mantle boundaries returns to the surface in concentrated form at this distance from large earthquakes and can help promote further seismicity

 

O: 11JUN2017 04:04:33  15.6N   92.6W ML=4.1  UNAM  l NORESTE de MAPASTEPEC, CHIS *: 1

O: 11JUN2017 03:13:48  14.2N   93.3W ML=4.1  UNAM  al SUROESTE de CD HIDALGO, CHIS *:

O: 10JUN2017 21:23:03  14.1N   93.3W ML=5.0  UNAM  al SUROESTE de CD HIDALGO, CHIS *:

O: 10JUN2017 20:52:51  13.9N   93.4W ML=4.2  UNAM  al SUROESTE de CD HIDALGO, CHIS *:

O: 10JUN2017 20:11:44  13.9N   93.3W ML=4.2  UNAM  al SUROESTE de CD HIDALGO, CHIS *:

O: 10JUN2017 19:31:43  15.0N   92.9W ML=4.1  UNAM  l SUR de MAPASTEPEC, CHIS *: 15.06

O: 10JUN2017 19:12:56  14.1N   93.3W ML=4.2  UNAM  al SUROESTE de CD HIDALGO, CHIS *:

O: 10JUN2017 19:10:39  14.3N   93.3W ML=4.3  UNAM  al SUROESTE de HUIXTLA, CHIS *: 14

O: 10JUN2017 18:47:32  14.3N   93.5W ML=5.2  UNAM  al SUROESTE de MAPASTEPEC, CHIS *:

O: 10JUN2017 21:23:09  14.4N   92.8W mb=4.9  EMSC   OFFSHORE CHIAPAS, MEXICO     

O: 10JUN2017 18:47:35  14.4N   93.0W mb=5.1  EMSC   OFFSHORE CHIAPAS, MEXICO     

O: 11JUN2017 03:13:59  14.9N   93.2W mb=4.2  EMSC   OFFSHORE CHIAPAS, MEXICO     

P:  9JUN2017 107821    14.0N   93.0W 3.5-5.3 AAAAA  Chiapas, Mexico            

 

 

Tropical Depression 04W also formed today south of Taiwan and west of central Philippines. While this storm was forming two moderate earthquakes, possibly promoted by stresses from TD 04W occurred in Taiwan. This storm will pass north of Taiwan around June 13-14. Increased seismicity with a moderate quake likely could occur in the central Philippines and/or in Taiwan while this storm is in the area. The first storms of the new typhoon season can strongly affect seismicity in the western Pacific region. Like the events in Vancouver and Mexico the mainshock in Taiwan occurred within minutes of  local solar midnight, and was probably promoted by high tidal stresses at this time of day.

 

CWB reported the earthquake of M 4.3 was felt with intensity III in Yilan; II in Taoyuan and I in Taipei, Hualien, Hsinchu, Taichung, Miaoli and Hsinchu Counties, Taiwan.

 

O: 10JUN2017 16:46:20  24.7N  121.6E ML=4.3  EMSC   TAIWAN                       

O: 10JUN2017 16:46:20  24.7N  121.6E ML=4.3  TAI    Hualien, Taiwan              

P: 16JUN2017 108119    24.0N  123.0E 4.0-5.4 CAAAA  Taiwan                     

 

O: 10JUN2017 22:13:33  25.8N  124.9E mb=4.6  EMSC   NORTHEAST OF TAIWAN          

P:  8JUN2017 107858    26.0N  125.0E 4.0-5.5 AAAAA  Ryukyu Islands             

 

One of the strongest events in the world today was an M 5.1 in the Southern Mid-Atlantic Ridge. This occurred in a remote area and was not reported felt. It may have been promoted from the Near Island earthquake of June 2 of M 6.8 as it lies

Within several hundred km of the antipode of that event – at 54S 10W. The event in the near Islands was at 54N 170E. Forecast 108040 had expected a moderate earthquake in the southern Mid-Atlantic Ridge about 400 km northwest of this epicenter around June 8.

 

 

O: 10JUN2017 10:57:35  47.5S   13.5W mb=5.1  EMSC   SOUTHERN MID-ATLANTIC RIDGE  

P:  8JUN2017 108040    44.0S   16.0W 4.0-5.5 ACBAA  So. Mid-Atlantic Ridge     

 

 

 

UNUSUAL SEISMICITY CONTINUES IN PACIFIC AREA

 

EARTHQUAKE SUMMARY FOR JUNE 9, 2017

 

The strongest earthquake in the world today was an M 5.7 on the Pacific-Antarctic Ridge. This is a remote area and this earthquake was not reported felt and no tsunami was observed. This event continues activation of the Central Pacific which, in the past several days, has included an M 5.3 in Hawaii and an M 4.8 in the north-central Pacific. Some of this has been directed tied by this report to high tidal stresses associated with the full moon which arrived today. The epicenter of the Pacific-Antarctic event today was probably also promoted by high tidal stresses. It lies within about one degree (146W) of the longitude of greatest stress associated with the full moon and occurred within about an hour of the full moon as noted in previous issues of this report:

 

"The full moon will arrive on May 9 at 21:43 UT. Longitudinal zones which are sub-solar at this time are near 145 West  longitude while those at anti-solar locations are near 35 East longitude. These include seismic areas of eastern Europe and the mid-east while those in the west are concentrated in east and central Alaska, (Hawaii) and the west coast of the U.S. While tidal triggering can occur in many areas including outside these zones, tidal stresses are highest in these areas and seismicity is likely to be elevated from about June 7 and June 12, 2017." (June 6-9, 2017)

 

The M 5.7 in the Pacific-Antarctic Ridge is the strongest on that ridge, which extends about 2000 km east-west and north of Antarctica, during the year 2017. The last earthquake of M>=5.7 within about 300 km of this epicenter was an M 5.8

on December 22, 2014. The strongest in the area in the past 10 years was an M 6.3-6.4 on October 30, 2010. 

 

O: 10JUN2017 05:42:13  54.4S  146.7W Mw=5.7  EMSC   PACIFIC-ANTARCTIC RIDGE      

 

Near the antipode of the Pacific event, a minor series of earthquakes shook western Turkey between 21:36 and 21:46 UT at the time of the full moon and may have also been triggered by high tidal stresses. They were followed less than an hour later by an M 3.3 in Romania. But the strongest earthquake near the antipode of the Pacific-Antarctic event was an M 5.2 in the area of the Greenland Sea. This event occurred within an hour of the full moon completion, as was an M 4.9 north of Colombia and Venezuela. The Greenland Sea event followed the second strongest earthquake of the day by 17 minutes - an M 5.3 in the Solomon Islands. The distance between these two events is 109 degrees, and the Greenland Sea event may have been triggered by concentrated seismic energy, including the P- and PP-wave from the Solomon Islands. The SS-wave from the Greenland sea may have helped trigger the event in Venezuela 27 minutes later at 76 degrees distance.  These are examples of dynamic triggering from seismic waves in association with strong tidal stresses. Examples such as these are common.

 

 

Earthquakes near full moon timing:

 

O:  9JUN2017 20:49:52  79.9N    0.6E mb=5.2  ANSS   Greenland Sea"                

O:  9JUN2017 20:49:49  79.9N    0.1E mb=5.2  EMSC   GREENLAND SEA                

P:  8JUN2017 107992    74.0N   14.0E 3.0-4.6 ACAAA  Norway                     

 

O:  9JUN2017 20:32:56  10.3S  161.2E mb=5.3  EMSC   SOLOMON ISLANDS               

P: 11JUN2017 108001    10.0S  162.0E 4.0-5.4 AAAAA  No. of Santa Cruz Islands  

 

O:  9JUN2017 21:17:38  11.7N   72.0W Mw=4.7  EMSC   NEAR NORTH COAST OF COLOMBIA 

P:  4JUN2017 107837    10.0N   70.0W 3.4-5.0 BBBAA  No. Venezuela              

 

O:  9JUN2017 21:46:49  38.8N   27.9E ML=2.0  EMSC   WESTERN TURKEY               

O:  9JUN2017 21:37:53  39.2N   29.0E ML=2.1  EMSC   WESTERN TURKEY               

O:  9JUN2017 21:35:11  40.8N   27.4E ML=2.8  EMSC   WESTERN TURKEY               

P:  8JUN2017 107864    39.0N   28.0E 3.0-4.9 AAAAA  Aegean Sea                 

 

O:  9JUN2017 22:23:13  45.5N   26.4E ML=3.3  EMSC   ROMANIA                      

P:  9JUN2017 107950    41.0N   26.0E 3.0-5.4 ACAAA  Romania/NW Turkey          

 

 

MODERATE EARTHQUAKE SHAKES HAWAII WITH FULL MOON

 

EARTHQUAKE SUMMARY FOR JUNE 8, 2017

 

A moderate earthquake in Hawaii of M 5.2-5.3 shook much of the area of Hawaii today. NEIC reported this event was felt with intensity V in Pepeekeo, IV in Ookala, Pahoa, Volcano, Mountain View, Hawaii National Park, Kurtistown, Keaau, Hilo, Pahala, Papaikou, and II-III in Hakalau, Honomu, Ninole, Papaaloa, Naalehu, Laupahoehoe, Captain Cook, Holualoa, Ookala, Kealakekua, Honokaa, Kamuela, Kailua Kona, Waikoloa, Kapaau, Hawi, Kihei, Kahului, Honolulu, Waianae, and Koloa, Hawaii. News reports indicated no tsunami but shaking included rattling and swaying and many people including more than 900 who reported effects to NEIC felt the quake with moderate intensity. As this event occurred within a day of the full moon which arrives today, tidal stresses were probably promotional in setting the timing of this event as they have been over the past several months with regionally significant Hawaiian quakes.

 

Many have asked over the years how the triggering effects detailed in this summary can help identify an upcoming major regional event. The case of this event in Hawaii may shed some light on that. Three days ago on June 5 following a large earthquake in Peru, a series of light earthquakes occurred in Hawaii. This summary noted this as a possible precursor to a larger upcoming event as follows:

 

"A strong swarm followed (the Peru quake) in the next half hour in the region of Hawaii, the largest of which was M 2.5. These light earthquakes began 42 minutes after the event in Peru of M 6.0. They are located at 77 degrees from that epicenter. Surface waves from Peru arrived in Hawaii about three minutes before this swarm began and may have begun movement of magma which resulted in the first of these Hawaiian shocks. Various P-reflections and core phases from Peru arrive in Hawaii in the next 10 minutes possibly triggering more of the swarm. These include PKPPKS, PPPP, SKSPP and SKSPPP phases among others. The earthquakes in Hawaii cease with the last of these reflective phases from Peru.

Triggering at this level suggests high stresses in the area and the potential for a moderate to strong quake in the near future. Forecast 107826 had expected light to moderate activity in Hawaii in early June." (June 5-6, 2017)

 

This was followed yesterday by additional unusual activity in the north Pacific including an unprecedented M 4.8 far north of Hawaii. This summary noted:

 

 

"A pair of light earthquakes at an unusual epicenter near Hawaii today were also reported with M 3.5 and 3.3. The location of these epicenters are noteworthy and are not part of the ongoing eruptive active in Kilauea or Mauna Loa.  NEIC reported this earthquake of M 3.5 in Hawaii was felt with intensity II-III in the area(s) of Kailua Kona, Kealakekua, Waikoloa, Holualoa, and Captain Cook, Hawaii. A foreshock of M 3.3 was felt with intensity IV in Kealakekua, and II-III in Holualoa, Captain Cook, Kailua Kona and Waikoloa, Hawaii. It is not known whether these are related to the moderate earthquake of M 5.4 in the North-central Pacific. The first Hawaii event occurred 37 minutes after the event in the North Pacific, so timing is suggestive of a promotional effect. This epicenter is located about 40 km south of an M 4.5 on February 17, 2017 and near an M 4.5 on April 5, 2015, two of the largest earthquakes in Hawaii in the past several years and may be an aftershock of this activity." (June 7-8, 2017)

 

Moderate earthquakes at volcanic centers, such as today's event, can change plumbing within the volcano array leading to changes in current eruptive phases either dampening or accelerating the flow of magma. In the current situation, a pair of light earthquakes occurred in the Loihi Seamount area south of Hawaii just before the mainshock. This seamount south of Hawaii was very active about a decade ago but has been quiet for  a number of years, so even light activity there, especially in association with the strange seismicity of the past several days could be notable. A p-wave from an M 4.6 which occurred 14 minutes earlier south of Australia and arrived in Hawaii at the time of one of these events in Hawaii 96 degrees away may have helped trigger it.

 

The last earthquake of M>=5.3 located in Hawaii within about 200 km of this epicenter occurred as an M 6.5 on August 14, 2007 but the last with larger  magnitude was an M 6.1 on October 15, 2006.  Forecast 108088 and 108109 had expected this activity was likely in mid-June. Hawaii is located at 51 degrees (node 7) from the M 6.8 in Vanuatu on May 9, a month ago and activity in the region has seen an upswing since that time.

 

It is likely that high tidal stresses associated with today's full moon helped promote the M 5.3 today. At the time of the past new moon on May 27 this summary noted the strongest foreshock of the year to today's event as follow:

 

"An earthquake of M 3.7 also shook the island of Hawaii lightly today but did no reported damage. NEIC reported this earthquake of M 3.7 in Hawaii was felt with intensity I in the area(s) of Hilo, Hawaii. As the last event within Hawaii of M>=3.7 coincided with the last new moon on April 27 (M 3.7) it is likely that high tidal stresses are promoting that and today's event. The only event in the island of Hawaii this year of larger  magnitude was an M 4.3 on March 23." (May 27-28, 2017)

 

The event on April 27 had also caught the attention of this summary as:

 

"probably promoted by tidal stresses. An M 3.7 in Hawaii and a series at  Mammoth Lakes, California were also probably promoted by tidal stresses in these environments where fluids are important to local seismicity." (April 26-27, 2017)

 

The tidal effects on seismicity forecast for the full moon today had also noted that the highest tidal stresses were in the longitude zone including Hawaii.

This read:

 

"The full moon will arrive on May 9 at 21:43 UT. Longitudinal zones which are sub-solar at this time are near 145 West  longitude while those at anti-solar locations are near 35 East longitude. These include seismic areas of eastern Europe and the mid-east while those in the west are concentrated in east and central Alaska, (Hawaii) and the west coast of the U.S. While tidal triggering can occur in many areas including outside these zones, tidal stresses are highest in these areas and seismicity is likely to be elevated from about June 7 and June 12, 2017." (June 6-9, 2017)

 

 

O:  8JUN2017 11:31:00  18.8N  155.3W MD=2.1  EMSC   HAWAII REGION, HAWAII        

O:  8JUN2017 09:55:58  18.9N  155.3W MD=2.1  EMSC   HAWAII REGION, HAWAII        

P: 14JUN2017 108088    18.8N  155.2W 3.0-4.5 CAAAA  Hawaii                     

 

O:  8JUN2017 11:16:45  49.9S  126.9E mb=4.6  EMSC   WESTERN INDIAN-ANTARCTIC RIDGE

P:  5JUN2017 108041    49.0S  122.0E 4.0-5.6 BACAA  So. of Australia           

 

O:  8JUN2017 17:05:26  19.3N  155.1W MD=2.1  EMSC   ISLAND OF HAWAII, HAWAII     

O:  8JUN2017 17:55:56  19.3N  155.1W ML=2.0  EMSC   ISLAND OF HAWAII, HAWAII     

O:  8JUN2017 19:14:06  19.3N  155.1W ML=2.2  EMSC   ISLAND OF HAWAII, HAWAII     

O:  8JUN2017 17:17:46  19.3N  155.2W Md=2.4  EMSC   ISLAND OF HAWAII, HAWAII     

O:  8JUN2017 18:20:26  19.4N  155.1W Md=2.0  EMSC   ISLAND OF HAWAII, HAWAII     

O:  8JUN2017 17:14:00  19.4N  155.1W Ml=2.2  EMSC   ISLAND OF HAWAII, HAWAII     

P: 14JUN2017 108088    18.8N  155.2W 3.0-4.5 CAAAA  Hawaii                     

 

O:  8JUN2017 17:01:19  19.4N  155.1W mb=5.2  EMSC   ISLAND OF HAWAII, HAWAII     

O:  8JUN2017 17:01:19  19.4N  155.1W mb=5.3  NEIC   ISLAND OF HAWAII, HAWAII     

P: 16JUN2017 108109    20.4N  155.1W 4.0-5.6 CAAAA  Hawaii area                

 

O:  9JUN2017 03:35:39  19.4N  155.9W MD=2.2  EMSC   ISLAND OF HAWAII, HAWAII     

P: 10JUN2017 107826    19.9N  156.1W 3.0-4.4 AAAAA  Hawaii                     

 

The strongest earthquake in the world today was an M 5.5 in the northern Mariana Islands. It was not reported felt in this region but was probably felt with intensity up to IV. This is the strongest earthquake in the Pagan region, No. Mariana Islands during 2017. The last of larger magnitude than M 5.6 in the area was an M 7.7 on July 29, 2016. This is probably an aftershock of that event.    Forecast 107836 had expected a moderate to large quake in the Northern Mariana Islands was likely around June 9.

 

O:  8JUN2017 23:23:49  18.5N  146.9E Mw=5.5  EMSC   PAGAN REG., N. MARIANA ISLANDS

O: 08JUN2017 23:23:43  18.5N  147.0E mb=5.6  ANSS   Pagan Northern Mariana Islands

P:  9JUN2017 107836    16.0N  145.0E 4.0-5.6 ACBAA  No. Marianas               

 

 

UNUSUAL EARTHQUAKE IN NORTH PACIFIC

 

EARTHQUAKE SUMMARY FOR JUNE 7, 2017

 

The most unusual earthquake in the world today was an unprecedented M 4.8 in the middle of the North Pacific Ocean about 2000 km north of Hawaii and 2000 km south of Alaska. There is little tectonics in this region which would support an M 4.8 earthquake such as this. The few earthquakes in the north-central Pacific which have occurred in recent years generally were associated with unusual hurricanes which it was thought triggered them and were of lesser magnitude. No earthquakes of M>=4.8 within about 500 km of this North Pacific epicenter have ever been recorded. An event about 700 km southwest of this epicenter with M 4.9-5.0 was recorded on February 14, 1984, the only such record of a regional event of this magnitude,  making today's earthquake an unprecedented event.

The cause of this event remains an active investigation.

 

O:  7JUN2017 23:23:27  34.9N  151.8W mb=4.8  EMSC   NORTH PACIFIC OCEAN          

 

A pair of light earthquakes at an unusual epicenter near Hawaii today were also reported with M 3.5 and 3.3. The location of these epicenters are noteworthy and are not part of the ongoing eruptive active in Kilauea or Mauna Loa.  NEIC reported this earthquake of M 3.5 in Hawaii was felt with intensity II-III in the area(s) of Kailua Kona, Kealakekua, Waikoloa, Holualoa, and Captain Cook, Hawaii. A foreshock of M 3.3 was felt with intensity IV in Kealakekua, and II-III in Holualoa, Captain Cook, Kailua Kona and Waikoloa, Hawaii. It is not known whether these are related to the moderate earthquake of M 5.4 in the North-central Pacific. The first Hawaii event occurred 37 minutes after the event in the North Pacific, so timing is suggestive of a promotional effect. This epicenter is located about 40 km south of an M 4.5 on February 17, 2017 and near an M 4.5 on April 5, 2015, two of the largest earthquakes in Hawaii in the past several years and may be an aftershock of this activity. Forecast 107826 had expected this earthquake within about 25 km of today's epicenter was likely around June 10.

 

O:  7JUN2017 23:00:24  19.5N  156.0W ML=3.3  EMSC   ISLAND OF HAWAII, HAWAII     

O:  8JUN2017 03:08:30  19.7N  156.1W ML=3.5  EMSC   HAWAII REGION, HAWAII        

P: 10JUN2017 107826    19.9N  156.1W 3.0-4.4 AAAAA  Hawaii                     

 

An unusual earthquake of M 2.1 also occurred in southeastern Maine today. It was reported by the press to have been lightly felt south of Bangor but NEIC did not issue any felt reports for this event. The last event centered in Maine with M>=2.1 was an M 2.1 about 100 km east of this epicenter on January 21, 2017. The last of larger magnitude within about 100 km of this epicenter occurred as an M 3.0 on June 21, 2013. Forecast 107932 had expected this event within about 50 km of this epicenter was likely around June 7. 

 

O:  7JUN2017 10:31:21  44.6N   69.0W ML=2.1  EMSC   MAINE                        

O: 07JUN2017 10:31:20  44.6N   69.0W ml=2.1  ANSS   NNW of Swanville Maine

P:  7JUN2017 107932    44.4N   68.2W 2.0-4.1 AAAAA  Maine                      

 

The strongest earthquake in the U.S. or Canada today was another in the current series in the western Andreanof Islands, Alaska. This remote event of M 4.8 was not reported felt in the epicentral area. It is probably an aftershock of the M 6.4 which hit the area a month ago on May 8, 2017 and is the largest in the aftershock sequence since May 10 when an M 5.9 hit the region. Forecast 107959 expected today's event was likely around June 8.

 

O:  7JUN2017 16:22:23  51.5N  178.4W mb=4.8  EMSC   ANDREANOF ISLANDS, ALEUTIAN IS

P:  8JUN2017 107959    50.6N  179.2W 3.5-5.0 AAAAA  Andreanoff Isls, Aleutians 

 

The largest earthquake in the world today, like the event in the North Pacific, also occurred at high latitudes beneath an ocean. This event of M 5.1 hit the Reykjanes Ridge south of Iceland. It is located near the antipode of the M 5.7 earthquake in the Balleny Islands of June 3 and had been anticipated in this report as follows:

 

"The last earthquake in the Balleny Islands region within about 250 km of this epicenter with M>=6.0 was an M 6.2 on April 17, 2014 and prior to that on October 29, 2013 with M 6.0. As this epicenter is directly antipodal to an active seismic region of Iceland, sympathetic activity at that antipode (62N 25W) is likely in the next several days." (June 4, 2017)

 

This is a remote area and this event in the Reykjanes Ridge of the North Atlantic Rift was not reported felt. While an M 5.3 hit about 500 km south of this on  the Southern Reykjanes Ridge on March 31, 2017, the last of M >=5.1 within about 250 km of this epicenter was an M 5.2 on October 12, 2014.  Forecast 108218 had expected the northern Reykjanes Ridge would see a moderate

earthquake in mid-June.

 

O:  7JUN2017 09:06:15  57.1N   33.9W mb=5.1  EMSC   REYKJANES RIDGE              

P: 15JUN2017 108218    59.0N   31.0W 4.0-5.8 CBBAA  North Mid-Atlantic Ridge   

 

MODERATE QUAKE IN NORTHERN CHILE

 

EARTHQUAKE SUMMARY FOR JUNE 6, 2017

 

The strongest earthquake of the day was an M 5.4 in the Antofagasta region of Northern Chile. CSN reported this earthquake was felt with intensity   V in  Sierra Gorda; IV Antofagasta, San Pedro de Atacama, Calama, Mejillones, Quillagua, Tocopilla and III in Ollague and Maria Elena, Chile. Felt in Antofagasta, Chile. NEIC reported this earthquake of M 5.4 in Northern Chile was felt with intensity II-III in the area(s) of Calama, Antofagasta, Chile.  There have been no shortage of moderate to large earthquakes in the Antofagasta region of Chile in recent years. The strongest during 2017 has been an M 6.3 on  April 15 about 100 km southeast of today's epicenter. The only other event in the region with M>=5.4 however was an M 5.7 on January 11, 2017. Forecast 108016 had expected today's event within about 25 km of this epicenter was likely around June 3. As with the event in Peru yesterday of M 5.7-6.0 this earthquake occurred about 10 degrees from the geomagnetic equator to the south of it and was probably promoted by geomagnetic effects as noted in  the previous summaries:

 

"Geomagnetic effects on seismicity are expected to peak with the now-concluded storm in the first several days of June, 2017. A major earthquake at high latitudes is most likely during this period but could also occur about 10-15 degrees from the geomagnetic equator." (May 29-31, 2017)

 

O:  6JUN2017 17:35:08  23.0S   68.7W Mw=5.4  EMSC   ANTOFAGASTA, CHILE           

O:  6JUN2017 17:35     22.9S   68.9W mb=5.4  GUC    Sierra Gorda; IV Antofagasta,

P:  3JUN2017 108016    23.0S   69.0W 4.0-5.6 BAAAA  Coast No. Chile            

 

An M 3.7 earthquake occurred near Gardnerville, Nevada today and was followed by a series of aftershocks. NEIC reported the mainshock was felt with intensity II-III in Gardnerville, Markleeville, Wellington, Minden, Glenbrook, South Lake Tahoe, Carson City, and Reno, Nevada and in California at Pine Grove, Placerville, Sonora, Redding, Kyburz,  Homewood, Pioneer, Arnold, Kings Beach,  Pollock Pines, Camino, Mountain Ranch.  This is the strongest earthquake within about 100 km of this epicenter since an M 4.5 on August 4, 2016 and is the largest within about 50 km since an M 4.0 on May 30, 2014. Forecast 107866 had expected a light to moderate event was possible in this area around June 8. A series of light earthquakes throughout California followed this event and may have been promoted by energy from this earthquake.

 

O:  6JUN2017 22:51:31  38.8N  119.6W ML=2.2  EMSC   NEVADA                       

O:  6JUN2017 22:48:21  38.8N  119.6W ML=2.4  EMSC   NEVADA                       

O:  6JUN2017 22:45:25  38.8N  119.6W ML=3.7  EMSC   NEVADA                       

O: 06JUN2017 22:45:25  38.8N  119.6W ml=3.7  ANSS   Gardnerville Ranchos Nevada

O:  6JUN2017 23:18:24  38.8N  119.7W ML=2.1  EMSC   NEVADA                       

P:  8JUN2017 107866    38.0N  118.8W 2.5-4.5 AAAAA  California/Nevada area     

 

A light earthquake in Missouri, U.S. of M 2.6 was widely felt in Missouri, Illinois, Tennessee and Indiana.  NEIC reported this earthquake of M 2.6 in Missouri was felt with intensity II-III in the area(s) of Bonne Terre, Park Hills, De Soto, Bloomdale, Festus, Farmington, Cadet, Doe Run, Sainte Genevieve, Crystal City, Hillsboro, Pevely, Ironton, Potosi, High Ridge, Saint Louis, Fenton, Pacific, Sullivan, Steelville, Earth City, Saint Peters, Salem, Wentzville, Warrenton, in Tennessee at Memphis, and possibly in Indianapolis, Indiana and Buchanan, Michigan and in Illinois at Pomona, Alton, Godfrey, Hamburg, Mount Vernon, Columbia, Chester, Red Bud, Belleville. This is the largest event within about 100 km of this epicenter in southeastern Missouri near Bonne Terre during the current year, 2017. The last event in this area with M>=2.6 was an M 2.6 on September 5, 2015 but the last of larger magnitude was an M 3.9 about 50 km to the west on June 7, 2011. Forecast 107887 had expected this earthquake was likely around June 8. Earthquakes in this area typically occur in late spring and summer months.

 

O:  6JUN2017 11:29:47  38.0N   90.5W MD=2.6  EMSC   SOUTHEASTERN MISSOURI        

O: 06JUN2017 11:29:47  37.9N   90.5W md=2.6  ANSS   Bonne Terre Missouri

P:  8JUN2017 107887    37.0N   89.0W 2.0-4.1 AAAAA  New Madrid area            

P:  8JUN2017 107887    38.0N   87.0W 2.0-4.3 AABAA  New Madrid area            

 

The strongest earthquake in the U.S. or Canada today once again occurred in the Andreanof Islands, Aleutians, Alaska. This event of M 4.3 was not reported felt in this remote epicentral area. This is probably an aftershock of an M 5.8 which occurred on May 28 within about 25 km of this epicenter. Forecast 107960 had expected this activity around June 3.

 

O:  6JUN2017 12:22:30  51.8N  175.4W mb=4.3  EMSC   ANDREANOF ISLANDS, ALEUTIAN IS

P:  3JUN2017 107960    51.9N  174.0W 3.5-4.9 BAAAA  Andreanoff Isls, Aleutians 

 

MODERATELY LARGE QUAKE IN PERU FOLLOWED BY SWARM IN HAWAII

 

EARTHQUAKE SUMMARY FOR JUNE 5, 2017

 

A moderately large earthquake of M 5.6 (EMSC) - 6.0 (IGP) occurred today in northern Peru. NEIC reported it was felt with maximum intensity V in Peru at Zorritos, Tumbes, Peru; Machala, El Oro and Catamayo, Loja, Ecuador. Lesser intensity was felt with IV up to 150 km from the epicenter and reported from Ecuador at Puebloviejo, Los Rios, Santa Lucia and Eloy Alfaro, Guayas, and in Peru at Santa Rosa, Lambayeque. Lesser shaking of II-III was reported from Peru at Barranca, Las Lomaas, Mancora, Talara, Piura and Barranca, and from Ecuador at Loja, Cuenca, Guayaquil. IGP reported this earthquake was felt with intensity V in  Mancora, Zorritos, Talara; IV Paita, Sullana, Tumbes, Piura; III Chulucanas, Ayabaca, Sechura, Olmos; II San Ignacio, Jaen, Ferrenape, Chiclayo, Trujillo, Peru. Similar earthquakes in northern Peru have occurred in 2017 on January 2 (M 5.9) and April 18 (M 6.0). The strongest quake in Ecuador during 2017 to date was of M 5.4. A great quake hit Ecuador on April 16, 2016 with M 7.9. Forecast 107801 had expected today's earthquake was likely around June 2. The location of this event at about 10 degrees north of the geomagnetic equator suggests triggering was likely from geomagnetic stresses as proposed in previous issues of this summary:

 

"Geomagnetic effects on seismicity are expected to peak with the now-concluded storm in the first several days of June, 2017. A major earthquake at high latitudes is most likely during this period but could also occur about 10-15 degrees from the geomagnetic equator." (May 29-31, 2017)

 

The immediate trigger for this earthquake in Peru, however, was probably concentrated energy from the M 6.8 in the Near Islands of June 2. The distance between the Near Islands and Peru is 104 degrees, a distance at which seismic energy is concentrated at the surface following large earthquakes due to reflection and refraction off the core-mantle boundary. Earthquake  triggering at this distance from large earthquakes is common. An M 4.4 foreshock in Peru occurred on June 2, the same day as the M 6.8 in the Near Islands.

 

O:  5JUN2017 11:34      4.2S   80.6W mb=6.0  IGP    Mancora, Zorritos, Talara; IV

O:  5JUN2017 11:34:11   4.1S   80.4W Mw=5.6  EMSC   PERU-ECUADOR BORDER REGION   

O:  5JUN2017 17:39:39   4.2S   80.7W mb=4.4  EMSC   PERU-ECUADOR BORDER REGION   

P:  2JUN2017 107801     4.0S   80.0W 4.0-5.6 AAAAA  Ecuador                    

 

A strong swarm followed in the next half hour in the region of Hawaii, the largest of which was M 2.5. These light earthquakes began 42 minutes after the event in Peru of M 6.0. They are located at 77 degrees from that epicenter. Surface waves from Peru arrived in Hawaii about three minutes before this swarm began and may have begun movement of magma which resulted in the first of these Hawaiian shocks. Various P-reflections and core phases from Peru arrive in Hawaii in the next 10 minutes possibly triggering more of the swarm. These include PKPPKS, PPPP, SKSPP and SKSPPP phases among others. The earthquakes in Hawaii cease with the last of these reflective phases from Peru. Triggering at this level suggests high stresses in the area and the potential for a moderate to strong quake in the near future. Forecast 107826 had expected light to moderate activity in Hawaii in early June.

 

O:  5JUN2017 12:22:40  19.1N  155.4W MD=2.5  EMSC   ISLAND OF HAWAII, HAWAII     

O:  5JUN2017 12:19:56  19.1N  155.5W MD=2.4  EMSC   ISLAND OF HAWAII, HAWAII     

O:  5JUN2017 12:24:12  19.1N  155.5W Md=2.8  EMSC   ISLAND OF HAWAII, HAWAII     

O:  5JUN2017 12:15:40  19.2N  155.5W ML=2.3  EMSC   ISLAND OF HAWAII, HAWAII     

O:  5JUN2017 12:25:12  19.2N  155.5W ML=2.5  EMSC   ISLAND OF HAWAII, HAWAII     

P:  2JUN2017 107826    18.8N  155.2W 3.0-4.6 AAAAA  Hawaii                     

 

The strongest seismicity in the U.S. or Canada today continued in the Aleutian Islands. The largest of these were of M 4.7 in the western Fox Islands and M 4.4 in the eastern Andreanof Islands. They were not reported felt in these remote epicentral areas. The strongest earthquake this year in the Fox Islands was an

M 5.8 on May 24 but strong and moderately strong earthquakes in the Aleutians have been common in the past month and have included an M 6.8 in the Near Islands on June 2; an M 6.4 on May 8 in the western Aleutians and aftershocks of M 5.9 on May 8 and 10. This is a strong activation of the area and more strong to major quakes in the area are likely in the next month. Forecasts 107961 and 107960  had expected today's activity within about 100 km of theses epicenters around May 3-4.

 

O:  5JUN2017 11:24:34  50.4N  170.1W ML=4.0  EMSC   SOUTH OF ALEUTIAN ISLANDS    

O:  5JUN2017 07:51:06  52.3N  170.5W mb=4.7  EMSC   FOX ISLANDS, ALEUTIAN ISLANDS

P:  4JUN2017 107961    52.3N  171.3W 3.5-4.9 AAAAA  Andreanoff Isls, Aleutians 

 

O:  5JUN2017 13:43:55  52.8N  174.4W ML=4.4  EMSC   ANDREANOF ISLANDS, ALEUTIAN IS

P:  3JUN2017 107960    51.9N  174.0W 3.5-4.9 AAAAA  Andreanoff Isls, Aleutians 

 

The strongest earthquake in California today was an M 3.3 in the Geysers region of northern California. NEIC reported this earthquake of M 3.3 in the Geysers, California was felt with intensity II-III in the area(s) of Kelseyville, Middletown and Calistoga, California. The last earthquake of M>=3.3 in this area of California was an M 3.7 on April 30, 2017.  Forecast 107873 had expected this event was possible within about 5 km of this epicenter around June 4.

 

O:  6JUN2017 01:49:38  38.8N  122.8W ML=3.3  EMSC   NORTHERN CALIFORNIA          

P:  4JUN2017 107873    38.8N  122.8W 2.5-4.4 AAAAA  Central California         

 

MODERATE SHAKING IN EASTERN JAPAN

 

EARTHQUAKE SUMMARY FOR JUNE 4, 2017

 

A pair of moderate earthquakes of M 4.5 and 4.6 shook the regions east of Tokyo, Japan today.  NEIC reported the earthquake of M 4.5 in Southwestern Honshu, Japan was felt with intensity II-III in the area(s) of Chiba at Mobara, Togane, Chiba, Tomisato, Narita, Urayasu, and Matsudo; in Kanagawa at Kawasaki, Yokosuka, Yokohama; in Tokyo at Tokyo, Hachioji, Japan. NEIC reported the earthquake of M 4.6 in southeastern Honshu, Japan was felt with intensity II-III in the area(s) of Tokyo at Tokyo and Hachiogi and in Chiba at Chia, Narita and Urayasu, Japan. This is a region which, while well prepared for earthquakes, could see considerable economic and structural damage from a major quake which is expected by many geoscientists in the near term. No damage or casualties were reported with today's earthquakes. The strongest recent earthquake near these epicenters was an M 5.5 on February 19, 2017. Forecast 107893 had expected

today's activity was likely in early June. The M 4.6 occurred within minutes of local solar noon and may have been promoted by tidal and geomagnetic stresses.

 

O:  4JUN2017 00:56:13  35.3N  140.4E mb=4.5  EMSC   NEAR EAST COAST OF HONSHU, JAP

O:  4JUN2017 02:09:58  35.4N  140.7E mb=4.6  EMSC   NEAR EAST COAST OF HONSHU, JAP

P:  2JUN2017 107893    35.0N  142.0E 4.0-5.4 AAAAA  Off East Coast Honshu      

 

The strongest earthquakes in the world today also occurred in the area near Japan. These included an M 5.2 in the Iwo Jima area of the Volcano Islands in Southeastern Japan and an M 4.6-5.4 in the area north of Taiwan. The last earthquake with M>=5.5 in Taiwan was an M 5.7 on May 15, 2017. The last in the Volcano Islands of M>=5.2 in the Volcano Islands occurred on October 20, 2016 with M 5.7 but today's event is probably an aftershock of the M 6.2-6.3 of August 4, 2016. Forecasts 107861, 107602 and 107845 had expected this activity in early June.

 

CWB reported the earthquake  north of Taiwan was felt with intensity III in Yilan and Hualien Counties and II in Taipei and I in Taoyuan and Taichung Counties, Taiwan. NEIC reported this earthquake of M 4.6 in Taiwan was felt with intensity II-III in the area(s) of Sanchung, Taipei, Taiwan.

 

O:  4JUN2017 13:24:45  24.7N  122.6E mb=4.6  EMSC   TAIWAN REGION                

O:  4JUN2017 13:24:49  24.6N  122.4E ML=5.4  TAI    Hualien, Taiwan              

P: 31MAY2017 107602    24.0N  123.0E 4.0-5.4 BAAAA  Taiwan                     

P:  5JUN2017 107861    24.0N  125.0E 4.0-5.4 AABAA  Taiwan                     

P: 31MAY2017 107602    24.0N  123.0E 4.0-5.4 BAAAA  Taiwan                     

 

O:  4JUN2017 18:46:12  24.9N  141.8E mb=5.2  EMSC   VOLCANO ISLANDS, JAPAN REGION

O: 04JUN2017 18:46:12  25.0N  142.3E mb=5.2  ANSS   Iwo Jima Japan

P:  5JUN2017 107845    28.0N  140.0E 4.0-5.5 ACAAA  Bonin Islands              

 

The strongest earthquakes in the U.S. or Canada today were aftershocks in the Aleutian Islands of M 4.6 in the eastern Rat Islands and M 4.5 in the Near Islands region. These are remote islands and neither of these events were reported felt in the area. Forecasts 107974 and 107968 had expected this activity within about 100 km of these epicenters was likely in early June. The mainshock in the Near Islands occurred with M 6.8 on June 2 while an M 5.8 hit the eastern Rat Islands on April 27.

 

O:  5JUN2017 04:00:13  51.2N  179.6E mb=4.6  EMSC   RAT ISLANDS, ALEUTIAN ISLANDS

P: 10JUN2017 107974    51.0N  178.0E 4.0-5.6 BAAAA  Rat Islands                

 

O:  5JUN2017 02:05:41  53.7N  170.7E mb=4.5  EMSC   NEAR ISLANDS, ALEUTIAN ISLANDS

P:  5JUN2017 107968    53.0N  170.0E 4.0-5.8 AAAAA  Near Islands               

 

STRONG EARTHQUAKE RECORDED IN BALLENY ISLANDS

 

EARTHQUAKE SUMMARY FOR JUNE 3, 2017

 

The activation of high latitude regions continued today with an M 5.7-6.0 in the Balleny Islands region south of New Zealand and Australia. While this is a strong event it was not reported felt in this remote oceanic area. This follows the high latitude M 6.8 in the Near Islands nearly directly to the north which occurred yesterday. High latitude activation of seismicity had been expected at this time having been promoted by a major high latitude geomagnetic storm in late May as noted in previous issues of this summary:

 

"Geomagnetic effects on seismicity are expected to peak with the now-concluded storm in the first several days of June, 2017. A major earthquake at high latitudes is most likely during this period but could also occur about 10-15 degrees from the geomagnetic equator." (May 29-31, 2017)

 

The last earthquake in the Balleny Islands region within about 250 km of this

epicenter with M>=6.0 was an M 6.2 on April 17, 2014 and prior to that on October 29, 2013 with M 6.0. As this epicenter is directly antipodal to an active seismic region of Iceland, sympathetic activity at that antipode (62N 25W) is likely in the next several days.

 

O:  3JUN2017 19:17:42  62.6S  155.7E mb=5.7  EMSC   BALLENY ISLANDS REGION       

O: 03JUN2017 19:17:33  62.6S  155.8E mw=6.0  ANSS   Balleny Islands region

 

A light earthquake of M 3.5 was widely felt in the area north of Los Angeles, California today. NEIC reported intensity II-III in Johannesburg, California City, Ridgecrest, Onyx, Los Angeles, Temecula, California. The last event within about 50 km of this epicenter outside the Coso Junction region occurred on January 14, 2016 with M 3.6 and prior to that on June 14, 2015 (M 3.6) and exactly two years ago on June 4, 2015 with M 3.0. The last event in the region with M>=4 was an M 4.0 on March 15, 2014.  Forecast 107907 had expected this event about 50 km to the north of today's epicenter was likely in early June. This earthquake is at 51.5 degrees from the epicenter of the M 6.8 in the Near Islands, Alaska of June 2 at node 7 and was probably promoted by energy from that event.

 

O:  4JUN2017 00:06:56  35.4N  117.7W ML=3.5  EMSC   SOUTHERN CALIFORNIA          

P:  7JUN2017 107907    35.9N  117.8W 2.5-4.4 BAAAA  So. California             

 

The strongest earthquake in the U.S. or Canada today occurred in southern Alaska near Ninilchik where it was felt with intensity II according to NEIC. It was also felt with intensity II-III at the Kenai NTL Wildlife Ref, Soldotna, Anchor Point, Homer, Cooper Landing, Seward, Moose Pass and Anchorage, Alaska. This is the strongest earthquake within about 100 km of this epicenter in the Kenai Peninsula, Alaska since an M 4.0 on January 7, 2017.  Forecast 107982 had expected this event within about 50 km of this epicenter was likely in early June.

 

O:  3JUN2017 12:48:49  60.1N  151.1W ML=3.9  EMSC   KENAI PENINSULA, ALASKA      

P:  8JUN2017 107982    60.1N  150.6W 3.2-5.3 BAAAA  Central Alaska              

 

An unusual earthquake of M 4.8 also shook regions of Peninsular India today.

EMSC reported this earthquake of M 4.8 in Maharashtra, India was felt with intensity II-III in the area(s) of Kolhaur, Belagawi, and Dharwad, India.

This follows a felt earthquake new Delhi two days ago. These may be reactions to landfall of TC Mora as noted in previous issues of this report:

 

"TC Mora (02B) continued today in the area north of the Andaman Islands with winds up to 80 kts. It is expected to track to the north reach Pakistan around May 30. This is an area in which strong cyclones can trigger seismicity and this is only the second tropical cyclone in the area in the current season. A moderate seismic watch is therefore in effect for areas near the Nicobar and Andaman Islands, India, Myanmar and eastern Pakistan through the end of May. A moderate earthquake could occur in the area at the end of May." (May 30-31, 2017)

 

The last earthquake within about 100 km of this epicenter in southern India with M>=4.8 occurred as an M 5.1 on December 12, 2009, but activity in the  beginning portion of the 2000's in the region has largely ceased until today's event. Forecast 107819 had expected this earthquake within about 25 km of the epicenter was likely around June 7.  This earthquake is at 51.5 degrees from the epicenter of the M 6.8 in Mindanao of April 28 at node 7 and was probably promoted by energy from that event.

 

O:  3JUN2017 18:14:52  17.1N   73.8E ML=4.8  EMSC   MAHARASHTRA, INDIA           

P:  7JUN2017 107819    17.0N   74.0E 3.5-5.0 BAAAA  Arabian Sea                

 

A second unusual earthquake in Asia today occurred in the Gansu region of southern China. The only other event in Gansu with moderate magnitude during 2017 was and M 4.6 on April 10, 2017 about 700 km south of today's epicenter. The last earthquake within about 250 km of this epicenter in Gansu, China with M>=4.8  was an M 5.2 on August 13, 2016 about 150 km west of today's epicenter. The last within about 100 km of today's event was an M 4.8 on September 1, 2000.  

Forecast 107908 had expected a moderate earthquake in this area about 150 km to the west of this epicenter was likely in early June.

 

NEIC reported this earthquake of M 4.9 in China was felt with intensity II-III in the area(s) of Xining, Qinghai; Lanzhou, Gansu and Yinchuan, Ningxia, China.

 

O:  3JUN2017 10:11:10  38.1N  103.4E mb=4.8  EMSC   GANSU, CHINA                 

P:  9JUN2017 107908    38.0N  101.0E 3.5-4.9 CABAA  So. China                  

 

 

STRONG QUAKE HITS NEAR ISLANDS, THEN NEW GUINEA

 

EARTHQUAKE SUMMARY FOR JUNE 2, 2017

 

A strong earthquake of M 6.8 occurred today at the westernmost point in the U.S, the Near Islands. These events occurred near local solar noon and were probably promoted by high tidal stresses at this hour and by the strong geomagnetic storm of late May. This summary had expected strong seismic event(s) at high latitude and near the geomagnetic equator were likely in early June based on geomagnetic effects as follows:

 

"Geomagnetic effects on seismicity are expected to peak with the now-concluded storm in the first several days of June, 2017. A major earthquake at high latitudes is most likely during this period but could also occur about 10-15 degrees from the geomagnetic equator." (May 29-31, 2017)

 

The M 6.8 was not reported felt nor were any of the aftershocks of M 4.0-5.5. An M 6.2 hit in the Near Islands region about 100 km east of today's activity on March 27 and this may be regional aftershock activity from that event. The last

Near Islands within about 200 km of this epicenter with M>=6.8 was an M 7.1 on November 6, 1990 more than 25 years ago. Forecast 107968 had expected today's event was possible around June 5 within about 100 km of this epicenter. This epicenter is 60 degrees from the M 6.8 in Mindanao or April 28 (node 6) and may have been promoted from that source.  Southern California lies at the seventh node (51.4) degrees from the Near Islands with the Simi Valley near that exact distance. Some triggering is this area is likely in the next few days.

 

O:  2JUN2017 23:01:55  53.3N  170.3E mb=4.5  EMSC   NEAR ISLANDS, ALEUTIAN ISLANDS

O:  3JUN2017 05:45:07  53.7N  170.3E mb=4.3  EMSC   NEAR ISLANDS, ALEUTIAN ISLANDS

O:  3JUN2017 01:28:32  53.8N  171.0E mb=4.2  EMSC   NEAR ISLANDS, ALEUTIAN ISLANDS

O:  2JUN2017 22:32:36  54.0N  170.9E mb=5.2  EMSC   NEAR ISLANDS, ALEUTIAN ISLANDS

O:  2JUN2017 22:24:49  54.0N  170.9E Mw=6.8  EMSC   NEAR ISLANDS, ALEUTIAN ISLANDS

O: 02JUN2017 22:24:48  54.1N  170.9E mw=6.8  ANSS   Attu Station Alaska

P:  5JUN2017 107968    53.0N  170.0E 4.0-5.8 AAAAA  Near Islands               

 

The strongest felt earthquake in the world today was an M 5.9-6.0 in Papua New Guinea. NEIC reported it was felt with maximum intensity VI in the area of Goroka, Eastern Highlands, PNG. Intensity V was reported from Mount Hagen, Western Highlands; Wabag, Enga; and Kainantu, Eastern Highlands. Lesser shaking of II-III was felt in Lae, Morobe and Madang, Papua New Guinea. This event occurred about 80 minutes after the Near Islands earthquake at a distance near the sixth node (60 degrees) from that event. It may have been promoted by seismic energy from the Near Islands, but was also probably promoted by the geomagnetic storm of late May as it lies about 15 degrees south of the local geomagnetic equator. The last earthquake of M>5.9 within about 200 km of this epicenter occurred on April 1, 2016 with M 6.1 and prior to that an M 6.2 on August 19, 2012.  Forecast 107806 had expected this event within about 100 km of this epicenter was likely as a possibly large event around June 4.

 

O:  2JUN2017 23:48:17   4.7S  145.1E Mw=5.7  EMSC   NEAR N COAST OF NEW GUINEA, PN

O: 02JUN2017 23:48:17   4.7S  145.1E mb=5.9  ANSS   Madang Papua New Guinea

P:  4JUN2017 107806     4.0S  145.0E 4.0-6.1 AAAAA  New Ireland                

 

An unusual earthquake of M 3.5 was widely felt in Ohio, U.S. today. NEIC reported the event was felt with maximum intensity IV in Ohio at Lewisville, Quaker City, Byesville, and II-III in Senecaville, Salesville, Barnesville, Sarahsville, Caldwell, Cambridge, Cumberland, Norwich, Beverly, Lowell, Marietta, Little Hocking and Warren and in Evans City, Pennyslvania and Louisville, Kentucky and in general within about 50 km of the epicenter.

This is the second earthquake to be felt in Ohio in the past week, An M 3.4 occurred about 150 km southwest of this on May 24. The last earthquake in Ohio within about 150 km of this epicenter occurred on November 20, 2013 with M 3.5. The only such earthquake in Ohio in the past 25 years of larger magnitude was an M 3.6 on February 19, 1995 about 250 km southwest of today's epicenter.  Forecasts 107947 and 107684 had expected this event about 100 km to the north  in late May or early June, 2017.

 

 

O:  3JUN2017 03:08:41  39.9N   81.3W ML=3.5  EMSC   OHIO                         

P:  2JUN2017 107947    41.8N   81.4W 2.0-3.9 ABAAA  Ohio/Lake Erie             

P: 29MAY2017 107684    41.0N   81.0W 2.0-4.3 BBAAA  Ohio/Lake Erie             

 

This followed an M 2.6 south of this in the region of Alabama earlier in the day. That event was reported felt with intensity II-III in Georgia at Lookout Mountain, Atlanta and Bishop and in Columbia, Tennessee. The most recent earthquake in Alabama was an M 2.4 west of this on May 19. The last event within about 100 km of this epicenter was an M 2.6 on October 30, 2016. Forecast 107882 had expected a light quake in the region was likely in early June.

 

O:  2JUN2017 14:08:35  34.4N   85.6W MD=2.6  EMSC   ALABAMA                      

O: 02JUN2017 14:08:35  34.4N   85.6W md=2.6  ANSS   Fort Payne Alabama

P:  6JUN2017 107882    35.0N   82.0W 2.0-4.3 BABAA  Kentucky/Tennessee/NC      

 

The strongest earthquake reported in California today was an M 3.3 in the Mount Shasta area. As this epicenter is located at 43 degrees from the Near Island earthquake and the purported quake occurred 8 minutes after that event, just as the P-waves was arriving, it is either a ghost event or a triggered earthquake.

A ghost event is output by an automatic location algorithm mistaking a teleseismic wave arrival for a local event. As the event in this area was not reported felt it is likely a non-occurrence. It is of some interest that the California press uses an automatic robot to send press releases about regional earthquakes and this event was reported by this robot. Perhaps a human cog is not unwarranted in this system.

 

O:  2JUN2017 22:32:56  41.4N  122.2W ML=3.3  EMSC   MOUNT SHASTA AREA, CALIFORNIA

P:  2JUN2017 107944    40.7N  122.3W 2.5-4.4 AAAAA  Northern California        

 

MODERATE NORTHERN INDIA QUAKE LIKELY ASSOCIATED WITH TC MORA

 

EARTHQUAKE SUMMARY FOR JUNE 1, 2017

 

The most widely felt earthquake in the world today was an M 4.7 in the area of Haryana, India. NEIC reported maximum intensity V in Haryana at Rohtak, and Ghrauda and IV in Kharkhoda, Gohana, Sonipat, Bahadurgarh, Sultanpur Maira, Jhajjar and Karnal; in Chandigarh, Hapar, Muradmagar, Noida,  Uttar Pradesh, in Tigri, Ni Dilli, Babarpur, Delhi, Bhalswa Jahangirpur, Delhi. Intensity II-III was reported from Haryana at Faridabad, Sohna, Sirsa, Panchkula, Gurgaon, Panipat, Roshan Pura, Gokalpur, Dilli Cantonment, Gharonda, Deoli,   Delhi, Loni, Shamli, Ghaziabad, Dankaur, Uttar Pradesh, and at Naraina, Rajasthan and within about 300 km of the epicenter. An earthquake of M 5.6 hit about 300 km northeast of this event on February 6, 2017 and an M 5.1 about 500 km north on April 18, but this is the strongest event in the region since an M 5.1 on March 5, 2012 and an M 4.7 on November 25, 2007. Forecast 107659 had expected this area could see a moderate earthquake around May 27. The occurrence of this event at this time may be related to stresses associated with Tropical Cyclone Mora which dissipated south of this epicenter over the past several days. This summary had expected seismic activity associated with this cyclone as:

 

 

"TC Mora (02B) continued today in the area north of the Andaman Islands with winds up to 80 kts. It is expected to track to the north reach Pakistan around May 30. This is an area in which strong cyclones can trigger seismicity and this is only the second tropical cyclone in the area in the current season. A moderate seismic watch is therefore in effect for areas near the Nicobar and Andaman Islands, India, Myanmar and eastern Pakistan through the end of May. A moderate earthquake could occur in the area at the end of May." (May 30-31, 2017)

 

This epicenter in India is located at 51.6 degrees from the M 6.8 in Sulawesi of May 29, 2017 and at 51.3 degrees from the Mindanao, Philippines M 6.8 of April 28. This is the seventh node from that event where surface earthquakes are often triggered by seismic energy from the mainshocks. Constructive interference of energy from several events increases the likelihood and magnitude of possible triggered seismicity.

 

O:  1JUN2017 22:55:54  29.0N   76.8E mb=4.7  EMSC   HARYANA - DELHI REGION, INDIA

O: 01JUN2017 22:55:55  29.0N   76.8E mb=4.7  ANSS   NNW of Kharkhauda India

P: 27MAY2017 107659    30.0N   80.0E 3.8-5.4 BABAA  Xizang                     

 

A light earthquake of M 3.0 was felt widely in the region of Salem, Oregon today. NEIC reported it was felt with intensity II-III in Salem, Rickereall, Dayton, McMinnville, Dallas, Hubbard, Carlton, Colton, Beaverton, Lake Oswego, Corvallis, Portland, Molalla, Eugene and La Pine and possibly in Vancouver, Washington. The last earthquake of M>=3.0 within about 100 km of this epicenter in Oregon occurred on June 25, 2015 with M 3.6.  Forecast 107948 had expected this event within this region was likely around  June 4.

 

O:  1JUN2017 16:02:57  45.1N  123.1W ML=3.0  EMSC   OREGON                       

P:  4JUN2017 107948    45.3N  121.7W 2.0-4.1 BAAAA  Oregon state, U.S.         

 

The strongest earthquake in the U.S. or Canada today was an M 3.8 in northern Alaska. It was not reported felt in this remote area in north-western Alaska. The last earthquake within about 200 km of this epicenter in Alaska was an M 4.5 on July 9, 2016 and prior to that an M 4.8 on May 21, 2011.

 

O:  1JUN2017 20:03:36  65.5N  166.7W ml=3.8  ANSS   Alaska                       

 

The strongest earthquake in North America today was an M 4.6 in the Gulf of California near Jose del Cabo, Mexico. It was not reported felt in this region. A similar pair of quakes in the region occurred on May 18, 2017, each with M 4.6. The only event this year of larger magnitude in the Gulf of California was an M 5.2 on March 29 about 200 km northwest of today's epicenter.  Forecast 107847 had expected this event in early June within about 10 km of this epicenter.

 

O:  2JUN2017 03:02:43  23.8N  108.9W mb=4.6  EMSC   GULF OF CALIFORNIA           

O: 02JUN2017 03:02:44  23.9N  109.0W mb=4.6  ANSS   Jose del Cabo Mexico

P:  6JUN2017 107847    24.0N  109.0W 3.5-5.1 BAAAA  Gulf of California         

 

MODERATE SHAKING IN SVALBARD AND CHILE

 

EARTHQUAKE SUMMARY FOR MAY 31, 2017

 

The strongest earthquakes in the world today barely reached M 5.0 returning a very quiet day in global seismicity. The strongest event was an M 5.0 in  the Svalbard region north of Norway. The Svalbard region is remote and there were no reports this event was felt in the area. Three moderate earthquakes of M 4.5-4.7 have been recorded in Svalbard in the current years, 2017. All occurred in May with the latest an M 4.7 about 1000 km northwest of today's epicenter on May 26. The last event within about 500 km of today's epicenter with M>=5 was an M 5.0 on March 29, 2016 and prior to that an M 5.0 on June 9, 2015. The last of larger magnitude occurred as an M 6.4 on January 11, 2015. Forecast 107992 had expected today's event was possible in early June about 300 km south of this epicenter.

 

O: 31MAY2017 13:59:11  77.1N   15.9E ML=5.0  EMSC   SVALBARD REGION              

O: 31MAY2017 13:59:13  77.0N   15.8E mb=5.0  ANSS   Svalbard and Jan Mayen

P:  8JUN2017 107992    74.0N   14.0E 3.0-4.6 CCAAA  Norway                     

 

A second event of M 5.0 occurred in the Antofagasta, Chile area today. NEIC reported this earthquake of M 4.9 in Northern Chile was felt with intensity II-III in the area(s) of Antofagasta, Chile. It is probably an aftershock of an M 6.3 which occurred April 15, 2017, the last event of M>=5 in the area. Forecast 108016 had expected this event was likely around June 3 within about 50 km of this epicenter.

 

O: 31MAY2017 17:38:51  22.8S   68.5W Mw=5.0  EMSC   ANTOFAGASTA, CHILE           

P:  3JUN2017 108016    23.0S   69.0W 4.0-5.6 BAAAA  Coast No. Chile            

 

The strongest seismicity in the western hemisphere over the past couple of days has been occurring in the region of Oaxaca and Chiapas, Mexico. Two events of M 5.3 and a series of moderate, smaller aftershocks have hit this area.  In the previous issue of this summary it was noted in this regard:

 

"The strongest earthquakes of the day felt outside Indonesia were a pair of events of M 5.3-5.4 south of Chiapas, Mexico. A strong weather system which can grow into a tropical storm according to NHC is in the vicinity of this seismic activity and may be promoting some of these events. The moderate activity in this region began about the same time that this storm which is stationary appeared in the region according to the NHC website.  They were reported by NEIC to have been felt with intensity II in Tuxtla Gutierrez, Chiapas, Mexico.

The only larger event in the year 2017 than M 5.3 occurred on March 31 with M 5.4. Forecast 107565 had expected today's activity was likely within about 50 km of these epicenters around May 29. These events are located at 144 degrees

from the earthquake in Sulawesi yesterday. Seismic energy is concentrated

at the surface after reflecting off core boundaries and often helps promote

additional seismicity at this distance. A similar M 5.7 in central Chile yesterday was probably also promoted at this distance from Sulawesi." (May 31, 2017)

 

The storm system referred to in this previous issue grew into a Tropical Depression today.  TD 02E formed today in the area south of Oaxaca, Mexico with winds up to 40 kts. It is expected to track to the north making landfall June 1 near Punta Escondido, Mexico. Strong cyclones can trigger seismicity and this is only the second tropical cyclone in the area in the current season. A moderate seismic watch is therefore in effect for areas of eastern Mexico in Oaxaca and Chiapas which is currently at high seismic levels as this system has lingered offshore to the south.

 

O: 31MAY2017 07:43:47  14.0N   93.2W ML=4.0  UNAM  al SUROESTE de CD HIDALGO, CHIS *:

O: 31MAY2017 07:20:43  14.0N   93.2W ML=4.2  UNAM  al SUROESTE de CD HIDALGO, CHIS *:

O:  1JUN2017 04:44:21  13.9N   92.6W ML=4.1  UNAM  l SUROESTE de CD HIDALGO, CHIS

P: 29MAY2017 107565    14.0N   93.0W 3.5-5.1 AAAAA  Chiapas, Mexico            

 

The strongest earthquake in the U.S. or Canada today was an M 4.7 in the eastern Andreanof Islands. This is a remote area and it was not reported felt in the area. The last earthquake of M>=4.7 within about 100 km of this epicenter with M>=4.7 was an M 4.9 on March 1, 2017. More recently an M 5.3 on November 23, 2016 and prior to that an M 4.9 about 50 km  west of today's epicenter on November 14, 2016, the last such event since December, 2015.  Forecast 107960 had expected this event within this area was likely at the beginning of June, 2017.

 

O: 31MAY2017 08:13:34  51.8N  175.3W mb=4.7  EMSC   ANDREANOF ISLANDS, ALEUTIAN IS

O: 31MAY2017 20:35:33  52.2N  174.0W Ml=3.1  EMSC   ANDREANOF ISLANDS, ALEUTIAN IS

P:  3JUN2017 107960    51.9N  174.0W 3.5-4.9 BAAAA  Andreanoff Isls, Aleutians 

 

An earthquake of M 2.8 in southern California was the strongest of the day in the region of the western U.S.  NEIC reported this earthquake of M 2.8 in  Southern California was felt with intensity II-III in the area(s) of Colton, Redlands, Moreno Valley, San Bernardino, Riverside, Bloomington, Fontana, Rancho Cucamonga, Norco, Lake Elsinore, San Dimas and Los Angeles, California.

It is the strongest within about 50 km of this epicenter since an M 3.1 on April 30. 2017. Forecast 107902 had expected it within about 25 km of the epicenter around June 2.

 

O: 31MAY2017 14:55:22  34.0N  117.2W ML=2.8  EMSC   GREATER LOS ANGELES AREA, CALI

P:  2JUN2017 107902    33.9N  116.9W 2.5-4.4 AAAAA  So. California             

 

OTHER GLOBAL EARTHQUAKE ACTIVITY

 

For most events there are two listings. The first line is the observed event starting with "O:" for Observed. There follows the date, month and year, the time in UT hours:minutes:seconds, the latitude and longitude, the given magnitude and the reporting agency followed by the geographic location. The second line starts with "P:" This is the forecast event as forecast in our summaries normally more than a month in advance. Magnitudes may vary in response to updated seismic watches and daily variations due to tidal and other influences. This line has the forecast date, month and year, the forecast number, latitude, longitude and forecast magnitude range.  This is followed by a comparison between the forecast and the event. The comparison includes letters A-D. The first is number of days difference from predicted (A:up to 2, B3-5; C:6-10; D:more than 10), Difference in latitude (A:up to 1 degree; B:1-2 degrees; C:2-4 degrees; D:more than 4 degrees); longitude (same comparison as with latitude); magnitude (A: within forecast range; B: higher than forecast range; C: lower than forecast range; D: no comparison possible). The last letter is a stand in for a future comparison which needs to be done statistically after a large number of forecasts have been made. In previous data, an excellent match is generally AAAAA; a good match as one or two B's; a fair match has several B's and C's and a poor match is one which contains a number of C's or D's. 

 

ASIA

 

O: 31MAY2017 23:47:41  25.0N  121.8E ML=4.5  TAI    Hualien, Taiwan              

P: 31MAY2017 107602    24.0N  123.0E 4.0-5.4 AAAAA  Taiwan                     

 

CWB reported this earthquake was felt with intensity I in Taipei, Yilan and Hualien Counties, Taiwan.

 

O: 31MAY2017 07:52:01  46.2N  142.3E mb=4.7  EMSC   SAKHALIN, RUSSIA             

P: 30MAY2017 107690    45.0N  146.0E 3.5-5.5 ABCAA  So. Kurils                 

 

No significant (M>=5) or unusual earthquakes were reported in Asia today.

 

INDONESIA AND PHILIPPINES

 

O: 31MAY2017 21:16:57   2.7N  128.6E mb=4.7  EMSC   HALMAHERA, INDONESIA         

P:  4JUN2017 107790     2.0N  127.0E 4.0-5.6 BABAA  Halmahera                   

P: 29MAY2017 107538     4.0N  127.0E 4.0-5.7 ABBAA  Halmahera                  

 

CENTRAL AND SOUTH AMERICA

 

O: 31MAY2017 19:50     18.1S   69.8W mb=4.0  IGP    E of Calana-Tacna, Peru.     

P:  4JUN2017 108006    18.0S   71.0W 4.0-5.8 BAAAA  So. Peru/Bolivia           

 

O: 31MAY2017 21:14:42  12.1N   73.8W mb=4.4  EMSC   CARIBBEAN SEA                

O: 31MAY2017 21:14:42  12.1N   73.8W mb=4.4  ANSS   Santa Marta Colombia

P: 24MAY2017 107582    12.0N   71.0W 3.5-5.1 CABAA  Northern Venezuela          

 

O: 31MAY2017 17:38:51  22.8S   68.5W Mw=5.0  EMSC   ANTOFAGASTA, CHILE           

P:  3JUN2017 108016    23.0S   69.0W 4.0-5.6 BAAAA  Coast No. Chile            

 

O: 31MAY2017 07:43:47  14.0N   93.2W ML=4.0  UNAM  al SUROESTE de CD HIDALGO, CHIS *:

O: 31MAY2017 07:20:43  14.0N   93.2W ML=4.2  UNAM  al SUROESTE de CD HIDALGO, CHIS *:

O:  1JUN2017 04:44:21  13.9N   92.6W ML=4.1  UNAM  l SUROESTE de CD HIDALGO, CHIS

P: 29MAY2017 107565    14.0N   93.0W 3.5-5.1 AAAAA  Chiapas, Mexico            

 

O: 31MAY2017 06:03:57  17.6N   95.7W ML=4.0  UNAM  l SUROESTE de ISLA, VER *: 17.6

P:  2JUN2017 107821    17.0N   94.0W 3.5-5.2 AABAA  Chiapas, Mexico            

 

No significant (M>=5) or unusual earthquakes were reported in Central or South America today.

 

AFRICA AND EUROPE

 

O: 31MAY2017 20:25:25  51.6N   16.2E ML=4.2  EMSC   POLAND                       

P:  3JUN2017 107972    51.0N   16.0E 3.0-4.6 BAAAA  Poland                     

 

NEIC reported this earthquake of M 4.2 in Poland was felt with intensity II-III in the area(s) of Glogow, Poland.

 

O: 31MAY2017 13:59:11  77.1N   15.9E ML=5.0  EMSC   SVALBARD REGION              

O: 31MAY2017 13:59:13  77.0N   15.8E mb=5.0  ANSS   Svalbard and Jan Mayen

P:  8JUN2017 107992    74.0N   14.0E 3.0-4.6 CCAAA  Norway                     

 

SOUTHWEST PACIFIC

 

No significant (M>=5) or unusual earthquakes were reported in the Southwest Pacific region today.

 

OCEAN RIDGES

 

No significant (M>=5) or unusual earthquakes were reported on Ocean Ridges today.

 

 

ZEALANDIA AND AUSTRALIA REGION

 

O:  1JUN2017 05:50:45  30.4S  179.1W mb=4.5  EMSC   KERMADEC ISLANDS REGION      

P: 25MAY2017 107763    30.0S  177.0W 4.0-5.4 CABAA  No. Kermadec Islands       

 

JAPAN AND KURIL ISLANDS

 

No earthquakes of M>=4 were located in Japan or the Kuril Islands today.

 

U.S./CANADA*

 

WESTERN U.S./CANADA

 

CALIFORNIA

 

O: 31MAY2017 14:55:22  34.0N  117.2W ML=2.8  EMSC   GREATER LOS ANGELES AREA, CALI

P:  2JUN2017 107902    33.9N  116.9W 2.5-4.4 AAAAA  So. California             

 

O: 31MAY2017 21:25:10  34.0N  117.6W Ml=2.0  EMSC   GREATER LOS ANGELES AREA, CALI

P:  1JUN2017 107905    33.8N  117.7W 2.5-4.4 AAAAA  So. California             

P: 29MAY2017 107640    33.8N  117.7W 2.5-4.6 AAAAA  So. California             

 

O: 31MAY2017 21:18:47  34.2N  116.8W ML=2.1  EMSC   SOUTHERN CALIFORNIA          

P:  1JUN2017 107906    34.6N  116.7W 2.5-4.6 AAAAA  So. California             

P: 29MAY2017 107641    33.9N  116.9W 2.5-4.5 AAAAA  So. California             

 

O: 31MAY2017 21:17:07  38.9N  123.0W MD=2.1  EMSC   NORTHERN CALIFORNIA          

P: 30MAY2017 107614    39.3N  123.2W 2.5-4.4 AAAAA  Central California         

 

ALASKA

 

O: 31MAY2017 08:13:34  51.8N  175.3W mb=4.7  EMSC   ANDREANOF ISLANDS, ALEUTIAN IS

O: 31MAY2017 20:35:33  52.2N  174.0W Ml=3.1  EMSC   ANDREANOF ISLANDS, ALEUTIAN IS

P:  3JUN2017 107960    51.9N  174.0W 3.5-4.9 BAAAA  Andreanoff Isls, Aleutians 

 

O: 31MAY2017 09:15:06  58.3N  154.4W Ml=3.1  EMSC   ALASKA PENINSULA             

P:  7JUN2017 107982    60.0N  153.5W 3.2-4.9 CBAAA  Central Alaska             

 

O: 31MAY2017 19:17:46  59.8N  136.8W ML=3.0  NRCA  113 km SE  of Haines Jct.     

P:  4JUN2017 107981    60.0N  137.0W 3.2-4.9 BAAAA  Central Alaska             

 

PACIFIC NORTHWESTERN U.S./WESTERN CANADA

 

O: 31MAY2017 22:47:11  48.5N  123.4W ML=2.1  EMSC   VANCOUVER ISLAND, CANADA REGIO

O: 31MAY2017 22:47:11  48.5N  123.4W ml=2.1  ANSS   NNW of Victoria Canada

P: 31MAY2017 107694    49.0N  123.0W 2.0-3.9 AAAAA  Washington state, U.S.     

 

ROCKY MOUNTAINS REGION

 

O: 31MAY2017 10:20:04  42.4N  111.6W ML=2.1  EMSC   SOUTHERN IDAHO               

P:  3JUN2017 107957    43.0N  111.5W 2.0-4.0 BAAAA  Yellowstone/Wyoming        

 

EASTERN U.S./CANADA

 

O:  1JUN2017 03:57:55  35.3N   97.8W mb=2.8  EMSC   OKLAHOMA                      

P:  2JUN2017 107913    35.0N   97.0W 2.0-4.2 AAAAA  Southern Plains            

 

NEIC reported this earthquake of M 2.8 in Oklahoma was felt with intensity IV in Tuttle, Oklahoma and II-III in the area(s) of Mustang, Oklahoma. The event of M 3.4 early in the day was felt with intensity II in Morrison and Mannford, Oklahoma. 

 

O: 31MAY2017 13:11:01  36.3N   97.5W mb=2.9  EMSC   OKLAHOMA                     

O: 31MAY2017 12:52:41  36.3N   97.5W mb=3.0  EMSC   OKLAHOMA                      

O: 31MAY2017 07:03:48  36.4N   96.8W mb=3.4  EMSC   OKLAHOMA                     

O: 31MAY2017 23:20:52  36.4N   98.8W mb=2.9  EMSC   OKLAHOMA                     

P:  2JUN2017 107912    37.0N   98.0W 2.0-3.9 AAAAA  Southern Plains            

 

O: 31MAY2017 09:45:16  38.2N   88.0W MD=2.2  EMSC   ILLINOIS                     

O: 31MAY2017 09:45:16  38.2N   88.0W md=2.2  ANSS   S of Grayville Illinois

P:  8JUN2017 107887    38.0N   87.0W 2.0-4.3 CAAAA  New Madrid area            

 

HAWAII

 

No earthquakes of M>=3 were located in Hawaii.

 

SULAWESI QUAKE CAUSES INJURIES, DAMAGE

 

EARTHQUAKE SUMMARY FOR MAY 30, 2017

 

Reports from Sulawesi where an M 6.8 occurred yesterday indicate that at least three people were injured and a number of buildings damaged in that earthquake.

There were no immediate reports of deaths and a tsunami was not generated according to local sources. Aftershocks continued in the region today with moderate magnitude. BMG reported the mainshock was felt with intensity V in Poso, Toroe; III-IV in Palu, Toli toli, III in Pasang Kayu, Tana Toraja, and II-III in Palopo, Masamba, Valikpapan, Gorontalo, Bone Bolango and Soroako, Sulawesi, Indonesia. Aftershocks were felt with intensity I-II in Dolo, and in Palu, Sulawesi, Indonesia. As reported in the previous summary:

 

"An M 5.6 quake hit Sulawesi on May 24 southeast of today's epicenter but the last earthquake within about 250 km of this epicenter with M>=6.8 was an M 7.9 on January 1, 1996 followed by the only other such event in the past 25 years - an aftershock of M 7.0 on July 22, 1996. These events occurred about 250 km north of today's epicenter. Data from BMG was not immediately available.  

Forecasts 107531 and 107560 had expected today's event in Sulawesi was likely at the end of May." (May 29-30, 2017)

 

O: 29MAY2017 13:35:22  01.3S  120.4E MS=6.6  BMG  Felt with intensity V

O: 30MAY2017 06:49:47  01.1S  120.1E MS=4.4  BMG  Felt with intensity I-II

O: 30MAY2017 12:02:00  01.3S  120.5E MS=4.9  BMG  Felt with intensity I-II

O: 30MAY2017 07:49:47   1.1S  120.1E ML=4.4  EMSC   SULAWESI, INDONESIA          

O: 31MAY2017 02:59:22   1.1S  120.6E ML=4.5  EMSC   SULAWESI, INDONESIA

O: 31MAY2017 04:42:05   1.1S  120.6E ML=4.9  EMSC   SULAWESI, INDONESIA

O: 30MAY2017 13:01:57   1.2S  120.6E mb=4.9  EMSC   SULAWESI, INDONESIA           

O: 30MAY2017 09:15:13   1.4S  120.5E mb=4.9  EMSC   SULAWESI, INDONESIA          

P: 25MAY2017 107531     0.0N  120.0E 4.0-5.4 BBAAA  Celebes Sea                

 

A moderate regional earthquake in Indonesia also occurred in southern Sumatra today and was probably promoted by the M 6.8 in Sulawesi. BMG reported this earthquake was felt with intensity III-IV in Lepahiang and I-II in Liwa, Sumatra, Indonesia. The antipode of this is in Colombia at 6N 77W. This is an active region and triggering of seismicity in this area of Colombia is common following large earthquakes near the antipode in Sumatra. Such a moderate Colombian quake is likely in the next four days.

 

 

O: 30MAY2017 08:28:21   5.4S  102.8E mb=5.3  EMSC   SOUTHERN SUMATRA, INDONESIA  

O: 30MAY2017 08:28:16  05.6S  102.7E MS=5.5  BMG  Felt with intensity III-IV

P: 29MAY2017 107558     6.0S  104.0E 4.0-5.4 AAAAA  So. of Sumatera            

 

The strongest earthquake of the day in the world was an unfelt event of M 5.7 in the remote South Sandwich Islands. Few moderate or large quakes are felt in this region. This is probably a regional aftershock of an M 6.4 of May 10, 2017, but at 200 km south of that epicenter could be an unrelated mainshock. The timing and nearness to the new moon suggest tidal stresses could have helped promote this high latitude earthquake at this time. Geomagnetic stresses from the  recent high latitude geomagnetic storm, the strongest in eight months could also have played a role in triggering this South Sandwich Islands event at this time. The last earthquake within about 200 km of this epicenter in the southern South Sandwich Islands occurred as an M 5.8 on August 2, 2016 and prior to that on August 26, 2015. The last of significantly larger magnitude was an M 6.0 on March 19, 2013.

Forecast 107778 had expected this event within about 60 km of the epicenter was likely in late May, 2017.

 

O: 30MAY2017 11:29:51  58.7S   26.1W Mw=5.7  EMSC   SOUTH SANDWICH ISLANDS REGION

P: 24MAY2017 107778    58.0S   26.0W 4.0-5.8 CAAAA  So. Sandwich Islands       

 

The strongest earthquakes in the U.S. or Canada today were two M 3.8 events in the region near Perry, Oklahoma. This area often becomes active with high tidal stresses associated with the new moon. NEIC reported today's events were felt with intensity II-III in Oklahoma at Covington, Enid, Garber, Hennessey, Stillwater and Tulsa and in Kansas at Clearwater and Wichita. The last earthquake in Oklahoma of M>=3.8 was an M 4.2 on May 13. Three other events of this magnitude level occurred during 2017 - of M 4.1 on March 29; M 4.0 on March 25 and M 3.9 on April 9, 2017. Forecasts 107653 had expected today's activity was likely at the end of May within about 50 km of these epicenters.

 

O: 30MAY2017 23:12:22  36.3N   97.5W Mw=3.8  EMSC   OKLAHOMA                     

O: 30MAY2017 23:42:18  36.3N   97.5W mb=2.3  EMSC   OKLAHOMA                     

O: 30MAY2017 16:30:37  36.3N   97.5W mb=2.4  EMSC   OKLAHOMA                     

O: 30MAY2017 23:47:02  36.3N   97.5W mb=2.7  EMSC   OKLAHOMA                     

O: 30MAY2017 13:57:24  36.3N   97.5W mb=3.8  EMSC   OKLAHOMA                     

P: 27MAY2017 107653    36.0N   97.0W 2.0-4.3 BAAAA  Southern Plains            

P: 29MAY2017 107653    36.0N   96.0W 2.0-4.0 AAAAA  Southern Plains            

 

O: 30MAY2017 09:23:15  36.5N   98.8W mb=3.2  EMSC   OKLAHOMA                     

P: 23MAY2017 107653    37.0N   98.0W 2.0-3.9 CAAAA  Southern Plains            

 

 

The strongest earthquakes of the day felt outside Indonesia were a pair of events of M 5.3-5.4 south of Chiapas, Mexico. A strong weather system which can grow into a tropical storm according to NHC is in the vicinity of this seismic activity and may be promoting some of these events. The moderate activity in this region began about the same time that this storm which is stationary appeared in the region according to the NHC website.  They were reported by NEIC to have been felt with intensity II in Tuxtla Gutierrez, Chiapas, Mexico.

The only larger event in the year 2017 than M 5.3 occurred on March 31 with M 5.4. Forecast 107565 had expected today's activity was likely within about 50 km of these epicenters around May 29. These events are located at 144 degrees from the earthquake in Sulawesi yesterday. Seismic energy is concentrated at the surface after reflecting off core boundaries and often helps promote additional seismicity at this distance. A similar M 5.7 in central Chile yesterday was probably also promoted at this distance from Sulawesi.

 

O: 30MAY2017 21:53:19  13.9N   93.1W ML=5.3  UNAM  al SUROESTE de CD HIDALGO, CHIS *:

O: 31MAY2017 05:17:21  14.2N   92.9W mb=5.3  EMSC   OFFSHORE CHIAPAS, MEXICO

O: 30MAY2017 22:01:57  14.2N   93.2W ML=4.6  UNAM  al SUROESTE de CD HIDALGO, CHIS *:

O: 30MAY2017 21:26:22  15.4N   93.3W ML=4.0  UNAM  l SUROESTE de PIJIJIAPAN, CHIS *:

O: 30MAY2017 22:03:02  14.2N   93.4W ML=4.2  UNAM  al SUROESTE de HUIXTLA, CHIS *: 14

O: 30MAY2017 06:02:16  13.8N   93.5W ML=4.1  UNAM  al SUROESTE de CD HIDALGO, CHIS *:

O: 30MAY2017 21:53:24  14.3N   92.8W mb=5.3  EMSC   OFFSHORE CHIAPAS, MEXICO     

P: 29MAY2017 107565    14.0N   93.0W 3.5-5.1 AAAAA  Chiapas, Mexico            

 

 

 

 

M 5.8 CHILE QUAKE TRIGGERED BY CORE REFLECTIONS FROM M 6.8 IN SULAWESI

 

EARTHQUAKE SUMMARY FOR MAY 29, 2017

 

The major geomagnetic storm of the past day appears to have been instrumental in promoting seismicity around the world today. The strongest earthquake lay near the geomagnetic equator and occurred in Sulawesi, Indonesia with M 6.6-6.8.  It was followed by an M 5.8 22.5 minutes later as core reflections arrived in Central Chile. This is apparently an example of dynamic triggering of distant earthquakes.

 

The mainshock of M 6.8 in Sulawesi was reported felt with minor damage about 300 km from the epicenter in Majene, Sulawesi and V in Palu, Sulawesi. Intensity IV was also reported from Luwuk, with III in Balikpapan, Kalimantan and in Rantepao, Sulawesi, Indonesia. An aftershock of M 5.1 was reported felt with intensity VI in Poso, Sulawesi, Indonesia. The mainshock occurred within about an hour of local solar midnight, a time when geomagnetic and tidal stresses are predominant and it was probably promoted from both these sources. An M 5.6 quake hit Sulawesi on May 24 southeast of today's epicenter but the last earthquake within about 250 km of this epicenter with M>=6.8 was an M 7.9 on January 1, 1996 followed by the only other such event in the past 25 years - an aftershock of M 7.0 on July 22, 1996. These events occurred about 250 km north of today's epicenter. Data from BMG was not immediately available.  Forecasts 107531 and 107560 had expected today's event in Sulawesi was likely at the end of May.

  

O: 29MAY2017 14:35:21   1.3S  120.5E mw=6.8  ANSS   WNW of Kasiguncu Indonesia

O: 29MAY2017 17:31:15   1.1S  120.4E ML=4.6  EMSC   SULAWESI, INDONESIA          

O: 29MAY2017 15:30:00   1.2S  120.4E mb=4.5  EMSC   SULAWESI, INDONESIA          

O: 29MAY2017 15:03:28   1.2S  120.4E mb=4.9  EMSC   SULAWESI, INDONESIA          

O: 29MAY2017 14:35:23   1.3S  120.4E Mw=6.6  EMSC   SULAWESI, INDONESIA          

O: 29MAY2017 14:53:42   1.3S  120.4E mb=4.7  EMSC   SULAWESI, INDONESIA          

O: 29MAY2017 15:18:47   1.3S  120.5E mb=5.0  EMSC   SULAWESI, INDONESIA          

O: 29MAY2017 15:04:32   1.3S  120.5E mb=5.1  EMSC   SULAWESI, INDONESIA          

P: 22MAY2017 107560     1.0S  120.0E 4.0-5.6 CAAAA  Sulawesi area              

P: 25MAY2017 107531     0.0N  120.0E 4.0-5.4 BBAAA  Celebes Sea                

 

 

The event in Sulawesi was followed by an M 5.8 in Central Chile. This event was also widely felt with maximum intensity V in BioBio, Chile at Cabrero, Bulnes, and Valparaiso and IV in Araucania at Temuco and Lautaro and in BioBio at Talcahuano, Lautaro, Penco, Concepcion, Laja, Yumbel, and Los Angeles. Lesser shaking of II-III was felt within about 500 km of the epicenter including in BioBio at Mulchen, San Rafael, Argentina, San Felipe, and lesser shaking of II-III in Santiago, Purranque, Machali, (O'Higgins), Valdivia, Curico, Villarrica, Talca, Nueva Imperial, Victoria, Angol, and Mulchen. CSN reported intensity VI in Chile at Lota, Coronel, Coelemu, Constitucion, V Cauquenes, Chanco, Empedrado, Linares, Maule, Parral, Pelluhue, Retiro, San Javier, Villa Alegre, Yerbas Buenas, Alto Biobio, Arauco, Cobwquecura, Concepcion, Florida, Hualpen, Laha, Lebu, IV in Villarca, Victoria, Tolten, Temuco, Puren, Padre La Casas,  Longquimay, Loncoche, Gorbea, Curarrehue, Curacautin, Collpulli, Talca, Romeral, Rio Claro, Pelarco, Curico, Constitucion, San Fernando, III in Valparaiso, Pichilemu, Rancagua, Rengo, Santa Cruz, Iloca, Pencahue, Angol, Carahue, Melipeuco, Pitrufquen, Teodoro Schmidt, Mafil, Panguipulli, Valdivia, and II in Saavedra, Nueva Imperial, Litueche, Puente Alto, Paine, Chile. Felt in the regions of Valparaiso, O'Higgins, Santiago, Maule, Biobio, La Araucania and Los Rios, Chile.  

 

This earthquake occurred 22.5 minutes following the Sulawesi earthquake at a distance of 140 degrees. PKS/SKP and PP phases from Indonesia arrived in Chile after  reflection off core boundaries just at the earthquake in Chile was occurring and probably dynamically triggered this large event. Large dyanamic triggering is not common but has been noted in Chile following major earthquakes elsewhere in the world.

 

O: 29MAY2017 14:57:53  37.3S   71.7W mw=5.8  ANSS   Los Angeles Chile

O: 29MAY2017 14:57:55  37.3S   71.8W mb=5.8  CSN    Lota, Coronel, Coelemu, Consti

O: 29MAY2017 14:57:53  37.3S   71.7W Mw=5.8  EMSC   BIO-BIO, CHILE               

P: 30MAY2017 107760    38.0S   74.0W 4.0-5.4 AABAA  Central Chile              

 

The largest earthquake in the U.S. or Canada today was an M 5.3-5.5 in the Kenai Peninsula area of Southern Alaska. This continues elevated seismicity in the region which have been ongoing for more than a week. NEIC reported this earthquake was felt with intensity IV in areas more than 100 km from the epicenter including in Alaska at Sterling, Tyonek, Cooper Landing, the Kenai NTL Wildlife Refuge, and with light shaking at II-III levels within about 200 km of the epicenter reported from Palmer, Talkeetna, Seward, Chugiak, Homer, Anchorate, Eagle River, Girdwood, Wasilla, Fort Richardson, Indian, Elmendorf AFB, Willow, Anchor Point, Ninilchik, Calm Gulch, Kenai, Soldotna, Kasilof, Alaska. No major damage or injuries were reported with this earthquake.      This event at a high latitude was probably promoted by the strong geomagnetic storm today which was the strongest at high latitudes in more than half a year. This had been expected to bring increased seismicity as noted in the previous issue of this summary:

 

 

"The geomagnetic field was at major storm conditions today.  The AP level was 51. High latitude geomagnetic field also saw major storms with AP at 84 reaching KP 9 about 03-06 UT on May 28. KP last reached this level of disturbance on March 27, 2017 when AP was 54 but high latitude AP was only 64 in this disturbance. The last high latitude AP greater than today's 84 was on October 26, 2016 when it reached 90. Geomagnetic effects on seismicity are expected to peak with this storm in the first several days of June, 2017. A major earthquake at high latitudes is most likely during this period but could also occur about 10-15 degrees from the geomagnetic equator." (May 28-29, 2017)

 

An M 5.2 about 50 km south of this epicenter occurred on May 7, 2017 but the last earthquake within about 200 km of this epicenter with M>=5.5 was an M 6.2 on September 25, 2014.  Forecast 107720 had expected this event within about 50 km of this epicenter was likely around May 26-27. This epicenter is located at the fourth node (90 degrees) from the earlier event in Sulawesi and may have been promoted by energy from that event.

 

O: 30MAY2017 02:18:45  60.8N  151.8W mb=5.5  EMSC   KENAI PENINSULA, ALASKA      

P: 26MAY2017 107720    61.1N  151.4W 3.2-5.1 BAAAA  Central Alaska             

P: 27MAY2017 107720    60.2N  151.7W 3.2-5.1 BAAAA  Central Alaska             

 

A smaller quake of M 4.2 also occurred northeast of the Kenai quake today. NEIC reported maximum intensity IV in Palmer, Alaska and II-III in Chugiak, Glennallen, Eagle River, Wasilla, Talkeetna, Fort Richardson, Sustina, Anchorage, Girdwood, and Willow and within about 125 km of the epicenter.

 

O: 29MAY2017 08:13:58  61.8N  147.9W mb=4.6  EMSC   SOUTHERN ALASKA              

P: 21MAY2017 107474    63.3N  147.5W 3.2-4.9 CBAAA  Central Alaska             

 

The strongest earthquake in California today was an M 3.5 north of Los Angeles in the Frazier Park area. This is a region where, after the Northridge quake, many geoscientists thought the next strong regional quake was likely to occur. As the 23rd year of the 23-year cycle of strong quakes in the region is current, this is useful to keep in mind. NEIC reported today's earthquake was felt with maximum intensity IV in Lebec, California and with intensity II-III in areas within about 100 km of the epicenter including at Frazier Park, Castai, Lancaster, Bakersfield, Tehachapi, Valencia, Santa Clarita, Simi Valley, Canyon Country, Newhall, Port Hueneme, Sylmar, Newbury Park, Encino, Glendale, Hacienda Heights, and Irvine, California. The last earthquake within about 50 km of Frazier Park in southern California with M>=3.5 was an M 4.1 on March 12, 2016 and prior to that an M 3.8 on May 10, 2015. Forecasts 107645 and 107642 had expected this earthquake was likely within about 50 km of this epicenter around May 29-31.

 

O: 30MAY2017 04:14:45  34.9N  119.0W Mw=3.5  EMSC   CENTRAL CALIFORNIA           

P: 29MAY2017 107645    34.3N  118.5W 2.5-4.5 AAAAA  So. California             

P: 31MAY2017 107642    34.0N  118.7W 2.5-4.4 AAAAA  So. California             

 

Two other light earthquakes of M>3.2 also occurred today in Southern California with M 3.4 and in northern California with M 3.3. These occurred near local  solar noon and may have been promoted by the sudden increase in solar activity yesterday and today.  NEIC reported the earthquake of M 3.4 in Southern California was felt with intensity II-III in the area(s) of within about 100 km of the epicenter including at Ontario, Spring Valley, Campo, Riverside, Vista, Fallbrook, Wildomar, Moreno Valley, Menifee, Murrieta, Temecula, Hemet, Palm Springs, Rancho Mirage, Idyllwild, Palm Desert, Aguanga, Mountain Center and Anza, California.

 

O: 29MAY2017 19:00:56  33.6N  116.6W ML=3.4  EMSC   SOUTHERN CALIFORNIA          

P: 29MAY2017 107641    33.7N  116.1W 2.5-4.7 AAAAA  So. California             

 

NEIC reported the earthquake of M 3.3 in Northern California was felt with intensity II-III in the area(s) of Hopland, Cloverdale, Lakeport, Kelseyville, Ukiah, Sebastopol, and within about 50 km of this epicenter.

 

O: 29MAY2017 18:21:25  38.9N  123.0W Mw=3.3  EMSC   NORTHERN CALIFORNIA          

P: 30MAY2017 107614    39.3N  123.2W 2.5-4.4 AAAAA  Central California         

 

 

MAJOR GEOMAGNETIC STORM MAY ACTIVATE GLOBAL SEISMICITY

 

EARTHQUAKE SUMMARY FOR MAY 28, 2017

 

The geomagnetic field was at major storm conditions today.  The AP level was 51. High latitude geomagnetic field also saw major storms with AP at 84 reaching KP 9 about  03-06 UT on May 28. KP last reached this level of disturbance on March 27, 2017 when AP was 54 but high latitude AP was only 64 in this disturbance. The last high latitude AP greater than today's 84 was on October 26, 2016 when it reached 90. Geomagnetic effects on seismicity are expected to peak with this storm in the first several days of June, 2017. A major earthquake at high latitudes is most likely during this period but could also occur about 10-15 degrees from the geomagnetic equator.

 

The strongest solar flare today was a C3.6, the largest observed flare since mid-April, 2017 as noted in the previous summary issue:

 

" the strongest flare observed since April 18, nearly a month-and-a-half ago when a C5.5 flare was seen. Today's flares come after a long period of solar quiet and may precede a period of global seismic activation." May 28, 2017)

 

Perhaps reflecting the reduction of ionospheric ring currents by  today's geomagnetic storm, global seismicity was very low today. Two events of M 5.0 each were the strongest in the world. These occurred as a second mainshock in northwestern Turkey south of Istanbul and as an M 5.0 in the South Sandwich Islands. The strong aftershock sequence in NW Turkey continued today and was felt with moderate intensity from Izmir to Istanbul. 

 

The earthquake in the South Sandwich Islands of M 5.0 was not unusual nor unexpected. It is probably an aftershock of an M 5.7 which hit the region to the east of this on May 11. Forecast 107778 expected this activity in the South Sandwich Islands was likely around May 23.

 

O: 29MAY2017 04:56:02  56.8S   27.3W mb=5.0  EMSC   SOUTH SANDWICH ISLANDS REGION

P: 23MAY2017 107778    56.0S   28.0W 4.0-5.9 CAAAA  So. Sandwich Islands       

 

The moderate quake in northwestern Turkey continued this series as described in the previous issue of this report:

 

"A moderate earthquake of M 5.0 in western Turkey was followed by several moderate aftershocks today. The mainshock of M 5.0 was reported felt with intensity VII in Golmarmara; IV in Izmir, Bursa and Eskisehir and II-III in Saruhanli, Manisa Urla, Izmir, Soke, Aydin, Yenisehir, Bursa and Buyukcekmece, Istanbul, Turkey. EMSC reported moderate shaking in Turkey at Manisa, Izmir, Yenifoca, Seferihisar, Didim, Tekirdag, Istanbul, and in Greece at Kokkari, Pythagoreio, An aftershock of M 4.9 was felt with intensity IV in Izmir and II-III in Mudanya, Bursa and Manisa, Turkey. An M 4.2 was also reported felt with intensity III in Izmir. No major damage was reported with these quakes. A foreshocik of M 5.0 hit within about 25 km of this epicenter on April 21 and an M 4.3 occurred on April 2. A series of such events  may indicate a strong earthquake is rapidly approaching in the region. Forecast 107654 had expected today's activity was likely at the end of May, 2017." (May 28, 2017)

 

 

NEIC reported this earthquake of M 5.0 in Northwestern Turkey was felt with intensity V in Buyukcekmece, Istanbul and II-III in the area(s) of Izmir and Manisa, Turkey.  Today's event occurred near local solar noon and may have been promoted by the high tidal stresses at this hour associated with the new moon.

 

O: 28MAY2017 11:04:59  38.7N   27.8E mb=5.0  EMSC   WESTERN TURKEY               

O: 28MAY2017 08:49:48  38.8N   27.8E mb=4.3  EMSC   WESTERN TURKEY               

P: 31MAY2017 107654    38.0N   28.0E 3.5-5.3 BAAAA  Turkey                     

 

The strongest activity in the U.S. or Canada continued in the Aleutian Islands of Alaska where events of M 4.3 hit the western Andreanof Islands; M 4.6 in the eastern Andreanof Islands and of M 4.4 and 4.2 in the Unimak Island region. These  continue the activation of this region which began in mid-May. These are remote islands and these earthquakes were not reported felt. Forecasts 107699 and 107700 had expected this activity towards the end of May.

 

O: 28MAY2017 20:33:13  51.0N  177.0W ML=3.9  EMSC   ANDREANOF ISLANDS, ALEUTIAN IS

O: 28MAY2017 09:45:10  51.7N  178.5W Ml=4.3  EMSC   ANDREANOF ISLANDS, ALEUTIAN IS

P: 29MAY2017 107699    50.2N  179.0W 3.5-5.0 ABAAA  Andreanoff Isls, Aleutians 

P: 31MAY2017 107700    51.9N  177.8W 3.5-5.0 BAAAA  Andreanoff Isls, Aleutians 

 

O: 28MAY2017 08:46:06  51.8N  175.3W mb=4.6  EMSC   ANDREANOF ISLANDS, ALEUTIAN IS

P: 25MAY2017 107699    51.0N  177.1W 3.5-4.9 BAAAA  Andreanoff Isls, Aleutians 

 

O: 28MAY2017 17:51:19  53.5N  163.6W mb=4.4  EMSC   UNIMAK ISLAND REGION, ALASKA 

O: 28MAY2017 17:59:01  53.6N  163.6W mb=4.1  EMSC   UNIMAK ISLAND REGION, ALASKA 

P: 29MAY2017 107716    54.1N  164.4W 3.5-5.0 AAAAA  Unimak Islands, Aleutians  

 

A pair of unusual event of M 4.4 and 4.7 occurred north of Taiwan today but were not reported felt in this region. They occurred at the height of solar flare 5600 and may have been triggered by SFE from that flare, the largest observed flare since April 18, 2017. The last events in this area within about 200 km of these epicenters occurred as an M 4.9 and 4.9 on March 7 and February 27, 2017.

Forecast 107602 had expected this activity was likely around May 31.

 

O: 28MAY2017 19:27:12  24.9N  122.7E mb=4.4  EMSC   TAIWAN REGION                

O: 28MAY2017 19:29:20  25.1N  122.3E mb=4.7  EMSC   TAIWAN REGION                

P: 31MAY2017 107602    24.0N  123.0E 4.0-5.4 BAAAA  Taiwan                     

 

MODERATE QUAKES HIT ALASKA AND TURKEY AS SOLAR ACTIVITY INTENSIFIES

 

EARTHQUAKE SUMMARY FOR MAY 27, 2017

 

With the return of solar flare activity today, seismicity at high latitudes increased. The largest earthquakes of the day were a pair of events of M 5.5 each in the central Andreanof Islands, Alaska and in the Alaska Peninsula.  An earthquake of M 5.0 and aftershock of M 4.9 were also widely felt in the region south of Istanbul, Turkey on the Anatolian Fault zone. A large earthquake in this area is widely anticipated. The largest solar flare of the day, a B9.2 class was the strongest flare observed since April 18, nearly a month-and-a-half ago when a C5.5 flare was seen. Today's flares come after a long period of solar quiet and may precede a period of global seismic activation.

 

The earthquake of M 5.5 in the Andreanof Islands, Aleutians, Alaska follows a period of seismic activation in the area but at a new epicenter.  An M 6.4 about 200 km west of this on May 8 was followed by a strong aftershock sequence through May 11. These earthquakes have, however, been only slightly felt in this remote area. The last event within about 150 km of today's M 5.5 occurred on March 19, 2016 with M 6.0 more than a year ago. Forecast 107699 expected today's activity around May 25.

 

O: 28MAY2017 07:06:18  52.0N  175.4W mb=5.5  EMSC   ANDREANOF ISLANDS, ALEUTIAN IS

O: 28MAY2017 07:06:17  51.8N  175.4W mb=5.5  ANSS   E of Adak Alaska

P: 25MAY2017 107699    51.0N  177.1W 3.5-4.9 BAAAA  Andreanoff Isls, Aleutians 

 

The earthquake in the Alaska Peninsula of M 5.2-5.5 was likewise reported unfelt in that remote area. This event occurred 30 minutes after the event in the Andreanof Islands and may have been triggered by seismic waves from that event. Both may have been promoted by a B7+ flare which maximized about 0645 UT minutes before the Andreanof Islands quake. The last earthquake with M>=5.5 in the Alaska Peninsula within about 150 km of this epicenter occurred more than five years ago on July 16, 2011 with M 5.7. A year ago on May 31, 2016 an M 5.7 hit about 200 km northeast of today's epicenter in the Alaska Peninsula. Forecast 107716 had expected today's activity within about 50 km of this epicenter was likely around May 29.

  

O: 28MAY2017 07:37:08  54.1N  160.9W ML=5.2  EMSC   ALASKA PENINSULA             

O: 28MAY2017 07:37:10  53.7N  160.9W Mi=5.5  ANSS   SW of Chernabura Island

P: 29MAY2017 107716    54.3N  161.4W 3.5-5.3 AAAAA  Unimak Islands, Aleutians  

 

A moderate earthquake of M 5.0 in western Turkey was followed by several moderate aftershocks today. The mainshock of M 5.0 was reported felt with intensity VII in Golmarmara; IV in Izmir, Bursa and Eskisehir and II-III in Saruhanli, Manisa Urla, Izmir, Soke, Aydin, Yenisehir, Bursa and Buyukcekmece, Istanbul, Turkey. EMSC reported moderate shaking in Turkey at Manisa, Izmir, Yenifoca, Seferihisar, Didim, Tekirdag, Istanbul, and in Greece at Kokkari, Pythagoreio, An aftershock of M 4.9 was felt with intensity IV in Izmir and II-III in Mudanya, Bursa and Manisa, Turkey. An M 4.2 was also reported felt with intensity III in Izmir. No major damage was reported with these quakes. A foreshocik of M 5.0 hit within about 25 km of this epicenter on April 21 and an M 4.3 occurred on April 2. A series of such events  may indicate a strong earthquake is rapidly approaching in the region. Forecast 107654 had expected today's activity was likely at the end of May, 2017.

 

O: 27MAY2017 15:53:23  38.7N   27.8E ML=5.0  EMSC   WESTERN TURKEY               

O: 28MAY2017 02:14:59  38.7N   27.8E mb=4.3  EMSC   WESTERN TURKEY               

O: 28MAY2017 04:38:20  38.7N   27.8E mb=4.3  EMSC   WESTERN TURKEY               

O: 28MAY2017 02:50:26  38.7N   27.8E mb=4.5  EMSC   WESTERN TURKEY               

O: 28MAY2017 02:16:41  38.8N   27.8E ML=4.0  EMSC   WESTERN TURKEY               

O: 28MAY2017 07:34:01  38.8N   27.8E ML=4.0  EMSC   WESTERN TURKEY               

O: 28MAY2017 02:52:56  38.8N   27.8E mb=4.6  EMSC   WESTERN TURKEY               

O: 27MAY2017 15:53:24  38.8N   27.8E mb=5.0  ANSS   WNW of Golmarmara Turkey

P: 31MAY2017 107654    38.0N   28.0E 3.5-5.3 BAAAA  Turkey                     

P: 31MAY2017 107654    39.0N   28.0E 3.5-5.2 BAAAA  Turkey                     

 

 

An unusually large earthquake shook regions of south-central Honshu, Japan today. NEIC reported it was felt with intensity II-IV in Kyoto at Seika, Miyazu and Maizuru; in Tsuruga, Fukui; Nagahama Shiga; Komatsu, Tsurugi, Kanazawa Ishikawa; Otsu, Shiga; in Osaka at Minoh, Settsu, Suita, Osaka,  Hirakata, in Nara and Kobe, Hyogo; in Aichi at Nagoya, Hekinan, and in Okayama, Japan.

The only moderate quakes in this area of Honshu in 2017 occurred as events of M 4.4-4.5 on January 2 and March 27. The last earthquake of larger magnitude within  about 150 km of this epicenter occurred on December 5, 2014 and prior to that on August 26, 2010 with M 5.4. Forecast 107629 had expected this event about 100 km from this epicenter was likely around May 22.

 

O: 27MAY2017 13:50:04  36.0N  135.5E mb=4.8  EMSC   WESTERN HONSHU, JAPAN        

O: 27MAY2017 13:50:04  35.9N  135.5E mb=4.9  ANSS   NNW of Obama Japan

P: 22MAY2017 107629    37.0N  135.0E 3.5-5.1 BAAAA  No. Honshu, Japan          

 

The earthquake near Kobe, Japan was followed hours later by an M 4.5 near Tokyo. NEIC reported this event was felt with intensity II-III in Saitama at Kawaguchi, Toda, Kasukabe; in Tokyo at Hino, Komai, Kunitachi, Tokyo; in Chiba at Ichikawa, Urayasu; in Kanagawa at Sagamihara, Yamato, Yokohama, Kawasaki, Kamakura, Ebina; in Ibaraki at Sowa, Ishige, Naka, Tsuchiura and in Utsunomiya, Tochigi, Japan. No major damage was reported with this earthquake and no tsunami was generated.  This was preceded by an M 4.6 northwest of this epicenter. Like the area of Turkey where the M 5.0 occurred today, a strong earthquake in this area of southern Honshu is also considered overdue. A similar event of M 4.5 hit about 150 km south of this on May 22, the largest event in this area in the current year, 2017. The last event in this region with M>=4.5  was an M 4.9 on January 28, 2017.  Forecasts 107616 and 107634 had expected this region would be active around May 28-29.

 

 

O: 28MAY2017 06:18:20  35.8N  139.7E mb=4.5  EMSC   5  NEAR S. COAST OF HONSHU, JA

P: 28MAY2017 107616    34.0N  139.0E 3.5-5.1 ABAAA  Central/So. Honshu Japan   

P: 29MAY2017 107634    35.0N  142.0E 4.0-5.6 AABAA  Off East Coast Honshu      

 

 

O: 27MAY2017 11:59:39  36.8N  138.4E mb=4.6  EMSC   EASTERN HONSHU, JAPAN        

P: 24MAY2017 107629    37.0N  139.0E 3.5-4.9 BAAAA  No. Honshu, Japan          

 

San Francisco, California also saw continued activity in the current active cycle. As noted in this summary in the previous issue, tidal stresses are at least partially promoting this activity. The largest earthquake in the area today of M 2.3 occurred within about 10 minutes of local solar noon today, an indication of tidal promotion. Forecast 107613 had expected the area would be active around May 29.

 

O: 28MAY2017 02:37:10  37.7N  121.8W Md=2.1  EMSC   SAN FRANCISCO BAY AREA, CALIF.

O: 27MAY2017 19:30:44  38.0N  122.1W MD=2.1  EMSC   SAN FRANCISCO BAY AREA, CALIF.

O: 27MAY2017 19:58:50  38.0N  122.1W MD=2.3  EMSC   SAN FRANCISCO BAY AREA, CALIF.

P: 29MAY2017 107613    37.4N  121.8W 2.5-4.4 AAAAA  Central California         

 

An earthquake of M 3.7 also shook the island of Hawaii lightly today but did no reported damage. NEIC reported this earthquake of M 3.7 in Hawaii was felt with intensity I in the area(s) of Hilo, Hawaii. As the last event within Hawaii of M>=3.7 coincided with the last new moon on April 27 (M 3.7) it is likely that high tidal stresses are promoting that and today's event. The only event in the island of Hawaii this year of larger  magnitude was an M 4.3 on March 23. Forecast 107570 had expected today's event was likely within about 15 km of this epicenter around May 25.

 

O: 27MAY2017 20:24:18  19.3N  155.4W ML=3.7  EMSC   ISLAND OF HAWAII, HAWAII     

P: 25MAY2017 107570    19.4N  155.3W 3.0-4.4 AAAAA  Hawaii                     

 

MODERATE QUAKES IN EL SALVADOR ON QUIET DAY

 

EARTHQUAKE SUMMARY FOR MAY 26, 2017

 

It was a generally quiet day in global seismicity. Regional and global seismicity was at subdued levels.  An earthquake of M 5.2 occurred in the area of El Salvador today. NEIC reported it was felt with intensity II in Nuevo Cuscatlan, La Libertad, El Salvador. No major damage was reported with this earthquake. The strongest earthquake near El Salvador during 2017 was an M 6.2 on May 12 followed by an aftershock of M 5.4. Today's event is the strongest aftershock of that event since May 12. Forecast 107569 had expected this activity was likely at the end of May.

 

O: 26MAY2017 15:01:55  12.8N   89.4W mb=4.6  EMSC   OFFSHORE EL SALVADOR         

O: 26MAY2017 15:23:39  12.9N   90.0W Mw=5.3  EMSC   OFFSHORE EL SALVADOR         

P: 23MAY2017 107569    13.0N   91.0W 3.5-5.1 BAAAA  Guatemala                  

P: 31MAY2017 107569    13.0N   90.0W 3.5-5.1 BAAAA  Guatemala                  

 

The strongest earthquake in the U.S. or Canada today was an M 4.0 in the Near Islands, Aleutians, Alaska. This event was not reported felt in the epicentral ara which is remote. The last event in the Near Islands of the Aleutians of M>=4 was an M 4.7 on April 2, 2017. This, and today's event appear to have been aftershocks of an M 6.2 which occurred on March 27. Forecast 107707 expected today's event within about 150 km of this epicenter was likely around May 29.

 

O: 27MAY2017 03:37:39  52.0N  172.4E mb=4.0  EMSC   NEAR ISLANDS, ALEUTIAN ISLANDS

P: 29MAY2017 107707    53.0N  170.0E 4.0-5.8 AABAA  Near Islands               

 

The strongest earthquake in California today was an M 2.5 in the region of San Francisco Bay. NEIC reported this earthquake of M 2.5 in Central California was felt with intensity II-III in the area(s) of Concord, Pleasant Hill, Walnut Creek, Lafayette, Martinez, Alamo, Benicia, Orinda, Berkeley, Oakland, San Francisco, San Jose and Manteca, California. This event occurred within 10 minutes of local solar midnight and was probably promoted by high tidal stresses associated with the new moon of May 25.  The strongest earthquake in the San Francisco Bay area this year occurred as an M 3.8 on April 30, associated with the last new moon. The only other event in the region this year of M>=3 was an M 3.0 on April 5, also closely associated with a new moon. The triggering of local seismicity by tidal stresses suggests the area is highly stresses and capable of a strong earthquake at this time. Earthquakes of M>=2.5 have been proliferating in the past several months also suggesting the approach of a moderate to strong quake. The last of M>=2.5 was an M 2.5 on May 15. Forecast 107613 had expected today's event within about 50 km around May 29.

   

O: 26MAY2017 07:56:59  38.0N  122.1W MD=2.5  EMSC   SAN FRANCISCO BAY AREA, CALIF.

P: 29MAY2017 107613    37.4N  121.8W 2.5-4.4 BAAAA  Central California         

 

MODERATE EARTHQUAKE FELT WIDELY IN LUZON, PHILIPPINES

 

EARTHQUAKE SUMMARY FOR MAY 25, 2017

 

A moderate earthquake of M 5.4 was widely felt in the region of Luzon, Philippines today. No major damage was reported with this event.  NEIC reported this earthquake of M 5.3 in Luzon, Philippines was felt with intensity IV in Angeles, Magliman and Mabalacat, Central Luzon and II-III in the area(s) of Central Luzon at Pulong Santol, Balibago, Calibutbut, Balsic, Pamatawan, Bulaon and Hermosa.  PHIVOLCS reported this earthquake was felt with intensity IV in San Marcelino, San Felipe, Iba, Santa Cruz, Cabangan and Castillejos, Zambales; Dinalupihan and Abucay, Bataan; Quezon City, Pateros; Malolos, Bulacan; Obando Bulacan, Olongapo City; III in Tagaytay City, Talisay, Batangas; San Jose Del Monte, Bulacan; Paasay City, Makati City, Mandaluyong; Manila City; Parangque City; Taguig City; Caloocan City; Pasig City; Valenzuela City; San Miguel, Tarlac; Marilao, Bulacan; Gapan City, Bongabon and Aliaga, Nueva Ecija; and II in Palayan City; Bacoor, Cavite; Calumpit, Bulacan; San Jacinto, Pangaasinan; Cabanatuan City, Lucban, Quezon, Philippines.

 

The last earthquake in Luzon, Philippines with M>=5.4 was an M 5.7 on October 2, 2016 and prior to that an M 4.7 on November 7, 2015. A major event of M 7.7 hit near this epicenter on July 16, 1990 doing considerable damage and casualties in the area. Forecast 107574 had expected this event about 100 km south of this epicenter in Luzon around May 22. Today's earthquake occurred within about an hour of  local solar midnight and was closely associated with maximum tidal stresses associated with the new moon and probably was promoted by these.

 

O: 25MAY2017 14:27:06  15.1N  120.4E mb=5.4  EMSC   LUZON, PHILIPPINES           

O: 25MAY2017 14:27:04  15.1N  120.0E MS=5.4  PHI  Felt with intensity IV

P: 22MAY2017 107574    14.0N  121.0E 3.5-5.0 BBAAA  Luzon, Philippines         

 

An earthquake of M 3.3 near Malibu, California was widely felt today. NEIC reported it was felt with intensity II-III in Newbury Park, Point Mugu Nawc, Malibu, Westlake Village, Oxnard, Camarillo, Thousand Oaks, Agoura Hills, Port Hueneme, Oak Park, Oxnard, Somis, Calabasas, Ventura, Moorpark, Simi Valley, Canoga Park, Santa Paula, Chatsworth, Sherman Oaks, Los Angeles, Ojai, and Santa Barbara, California.

 

This appears to be another in the series of events in and around Santa Barbara and the Simi Valley of California. A moderate to large event in the area is still possible with the 22-year cycle previously described in this summary. The last event of M>=3.5 in the area was an M 3.3 on December 27, 2016. The last of larger magnitude was an M 3.5 more than a year ago on April 6, 2016. Forecast 107642 had expected a light earthquake within about 25 km of this epicenter in late May, 2017.

 

O: 25MAY2017 14:19:51  34.0N  119.0W ML=3.3  EMSC   CHANNEL ISLANDS REG., CALIFORN

O: 25MAY2017 14:19:51  34.0N  119.0W ml=3.3  ANSS   W of Malibu CA

P: 24MAY2017 107642    33.9N  118.3W 2.5-4.4 AAAAA  So. California             

P: 31MAY2017 107642    34.0N  118.7W 2.5-4.4 CAAAA  So. California             

 

The event near Malibu, California occurred about an hour before two light earthquakes of M 3.4 and 3.7 in the Coso Junction area of California. These occurred within several hours of the new moon and may have been promoted by tidal stresses. The area of Coso Junction, in particular is underlain by fluid magma and has been associated with high tides in the past. The M 3.7 in the Coso Junction region is the largest to occur in that area since an M 3.7 three years ago on August 12, 2013. The last earthquake of significantly larger magnitude in the Coso Junction area was an M 4.5 on May 3, 2011 in association with tidal stresses from the new moon of May 3, 2011. Prior to that the largest had been an M 4.5 on October 3, 2009. This event occurred with the full moon of October 3, 2009.  Forecast 107607 had expected activity associated with the new moon in this region. This activity is located at 104-105 degrees from the M 5.4 in Luzon, Philippines and occurred about an hour after that event. Surface waves from  Luzon may have helped promoted this subsequent activity in Coso Junction, California.

 

O: 25MAY2017 15:22:53  36.2N  117.9W ML=3.4  EMSC   CENTRAL CALIFORNIA           

O: 25MAY2017 15:42:51  36.2N  117.9W Mw=3.7  EMSC   CENTRAL CALIFORNIA           

P: 22MAY2017 107607    37.3N  118.3W 2.5-4.6 BBAAA  California/Nevada area     

 

The largest earthquake in the U.S. or Canada today was an M 4.1 on the Alaska Peninsula where it was not reported felt. The last earthquake of M>=4.1 in the Alaska Peninsula occurred as an M 4.5 on April 27, 2017. Forecast 107697 had expected today's earthquake around May 24. An earthquake of M 3.3 in the Kodiak Island area occurred near local solar noon and may have been promoted by high tides associated with the new moon as noted in previous summaries:

 

"The new moon will arrive on May 25 at 19:44 UT. Longitudes which are sub-solar  at this time are near 116 West longitude while anti-solar longitudes are near 64 East longitude. In the west these include areas of California, Nevada and western Mexico as well as other areas of the western U.S. In the east areas seeing highest tidal stresses include Iran, Pakistan and Afghanistan, among others. While these are the regions most likely to see high tidal stresses at this time, many areas can see tidal triggering of seismicity at this time and global seismicity is likely to be high from May 23-28 with the possibility of a strong or major earthquake associated with this new moon." (May 22-25, 2017)

 

 

O: 26MAY2017 07:09:35  56.1N  157.7W Ml=4.1  EMSC   ALASKA PENINSULA             

P: 24MAY2017 107697    54.7N  156.9W 3.5-5.0 ABAAA  Alaska Peninsula           

 

O: 25MAY2017 22:27:37  57.8N  154.2W ML=3.3  EMSC   KODIAK ISLAND REGION, ALASKA 

P: 24MAY2017 107697    54.7N  156.9W 3.5-5.0 ACBAA  Alaska Peninsula           

 

 

MODERATELY STRONG QUAKES HIT JAVA, FOX and SOLOMON ISLANDS

 

EARTHQUAKE SUMMARY FOR MAY 24, 2017

 

Global seismicity today saw a series of three moderate earthquakes. These occurred as an M 5.8 in the Solomon Islands; an M 5.8 in the Fox Islands, Alaska and an M 5.6 in Java, Indonesia. None of these triggered a tsunami and reported damage and moderate shaking occurred only in the Java event.

 

The earthquake in the Solomon Islands of M 5.8 is the strongest earthquake in this region since events of M 6.4 on January 10 and an M 6.7 on January 19 and is the strongest long-term aftershock since those events. Forecast 107734 had expected this event within about 20 km of this epicenter around May 30.

 

O: 24MAY2017 11:05:21  10.0S  161.8E Mw=5.8  EMSC   SOLOMON ISLANDS              

P: 30MAY2017 107734    10.0S  162.0E 4.0-5.4 CAAAA  No. of Santa Cruz Islands  

 

The earthquake of M 5.4-5.6 in the area south of Java, Indonesia was the strongest widely felt earthquake of the day.  BMG reported this earthquake was felt with intensity III in Blitar, Malang, Batu, Karangkates and II-III in Nganjuk, Tulungagung, Kediri, Wonogiri and Bantul, Java, Indonesia.

NEIC reported this earthquake of M 5.4 in Java, Indonesia was felt with intensity V in Ponorogo, Java; IV in Tulungagung, Java and II-III in the area(s) of Java at Boyolangu, Blitar, Malang, Surakarta, Ceper; in Yogyakarta and Kasihan and in Tabanan, Bali, Indonesia. A similar event of M 5.6 hit this area south of Java on April 29 but the largest prior to that was an M 5.6 on November 11, 2016. Forecasts 107318 and 107557  had expected this activity within about 100 km of this epicenter was likely around May 21-23.

 

O: 24MAY2017 16:44:52   9.1S  111.9E mb=5.4  EMSC   SOUTH OF JAVA, INDONESIA     

O: 24MAY2017 16:44:51  09.1S  111.9E MS=5.6  BMG  Felt with intensity III

P: 21MAY2017 107318     9.0S  111.0E 4.0-5.6 BAAAA  So. of Java                

P: 23MAY2017 107557     9.0S  113.0E 4.0-5.5 AAAAA  So. of Bali                

 

The strongest earthquake in the U.S. or Canada today was an M 5.8 in the Fox Islands, Alaska. NEIC reported it was felt with intensity II in Unalaska. The last earthquake in the Fox Islands with M>=5.8 was an M 5.8 on July 3, 2013. The last of larger magnitude in the area was an M 6.2 on August 10, 2012 and M 6.4 on October 13, 2009. The relation between the timing of today's event and the nor'easter hitting the northeast U.S. at the same time is unclear but in the past nor'easters have been closely associated with increased seismicity in Alaska and the northwestern portion of North America. Forecast 107704 had expected this activity was likely within about 50 km of this epicenter between May 23 and 26 in the Fox Islands.

 

O: 24MAY2017 16:36:00  52.4N  166.6W Mw=5.8  EMSC   FOX ISLANDS, ALEUTIAN ISLANDS

O: 24MAY2017 16:07:03  52.4N  166.7W Mw=5.3  EMSC   FOX ISLANDS, ALEUTIAN ISLANDS

P: 23MAY2017 107704    52.3N  165.7W 3.5-5.0 AAAAA  Fox Islands, Aleutians     

P: 26MAY2017 107704    53.6N  166.1W 3.5-4.9 ABAAA  Fox Islands, Aleutians     

 

Twelve minutes prior to the Fox Islands quake (the travel time of a PP-wave between these two epicenters) an M 3.4 earthquake was widely felt in the region of Ohio. NEIC reported this quake was felt with intensity IV in Ohio at Lancaster, Rockbridge, Vinton, Albany and Creola. Intensity II-III was reported from Hamden and McArthur both within 10 km of the epicenter and in Wilkesville, Wellston, New Plymouth, South Bloomingville, Londonderry, Jackson, Nelsonville, Laurelville, Logan, Athens, Beaver, Bidwell, Kingston, Oak Hill, Middleport, Chillicothe, Sugar Grove, Waverly, Minford, South Webster, Stoutsville, Piketon, Portsmouth, Frankfort, Canal Winchester, Roseville, Columbus, and other communities within about 100 km of the epicenter.

 

No major damage was associated with this earthquake. The last earthquake in Ohio within about 150 km of this epicenter with M>=3.4 occurred on M 3.5 on November 20, 2013 about 50 km northeast of this epicenter. The only other event in this region in the past 25 years was an M 3.6 on February 19, 1995. Two earthquakes have occurred with M>2 during 2017 - an M 2.5 on January 23 and an M 3.0 on April 2. Forecasts 107436 and 107684 had expected this earthquake within this area was likely between May 21 and 27 in the area of Ohio.

 

O: 24MAY2017 16:24:04  39.2N   82.5W mb=3.4  EMSC   OHIO                         

O: 24MAY2017 16:24:04  39.2N   82.5W mb=3.4  ANSS   S of McArthur Ohio

P: 21MAY2017 107436    40.0N   84.0W 2.0-3.9 AAAAA  Ohio/Lake Erie             

P: 27MAY2017 107684    40.0N   84.0W 2.0-4.0 AAAAA  Ohio/Lake Erie             

 

A moderate earthquake occurred with M 4.5-4.6 in the region of Albania today where it was widely felt.  NEIC reported this earthquake of M 4.6 in Albania was felt with intensity IV in Bulqize, Trana, Albania and II-III in the area(s) of Cerrik, Albania and Ohrid, Macedonia.  No major damage was reported with this earthquake. This is the largest aftershock to date of an M 5.0 near this epicenter which occurred on April 8, 2017. Forecast 107661 had expected this earthquake was likely within about 100 km of this epicenter around May 24.

 

O: 24MAY2017 10:30:57  41.6N   20.3E mb=4.5  EMSC   ALBANIA                      

O: 24MAY2017 10:30:58  41.6N   20.2E mb=4.6  ANSS   N of Bulqize Albania

P: 24MAY2017 107661    42.0N   19.0E 3.0-5.1 AAAAA  Adriatic Sea               

 

An unusually large earthquake of M 4.3 occurred today in the Virgin Islands. It was not reported felt in the region. No earthquakes of M>4 have previously occurred in the Virgin Islands during 2017. The last of M>=4.3 was an M 4.4 on November 18, 2016. The last of significantly larger magnitude occurred on August 27, 2016 with M 4.6. Forecast 107572 had expected this event to the south around May 25.

 

O: 24MAY2017 15:17:36  18.9N   64.8W MD=3.2  EMSC   VIRGIN ISLANDS REGION        

O: 24MAY2017 14:25:44  19.2N   64.9W mb=4.3  EMSC   VIRGIN ISLANDS REGION        

P: 25MAY2017 107572    18.0N   65.0W 3.0-5.3 ABAAA  Leeward Islands            

 

 

MODERATE QUAKE HITS SULAWESI, INDONESIA

 

EARTHQUAKE SUMMARY FOR MAY 23, 2017

 

An earthquake of M 5.6-5.7 in Sulawesi, Indonesia was the largest in the world today. It was reported by BMG to have been felt with intensity up to IV in Marowali; III-IV in Bungku; III in Sorowako and II in Palu, Kendari and Kolaka, Sulawesi. The last earthquake within about 200 km of this epicenter in Sulawesi with M>=5.6 occurred on December 3, 2014 with M 5.7, but the last of larger magnitude was an M 6.1 on February 15, 2011.  Forecast 107321 had expected this event was possible in Sulawesi around May 19.

 

O: 24MAY2017 09:10:16  02.8S  122.2E MS=5.7  BMG  Felt with intensity IV

O: 24MAY2017 09:10:17   2.8S  122.2E Mw=5.6  EMSC   SULAWESI, INDONESIA          

P: 19MAY2017 107321     1.0S  123.0E 4.0-5.4 BBAAA  Sulawesi area              

 

The strongest earthquake in the U.S. or Canada today was an M 5.1 in the Unimak Island region of Alaska. The last moderate earthquake in this area occurred as an M 4.4 on March 11, 2017. The last of larger magnitude was an M 5.8 on October 27, 2016. Today's event appears to be the strongest aftershock to date of that mainshock.  Forecast 107716 and 107704 had expected this event between May 22 and 29 within about 50 km of this epicenter.

 

O: 24MAY2017 06:35:18  53.5N  164.4W mb=5.1  EMSC   UNIMAK ISLAND REGION, ALASKA 

P: 22MAY2017 107704    53.9N  165.3W 3.5-5.0 AAAAA  Fox Islands, Aleutians     

P: 29MAY2017 107716    54.1N  164.4W 3.5-5.0 BAAAA  Unimak Islands, Aleutians  

 

A light earthquake of M 3.0 was felt in the region of Beaupre, Quebec, Canada today. Earthquakes Canada reported this earthquake of M 3.0 in Quebec, Canada was felt with intensity II-III in the area(s) of Beaupre, Stoneham, Sainte-Brigitte-de-Laval, Saint-Ferreol-les-Neiges, Quebec. While earthquakes in this area of the Charlevoix Seismic Zone are not uncommon, they are seldom felt. The last earthquake of M>=3 within about 50 km of Beaupre was an M 3.8 on August 4, 2012. The strongest in the area in the past 25 years was an M 5.1 on November 6, 1997.  Forecast 107675 had expected this earthquake was likely within 50 km of the epicenter around May 24.

 

O: 23MAY2017 07:33:08  47.8N   70.0W ML=1.2  NRCA  CHARLEVOIX SEISMIC ZONE       

O: 22MAY2017 19:05:51  47.1N   70.9W ML=3.0  NRCA  4 km NW from Beaupre          

P: 24MAY2017 107675    47.3N   70.5W 2.0-3.9 AAAAA  New England                

 

A light earthquake of M 1.3 also occurred southwest of the Beaupre, Quebec event six hours earlier. This event southwest of Gouldsboro, Maine is the first of any size located by ANSS within about 50 km of this epicenter since an 2.4 on November 1, 2015 and prior to that an M 1.8 and 2.3 on February 17, 2012.  Forecast 107670 had expected this earthquake was likely in Maine within about 20 km of this epicenter around May 22.

 

O: 23MAY2017 01:35:42  44.5N   68.0W ml=1.3  ANSS   SSW of Gouldsboro Maine      

P: 22MAY2017 107670    44.4N   68.2W 2.0-4.1 AAAAA  Maine                      

 

MODERATE ACTIVITY IN KURILS, TONGA

 

EARTHQUAKE SUMMARY FOR MAY 22, 2017

 

The strongest earthquake in the world today occurred in the southern Kuril Islands. This event of M 5.4 was lightly felt in Hokkaido, Japan but did no damage and did not generate a tsunami. One other event of M>=5.4 had struck the Kuril Islands during the year to date 2017. This was an M 5.5 on April 20 about 100 km northeast of today's epicenter. Today's event had been expected within about 50 km of the epicenter to occur around May 26.

 

NEIC reported this earthquake of M 5.4 in the Kuril Islands was felt with intensity IV in the area(s) of Nakashibetsu, Hokkaido, Japan.

 

O: 22MAY2017 11:00:57  43.9N  147.7E Mw=5.4  EMSC   KURIL ISLANDS                

P: 26MAY2017 107666    44.0N  147.0E 3.5-5.8 BAAAA  Hokkaido, Japan            

 

A moderate earthquake of M 5.3 also occurred in Tonga today. A tropical storm passed through this area a week ago and may have helped promote this event. This is the strongest earthquake within about 200 km of this epicenter since an M 5.5 on April 27. The only larger event in the region this year, 2017,  occurred as an M 5.6 on January 28. Forecast 107741 had expected today's event was likely within about 25 km of this epicenter around May 26.

 

O: 22MAY2017 16:41:06  17.1S  173.7W mb=5.3  EMSC   TONGA                        

P: 26MAY2017 107741    17.0S  174.0W 4.0-5.8 BAAAA  Tonga Islands              

 

The strongest earthquake in the U.S. or Canada today continued the sequence in the western Fox Islands, Aleutians, Alaska. This event of M 4.3 was not reported felt in this remote region. The last event of M>=4.3 within about 100 km of this epicenter was an M 5.3 on May 6, 2017. Forecast 107704 had expected a moderate event in the Fox Islands around May 23.

 

O: 22MAY2017 16:51:22  51.3N  169.0W mb=4.3  EMSC   FOX ISLANDS, ALEUTIAN ISLANDS

P: 23MAY2017 107704    52.3N  165.7W 3.5-5.0 AAAAA  Fox Islands, Aleutians     

 

MODERATE EARTHQUAKE IN BAFFIN BAY

 

EARTHQUAKE SUMMARY FOR MAY 21, 2017

 

A moderate earthquake of M 4.6 was recorded in Baffin Bay west of Qaanaaq, Greenland today. This is a seismic zone but earthquakes in the area are seldom reported felt due to the remote location. The last earthquake of M>=4.6 in this area of the Baffin Bay within about 200 km of this epicenter was an M 4.6 on February 12, 2015. The last of significantly larger magnitude was an M 6.0 on July 7, 2009, the largest of five events of M>=4.6 in the area in the past 25 years.  Forecast 107481 had expected this event was likely about 200 km south of today's epicenter around May 21. Today's event may have been promoted by the moderate geomagnetic storm of the past two days, the strongest in nearly a month. Northern lights (aurora borealis) were observed and photographed as far south as Maine with this storm yesterday.

 

O: 22MAY2017 01:35:50  75.1N   72.7W mb=4.6  EMSC   BAFFIN BAY                   

O: 22MAY2017 01:35:51  75.1N   72.7W mb=4.6  ANSS   SSW of Qaanaaq Greenland

P: 21MAY2017 107481    73.3N   73.5W 2.5-4.0 ABAAA  Baffin/Davis Strait Canada 

 

The strongest earthquake in the U.S. today was an M 4.3 in the area of southeastern Alaska. NEIC reported this earthquake of M 4.3 in Southeastern Alaska was felt with intensity II-III in the area(s) of Alaska at Douglas, Juneau and Skagway, and in Whitehorse, Yukon, Canada. This is an aftershock of the pair of M 6.2 quakes at this epicenter on May 1. It is the strongest aftershock since May 4 when an M 4.5 occurred. Forecast 107715 had expected this event within about 100 km of this epicenter was likely around May 23.

 

O: 21MAY2017 19:33:38  59.8N  136.5W ML=4.3  EMSC   SOUTHEASTERN ALASKA          

O: 22MAY2017 03:13:27  59.9N  136.6W Ml=3.3  EMSC   SOUTHEASTERN ALASKA          

P: 23MAY2017 107715    59.0N  136.0W 3.0-4.4 AAAAA  Southeast Alaska           

 

A moderate earthquake of M 4.6 was also widely felt in the area of New Zealand today.  GEONET reported this earthquake was felt with strong intensity in the area NE of Kaikoura, South Island, New Zealand. There were 165 reports the quake was felt with 91 of weak shaking; 52 light; 19 moderate and 3 strong in the area of northern South Island and southern North Island. This is an aftershock of the M 7.8 that hit the area on November 13, 2016. It is the largest aftershock in the area in nearly two months, since an M 4.6-4.7 on April 9. The strongest aftershock during the year 2017 was an M 5.0 on February 1. Forecasts 107522 and 107772 had expected today's event within about 25 km of the epicenter was most likely around May 21-23.

 

O: 22MAY2017 02:10:04  42.4S  173.8E mb=4.2  EMSC   SOUTH ISLAND OF NEW ZEALAND  

O: 22MAY2017 02:10:03  42.2S  173.7E mb=4.2  ANSS   Kaikoura New Zealand

O: 22MAY2017 02:10:04  42.3S  173.9E MS=4.6  GEONET Felt with strong intensity

P: 21MAY2017 107522    42.0S  174.0E 3.0-5.1 AAAAA  So. Island, N.Z.           

P: 23MAY2017 107772    42.0S  174.0E 3.0-5.1 AAAAA  So. Island, N.Z.           

 

An earthquake in Spain today was within about 100 km of antipodal with the M 4.6 in South Island, New Zealand and occurred one hour and 26 minutes later as surface waves from the New Zealand quake would have been arriving in Spain. It is likely these waves promoted this light earthquake in Spain. This earthquake had been expected in forecast 107685 within about 100 km of this epicenter in late May.

 

O: 22MAY2017 03:36:41  42.3N    9.2W ML=2.1  EMSC   SPAIN                        

P: 27MAY2017 107685    43.0N    9.0W 3.0-5.1 BAAAA  Portugal                   

 

The strongest earthquake in California today was an M 3.5 in the Ridgemark area south of San Francisco in central California.  NEIC reported this earthquake of M 3.5 in Central California was felt with intensity II-III in the area(s) of Gonzales, Hollister, San Juan Bautista, Salinas, Carmel Valley, Paicines, Morgan Hill, Mountain View, and San Francisco, California.  The M 3.5 was preceded by regional foreshocks of M 2.3 and 2.4 about 40 km northwest of the M 3.5. No major damage was recorded with this earthquake. The last event of M>=3.5 within about 50 km of this epicenter was an M 3.5 on April 13, 2017. Forecast  107611 had expected this event about 50 km southeast of this epicenter was likely around May 24.

 

O: 22MAY2017 01:36:16  36.7N  121.3W Mw=3.5  EMSC   CENTRAL CALIFORNIA           

O: 21MAY2017 06:53:51  36.9N  121.6W MD=2.3  EMSC   CENTRAL CALIFORNIA           

O: 21MAY2017 07:34:15  36.9N  121.6W MD=2.4  EMSC   CENTRAL CALIFORNIA           

P: 24MAY2017 107611    36.4N  121.0W 2.5-4.5 AAAAA  Central California         

 

There were no moderately strong or strong earthquakes in the world today.  The strongest earthquakes of the day were of M 5.0-5.1 and generally occurred in the southwest Pacific where recent topical storms probably helped set a  higher magnitude level, espcially in in Tonga, Vanuatu and the Loyalty Islands. An M 5.0 in the South Indian Ridge was nearly antipodal to two light shocks in the Gulf of California. Seismicity in Mexico was considerably reduced over that which occurred on May 20.

 

O: 22MAY2017 00:18:59   5.0S  153.6E mb=5.1  EMSC   NEW IRELAND REGION, P.N.G.   

P: 19MAY2017 107311     6.0S  154.0E 4.0-5.8 AAAAA  New Britain                

 

O: 21MAY2017 07:10:37  20.4S  169.4E mb=5.0  EMSC   VANUATU                      

P: 23MAY2017 107748    21.0S  170.0E 4.0-5.4 AAAAA  Loyalty Islands            

 

O: 21MAY2017 08:12:07  28.6S   74.2E mb=5.0  EMSC   MID-INDIAN RIDGE             

 

O: 21MAY2017 05:44:03  28.0N  112.1W ML=3.8  EMSC   GULF OF CALIFORNIA           

O: 21MAY2017 05:25:48  28.2N  112.3W ML=3.6  EMSC   GULF OF CALIFORNIA           

P: 13MAY2017 107350    28.0N  112.0W 3.5-4.9 CAAAA  Gulf of California         

 

 

MEXICO SUBDUCTION ZONE ACTIVE

 

EARTHQUAKE SUMMARY FOR MAY 20, 2017

 

The region of Mexico saw seismic activation today along nearly the entire Mexico-Pacific subduction zone. This appears to be part of the boundary activation which this summary has been following for the past week. The strongest quakes occurred in western Mexico off Jalisco and in the Veracruz area of eastern Mexico north of Chiapas. NEIC reported the Veracruz quake at M 5.7. It was felt with intensity V in Rinconada, Veracruz, Xadani, Oaxaca and Comalcalco, Tabasco. Intensity IV was felt in Chiapas at San Cristobal de las Casas, Tuxtla Gutierrez, in Veracruz at Cordoba, Fortin, Orizaba, Jaltipan, and Coatzacoalcos. Intensity II-III was reported within about 500 km of the epicenter with reports from Puebla at Momoxpan, Acatzingo; Guatemala at Alta Verapaz, Salcaja, Quezaltenango; in Veracruz at Coatepec, El Castillo; in Oaxaca at Atzompa, Oaxaca, San Antonio de la Cal, Huatulco, Tlalixtac, Teotitlan den Valle, Mitla; in Jesus Carranza, Veracruz; Villahermosa and Cardenas, Tabasco and in Chiapas at La Trinitaria, Chiapa, Bochil. This is the strongest event in the Veracruz area of Mexico since an M 6.7 on April 7, 2011. Forecast 107327 had expected this event within about 20 km of the epicenter was most likely to occur around May 17. This epicenter is at 103 degrees from the M 6.8 in Vanuatu of May 9, the last major global earthquake. Seismic energy is concentrated at this distance from major events and can help promote subsequent seismicity. Other earthquakes today hitting at or near 103 degrees from Vanuatu occurred in Kansas, Oklahoma, Central Chile, the South Sandwich Islands and Hindu Kush, Afghanistan. A further promotional factor was the intensification of a geomagnetic storm which reached minor storm levels today about the time of the earthquakes in Mexico. This is the strongest disturbance in the geomagnetic field in nearly a month.

 

An earlier event of M 5.6-5.8 in western Mexico south of Colima was not reported felt in the epicentral region. Felt reports from eastern Mexico attributed to this event were probably related to the later Veracruz M 5.7. The last moderate event in Colima occurred as an M 4.3 on April 29, 2017. Events of M 4.0 occurred on March 20 and February 4, 2017. The last earthquake with M>=5.8 within about 200 km of today's epicenter occurred on June 2, 2016. That followed a quiet period which was the shadow of an M 7.6 in the area of January 22, 2003 lasting from 2003 through 2015. Forecast 107578 had expected today's activity in western Mexico was likely around May 22. This activity is located at node 4 (90 degrees) from the Vanuatu quake of May 9  and at the sixth node (60 degrees) from the Chile quake of M 6.9 of April 24, 2017 and was probably promoted from those sources.

 

O: 21MAY2017 04:58:24  16.0N   98.5W ML=4.0  EMSC   OFFSHORE OAXACA, MEXICO      

O: 21MAY2017 04:27:06  16.1N   98.4W ML=4.1  EMSC   OFFSHORE OAXACA, MEXICO      

P: 15MAY2017 107343    17.0N   98.0W 3.5-5.3 CAAAA  Oaxaca, Mexico             

 

O: 20MAY2017 17:58:47  17.1N   93.9W Mw=5.7  EMSC   OAXACA, MEXICO               

O: 20MAY2017 17:58:42  16.8N   94.1W ML=5.7  UNAM  l NOROESTE de CINTALAPA, CHIS *: 1

P: 17MAY2017 107327    17.0N   94.0W 3.5-5.3 BAAAA  Chiapas, Mexico            

 

O: 20MAY2017 16:58:41  17.2N  105.4W mb=4.7  EMSC   OFF COAST OF COLIMA, MEXICO  

O: 20MAY2017 16:58:41  17.5N  105.4W ML=4.7  UNAM  al SUROESTE de MANZANILLO, COL *:

O: 20MAY2017 06:02:03  16.9N  105.8W ML=5.6  UNAM  al SUROESTE de MANZANILLO, COL *:

O: 20MAY2017 06:02:13  17.4N  105.4W mw=5.8  ANSS   Colima, Mexico

O: 20MAY2017 06:02:14  17.5N  105.4W Mw=5.6  EMSC   OFF COAST OF COLIMA, MEXICO  

P: 22MAY2017 107578    18.0N  104.0W 3.5-5.3 AABAA  Michoacan, Mexico          

 

 

The antipode to western Mexico is in the mid-Indian Ridge. Several quakes have occurred in this area with moderate magnitude in the past several days, especially in connection with the strong swarm in the Gulf of California two days ago. An M 5.0 in this region of the south Indian Ocean occurred today

within several hours of the M 5.8 in Colima, Mexico.

 

O: 21MAY2017 08:12:08  28.6S   74.2E mb=5.0  EMSC   MID-INDIAN RIDGE             

 

The strongest activity in the U.S. or Canada today continued in the Aleutian Islands aftershock zones in the Rat and the Andreanof Islands. The strongest

of three moderate quakes in this area today was an M 4.4 in the western Andreanof Islands where it was not felt. These events had been expected at this time in forecasts 107713 and 107699.

 

O: 21MAY2017 03:53:15  51.5N  176.3E mb=4.1  EMSC   RAT ISLANDS, ALEUTIAN ISLANDS

P: 23MAY2017 107713    52.0N  177.0E 4.0-5.7 AAAAA  Rat Islands                

 

O: 21MAY2017 00:23:55  51.6N  176.4W Ml=4.2  EMSC   ANDREANOF ISLANDS, ALEUTIAN IS

P: 25MAY2017 107699    51.0N  177.1W 3.5-4.9 BAAAA  Andreanoff Isls, Aleutians 

 

O: 20MAY2017 22:37:51  51.7N  178.5W ML=4.4  EMSC   ANDREANOF ISLANDS, ALEUTIAN IS

P: 23MAY2017 107699    51.2N  178.9W 3.5-4.9 BAAAA  Andreanoff Isls, Aleutians 

 

An unusual event of M 4.3 also hit north of the Aleutians near the south coast of Chukotka, Russia. It was not reported felt in this remote area. The last earthquake within about 250 km of this epicenter with M>=4.3 occurred on April 8, 2006 with M 4.5. A strong earthquake of M 6.3-6.5 hit the area on April 30, 2010 about 350 km south of today's epicenter.

 

O: 20MAY2017 06:23:19  62.9N  179.2E mb=4.3  EMSC   NEAR S COAST OF CHUKOTKA, RUSS

 

 

STRONG EARTHQUAKE HITS CENTRAL PHILIPPINES

 

EARTHQUAKE SUMMARY FOR MAY 19, 2017

 

The largest earthquake in the world today was an M 5.9-6.0 in the region of Bohol, Central Philippines. The hypocenter of this event was at a deep focus, so while the  magnitude is large, the event was hardly felt at the surface. Shallow earthquakes in the area can have a major effect on the local population. An M 6.5 hit about 150 km east of this epicenter on February 10, 2017 but the strongest event within about 100 km of this epicenter with M>=6 was an M 7.1 on October 15, 2013. That came to be known as the Bohol earthquake. Thousands were killed and damage was in the billions of U.S. Dollars. Relief came from many sectors of private and public funding. That earthquake was probably triggered by Tropical Storm  Nari which passed over the epicenter several days before and had been expected in this summary to bring about a significant regional earthquake as noted on October 11-13, 2013:   

 

 

"TS Nari (TD 24W) continued today west of the central Philippines with winds up to 110 kts. A seismic watch is being called for the area of the central and northern Philippines and Taiwan for the next five days. Meteorologically triggered earthquakes are possible in the area during this time. One of these may be moderately strong." (October 11-13, 2013)

 

PHIVOLCS reported this earthquake was felt with intensity I in Catbalogan, Samar; Broongan, Eastern Samar, Philippines. Forecasts 107334 and 107296 had expected this activity was most likely around May 16-18.

 

O: 20MAY2017 01:06:13   9.4N  124.0E Mw=6.0  EMSC   BOHOL, PHILIPPINES           

O: 20MAY2017 01:06:12  09.4N  124.1E MS=5.6  PHI  Felt with intensity I

P: 16MAY2017 107334    10.0N  125.0E 3.5-5.1 BAAAA  Luzon, Philippines         

P: 18MAY2017 107296     9.0N  126.0E 4.0-5.7 AABAA  Central Philippines        

 

An earthquake of M 4.5 was felt throughout much of Romania today. The depth at 117 km meant it would be felt in a wide area. NEIC reported intensity II-III in Romania at Focsani, Vrancea; Brasov, Cristian, Galati, Bucharest, Popesti-Leordni, Ilfov, Romania and in Chisinau, Moldova.  The last earthquake within about 100 km of this epicenter of M 4.5 or greater was an M 4.7 on February 8, 2017.  Forecast 107688 had expected this earthquake in this region of Romania was likely around May 23.

 

O: 19MAY2017 23:46:02  45.8N   26.7E ML=3.4  EMSC   ROMANIA                      

O: 19MAY2017 20:02:42  45.8N   26.7E ML=4.5  EMSC   ROMANIA                      

P: 23MAY2017 107688    46.0N   26.0E 3.0-5.0 BAAAA  Romania/NW Turkey          

 

An M 5.2 also occurred in the Solomon Islands and was accompanied by a series of shocks of slightly smaller magnitude. It was reported from this as being felt with intensity III in Honiara, Guadalcanal and reported by GeoNet to have been felt in Honiara, Guadalcanal Solomon Islands. This is the strongest activity in the Solomon Islands since an M 6.0 on March 19, 2017. Forecast 107320 had expected this was likely around May 18.

 

O: 19MAY2017 14:31:33   9.2S  158.9E mb=4.9  EMSC   SOLOMON ISLANDS              

O: 19MAY2017 11:17:16   9.3S  158.8E mb=5.2  EMSC   SOLOMON ISLANDS              

O: 19MAY2017 16:49:42   9.3S  158.9E mb=4.8  EMSC   SOLOMON ISLANDS              

P: 18MAY2017 107320     9.0S  157.0E 4.0-5.4 AAAAA  Solomon Islands            

 

O: 19MAY2017 17:57:52   9.8S  159.2E mb=4.6  EMSC   SOLOMON ISLANDS              

P: 20MAY2017 107490    10.0S  160.0E 4.0-5.4 AAAAA  No. of Santa Cruz Islands  

 

The strongest earthquake recorded in the U.S. or Canada today was an M 3.5 (EMSC) to 4.4 (Earthquakes Canada) in the area of Vancouver Island off the coast of Washington. It was not reported felt in this epicentral area. The last earthquake within about 100 km of this epicenter occurred as an M 5.7 and an aftershock of M 4.8 on February 4, 2012. These are the only earthquakes of M>=4.4 to be registered in this area in the past 25 years.  Forecast 107693 had expected this event within this area was likely around May 24.

 

O: 19MAY2017 12:09:16  47.8N  127.9W ML=3.5  EMSC   OFF COAST OF WASHINGTON      

O: 19MAY2017 12:09:13  47.5N  128.3W ML=4.4  NRCA  250 km SW  of Tofino

P: 24MAY2017 107693    48.3N  128.5W 2.8-4.9 BAAAA  Vancouver Island area      

 

Current volcanic eruptions continued in the Aleutians near Umnak Island where

a moderate earthquake occurred yesterday. This was part of an ongoing eruption of Bogoslof Volcano. Cleveland Volcano also experienced a minor eruption with several moderate earthquakes over the past several days. Volcanic activity is also continuing at Mt. Etna, Italy; at Piton de la Fournaise, Reunion Island in the south Indian Ocean and at Manam in Papua New Guinea.

 

The strongest earthquake in California today was an M 2.4 shock in the current sequence near Santa Barbara in southern California. This follows similar regional activity over the past week. The area often becomes active in

late May as noted in previous summaries and moderate quakes in the region

may still occur in the next week. Forecast 107396 had expected today's  earthquake to the east around May 20.

 

O: 19MAY2017 22:37:51  34.3N  119.7W ML=2.1  EMSC   SANTA BARBARA CHANNEL, CALIF.

O: 19MAY2017 22:12:57  34.3N  119.7W ml=2.1  ANSS   Santa Barbara California

O: 19MAY2017 22:37:51  34.3N  119.7W ml=2.1  ANSS   Santa Barbara California

O: 19MAY2017 22:13:08  34.3N  119.7W ml=2.4  ANSS   Santa Barbara California

O: 19MAY2017 22:12:57  34.3N  119.7W ML=2.2  EMSC   SANTA BARBARA CHANNEL, CALIF.

P: 20MAY2017 107396    34.4N  118.6W 2.5-4.4 AAAAA  So. California             

 

STRONG SWARM SHAKES GULF OF CALIFORNIA

 

EARTHQUAKE SUMMARY FOR MAY 18, 2017

 

A strong sequence of light and moderate earthquakes hit the Gulf of California today. These events were not reported felt but continue the activation of the Pacific-North American boundary described in previous issues of this report. In the previous issue this report suggested an antipodal link between this area and a moderate event in  the South Indian Ocean as follows:

 

"A near-antipodal pair occurred today with an M 3.9 in the Gulf of California and a subsequent M 4.7 in the Mid-Indian Ridge. Neither of these were regionally felt or significant. The antipodal nature may be due coincidence or to tides or geomagnetic effects.

 

O: 17MAY2017 22:42:17  28.3S   74.3E mb=4.7  EMSC   MID-INDIAN RIDGE             

 

O: 17MAY2017 10:59:29  26.8N  111.0W ML=3.9  EMSC   GULF OF CALIFORNIA           

P: 13MAY2017 107350    28.0N  112.0W 3.5-4.9 BAAAA  Gulf of California " (May 18, 2017)        

 

The earthquake on the Mid-Indian Ridge of M 4.7 was the strongest within

about 200 km of that epicentere since an M 5.0 on June 8, 2016 and a similar M 5.0 on October 22, 2015.  An M 5.2 about 200 km northwest of this occurred on March 29, 2017. Forecast 107347 had expected this activity in the Gulf of California was likely around May 21 within about 50 km of these epicetner. The strongest of M 4.6 was the largest within about 200 km of this epicenter since an M 4.9 half a year ago on November 20, 2016 and a year befor that with M 4.9 on September 13, 2016 with M 6.5.

 

O: 18MAY2017 10:49:39  24.5N  109.0W Mw=4.6  EMSC   GULF OF CALIFORNIA

O: 18MAY2017 10:39:03  24.6N  109.0W ML=3.7  EMSC   GULF OF CALIFORNIA

O: 18MAY2017 10:29:10  24.6N  109.1W ML=3.8  EMSC   GULF OF CALIFORNIA

O: 18MAY2017 11:01:24  24.6N  109.2W ML=4.1  EMSC   GULF OF CALIFORNIA

O: 18MAY2017 10:46:22  24.7N  109.1W ML=3.8  EMSC   GULF OF CALIFORNIA

O: 18MAY2017 10:42:26  24.7N  109.1W ML=4.0  EMSC   GULF OF CALIFORNIA

O: 18MAY2017 10:21:45  24.7N  109.2W ML=3.6  EMSC   GULF OF CALIFORNIA

O: 18MAY2017 10:23:33  24.7N  109.2W ML=3.7  EMSC   GULF OF CALIFORNIA

O: 18MAY2017 10:59:54  24.7N  109.3W ML=3.4  EMSC   GULF OF CALIFORNIA

O: 18MAY2017 10:24:56  24.7N  109.3W ML=4.0  EMSC   GULF OF CALIFORNIA

O: 18MAY2017 18:50:07  25.8N  110.4W ML=4.2  EMSC   GULF OF CALIFORNIA

O: 18MAY2017 10:32:43  24.5N  108.8W ML=3.9  UNAM  al SUROESTE de GUASAVE, SIN *: 24.

O: 18MAY2017 10:39:03  24.6N  109.0W ML=3.7  UNAM  al SUROESTE de GUASAVE, SIN *: 24.

O: 18MAY2017 10:29:10  24.6N  109.0W ML=3.8  UNAM  al SUROESTE de GUASAVE, SIN *: 24.

O: 18MAY2017 10:46:22  24.6N  109.0W ML=3.8  UNAM  al SUROESTE de GUASAVE, SIN *: 24.

O: 18MAY2017 11:59:47  24.6N  109.0W ML=4.3  UNAM  al SUROESTE de GUASAVE, SIN *: 24.

O: 18MAY2017 10:23:33  24.6N  109.1W ML=3.7  UNAM  al SUROESTE de G LEYVA SOLANO(BENI

O: 18MAY2017 10:42:26  24.6N  109.1W ML=4.0  UNAM  al SUROESTE de GUASAVE, SIN *: 24.

O: 18MAY2017 11:01:24  24.6N  109.1W ML=4.1  UNAM  al SUROESTE de GUASAVE, SIN *: 24.

O: 18MAY2017 10:49:41  24.6N  109.1W ML=4.3  UNAM  al SUROESTE de GUASAVE, SIN *: 24.

O: 18MAY2017 10:21:45  24.6N  109.2W ML=3.6  UNAM  al SUROESTE de G LEYVA SOLANO(BENI

O: 18MAY2017 10:24:56  24.6N  109.2W ML=4.0  UNAM  al NORESTE de LA PAZ, BCS *: 24.67

O: 18MAY2017 10:59:54  24.7N  109.3W ML=3.4  UNAM  al NORESTE de LA PAZ, BCS *: 24.7°

O: 18MAY2017 18:50:07  25.8N  110.3W ML=4.2  UNAM  al ESTE de LORETO, BCS *: 25.82°,

O: 18MAY2017 11:59:45  24.4N  108.9W Mw=4.6  EMSC   GULF OF CALIFORNIA           

P: 21MAY2017 107349    24.0N  109.0W 3.5-5.0 BAAAA  Gulf of California         

 

 

The strongest earthquake in the world today was an M 5.5 deep under Mendoza, Argentina. While it was not initially reported felt, light shaking probably did occur with this earthquake. An earthquake of M 5.4 hit about 200 km northwest of this on February 3, 2017 but this is the strongest earthquake within about 200 km of this epicenter since an M 6.3 on February 2, 2015 and prior to that an M 5.5 on November 15, 2013. Forecast 107759 had expected this event was likely around May 23.

 

O: 18MAY2017 23:45:42  32.7S   67.3W ML=5.5  EMSC   MENDOZA, ARGENTINA           

P: 23MAY2017 107759    33.0S   69.0W 4.0-5.7 BABAA  Central Chile              

 

A series of light earthquakes in Hawaii today also occurred with maximum magnitude M 3.2. NEIC reported this earthquake was felt with intensity II-III in Hawaii at Pahoa, Volcano, Hilo, Papaikou and Pepeekeo. Earthquakes of M>=3.2 have not been common in Hawaii in the past month and have included an M 3.3 on May 3; and M 3.7 on April 27 only. Forecast 107570 had expected a light to moderate quake in Hawaii in late May.

 

O: 18MAY2017 21:07:34  19.1N  155.3W ML=2.9  EMSC   ISLAND OF HAWAII, HAWAII

O: 18MAY2017 13:34:45  19.1N  155.4W MD=2.6  EMSC   ISLAND OF HAWAII, HAWAII

O: 18MAY2017 13:23:14  19.1N  155.5W MD=2.5  EMSC   ISLAND OF HAWAII, HAWAII

O: 18MAY2017 21:15:34  19.4N  155.1W ML=3.2  EMSC   ISLAND OF HAWAII, HAWAII     

P: 25MAY2017 107570    19.4N  155.3W 3.0-4.4 CAAAA  Hawaii                     

 

The series in the region of Seattle, Washington also continued today. The largest event in this sequence today was an M 2.5. NEIC reported it was felt with intensity II-III in Washington at Bremerton, Bainbridge Island, Kingston, Carnation, and Anacortes. The strongest in this recent set was an M 3.6 on May 11 and an M 3.4 on May 10. Forecast 107446 had expected this activity was likely within about 50 km around May 19.

 

O: 18MAY2017 18:11:32  47.6N  122.6W ML=2.2  EMSC   SEATTLE-TACOMA AREA, WASHINGTO

O: 18MAY2017 18:15:32  47.6N  122.6W ML=2.5  EMSC   SEATTLE-TACOMA AREA, WASHINGTO

P: 19MAY2017 107446    48.0N  123.0W 2.0-4.1 AAAAA  Washington state, U.S.     

 

The earthquake off the coast of Northern California, initially reported as unfelt in the previous issue of this summary was felt with light intensity. NEIC reported intensity I-II in California at Eureka, Scotia and Arcata. It may have been felt with intensity I-II in McKinleyville and Myers Flat up to 150 km from the offshore epicenter.

 

O: 18MAY2017 03:20:37  40.4N  125.5W Mw=4.0  EMSC   OFFSHORE NORTHERN CALIFORNIA 

P: 17MAY2017 107434    40.9N  126.3W 2.5-4.9 AAAAA  Off Coast of No. Calif     

 

The strongest earthquake in the U.S. or Canada today was an M 5.2 in the Amukta Pass area of the western Fox Islands. NEIC did not issue any felt reports for this event. An event of M 5.3 hit about 50 km northwest of today's epicenter on May 6 and this may be a regional aftershock of that event. Forecast 107450 had expected today's event was likely within about 25 km of this around May 16. Moderate earthquakes in Alaska today also occurred on the Alaska Peninsula (M 4.5) and in the western Andreanof Islands (M 4.3).

 

O: 19MAY2017 01:24:55  51.8N  170.3W ML=4.0  EMSC   FOX ISLANDS, ALEUTIAN ISLANDS

O: 19MAY2017 01:21:40  52.1N  170.6W mb=5.2  EMSC   FOX ISLANDS, ALEUTIAN ISLANDS

O: 18MAY2017 05:29:04  52.3N  170.5W ML=4.0  EMSC   FOX ISLANDS, ALEUTIAN ISLANDS

P: 16MAY2017 107450    52.4N  170.7W 3.5-5.0 AAAAA  Andreanoff Isls, Aleutians 

 

MODERATE QUAKES IN MEXICO, GREECE AND AFGHANISTAN

 

EARTHQUAKE SUMMARY FOR MAY 17, 2017

 

There were no strong or moderately strong earthquakes in the world today. The day marked a transition between tidal and weather-controlled seismicity and seismicity  in the next several days likely to be promoted by effects of a major geomagnetic storm. The strongest earthquake of the day was an M 5.3 in western Mexico in the Michoacan State but two moderate earthquakes of M 4.9 and 4.2 also struck the region of Greece and Turkey and moderate event were also felt in Afghanistan and Pakistan.

 

The strongest earthquake in the world today was an M 5.2-5.3 south  of Guerrero, Mexico. This appears to be related to the activation of the Pacific-North American boundary but may also be related to stresses from the remnants of Tropical Storm Adrian which passed near this epicenter in the past several days. It was too far off the coast of Mexico to have been felt with moderate intensity in coastal communities. The last earthquake with M>=5.2 within about 200 km of this epicenter was an M 5.4 on July 23, 2016 and prior to that on January 22, 2011 with M 5.5. Only two ther events of M>=5.2 have occurred in this region in the past 25 years with the only one of M>5.2, an M 5.9 on October 28, 1994.

Forecast 107336 had expected this event within this region was likely around May 18. 

 

O: 17MAY2017 09:13:30  14.4N  103.4W mb=5.2  EMSC   OFF COAST OF GUERRERO, MEXICO

O: 17MAY2017  9:13:28  14.3N  103.0W ML=5.3  UNAM  al SUROESTE de ZIHUATANEJO, GRO *:

P: 18MAY2017 107336    15.0N  104.0W 3.5-5.2 AAAAA  Michoacan, Mexico          

 

The M 4.9 in the Dodecanese Islands of Greece was the strongest in that region during the current year, 2017.  NEIC reported this earthquake of M 4.9 in the Dodecanese Islands, Greece was felt with intensity IV in Falirakion, Greece and II-III in the area(s) of the Dodecanese Islands at Lardos, Soroni, Afantou, Ialisos, Sgourou, Rodos, Greece and in western Turkey at Marmaris and Fethiye, Mugla.  The last earthquake of M>=4.9 in this region of the Aegean Sea within about 100 km of this epicenter occurred on December 20, 2016 with M 5.4. Forecast 107364 had expected this event was likely around May 19.

 

O: 17MAY2017 13:02:06  35.6N   28.4E mb=4.2  EMSC   EASTERN MEDITERRANEAN SEA    

P: 16MAY2017 107406    36.0N   29.0E 3.5-5.1 AAAAA  Turkey                     

 

O: 17MAY2017 11:30:32  35.9N   27.5E Mw=4.9  EMSC   DODECANESE ISLANDS, GREECE   

P: 19MAY2017 107364    37.0N   27.0E 3.0-4.8 ABAAA  Aegean Sea                  

 

The most unusual earthquakes of the day occurred as an M 4.6 in Central Afghanistan with an M 4.3 foreshock.  NEIC reported this earthquake of M 4.6 in Afghanistan was felt with intensity II-III in the area(s) of Baghrami, Kabul, Afghanistan. A foreshock of M 4.3 was similarly felt. The last earthquake of M>=4.6 in Central Afghanistan within about 100 km of these epicenters occurred on December 8, 2016 with M 4.6 but the last of larger magnitude was an M 4.8 on May 18, 2012. Forecast 107390 had expected this activity within about 50 km of these epicenters was likely around May 14.

 

O: 17MAY2017 15:05:26  34.1N   69.2E mb=4.3  EMSC   CENTRAL AFGHANISTAN          

O: 17MAY2017 16:19:30  34.3N   69.5E mb=4.6  EMSC   CENTRAL AFGHANISTAN           

P: 14MAY2017 107390    34.0N   70.0E 3.8-5.2 BAAAA  Pakistan                   

 

Earthquakes of M 4.0 off northern California; M 4.1 in the western aftershock zone of the Aleutian Islands and M 4.1 south of Santa Barbara, California today kept up a brief, but important activation of the Pacific-North American plate  boundary today. The Santa Barbara sequence was discussed in the previous issue of this summary. The event in the Aleutians was the latest aftershock near 178 West longitude and was unfelt. The earthquake off Northern California of M 4.0 was too far offshore to have been felt in the coastal communities. A similar M 4.0 hit east of this on March 6, 2017. The last event of M>4 in this area west of 125 West longitude was an M 4.7 more than half a year ago, on December 8, 2016, an aftershock of an M 6.5 on the same day. Forecast 107434 had expected this event was possibly in this region around May 17.

 

O: 18MAY2017 03:20:33  40.4N  125.7W Mw=4.0  EMSC   OFF COAST OF NORTHERN CALIFORN

O: 18MAY2017 03:20:33  40.4N  125.7W mw=4.0  ANSS   124km W of Ferndale

O: 17MAY2017 08:22:22  40.3N  124.6W md=2.1  ANSS   SW of Ferndale California

P: 17MAY2017 107434    40.9N  126.3W 2.5-4.9 AAAAA  Off Coast of No. Calif     

 

O: 17MAY2017 06:03:09  51.5N  178.4W mb=4.1  EMSC   ANDREANOF ISLANDS, ALEUTIAN IS

P: 15MAY2017 107449    51.9N  178.8W 3.5-4.9 AAAAA  Andreanoff Isls, Aleutians 

 

A near-antipodal pair occurred today with an M 3.9 in the Gulf of California and a subsequent M 4.7 in the Mid-Indian Ridge. Neither of these were regionally felt or significant. The antipodal nature may be due coincidence or to tides or geomagnetic effects.

 

O: 17MAY2017 22:42:17  28.3S   74.3E mb=4.7  EMSC   MID-INDIAN RIDGE             

 

O: 17MAY2017 10:59:29  26.8N  111.0W ML=3.9  EMSC   GULF OF CALIFORNIA           

P: 13MAY2017 107350    28.0N  112.0W 3.5-4.9 BAAAA  Gulf of California         

 

MODERATE QUAKE SHAKES SANTA BARBARA, CALIFORNIA

 

EARTHQUAKE SUMMARY FOR MAY 16, 2017

 

A moderate earthquake of M 4.1 south of Santa Barbara, California today was widely felt in the area of Goleta and Santa Barbara and was followed by several light aftershocks. NEIC reported the mainshock was felt with intensity II-III in Goleta, Santa Barbara, Solvang, Santa Ynez, Buellton, Los Olivos, Lompoc, Carpinteria, Santa Maria, Ventura, Maricopa, Guadalupe, Nipomo, Camarillo, Arroyo Grande, Oceano, Grover Beach, Moorpark, Thousand Oaks, Simi Valley, Malibu, Sherman Oaks, Marina del Rey, Los Angeles and in general within about 100 km of the epicenter. An M 3.1 aftershock was felt with intensity II-III in Santa Barbara, Lompoc, Santa Maria and Atascadero, California. On May 7, 2017, this summary reported on foreshocks to today's M 4.1 in the Santa Barbara area as follows:

 

"A series of light earthquakes in the region of Santa Barbara, California today included an M 3.2. These events were reported by NEIC to have been felt with intensity II-III in Santa Barbara, Summerfield, Carpinteria, Goleta, Ventura, Port Hueneme, Lompoc, Camarillo and in general within about 100 km of the epicenters. The region of Santa Barbara, California has seen an activation of light earthquakes over the past several weeks which could indicate a larger event is in the works. These have included an M 3.4-3.6 on April 23, 2017 about 15 km from today's epicenter. Prior to that events of M>=3.2 hit the area on November 23, 2016 and with M 3.5 on April 6, 2016. Forecast 107163 had expected active seismic conditions in the region near Santa Barbara around May 11." (May 7, 2017)

 

Earlier in the year, this summary had linked moderate to strong earthquakes in Santa Barbara to a 23-year seismic cycle in Southern California as:

 

"Activity, normally associated with seasonal cyclones moving north of Madagascar often occurs in southern California at this time of year. An interesting 23-year cycle occurs in Southern California recently active in the San Fernando/Simi Valley/Northridge areas but extending way back. The last major earthquake to hit the greater Los Angeles area was the M 6.7 of January 17, 1994 in Northridge, 23 years ago. This was preceded by the San Fernando (also M 6.7) earthquake of February 9, 1971, 23 years prior to that. In December, 1948 an M 6.5 occurred east of Los Angeles (again 23 years prior); Likewise the Santa Barbara quake of M 6.3 on June 29, 1925 was 23 years earlier than that with two events of M 6.5 and 6.7 25 years earlier in the Riverside and eastern L.A. area in July and

December, 1899. There is no record of a strong quake in 1880, 23 years prior to 1902, the expected date prior to 1925 however, the Fort Tejon earthquake of M 8.3 did hit southern California on January 9, 1857 and 45 years (missing 1834) a strong quake of M 7.2 hit western Los Angeles on December 21, 1812. This cyclic earthquake history of the region is pretty precise at the 23 year period often with the quake of note occurring in the period December through February. Some have speculated that this may be related to strong winter rains in the region which can lubricate faults and trigger strong, shallow earthquakes. Of course, 22-23 years is also the major solar cycle. Whatever the cause, the historical series is clear and residents of the region should be prepared for a strong earthquake in the next two months. The history of predictions based on cyclic behavior, however, is not good (consider the Parkfield experiment which used a similar 22-23 year cycle and failed, perhaps because a series of earthquakes in Coalinga reset the regional stresses). With this caveat, however, the mainshocks are often preceded by a series of strong regional foreshocks up to several years in advance. These have not yet occurred in the current cycle, and perhaps an ominous quiet has settled in the area in the past several years - a seismic quiescence? This report will look for signs that this event is about to occur and attempt to give some days prior warning, but the season is now here. A strong antipodal cyclone in the Indian Ocean could be a trigger as could the earthquake today in Madagascar." (January 11, 2017)

 

The M 4.1 in Santa Barbara is the strongest earthquake within about 50 km of that epicenter since an M 4.1 on March 12, 2016. The last event in the region with higher magnitude was an M 4.8 on May 28, 2013.   Forecast 107163 had expected this event in this area was likely in mid-May. This summary placed the Santa Barbara activity in historical context on May  29, 2013 following the M 4.8. Part of that discussion follows:

 

"This is the strongest earthquake to hit the Santa Barbara area in at least 25 years. The only similar event since 1990 occurred about 100 km southeast of this on March 16, 2002 with M 4.8. This is an uncommon epicenter, the last event of M 3 within 50 km of this epicenter was an M 3.0 on January 6, 2012 and the last of M>3 was an M 3.4 on November 17, 2007. Moderate earthquakes of M>4.5 in this region near Santa Barbara have largely been confined to occur at the end of June or the end of May. The last event of M>4.7 in the area also occurred on May 29, that one in 1980 with M 5.1 to the northwest of today's earthquake. One other moderate earthquakes have also hit the area  on May 29 - in 1854 - an M 6.0 and two have occurred at the end of May – on May 19, 1893 (M 5.9); May 25, 1953 (M 4.8); and May 24, 1954 (M 5.1). Stronger events in the area tend to recur within a few days of June 29, a month later. These have included an M 6.3 on June 29, 1925, the strongest recorded in the area of today's epicenter followed a year later on June 29, 1926 by an M 5.5 aftershock. On July 1, 1941 the area experienced an M 6.0 and an M 5.0 hit the area on June 29, 1968.  Seasonal activity in an area such as this can be related to meteorological conditions or to geomagnetic or tidal conditions as the sun is nearly directly over head in this area at this time of year. In previous years this summary has emphasized this seasonal variation in the Santa Barbara area in the history section of this summary." (May 29, 2013)

 

 

O: 17MAY2017 04:49:09  34.4N  120.0W Ml=2.2  EMSC   SANTA BARBARA CHANNEL, CALIF.

O: 17MAY2017 04:50:42  34.4N  120.0W Ml=2.2  EMSC   SANTA BARBARA CHANNEL, CALIF.

O: 17MAY2017 04:42:25  34.4N  120.0W Ml=4.0  EMSC   SANTA BARBARA CHANNEL, CALIF.

O: 17MAY2017 04:42:25  34.4N  120.0W mw=4.1  ANSS   W of Isla Vista

O: 17MAY2017 04:43:29  34.5N  120.0W Ml=3.1  EMSC   SOUTHERN CALIFORNIA          

P: 11MAY2017 107163    34.7N  119.0W 2.5-4.4 CAAAA  So. California              

 

The most widely felt earthquake in the U.S. or Canada outside California today occurred on the New Madrid faultline in Missouri. NEIC reported intensity IV in Cairo, Illinois and II-III in Bardwell, Barlow, Cunningham, Clinton, Fancy Farm, Kevil, Paducah, West Paducah, Boaz, Mayfield, Ledbetter, Gilbertsville, Murray, Arlington,  and Wickliffe, Kentucky; in Illinois at Jacob, Waterloo, Golconda, Pomona, Elizabethtown, Waterloo; in Indiana at West Lafayette, Lexington; in Missouri at Cape Girardeau, Jackson, Fredericktown, Saint Louis, Pacific. Also it was reported felt in Boles, Arkansas; Clarksville and Memphis, Tennessee. This appears to be the strongest aftershock to date of the M 3.6 which hit the same epicenter on March 15, 2017. A foreshock occurred as an M 2.2 on February 13. Forecast 107381 had expected today's event within about 15 km of the epicenter was likely around May 17.

 

O: 16MAY2017 10:21:52  36.9N   89.1W Mw=3.3  EMSC   WESTERN KENTUCKY             

O: 16MAY2017 10:21:52  36.9N   89.1W mw=3.3  ANSS   10km W of Bardwell

P: 17MAY2017 107381    37.0N   89.0W 2.0-4.2 AAAAA  New Madrid area            

 

The strongest earthquake in the U.S. or Canada today, however went unfelt. This event was an aftershock of the M 5.8 of April 27, 2017 which began a strong series of earthquakes in the Aleutian Islands. Forecast 107461 had expected today's event within about 100 km of this epicenter was likely around May 17.

 

O: 16MAY2017 11:41:55  51.2N  179.3E mb=4.9  EMSC   RAT ISLANDS, ALEUTIAN ISLANDS

P: 17MAY2017 107461    52.0N  179.0E 4.0-5.7 AAAAA  Rat Islands                

 

A moderate earthquake in Central Peru was recorded today with M 5.4. NEIC reported it was felt with minor damage in Tambo, Ayacucho about 60 km from the epicenter with intensity VI. Intensity V was felt in Coracora and IV in Puquio, Ayacucho. Lesser intensity of II-III was felt within about 180 km of the epicenter in Ayacucho, Nazca, Acari, Orcopampa, Arequipa and in Apurimac at Abancay and San Jeronimo, Peru. IGP reported this earthquake was felt with intensity VI in  Pampamarca; IV Chalhuanca; III Cora Cora, Querobamba; II-III Antabamba, II Puquio, Pausa, Peru. Forecast 107494 had expected this event south of this epicenter around May 18. The last event with M>=5.4 within about 200 km of this epicenter occurred on August 15, 2016 with M 5.4-5.5. The last of stronger magnitude was an M 6.9 on August 24, 2014. Forecast 107494 had expected an event of moderately large magnitude was possible in this region around May 18.

 

O: 16MAY2017 17:09:06  14.4S   73.4W mb=5.4  EMSC   CENTRAL PERU                 

O: 16MAY2017 06:06     15.3S   73.6W mb=4.2  IGP    Pausa-Ayacucho, Peru.        

O: 16MAY2017 17:09     14.6S   73.6W mb=5.2  IGP    Pampamarca; IV Chalhuanca; III

P: 18MAY2017 107494    16.0S   73.0W 4.0-5.6 AAAAA  So. Peru/Bolivia           

 

The strongest earthquake in the world today occurred as an M 5.7 in the Tonga/Fiji region. It was not reported felt in this remote area. It was probably promoted by Tropical Cyclone Ella which passed through the region late last week. This summary had noted this as follows:

 

"TC Ella continued west of Samoa and northern Tonga today with winds up to 55 kts. It is expected to track to the west over the next four days. Seismicity in the region of northern Tonga and Samoa is expected to be high while Ella is in the area. A moderate to strong quake is possible during the period May 10-15 in this area." (May 12-14, 2017)

 

This may be an aftershock of the M 6.9 which hit about 100 km west of this on February 24 but may also be a new mainshock. Forecast 107508 had expected this event within about 100 km of the epicenter was likely around May 17.

 

O: 16MAY2017 07:08:03  22.1S  175.9W mb=4.6  EMSC   TONGA REGION                 

O: 16MAY2017 15:29:18  23.8S  177.6W Mw=5.7  EMSC   SOUTH OF FIJI ISLANDS        

P: 17MAY2017 107508    23.0S  177.0W 4.0-5.6 AAAAA  Tonga Islands              

 

Another area where storm-promoted seismicity is occurring is the Vanuatu-Loyalty Islands region. This continues the seismicity associated with TC Donna as noted in previous issues of this summary:

 

"A series of moderate earthquake struck central and southern Vanuatu and the

Loyalty Islands today with maximum magnitude M 4.9. While none of these were widely felt in the Vanuatu Islands, they do illustrate the triggering effects of strong meteorological events. These events occurred as Tropical Cyclone Donna, currently with winds up to 140 kts, a major storm, swept through the region. The seismicity had been expected to accompany this cyclone as noted in this summary in previous issues:

 

 

"(TC Donna will) follow the Vanuatu Islands along through May 8. Seismicity in the Vanuatu region is expected to be high while TC Donna is in the region with a potential large earthquake in the next three days. This is most likely  towards the end of this period as winds associated with Donna reach upwards towards 135 kts. The area is under a seismic watch through May 9." (May 5-7, 2017)

(May 7-9, 2017)

 

O: 16MAY2017 22:02:30  20.7S  168.7E mb=4.9  EMSC   LOYALTY ISLANDS              

P: 11MAY2017 107274    20.0S  169.0E 4.0-5.4 BAAAA  Vanuatu Islands            

 

O: 16MAY2017 11:22:25  21.6S  169.7E mb=4.6  EMSC   SOUTHEAST OF LOYALTY ISLANDS 

P: 17MAY2017 107502    21.0S  170.0E 4.0-5.4 AAAAA  Loyalty Islands            

 

STRONG EARTHQUAKES IN WEST PACIFIC

 

EARTHQUAKE SUMMARY FOR MAY 15, 2017

 

A series of moderately strong to strong earthquake hit three different tectonic settings along the western edge of the Pacific plate today. These events of M 6.2 in New Britain; M 5.6 in Guam and M 5.7 in Taiwan appear to be resetting the global seismic pattern to a more normal spring and summer distribution after a series of unusual earthquakes during this relatively quiet spring. This pattern is often strong ocean storms at this time of year. As the occurred near the geomagnetic equator, they may also reflect stresses from renewed geomagnetic activity which is expected to peak with major storms in the new two days. The strongest earthquake in the world today occurred as an M 6.2 in the area of New Britain. NEIC reported it caused minor damaged in New Ireland at Namatanai and in East New Britain at Rabaul and Kokopo. This is the strongest earthquake within the New Britain area since an M 6.3 on March 5, 2017 and the strongest in this generally active seismic area within about 200 km of this epicenter since an earthquake of M 6.7 on August 31, 2016. A great earthquake of M 7.9 hit about 200 km southeast of this on December 17, 2016, the last strong quake in the area.  Forecast 107311 had expected today's event within about 50 km of this epicenter to occur around May 17.

 

O: 15MAY2017 13:22:38   4.0S  152.5E Mw=6.2  EMSC   NEW BRITAIN REGION, P.N.G.   

P: 17MAY2017 107311     4.0S  152.0E 4.0-5.6 AAAAA  New Britain                

 

The strongest earthquake in the U.S. or Possessions today was an M 5.6 in the area of Guam. NEIC reported felt intensity IV in Guam at Talofofo, Agat, Santa Rita, and II-III in Yona, Mangilao, Barrigada, Mongmong, Hagatna, Asan, Tamuning, Piti, Yigo and Dededo, Guam. The most recent moderate quake in the region of Guam occurred on May 9, 2017 with M 5.2, the largest previously in 2017. The last event of M>=5.6 in the Guam region occurred on October 20, 2015 with M 5.6 but the last of larger  magnitude was an M 6.7 on September 17, 2014. Seismicity in Guam increases during the summer typhoon season. In the past seven years 7 of 9 events of M>=5.6 in the area have occurred in the months of July through October, major typhoon season months. Forecast 107345 had expected this activity in Guam around May 16-19.

 

O: 16MAY2017 03:56:27  12.8N  145.1E mb=5.6  ANSS   Inarajan Village Guam

O: 16MAY2017 03:56:27  12.8N  145.2E mb=5.6  EMSC   GUAM REGION                  

P: 16MAY2017 107345    13.0N  143.0E 4.0-5.6 AABAA  So. Marianas/Guam          

P: 19MAY2017 107345    14.0N  145.0E 4.0-5.6 ABAAA  So. Marianas/Guam          

 

A moderately large earthquake also shook the region of Taiwan today. CWB reported this earthquake was felt with intensity V in Taitung County; III in Hualien, Kaohsiung, Yunlin, Chiayi and Tainan; II in Nantou, Pingtung, Taichung, Changhua, Tainan, Miaoli, and I in Yilan, Taoyuan, Hsinchu and Penghu Counties, Taiwan. NEIC reported this earthquake of M 5.3 in Taiwan was felt with intensity II-III in the area(s) of Taitung, Hualien, Peitou, Taichung, Tainan, Fengshan, Kaohsiung, Chungho and Yungho, Taipei, Taiwan. The largest earthquake in Taiwan during the current year was an M 5.4-5.7 on April 30. There was no major damage associated with today's event though it shook most of the island of Taiwan. Forecast 107361 had expected this event within Taiwan was possibly around May 16.  Earlier in the day a pair of earthquakes of M 5.4 and 4.6 hit north of Taiwan in the Ryukyu Islands of Japan. These were not felt strongly. Forecast 107353 had expected activity about 200 km north of this was likely around May 18. An M 6.1 hit about 500 km southwest of this in the Ryukyu Islands on May 9 and this may be regional aftershocks to that event. The last moderate quakes within about 100 km of these epicenters occurred April 17, 2017 with two events of M 4.9 each.

 

O: 15MAY2017 23:12:54  23.2N  121.4E Mw=5.3  EMSC   TAIWAN                       

O: 15MAY2017 23:12:54  23.3N  121.5E ML=5.7  TAI    Hualien, Taiwan               

P: 16MAY2017 107361    24.0N  121.0E 4.0-5.4 AAAAA  Taiwan                     

 

NEIC reported the earthquake of M 5.5 in the Ryukyu Islands was felt with intensity II-III in the area(s) of Maze, Kagoshima and in Okinawa at Ishikawa, Okinawa, Chatan and Tomigusuku, Japan. An M 4.6 foreshock was felt with intensity II in Chatan, Okinawa.

 

O: 15MAY2017 07:05:36  27.2N  130.2E Mw=5.4  EMSC   RYUKYU ISLANDS, JAPAN        

O: 15MAY2017 07:03:30  27.3N  130.1E mb=4.6  EMSC   RYUKYU ISLANDS, JAPAN         

P: 18MAY2017 107353    29.0N  131.0E 4.0-5.4 BBAAA  Kyushu Japan               

 

The strongest earthquakes in the U.S. or Canada continued as aftershocks in  the Andreanof Island, Aleutians, Alaska. Aftershocks in the western Andreanof Island of the M 6.4 in that region of May 8 reached magnitudes of M 4.1 and 4.3 but were not felt. This activity had been expected within about 35 km of these epicenters around May 15 in forecast 107449. The largest event in the region today, however, was an M 4.7 at the eastern end of the Andreanof Islands. This is the strongest in this area since an M 5.2 on March 1. Forecast 107450 had expected this event was likely around May 12.

   

O: 15MAY2017 19:26:13  51.6N  178.3W ML=4.1  EMSC   ANDREANOF ISLANDS, ALEUTIAN IS

O: 15MAY2017 19:57:51  51.6N  178.4W ML=4.3  EMSC   ANDREANOF ISLANDS, ALEUTIAN IS

O: 15MAY2017 09:09:18  51.7N  178.7W ML=3.4  EMSC   ANDREANOF ISLANDS, ALEUTIAN IS

P: 15MAY2017 107449    51.9N  178.8W 3.5-4.9 AAAAA  Andreanoff Isls, Aleutians 

 

O: 15MAY2017 14:31:32  52.4N  173.6W mb=4.7  EMSC   ANDREANOF ISLANDS, ALEUTIAN IS

P: 12MAY2017 107450    51.2N  174.4W 3.5-4.9 BBAAA  Andreanoff Isls, Aleutians 

 

The strongest earthquake in California today was an M 3.6 in the Big Bear Lake region east of Los Angeles, California.  NEIC reported this earthquake of M 3.6 in Southern California was felt with intensity II-III in the area(s) of Angelus Oaks, Big Bear City, Big Bear Lake, Yucaipa, Palm Springs, Redlands, Cathedral City, Palm Desert, Ontario, Temecula, Whittier, Santa Ana, Carson, and Torrance, California.  This is the strongest event within about 50 km of this epicenter since an M 3.9 on December 28, 2016, the only such event in the region in the past year since an M 4.1 on February 23, 2016. Forecast 107395 had expected this event within about 25 km of this epicenter was likely around May 15.

 

O: 15MAY2017 18:43:08  34.2N  116.7W ML=3.6  EMSC   SOUTHERN CALIFORNIA          

P: 15MAY2017 107395    34.4N  116.5W 2.5-4.7 AAAAA  So. California              

 

A pair of light earthquakes of M 2.5 and 2.7 also lightly shook the San Francisco Bay area today. The first of these of M 2.5 had been expected within about 10 km to occur on May 17 in forecasts 107370. This area could get more active as the new geomagnetic storms intensity over the next several days.  The last event of M>2.7 in the area was an M 3.8 on April 30, 2017 several days

after a major geomagnetic storm in late April. Since September, 2016 all but this event of M 3.8 have had magnitude less than M 3.0. Tidal stresses also help promote regional seismicity in the San Francisco area.

 

NEIC reported the earthquake of M 2.7 in the area east of San Francisco, California was felt with intensity II-III in the area(s) of Pleasant Hill, Concord, Martinez, Oakland, and Livermore, California.  The M 2.5 in the East Foothills near San Francisco was reported felt with intensity III in San Jose, California within about 5 km of the epicenter.

 

O: 15MAY2017 22:22:04  37.4N  121.8W MD=2.5  EMSC   SAN FRANCISCO BAY AREA, CALIF.

O: 15MAY2017 22:50:03  38.0N  122.1W MD=2.7  EMSC   SAN FRANCISCO BAY AREA, CALIF.

P: 17MAY2017 107370    37.4N  121.7W 2.5-4.6 AAAAA  Central California         

 

STRONG QUAKE HITS BOLIVIA

 

EARTHQUAKE SUMMARY FOR MAY 14, 2017

 

The strongest earthquake of the day was an M 5.7 (NEIC) to M 6.0 (CSN) in the Tarapaca region near the border of Bolivia and northern Chile.  CSN reported this earthquake was felt with intensity IV in  Codpa, Cuya, Camina, Maria Elena, Quillagua, Tocopilla; III Arica, Alto Hospicio, Iquique, II Colchane, Pica, Pisagua, Felt in Arica, Parinacota, Tarapaca and Antofagasta, Chile.

NEIC reported this earthquake of M 5.6 in Northern Chile was felt with intensity V in Iquique, Tarapaca, Chile and II-III in the area(s) of Calama, Antofagasta and Arica, Tarapaca, Chile. No damage was reported with this intermediate depth hypocenter. The last earthquake of M>=5.7 in the Potosi, Bolivia area was an M 5.7 on January 6, 2017. The last of M>=6 occurred on March 24, 2008 with M 6.1-6.2.   Forecast 107507 had expected this event within about 100 km of this epicenter was most likely around May 12.

 

O: 14MAY2017 19:44:23  20.8S   68.6W Mw=5.7  EMSC   POTOSI, BOLIVIA              

O: 14MAY2017 19:44     20.8S   68.7W mb=6.0  GUC    Codpa, Cuya, Camina, Maria Ele

P: 12MAY2017 107507    20.0S   69.0W 4.0-5.4 AAAAA  So. Peru/Bolivia           

 

The second strongest earthquake today was an M 5.2 in the Central Atlantic near Ascension Island. It was also not felt in this remote area. The last earthquake to occur within about 200 km of this epicenter with M>=5.2 occurred as an M 5.2 on June 12, 2013. Earthquakes of M 5.2 and 5.6 have since occurred between 200 and 250 km from this epicenter on April 30, 2014 (M 5.6) and April 14, 2016 (M 5.2).  Forecast 107315 had expected a moderate earthquake within about 50 km of this epicenter was likely around May 17.

 

O: 14MAY2017 22:11:07   2.4S   12.5W mb=5.2  EMSC   NORTH OF ASCENSION ISLAND    

P: 17MAY2017 107315     2.0S   13.0W 4.0-5.9 BAAAA  No. of Ascension Isl       

 

The strongest earthquake in the U.S. or Canada on this quiet day was an M 3.8 aftershock in the Rat Islands, Aleutians, Alaska. This is an aftershock of the M 5.8 in that region of April 27, the first in a series of strong quakes across Alaska in the past two weeks. The last event in this area with M>=3.8 occurred

on May 9 with M 3.9. Today's event was not reported felt in this remote

area. Forecast 107461 had expected this within about 50 km of this epicenter  around May 17.

 

O: 14MAY2017 11:54:24  51.6N  178.6E ml=3.8  ANSS   Rat Islands, Alaska          

P: 17MAY2017 107461    52.0N  179.0E 4.0-5.7 BAAAA  Rat Islands                

 

 

UNUSUAL MODERATE QUAKE SHAKES NORTHEASTERN IRAN

 

EARTHQUAKE SUMMARY FOR MAY 13, 2017

 

An earthquake of M 5.8 in northeastern Iran today was widely felt with intensity IV in Iran within about 200 km of the epicenter.  NEIC reported it was felt with intensity VI (slight damage) in Iran at Bicnord, Khorasan Shamali and IV in Chenaran and Meshed, Khorasan-e Razavi and II-III in Asgabat, Turkmenistan and in Iran at Ghouchan, Gonbad-e Kavus and in Soltanabad, Khorasan-e Razabi, Iran. An earthquake of M 6.1 hit northeastern Iran on April 5 about 400 km southwest of this epicenter but this is the strongest event within about 200 km of this epicenter since an event of M 5.9 seventeen years ago on August 22, 2000. The  only other such event in the area in the past 25 years was an M 6.5 on February 4, 1997.  Forecast 107384 had expected an event in this region was likely with magnitude up to M 5.5 in mid-May.

 

O: 13MAY2017 18:01:01  37.7N   57.3E mb=5.4  EMSC   NORTHEASTERN IRAN            

O: 13MAY2017 18:01:01  37.7N   57.3E mb=5.8  ANSS   NORTHEASTERN IRAN            

P: 17MAY2017 107384    37.0N   59.0E 3.8-5.5 BAAAA  No. Iran                   

 

A series of significant earthquakes around the world today occurred in the 103-106 degrees from the M 6.8 in Vanuatu of May 9 and were probably promoted by concentrated seismic energy from that event. Other activity at this distance from Vanuatu today included moderate earthquakes in the South Sandwich Islands (M 4.7); central Chile (M 5.2-5.3); south of El Salvador; an M 4.2 in Oklahoma; an M 4.2 in Hindu Kush, Afghanistan; activity of M 4.0-4.6 in Chiapas, Mexico and Guatemala; an M 4.4 and 5.1 in Severnaya, Zemlya, north of Siberia. This last pair of events is particularly noteworthy as the M 5.1 it is the largest within about 500 km of this epicenter since a similar M 5.1 on April 15, 2008 and occurred at 103 degrees from Vanuatu.

 

O: 13MAY2017 09:46:49  84.8N   99.2E mb=4.4  EMSC   NORTH OF SEVERNAYA ZEMLYA    

O: 13MAY2017 08:43:42  84.9N   99.3E Mw=5.1  EMSC   NORTH OF SEVERNAYA ZEMLYA    

 

The strongest earthquake within the U.S. or Canada outside Alaska today was an M 4.2 in Oklahoma. NEIC reported it was felt with intensity IV in Seiling, Oklahoma and II-III in Fairview, Mooreland, Helena, Alva, Cherokee, Ames, Vici, Woodward, Sharon, Drummond, Thomas, Arnett, Clinton, El Reno, Nardin, Yukon, Oklahoma City, and in Kansas at Mayfield, Milton, Wichita, Derby, Hutchinson, among others. It may have been felt as far as Rogers, Arkansas and Joplin, Missouri, 400 km from the epicenter. Like much of the recent significant seismicity in the world, this event is located near 103 degrees from the Vanuatu quake of May 9 of M 6.8, a distance at which triggering was considered likely in this area. The last earthquake in Oklahoma with M>=4.2 occurred on November 25, 2016 (M 4.3) and prior to that on July 9, 2016 (M 4.4).  This event was accompanied by a series of lighter shocks throughout much of Oklahoma. Forecast 107405 had expected this event was likely around May 12.

 

O: 14MAY2017 03:28:16  36.2N   98.9W mb=2.6  EMSC   OKLAHOMA                     

O: 14MAY2017 01:52:06  36.2N   98.9W mb=2.8  EMSC   OKLAHOMA                     

O: 13MAY2017 08:32:37  36.5N   98.7W Mw=4.2  EMSC   OKLAHOMA                     

O: 13MAY2017 09:06:47  36.5N   98.7W mb=2.7  EMSC   OKLAHOMA                     

O: 13MAY2017 08:20:49  36.5N   98.8W mb=2.6  EMSC   OKLAHOMA                     

O: 13MAY2017 13:55:05  36.5N   98.8W mb=2.9  EMSC   OKLAHOMA                     

O: 13MAY2017 21:59:30  36.7N   98.4W mb=3.1  EMSC   OKLAHOMA                     

P: 12MAY2017 107405    37.0N   98.0W 2.0-3.9 AAAAA  Southern Plains            

 

The strongest event in Alaska today was an M 4.5 in the western Andreanof Islands, Aleutians. This is an unfelt aftershock of the M 6.4 which hit this epicenter three days ago. Forecast 107449 had expected this event was likely within about 50 km of this epicenter around May 15.

 

O: 13MAY2017 06:43:14  51.6N  178.4W ML=4.5  EMSC   ANDREANOF ISLANDS, ALEUTIAN IS

P: 15MAY2017 107449    51.9N  178.8W 3.5-4.9 AAAAA  Andreanoff Isls, Aleutians 

 

An event of M 4.4 also occurred off the coast of Oregon today. It was not reported felt along the coastline as it was too far out to sea. A smaller M 4.2 hit the area about 100 km south of this on May 4 and April 12, 2017. This is the strongest earthquake located off Oregon within about 100 km of this epicenter since an M 4.8 shook this region of vents and smokers on October 9, 2016 and prior to that an M 5.9 on June 1, 2015.  Forecast 107435 had expected this event within about 40 km of the epicenter was likely around May 17.

 

O: 13MAY2017 20:10:30  44.5N  129.8W mb=4.4  EMSC   OFF COAST OF OREGON          

P: 17MAY2017 107435    44.3N  129.4W 3.0-4.4 BAAAA  Off Coast of Oregon        

 

An event of M 5.2-5.3 was also felt in central Chile today.  CSN reported it was felt with intensity IV in  Salamanca, Quillota, Rinconada, Valparaiso, Vina del Mar, Zapallar; III Cartagena, Santiago, Tiltil; II Navidad. Felt in Coquimbo, Valaraiso, Santiago and O'Higgins, Chile. This is an aftershock of the M 6.5 of April 24, 2017 in Central Chile. Forecast 107511 had expected this aftershock was likely within about 10 km of this epicenter around May 13.

 

O: 13MAY2017 16:54:47  33.0S   71.9W mb=5.3  EMSC   OFFSHORE VALPARAISO, CHILE   

O: 13MAY2017 16:54     32.9S   72.0W mb=5.2  GUC    Salamanca, Quillota, Rinconada

P: 13MAY2017 107511    33.0S   72.0W 4.0-5.4 AAAAA  Central Chile              

 

An earthquake of M 4.7 in Samoa today continued to illustrate the triggering potential of stresses associated with major ocean storms. The storm  - TC Ella - passed over this epicenter two to three days ago and seismicity had been expected to be high in Samoa at this time as noted in previous issues of this report:

 

"TC Ella continued over Samoa and northern Tonga today with winds up to 90 kts. It is expected to track to the west over the next four days. Seismicity in the region of northern Tonga and Samoa is expected to be high while Ella is in the area. A moderate to strong quake is possible during the period May 10-15 in this area. A moderate seismic watch is in effect for northern Tonga and Fiji and Samoa through May 10." (May 12, 2017)

 

This is the strongest earthquake in the region of Samoa since an M 4.9 on  January 21, 2017 - the only other such event of M>=4.7 in the area this year. Forecast 107491 had expected this activity within about 100 km in mid-May.

 

O: 14MAY2017 02:01:48  15.3S  172.7W mb=4.7  EMSC   SAMOA ISLANDS REGION         

P: 17MAY2017 107491    15.0S  174.0W 4.0-5.4 BAAAA  Samoa Islands              

 

TROPICAL STORM ADRIAN TRIGGERS STRONG EARTHQUAKE SOUTH OF EL SALVADOR

 

EARTHQUAKE SUMMARY FOR MAY 12, 2017

 

A strong earthquake of M 6.2 hit south of El Salvador today and was followed by a moderate M 5.4 aftershock. It is likely that this event was triggered by stresses associated with Tropical Storm Adrian. This summary had anticipated  this was likely in previous issues as:

 

"TS Adrian formed today in the area south of Guatemala with winds up to 45 kts. It is expected to track to the west over the next four days turning north towards Chiapas around May 15. The M 5.2 in Guatemala today was directly north of the eyc of this storm and may have been promoted by stresses associated with it. As this is the first Tropical Storm of the season in this area, the effects on triggering seismicity are likely to be strong in the coming week. A seismic watch for the area from El Salvador to Chiapas, Mexico, including Guatemala

is in effect through May 16. Further strong seismicity in this area is possible in the watch period." (May 9-12, 2017)

 

TS Adrian passed over the epicenter of this M 6.2 in El Salvador two days ago. The mainshock was widely felt in El Salvador according to NEIC which reported maximum intensity V in El Salvador at San Marcos, and Opico and IV in Nuevo Cuscatlan, Nueva San Salvador, Santa Catarina Pinula, Santa Ana, and in Guatemala at Guatemala City and Santa Catarina, Pinula and II-III in El Salvador at Acajutla, Concepcion de Ataco, Zaragoza, Antiguo Cuscatlan, San Salvador, El Rosario, Cuscatancingo, Delgado, and San Martin; in Guatemala at Jutiapa, San Rafael las Flores, Fraijanes, Santa Catarina Pinula, Guatemala City, Antigua Guatemala, and as far as Managua,  La Concepcion, and Tola, Nicaragua nearly 500 km east of the epicenter. NEIC reported the M 5.4 aftershock was felt with intensity II-III in El Salvador at Mejicanos, Nuevo Cuscatlan, La Libertad, and in La Libertad, El Salvador. No major damage from this offshore earthquake was reported. The last earthquake offshore El Salvador within about 200 km of this epicenter with M>=6.2 occurred on November 24, 2016 about 200 km southeast of this epicenter but the last within the 200 km radius was an M 6.7 ten years ago on June 13, 2007. Forecast 107102 and 107328 had expected this activity within about 100 km of this epicenter between May 10 and 16. Additional promotion of this earthquake at this time probably came from its location at 104-105 degrees from the M 6.8 in Vanuatu of May 9. This effect had been emphasized in this summary immediately after the Vanuatu quake on May 10 as follows:

 

"The strongest earthquakes in the U.S. outside Alaska and in the western hemisphere today followed the Vanuatu quake at 25 and 35 minutes later at 101-103 degrees from Vanuatu in Guatemala (M 5.2) and Oklahoma (M 3.6). An earthquake in Washington State of M 2.5, twelve minutes after Vanuatu at the fourth node from that event (90 degrees) was also probably triggered by P-waves from Vanuatu. These illuminate the oft-described triggering (in this summary) at a distance effect of major earthquakes." (May 10, 2017)

 

An event of M 4.6 in Hindu Kush and quakes of M 3.0-3.5 in Oklahoma shared this distance to Vanuatu today. Oklahoma is likely to continue to see increased seismicity for the next several days. Other areas experiencing strong quakes at 103 degrees from Vanuatu in May have included Southern Xinjiang, China and the South Sandwich Islands.

 

O: 12MAY2017 15:22:36  12.8N   90.2W mb=4.7  EMSC   OFFSHORE EL SALVADOR         

O: 12MAY2017 10:41:25  13.0N   90.1W Mw=6.2  EMSC   OFFSHORE EL SALVADOR         

P: 10MAY2017 107102    13.0N   88.0W 3.5-5.2 AABAA  Nicaragua                  

 

O: 12MAY2017 10:51:07  13.0N   90.1W mb=5.4  EMSC   OFFSHORE EL SALVADOR         

P: 16MAY2017 107328    13.0N   89.0W 3.5-5.2 BAAAA  Coast of Central America   

 

The strongest earthquake in the U.S. or Canada today was an M 4.4 in the Unimak Island region. It was not reported felt in this remote area. The only other event in the Unimak Island area in the year 2017 with M>=4.4 was an M 4.4 on March 11. Forecast 107229 had expected today's earthquake with this area around May 9.

 

O: 12MAY2017 22:53:44  54.7N  164.6W ML=4.4  EMSC   UNIMAK ISLAND REGION, ALASKA 

P:  9MAY2017 107229    54.5N  163.5W 3.5-4.9 BAAAA  Unimak Islands, Aleutians  

 

MODERATELY STRONG QUAKES HIT AT SOLAR MIDNIGHT AND NOON

 

EARTHQUAKE SUMMARY FOR MAY 11, 2017

 

The strongest and most unusual earthquakes today occurred near local solar midnight and local solar noon. These events of M 5.7 in the South Sandwich Islands, and the Kermadec Islands of northern New Zealand as well as an M 5.4 in Kodiak Island Alaska illustrated the triggering power of tides associated with the full moon which was complete late on May 10.

 

The earthquake of M 5.7 in the northern Kermadec Islands, New Zealand was not reported felt in that remote area. It occurred within about half an hour of local solar midnight and was probably promoted by tidal stresses which maximize at this hour. It is the strongest event within about 150 km of this epicenter since an M 6.3 on July 13, 2016 and prior to that an M 5.9 on August 9, 2015.  Forecast 107503 had expected this event in the northern Kermadec Islands was likely around May 16.

 

O: 12MAY2017 00:46:54  27.7S  176.8W Mw=5.7  EMSC   KERMADEC ISLANDS REGION      

P: 16MAY2017 107503    29.0S  176.0W 4.0-5.8 BBAAA  No. Kermadec Islands       

 

A strong aftershock sequence continued today in the South Sandwich Islands after an  M 6.4-6.5 hit the area yesterday. The strongest aftershocks today were M 5.7, 5.5 and 5.3 but none were felt in this remote area. Forecast 107528 expected this activity was likely around May 12 within about about 50 km of these epicenters. The largest of these - the M 5.7 - occurred within about an hour of local solar noon and was probably promoted by tidal stresses associated with the full moon.

 

O: 12MAY2017 05:21:33  56.6S   25.8W mb=5.1  EMSC   SOUTH SANDWICH ISLANDS REGION

O: 11MAY2017 09:33:26  56.4S   25.6W mb=5.1  EMSC   SOUTH SANDWICH ISLANDS REGION

O: 11MAY2017 16:36:16  56.5S   25.4W mb=5.0  EMSC   SOUTH SANDWICH ISLANDS REGION

O: 11MAY2017 22:50:33  56.6S   25.6W mb=4.9  EMSC   SOUTH SANDWICH ISLANDS REGION

O: 11MAY2017 18:34:03  56.6S   25.6W mb=5.1  EMSC   SOUTH SANDWICH ISLANDS REGION

O: 11MAY2017 15:41:11  56.6S   25.8W Mw=5.7  EMSC   SOUTH SANDWICH ISLANDS REGION

O: 11MAY2017 15:57:34  56.7S   25.7W mb=5.5  EMSC   SOUTH SANDWICH ISLANDS REGION

O: 11MAY2017 16:04:29  56.7S   26.0W mb=5.3  EMSC   SOUTH SANDWICH ISLANDS REGION

O: 11MAY2017 16:05:30  56.8S   26.2W mb=5.3  EMSC   SOUTH SANDWICH ISLANDS REGION

P: 12MAY2017 107528    57.0S   26.0W 4.0-6.2 AAAAA  So. Sandwich Islands       

 

An M 4.8 in the Kuril Islands was nearly antipodal to the South Sandwich Islands today. It was not reported felt in this epicentral area. Forecast 107207 had expected this event was likely around May 7.

 

O: 11MAY2017 08:31:21  50.1N  155.5E mb=4.8  EMSC   KURIL ISLANDS                

P:  7MAY2017 107207    49.0N  153.0E 3.5-5.4 BBBAA  So. Kurils                 

 

 

The largest earthquake in the U.S. or Canada today was a moderate event of M 5.2 in Southern Alaska. NEIC reported it was felt with intensity II in Kodiak, Alaska. An aftershock of M 4.5 followed 10 hours later and was similarly felt. This event occurred within about 30 minutes of local solar noon, a time when tidal stresses associated with the full moon maximize and was probably promoted by these stresses, only about 250 km east of the longitude of this event. Maximum tidal stresses had been expected near 145 West longitude during the full moon on May 10. The last earthquake in the Kodiak Island area within about 150 km of this epicenter with M>=5.4 occurred on May 16, 2009 when an M 5.8-5.9 event occurred. Forecast 106980 expected the area to be active in early May.

 

O: 12MAY2017 00:54:57  56.9N  152.8W Mw=4.5  EMSC   KODIAK ISLAND REGION, ALASKA 

O: 11MAY2017 06:07:26  57.0N  152.5W Ml=3.0  EMSC   KODIAK ISLAND REGION, ALASKA 

O: 11MAY2017 14:36:32  57.1N  152.9W Mw=5.4  EMSC   KODIAK ISLAND REGION, ALASKA 

P:  1MAY2017 106980    60.0N  153.5W 3.2-5.0 CCAAA  Central Alaska             

 

A pair of moderate earthquakes were felt in Turkey today. The first of these - an M 5.0 in eastern Turkey was followed by an M 4.1 early on May 12 in western Turkey. Both occurred along the Anatolian Fault.  EMSC reported the quake in western Turkey was lightly felt in Selcuk, Turkey, an aftershock of an event there of M 5.0 on April 21 about 100 km north of this epicenter.  Forecast 107408 had expected this event within about 100 km of the epicenter in mid-May.

 

NEIC reported this earthquake of M 5.0 in Turkey was felt with intensity VII (slight damage) in Askale and II-III in the area(s) of Erzurum and Askale, Erzurum.

 

O: 12MAY2017 05:55:44  37.9N   27.2E mb=4.1  EMSC   WESTERN TURKEY               

P: 15MAY2017 107408    39.0N   28.0E 3.5-5.3 BBAAA  Turkey                     

 

The second event of M 5.0 occurred in eastern Turkey near Askale. This is the strongest event within about 150 km of this epicenter since an M 5.5 about 100 km south of this on December 2, 2015. The last this far north was an M 5.4 on April 20, 1990. Forecast 107180 had expected this event within about 20 km of this epicenter was likely around May 11.

 

O: 11MAY2017 17:58:01  40.0N   40.7E mb=4.8  EMSC   EASTERN TURKEY               

O: 11MAY2017 17:58:02  40.0N   40.8E mb=5.0  ANSS   NNE of Askale Turkey

P: 11MAY2017 107180    40.0N   41.0E 3.5-5.2 AAAAA  Caucasus/Caspian Sea       

 

These events may have been tidally promoted. The tidal seismicity forecast had emphasized the possibility of enhanced seismicity in eastern Europe at this time as follows:

 

"The full moon arrived at 21:43 UT on May 10. Longitudes which were sub-solar at this time are within about 20 degrees of 35 East and those which were sub-lunar are within about 20 degrees of 145 West longitude. In the west these include areas of Alaska and the Aleutian Islands. In the east these areas are in eastern Europe and the eastern Mediterranean Sea as well as along the East African Rift

tectonic zone. These are the regions most likely to see increased tidal triggering within a week of May 10." (May 7-11, 2017)

 

Several unusual earthquakes hit in the eastern U.S. and Canada today. The largest of these was an M 3.7 in the Baffin Bay region of Canada. This is a remote area and this event was not reported felt. It is the strongest within

about 250 km since an M 3.8 of May 17, 2008, nine years ago. Forecast 107231 had expected this event was likely around May 7 within about 50 km of the epicenter.

 

O: 10MAY2017 22:33:44  60.6N   58.0W ML=3.7  NRCA  376 km E from Killiniq        

P:  7MAY2017 107231    61.0N   58.0W 2.5-4.2 BAAAA  Baffin/Davis Strait Canada 

 

A light earthquake of M 2.2 also occurred today in the region near the border of Pennsylvania and West Virginia. It was not reported felt. It is the first earthquake in this region within about 100 km of this epicenter since an M 2.0 on August 3, 2016 and the largest since an M 2.3 on April 12, 2015.   Forecast 107436 had expected this activity within about 100 km of today's epicenter. Occasionally earthquake in Pennsylvania are followed by significant seismic activity in the area of southern or central California as the region is experiencing a major, possibly precursory, quiescence. This is unlikely in this case but may occur later as a nor'easter is forming off the east coast of the U.S. This, as yet unformed,  meteorological storm may stress the North American plate into a moderate quake in California around May 13-16.

 

O: 11MAY2017 06:53:22  40.2N   80.5W ML=2.1  EMSC   PENNSYLVANIA                 

O: 11MAY2017 06:53:22  40.1N   80.5W ml=2.1  ANSS   West Liberty West Virginia

P: 14MAY2017 107436    41.0N   81.0W 2.0-4.5 BAAAA  Ohio/Lake Erie              

 

The current activation of the Seattle, Washington area continued and expanded today with an M 3.4 in the Seattle area and a similar M 3.4 about 50 km north of this in the Puget Sound region of Washington. This event was the second strongest in the Puget Sound area during 2017 - an M 4.2 hit south west of this on February 23. Forecast 107210 had expected this activity was likely around May 8.

 

NEIC reported this earthquake of M 3.4 in Washington State was felt with intensity II-III in the area(s) of Washington at Clinton, Langley, Freeland, Hansville, Mukilteo, Everett, Greenbank, Kingston, Edmonds, Camano Island, Lynnwood, Port Ludlow, Port Hadlock, Mountlake Terrace, Marysville, Bothell, Chimacum, Seattle, Poulsbo, Bothell, Suquamish, Kenmore, Coupeville, Port Townsend, Stanwood, Keyport, Quilcene, Kirkland, and in general within about 50 km of the epicenter. An M 2.6 was also felt in the same general area with intensity II-III in Silverdale, Bremerton, Suquamish, Seattle and Indianola among others. This was an aftershock of an M 3.4 which hit this epicenter near local solar midnight and was reported in the last issue of this summary. This activity is occurring at 101 degrees from the M 6.8 in Mindanao of April 28, a distance at which seismic energy is concentrated on the surface following large earthquakes.

 

O: 11MAY2017 17:56:35  48.0N  122.5W ML=3.4  EMSC   PUGET SOUND REGION, WASHINGTON

O: 11MAY2017 21:37:42  48.1N  121.9W ML=1.8  NRCA  62 km NE  of Seattle

O: 11MAY2017 17:56:35  48.0N  122.5W ML=3.2  NRCA  41 km NNW of Seattle

O: 11MAY2017 17:56:35  48.0N  122.5W ml=3.4  ANSS   SE of Freeland Washington

P:  8MAY2017 107210    46.9N  122.0W 2.0-3.9 BBAAA  Washington state, U.S.     

 

O: 11MAY2017 09:19:09  47.6N  122.6W ML=2.1  EMSC   SEATTLE-TACOMA AREA, WASHINGTO

O: 11MAY2017 09:19:09  47.6N  122.6W ML=2.1  EMSC   SEATTLE-TACOMA AREA, WASHINGTO

O: 11MAY2017 09:36:36  47.6N  122.6W ML=2.6  EMSC   SEATTLE-TACOMA AREA, WASHINGTO

O: 11MAY2017 07:35:24  47.6N  122.6W ML=3.5  EMSC   SEATTLE-TACOMA AREA, WASHINGTO

P:  8MAY2017 107210    46.9N  122.0W 2.0-3.9 BAAAA  Washington state, U.S.     

 

 

STRONG QUAKES CONTINUE AT HIGH LATITIDES IN SOUTH SANDWICH AND ANDREANOF IS.

 

EARTHQUAKE SUMMARY FOR MAY 10, 2017

 

The strong activation of seismicity at high latitudes in association with the full moon continued today with an M 6.4 in the South Sandwich Islands; an M 5.9 in the Andreanof Islands; an M 5.4 in Xinjiang, China and an M 4.8-5.3 in the Yukon Territory, Canada. Many of these were associated with the full moon or occurred near local solar noon or midnight, a time of high tidal stresses.

 

The events in the South Sandwich Islands, nearly antipodal to the M 5.9 aftershock in the Andreanof Islands were closely associated with a similar swarm in the Xinjiang, China area. These two regions are both between 101 and 108 degrees from the M 6.8 in the Vanuatu Islands which occurred on May 9. Strong seismic enhancement at this distance from major quakes is often seen and is probably due to triggering effects from concentrated seismic energy reflected and refracted off the core-mantle boundary which returns to the surface of the earth in this distance range.

 

The M 6.4 in the South Sandwich Islands was preceded by an M 5.0 at a different epicenter, but also in the South Sandwich Islands. These series occurred near local solar midnight in association with the full moon. The full moon seismic

forecast published in this summary had read:

 

 

"The full moon will arrive at 21:43 UT on May 10. Longitudes which are sub-solar at this time are within about 20 degrees of 35 East and those which are sub-lunar are within about 20 degrees of 145 West longitude. In the west these include areas of Alaska and the Aleutian Islands. In the east these areas are in eastern Europe and the eastern Mediterranean Sea as well as along the East African Rift tectonic zone. These are the regions most likely to see increased tidal triggering within a week of May 10." (May 7-10, 2017)

 

A pair of moderate earthquakes also accompanied the new moon on April 26, 2017. At the time this summary noted:

 

"In the western portion of the tidal stress zone two moderate earthquakes hit in the South Sandwich Islands with M 4.8 and M 5.1. These events were not reported felt in this region and occurred west of most of the activity in the region. Forecast 107048 had expected the South Sandwich Islands to be active at this time. The last earthquake of M >=5.1 within about 150 km of this epicenter in the South Sandwich Islands was an M 5.3 on February 24, 2017. These are regional aftershocks of the M 7.4 which hit the area on August 18, 2016.  Today's events in the South Sandwich Islands occurred within about an hour of local solar noon and were probably promoted by high tidal stresses which maximized at this hour. These epicenters in the South Sandwich Islands lie at 36 degrees (node 10) from  Central Chile and at node 7 (51-52 degrees) from Botswana and were probably promoted by energy from these two recent large earthquakes." (April 27, 2017)

  

 

The events in the South Sandwich Islands were not reported felt in this region. The M 6.4-6.5 is the strongest within that region and within about 200 km of the epicenter since an M 7.2 on May 28, 2016 and prior to that an M 6.5 on March 6, 2011 and September 6, 2004. A foreshock of M 5.3 occurred on May 3 in the South Sandwich Islands. Forecast 107528 and 107290 had expected this event within about 50 km of this epicenter was likely as a large earthquake around May 9-12. Today's activity was also probably promoted by concentrated seismic energy from the Vanuatu event of M 6.8 at a distance of 108 degrees.

 

O: 11MAY2017 01:16:58  56.4S   25.8W mb=5.4  EMSC   SOUTH SANDWICH ISLANDS REGION

O: 11MAY2017 01:09:42  56.5S   25.8W mb=5.6  EMSC   SOUTH SANDWICH ISLANDS REGION

O: 10MAY2017 23:23:36  56.6S   25.9W Mw=6.4  EMSC   SOUTH SANDWICH ISLANDS REGION

O: 10MAY2017 23:23:36  56.4S   25.8W mw=6.5  ANSS   Georgia and the South

P: 12MAY2017 107528    57.0S   26.0W 4.0-6.2 AAAAA  So. Sandwich Islands       

 

O: 10MAY2017 22:08:27  56.1S   28.1W mb=5.0  ANSS   the South Sandwich Islands   

P:  9MAY2017 107290    56.0S   27.0W 4.0-6.0 AAAAA  So. Sandwich Islands       

 

The full moon was immediately followed by an M 5.4 in Southern Xinjiang, China fifteen minutes later and by the first M 5.0 in the South Sandwich Islands 10 minutes after that. These were likely triggered by high tidal stresses as the event in the South Sandwich Islands occurred before seismic waves from Xinjiang arrived at that location. The M 6.4-6.5 in the South Sandwich Islands, about an hour-and-a-half later was followed by an M 4.0 aftershock in Xinjiang, China 15 minutes later. This appears to have been triggered by diffracted P-waves from the South Sandwich Islands which arrived there at the time of that aftershock. The next events in the sequence were aftershocks of M 5.6 and 5.4 in the South Sandwich Island about 30 minutes later. These occurred within about 10 minutes of local solar midnight and were probably triggered by tidal stresses. The events in Xinjiang were probably promoted by concentrated energy from the M 6.8 in Vanuatu of  May 9 as they lie at 102-103 degrees from that epicenter, a distance at which triggering often occurs following strong earthquakes.

 

The last earthquake in southern Xinjiang, China with M>=5.4 within about 200 km  of this epicenter occurred on November 25, 2016 with M 6.6 and these are probably aftershocks of that event.  Forecast 107139 had expected a moderate event in this area around May 9.

 

NEIC reported the earthquake of M 5.4 in  Xinjiang, China was felt with intensity II-III in the area(s) of Kashi, China.

 

 

O: 10MAY2017 23:38:23  39.4N   74.4E mb=4.0  EMSC   SOUTHERN XINJIANG, CHINA     

O: 11MAY2017 04:03:42  37.5N   75.4E mb=4.5  EMSC   SOUTHERN XINJIANG, CHINA     

O: 10MAY2017 22:00:58  37.6N   75.4E mb=5.0  EMSC   SOUTHERN XINJIANG, CHINA     

O: 10MAY2017 21:58:22  37.6N   75.4E mb=5.4  EMSC   SOUTHERN XINJIANG, CHINA     

P:  9MAY2017 107139    38.0N   73.0E 3.8-5.3 AABAA  Hindu Kush/Pakistan        

 

The most unusual and strongest earthquake in the U.S. or Canada since last report was an M 4.8-5.3 in the northern Yukon Territory of Canada. This event in the Yukon is not an aftershock of the M 6.2's of May 1 in Southeastern Alaska as it lies more than 500 km to the northeast of those epicenter. While it was not immediately reported felt in this remote area, it was likely felt with moderate intensity. It was followed 22 minutes later by an M 3.2 at a distance of 60.0

degrees (node 6) which was felt in Guantanamo, Cuba and may have been triggered dynamically by SS waves from the Yukon event.  NEIC reported this earthquake of M 3.2 in Cuba was felt with intensity II-III in the area(s) of Guantanamo, Cuba. This epicenter is locate at 90 degrees from the M 6.8 in the Vanuatu region of May 9 and the M 6.8 in Mindanao of April 28 and was probably promoted at this fourth nodal distance from those events.

The last earthquake in the northern Yukon Territory of Canada within about 200 km of today's epicenter with M>=5.2 occurred on February 5, 2001 about 250 km  southeast of this epicenter. No other such events have occurred in this region since 1990. Forecast 107241 had expected a moderate event at this epicenter was likely around May 10 within about 15 km of this epicenter.

 

O: 10MAY2017 15:14:26  65.0N  134.2W mb=4.8  EMSC   NORTHERN YUKON TERRITORY, CANA

O: 10MAY2017 15:14:26  65.0N  134.3W ML=5.2  NRCA  266 km E   of Dawson

P: 10MAY2017 107241    65.0N  134.0W 2.5-4.1 AAAAA  Yukon Territory, Canada    

 

O: 10MAY2017 15:36:34  19.8N   75.2W ML=3.2  EMSC   CUBA REGION                  

 

Seismicity also continued active in the western Andreanof Islands today where the largest event of the day was an M 5.9. These are aftershocks of the M 6.4 two days ago at this epicenter and had been expected to occur around  May 10-15 in forecasts 107214 and 107449.  NEIC reported some of these earthquakes in the Andreanof Islands were felt with intensity II-III in the area(s) of Adak, Alaska.

 

O: 11MAY2017 02:04:07  51.5N  178.4W mb=4.8  EMSC   ANDREANOF ISLANDS, ALEUTIAN IS.

O: 10MAY2017 16:12:02  51.5N  178.5W mb=3.9  EMSC   ANDREANOF ISLANDS, ALEUTIAN IS.

O: 10MAY2017 08:03:51  51.6N  178.4W ML=4.0  EMSC   ANDREANOF ISLANDS, ALEUTIAN IS.

O: 10MAY2017 20:13:55  51.6N  178.5W ML=3.9  EMSC   ANDREANOF ISLANDS, ALEUTIAN IS.

O: 11MAY2017 02:50:42  51.6N  178.6W mb=4.8  EMSC   ANDREANOF ISLANDS, ALEUTIAN IS.

O: 10MAY2017 20:02:45  51.7N  178.4W ML=3.8  EMSC   ANDREANOF ISLANDS, ALEUTIAN IS.

O: 10MAY2017 07:59:57  51.8N  178.5W Mw=5.9  EMSC   ANDREANOF ISLANDS, ALEUTIAN IS.

O: 10MAY2017 19:25:53  51.8N  178.6W mb=5.0  EMSC   ANDREANOF ISLANDS, ALEUTIAN IS.

O: 10MAY2017 19:46:14  51.5N  178.4W ML=3.9  EMSC   ANDREANOF ISLANDS, ALEUTIAN IS

P: 10MAY2017 107214    51.1N  180.0W 3.5-4.9 AAAAA  Andreanoff Isls, Aleutians 

P: 15MAY2017 107449    51.9N  178.8W 3.5-4.9 BAAAA  Andreanoff Isls, Aleutians 

 

An M 3.6 earthquake also continued the current activation in the Seattle, Washington area. NEIC reported this event was felt with intensity IV in Bremerton and II-III in Port Orchard, Bainbridge Island, Keyport, Silverdale, Seattle, Suquamish, Indianola, Poulsbo, Vashon, Seabeck, Kingston, Belfair, Edmonds, Mountlake Terrace, Bellevue, Kenmore, Kirkland, Bothell, Quilcene, Port Ludlow, Tacoma, Redmond, Clinton, Lilliwaup, Snohomish, Issaquah, Carnation, Everett, Duvall, Olympia, Port Angeles, and Gold Bar, Washington.

No major damage was reported with this latest in a series which included an M 3.3-3.4 yesterday at the same epicenter. The last earthquake of M>=3.6 in the Seattle area of Washington  State was an M 4.0 on February 23, 2017 and prior to that an M 4.0 on September 12, 2015. Today's event was probably promoted by strong tidal stresses associated with the full moon. It occurred within about 30 minutes of local solar midnight, a prime time for tidally promoted seismicity, not dissimilar to the M 3.4 yesterday at this time. Forecast 107210 had expected this event was likely around May 8. It is likely this sequence is not over and more such aftershocks may be expected with the current activation of this area north to Alaska and the Yukon.

 

 

O: 11MAY2017 07:35:24  47.6N  122.6W ML=3.6  EMSC   SEATTLE-TACOMA AREA, WASHINGTO

O: 10MAY2017 11:18:54  47.6N  122.6W ML=2.2  EMSC   SEATTLE-TACOMA AREA, WASHINGTO

O: 10MAY2017 08:14:32  47.6N  122.6W ML=3.4  EMSC   SEATTLE-TACOMA AREA, WASHINGTO

P:  8MAY2017 107210    46.9N  122.0W 2.0-3.9 BAAAA  Washington state, U.S.     

 

MAJOR VANUATU QUAKE FOLLOWED BY FAR-FIELD AFTERSHOCKS NEAR 103 DEGREES

 

EARTHQUAKE SUMMARY FOR MAY 9, 2017

 

A series of earthquakes today illustrated triggering principles. This began with a major earthquake of M 6.8-6.9 in northern Vanuatu. NEIC reported this event was felt with intensity VI (slight damage) in Port Olry, Sanma, Vanuatu. Readers of this summary should not be surprised at the magnitude or location of this event. It had been expected at this time in this summary as a result of triggering stresses associated with the major Tropical Cyclone, Donna which  is currently in the Vanuatu Islands. Previous issues of this report had noted:

 

"Tropical cyclone Donna (18P) continued today in  northern Vanuatu with winds up to 110 kts. This system is expected to track to the south and to follow the Vanuatu Islands along through May 8. Seismicity in the Vanuatu region is expected to be high while TC Donna is in the region with a potential large earthquake in the next three days. This is most likely  towards the end of this period as winds associated with Donna reach upwards towards 135 kts. The area is under a seismic watch through May 9." (May 5-9, 2017)

 

The association with TC Donna of this earthquake should give pause to naysayers who claim no relation exists between strong ocean storms and subsequent major seismic events and that "earthquake prediction" is impossible. This report has often claimed the opposite, that ocean storms can and do trigger significant earthquake - a claim just as often backed up by observation. In these cases, the predictability of such events is highly predictable. The Vanuatu quake appears also to have been promoted by high tidal stresses as it occurred within about an hour of local solar midnight and in association with the full moon, conditions which maximized tidal stresses in this area at the time of this earthquake. The M 6.8 was followed by a regional aftershock near local solar noon about 100 km to the south. The only strong earthquake in Vanuatu during 2017 prior to today's event was an M 6.0 on January 30. The last earthquake with M>=6.8 in the northern Vanuatu area within about 200 km of today's epicenter was an M 6.9 more than a year ago on April 3, 2016 and prior to that events of M 7.1 on October 20, 2015 and May 27, 2010.   Forecast 107262 had expected this activity within about 50 km was likely in early May.  

 

O:  9MAY2017 13:52:12  14.6S  167.4E Mw=6.8  EMSC   VANUATU                      

O: 09MAY2017 13:52:10  14.6S  167.4E mw=6.8  ANSS   NE of Port-Olry Vanuatu

P:  5MAY2017 107262    15.0S  168.0E 4.0-5.6 BAAAA  Vanuatu Islands            

 

O: 10MAY2017 00:10:06  15.6S  167.6E mb=5.0  EMSC   VANUATU                      

P:  5MAY2017 107262    15.0S  168.0E 4.0-5.6 BAAAA  Vanuatu Islands            

 

The strongest earthquakes in the U.S. outside Alaska and in the western hemisphere today followed the Vanuatu quake at 25 and 35 minutes later at 101-103 degrees from Vanuatu in Guatemala (M 5.2) and Oklahoma (M 3.6). An earthquake in Washington State of M 2.5, twelve minutes after Vanuatu at the fourth node from that event (90 degrees) was also probably triggered by P-waves from Vanuatu. These illuminate the oft-described triggering (in this summary) at a distance effect of major earthquakes.

 

The strongest earthquake in the U.S. or Canada outside Alaska today occurred as

an M 3.6 in the Enid, Oklahoma area. NEIC reported it was felt with intensity VI in Medford, Oklahoma and IV-V in Tulsa, Oklahoma. It was felt with intensity II-III in Muskogee, Maud, Oklahoma City, Belle Plaine, Stillwater, Medford, Enid, and Tulsa, Oklahoma. The earthquake occurred 14:30:05 UT, 38 minutes after the M 6.8 in Vanuatu which occurred at 13:52:10 UT. It is located at 101-102 degrees from Vanuatu and appears to have been triggered by a cusp of energy from Vanuatu incident in Oklahoma  as PPP and ScS waves which arrived in Oklahoma at this time. Forecast 107170 had expected this earthquake was likely around May 8.

 

O:  9MAY2017 14:30:05  36.6N   97.6W mb=3.6  EMSC   OKLAHOMA                      

P:  8MAY2017 107170    36.0N   98.0W 2.0-3.9 AAAAA  Southern Plains            

 

An earthquake in Washington State which occurred about 12 minutes after Vanuatu with M 2.5 also appears to have been dynamically triggered by seismic waves from the Vanuatu quake - in this case P-waves which arrived in Washington  simultaneously with the quake there and probably triggered it. The M 2.5 was followed later in the day by an M 3.3 in the region of Seattle, Washington, also at the fourth node from Vanuatu. This event may also have been promoted from the full moon today as it occurred within a few minutes of local solar midnight, a prime time for tidal stresses to trigger seismicity. NEIC reported it was widely felt in the Seattle area with maximum intensity IV in Indianola, Washington and

intensity II-III within about 50 km of the epicenter reported from Bremerton, Bainbridge Island, Port Orchard, Keyport, Seattle, Silverdale, Suquamish, Poulsbo, Kingston, Mountlake Terrace, Belfair, Kenmore, Kirkland, Bothell, Hansville, Port Ludlow, Clinton, Snohomish, Freeland and Langley, Washington. This event of M 3.3 matches the largest in the Seattle area during 2017 – an M 3.3 on May 3. Forecast 107210 had expected this activity around May 8.

 

O: 10MAY2017 08:14:32  47.6N  122.6W MD=3.3  EMSC   SEATTLE-TACOMA AREA, WASHINGTO

P:  8MAY2017 107210    46.9N  122.0W 2.0-3.9 AAAAA  Washington state, U.S.     

 

O:  9MAY2017 14:04:25  46.2N  121.2W MD=2.5  EMSC   WASHINGTON                   

O: 10MAY2017 02:38:24  46.5N  122.5W MD=2.1  EMSC   WASHINGTON                   

P:  8MAY2017 107210    46.9N  122.0W 2.0-3.9 AAAAA  Washington state, U.S.     

 

A second quake occurred at 103 degrees from the Vanuatu epicenter. This event of M 5.2 shook the region of Guatemala, Chiapas, Mexico and El Salvador.  NEIC reported this earthquake of M 5.2 in Guatemala  was felt with intensity II-III in the area(s) of Santa Catarina Pinula; Guatemala City, San Juan la Laguna, in Socoltenango, Chiapas, Mexico and Opico, El Salvador. It occurred 25 minutes after the Vanuatu quake as the S-wave from Vanuatu  was passing through the Guatemala epicenter. A series of other diffracted and reflected S- and P-phases from Vanuatu are also incident in Guatemala at this time after reflecting off the core-mantle boundary. This is an excellent example of immediate, dynamic earthquake triggering at 103 degrees from a strong earthquake - a distance often seen to include strong seismicity in days following large earthquakes. The earthquake in Guatemala was associated with a tropical storm in its own right as well.

 

TS Adrian formed today in the area south of Guatemala with winds up to 45 kts. It is expected to track to the west over the next four days turning north towards Chiapas around May 15 as a hurricane. The M 5.2 in Guatemala today was directly north of the eye of this storm and may have been promoted by stresses associated with it. As this is the first Tropical Storm of the season in this area, the effects on triggering seismicity are likely to be strong in the coming week. A seismic watch for the area from El Salvador to Chiapas, Mexico, including Guatemala is in effect through May 16. Further strong seismicity in this area is possible in the watch period.

 

Only one other earthquake has hit Guatemala with M>=5.2 during the year 2017. This was an M 5.3 on January 12, 2017. Forecast 107092 had expected today's event was likely within about 100 km of this epicenter around May 7.

 

O:  9MAY2017 14:15:49  13.8N   90.5W mb=5.2  EMSC   OFFSHORE GUATEMALA            

P:  7MAY2017 107092    14.0N   92.0W 3.5-5.1 AAAAA  Guatemala                  

 

The second strongest earthquakes in the world today continued as aftershocks in the Andreanof Islands - a pair of events of M 5.4 east of the mainshock at 176 and 177 West longitude. An M 5.9 later occurred at 178 West longitude. They were note reported felt in this remote epicentral area. This summary had also expected these events at this time. These are aftershocks of the M 6.4 which hit the area yesterday. Forecasts 107214 and 107449 had expected this activity around May 10-15 was likely within about 25 km of these epicenters.

 

O: 09MAY2017 08:59:05  51.2N  177.2W Mw=5.4  EMSC   ANDREANOF ISLANDS, ALEUTIAN IS.

O: 09MAY2017 09:54:33  51.2N  177.2W mb=4.6  EMSC   ANDREANOF ISLANDS, ALEUTIAN IS.

O: 09MAY2017 08:34:57  51.6N  178.4W ML=3.0  EMSC   ANDREANOF ISLANDS, ALEUTIAN IS.

O: 09MAY2017 05:36:50  51.6N  178.4W ML=4.1  EMSC   ANDREANOF ISLANDS, ALEUTIAN IS.

O: 09MAY2017 17:27:28  51.6N  178.4W mb=4.0  EMSC   ANDREANOF ISLANDS, ALEUTIAN IS.

O: 10MAY2017 00:39:54  51.6N  178.5W ML=3.7  EMSC   ANDREANOF ISLANDS, ALEUTIAN IS.

O: 10MAY2017 01:35:04  51.7N  178.5W ML=3.2  EMSC   ANDREANOF ISLANDS, ALEUTIAN IS.

O: 09MAY2017 20:09:07  51.7N  178.5W mb=4.8  EMSC   ANDREANOF ISLANDS, ALEUTIAN IS.

O: 09MAY2017 06:18:58  51.7N  178.6W ML=3.9  EMSC   ANDREANOF ISLANDS, ALEUTIAN IS.

O: 09MAY2017 04:38:37  51.7N  178.6W ML=4.3  EMSC   ANDREANOF ISLANDS, ALEUTIAN IS.

O:  9MAY2017 09:01:56  51.0N  176.8W Mw=5.4  EMSC   ANDREANOF ISLANDS, ALEUTIAN IS

O: 10MAY2017 07:59:56  51.6N  178.4W Mw=5.9  EMSC   ANDREANOF ISLANDS, ALEUTIAN IS.

O: 10MAY2017 07:22:48  51.5N  178.2W mb=3.9  EMSC   ANDREANOF ISLANDS, ALEUTIAN IS.

P: 10MAY2017 107214    51.1N  180.0W 3.5-4.9 AABAA  Andreanoff Isls, Aleutians 

P: 15MAY2017 107449    51.9N  178.8W 3.5-4.9 CABAA  Andreanoff Isls, Aleutians 

 

STRONG EARTHQUAKES STRIKE ANDREANOF ISLANDS, ALASKA

 

EARTHQUAKE SUMMARY FOR MAY 8, 2017

 

A series of moderately strong to strong earthquakes occurred today in the western Andreanof Islands. These included an event with magnitude up to M 6.4 at the westernmost point of the rupture and events of M 5.9 and 5.7 which began the series about 150 km east of this near the easternmost point of the rupture. Two moderate events near 176 West longitude marked the eastern boundary of this series. While most of this activity was not reported felt in this remote area, the M 6.4 was felt in Adak, Alaska. This summary had pinpointed this area as possibly ripe for such an event in previous issues.

 

"In the U.S. and Canada, the most active area continued to be the region of Alaska. The strongest events in this area were a pair of M 4.0 quakes in the western Andreanof Islands, Aleutians, where they were not felt." (May 8, 2017)

 

"Alaska often experiences strong regional activation in early to mid-May, possibly related to strong meteorological stresses." (May 7, 2017)

 

"The strongest earthquakes in the U.S. or Canada today occurred in the western Andreanof Islands, Aleutians, Alaska. These events of M 4.3 and 4.5 were not reported felt in this remote area. The region has been active during the past several week with moderate events including an M 5.6 on April 4 and an M 4.7 on April 28." (May 4, 2017)

 

Tidal stresses associated with the last new moon and the upcoming full moon of May 10 probably were promoters of this activity as previously noted in this  summary:

 

"The new moon will arrive on April 26, 2017 at 12:16 UT. Longitudes which are sub-solar at this time are near 4 West longitude while those which are sub-lunar are near 176 East longitude. Those in the west include much of western Europe and the mid-Atlantic Ridge and western Africa; those in the east include the Aleutians, and the Tonga-Fiji-New Zealand arc. These are the areas most likely to see tidal triggering in the next week." (April 24-26, 2017)

 

"The full moon will arrive at 21:43 UT on May 10. Longitudes which are sub-solar at this time are within about 20 degrees of 35 East and those which are sub-lunar are within about 20 degrees of 145 West longitude. In the west these include areas of Alaska and the Aleutian Islands. In the east these areas are in eastern Europe and the eastern Mediterranean Sea as well as along the East African Rift tectonic zone. These are the regions most likely to see increased tidal triggering within a week of May 10." (May 8, 2017)

 

It was shortly after the new moon that an M 5.8 in the Rat Islands occurred beginning the current activation of Alaska. Today's earthquake of M 6.2-6.4 in the  Western Andreanof Islands was reported felt with intensity IV in Adak, Alaska. The last earthquake of M>=6.4 in the central and western Andreanof Islands within about 200 km of today's activity occurred on November 26, 2012 with M 6.4 and prior to that on August 4, 2010 also with M 6.4. Typically, major earthquakes hit this region of the Aleutians every 10 years. In recent yeats these have included events of M 7.2 in 2007; M 7.9 in June, 1996; and May 1986 with M 7.9. Other strong sequences hit the area in 1977-1978 (M 6.7); 1965 (M 8.0); 1957 (M 8.6). This 10-year cycle has been noted in this summary before as on December 20, 2007 and July 7, 2006 when it was noted:

 

"The strongest earthquakes and subsequent aftershock sequences in the area in the past 50 years have occurred in 1957, 1965, 1986, 1996, so this is the year in which a great earthquake might be expected in the region." (July 7, 2006, December 20, 2007) 

 

Aftershock sequences normally include several strong quakes in the year following the mainshock.

 

Forecasts 107214 and 107449 had expected this activity in the Andreanof Islands was likely around May 10-15. This continues the activation of Alaska which

included a pair of M 6.2 events on May 1 in Southeastern Alaska. As noted in previous issues of this report, this epicenter became active after the M 6.6 in Botswana of April 3, 2017. It lies at 144-145 degrees from  that earthquake, a distance at which strong concentration of seismic energy returns to the surface after major earthquakes, having been reflected and refracted off core boundaries.

 

O:  8MAY2017 15:59:01  50.8N  176.9W ML=3.8  EMSC   ANDREANOF ISLANDS, ALEUTIAN IS

O:  8MAY2017 19:24:56  51.1N  176.7W ML=4.1  EMSC   ANDREANOF ISLANDS, ALEUTIAN IS

P: 12MAY2017 107450    51.2N  174.4W 3.5-4.9 BABAA  Andreanoff Isls, Aleutians 

 

O:  8MAY2017 15:47:29  51.1N  177.0W Mw=5.9  EMSC   ANDREANOF ISLANDS, ALEUTIAN IS

O:  8MAY2017 15:31:26  51.1N  177.1W Mw=5.7  EMSC   ANDREANOF ISLANDS, ALEUTIAN IS

P: 10MAY2017 107214    51.1N  180.0W 3.5-4.9 AABAA  Andreanoff Isls, Aleutians 

 

O: 08MAY2017 22:22:27  51.5N  178.1W mb=4.5  EMSC   ANDREANOF ISLANDS, ALEUTIAN IS.

O: 08MAY2017 21:25:22  51.5N  178.5W mb=4.6  EMSC   ANDREANOF ISLANDS, ALEUTIAN IS.

O: 09MAY2017 00:58:32  51.5N  178.6W ML=4.2  EMSC   ANDREANOF ISLANDS, ALEUTIAN IS.

O: 08MAY2017 20:23:15  51.6N  178.3W ML=4.8  EMSC   ANDREANOF ISLANDS, ALEUTIAN IS.

O: 08MAY2017 17:44:05  51.6N  178.4W ML=4.1  EMSC   ANDREANOF ISLANDS, ALEUTIAN IS.

O: 08MAY2017 18:10:14  51.6N  178.4W ML=4.4  EMSC   ANDREANOF ISLANDS, ALEUTIAN IS.

O: 08MAY2017 18:14:06  51.6N  178.4W Ml=4.2  EMSC   ANDREANOF ISLANDS, ALEUTIAN IS.

O: 08MAY2017 19:53:18  51.6N  178.4W mb=5.0  EMSC   ANDREANOF ISLANDS, ALEUTIAN IS.

O: 08MAY2017 14:41:05  51.6N  178.5W ML=3.4  EMSC   ANDREANOF ISLANDS, ALEUTIAN IS.

O: 08MAY2017 18:38:53  51.6N  178.5W ML=3.9  EMSC   ANDREANOF ISLANDS, ALEUTIAN IS.

O: 08MAY2017 10:59:42  51.6N  178.5W ML=4.4  EMSC   ANDREANOF ISLANDS, ALEUTIAN IS.

O: 08MAY2017 20:28:13  51.6N  178.5W ML=4.5  EMSC   ANDREANOF ISLANDS, ALEUTIAN IS.

O: 08MAY2017 17:39:16  51.6N  178.6W mb=4.6  EMSC   ANDREANOF ISLANDS, ALEUTIAN IS.

O: 08MAY2017 21:53:07  51.6N  178.6W mb=4.9  EMSC   ANDREANOF ISLANDS, ALEUTIAN IS.

O: 08MAY2017 20:39:48  51.6N  178.7W mb=4.7  EMSC   ANDREANOF ISLANDS, ALEUTIAN IS.

O: 09MAY2017 05:36:52  51.7N  178.3W mb=4.3  EMSC   ANDREANOF ISLANDS, ALEUTIAN IS.

O: 09MAY2017 00:54:51  51.7N  178.4W ML=4.1  EMSC   ANDREANOF ISLANDS, ALEUTIAN IS.

O: 08MAY2017 21:37:13  51.7N  178.5W ML=3.2  EMSC   ANDREANOF ISLANDS, ALEUTIAN IS.

O: 08MAY2017 22:27:02  51.7N  178.5W ML=4.0  EMSC   ANDREANOF ISLANDS, ALEUTIAN IS.

O: 08MAY2017 23:43:51  51.7N  178.5W ML=4.2  EMSC   ANDREANOF ISLANDS, ALEUTIAN IS.

O: 08MAY2017 21:47:40  51.7N  178.6W ML=4.1  EMSC   ANDREANOF ISLANDS, ALEUTIAN IS.

O: 08MAY2017 18:03:49  51.7N  178.6W ML=4.4  EMSC   ANDREANOF ISLANDS, ALEUTIAN IS.

O: 08MAY2017 08:46:24  51.7N  178.6W Ml=4.1  EMSC   ANDREANOF ISLANDS, ALEUTIAN IS.

O: 08MAY2017 17:08:32  51.7N  178.6W mb=5.2  EMSC   ANDREANOF ISLANDS, ALEUTIAN IS.

O: 08MAY2017 21:59:16  51.8N  178.5W ML=3.4  EMSC   ANDREANOF ISLANDS, ALEUTIAN IS.

O:  8MAY2017 17:00:47  51.8N  178.6W Mw=6.4  EMSC   ANDREANOF ISLANDS, ALEUTIAN IS

P: 10MAY2017 107214    51.1N  180.0W 3.5-4.9 AAAAA  Andreanoff Isls, Aleutians 

P: 15MAY2017 107449    51.9N  178.8W 3.5-4.9 CAAAA  Andreanoff Isls, Aleutians  

 

 

A strong earthquake of M 6.0 also hit the Japanese Ryukyu Islands today. This event was reported felt with intensity II in Okinawa at Chatan and Okinawa. The last earthquake with M>=6.0 within about 150 km of this epicenter in the Ryukyu Islands of Japan occurred on October 4, 2010 with M 6.3 and prior  to that on April 20, 2007 with M 6.2-6.3 - the largest events in this area in at least 25 years.  Forecast 107121 had expected this event in this region around May 7 to the north of today's epicenter.

 

O:  9MAY2017 01:54:13  24.5N  126.4E Mw=6.1  EMSC   RYUKYU ISLANDS, JAPAN        

P:  7MAY2017 107121    26.0N  126.0E 4.0-5.6 ABAAA  Ryukyu Islands             

 

TROPICAL CYCLONE DONNA HELPS TRIGGER VANUATU SERIES

 

EARTHQUAKE SUMMARY FOR MAY 7, 2017

 

A series of moderate earthquake struck central and southern Vanuatu and the Loyalty Islands today with maximum magnitude M 4.9. While none of these were widely felt in the Vanuatu Islands, they do illustrate the triggering effects of strong meteorologic events. These events occurred as Tropical Cyclone Donna, currently with winds up to 140 kts, a major storm, swept through the region. The seismicity had been expected to accompany this cyclone as noted in this summary in previous issues:

 

 

"(TC Donna will) follow the Vanuatu Islands along through May 8. Seismicity in the Vanuatu region is expected to be high while TC Donna is in the region with a potential large earthquake in the next three days. This is most likely  towards the end of this period as winds associated with Donna reach upwards towards 135 kts. The area is under a seismic watch through May 9." (May 5-7, 2017)

 

Forecasts 107262, 107274 and 107265 had expected these events, each within about 50 km of the epicetner were likely around May 8-11. Much of this activity is also located at 51 degrees (node 7) from the quake of M 6.8 on April 28 in Mindanao and 101-103 degrees from the M 6.9 in Central Chile of April 24 and may have been promoted by seismic energy from that event. Other seismic events at this distance range from Central Chile today included an M 3.5 in France and continuing aftershocks in southeastern Alaska.

 

O:  7MAY2017 11:14:31  19.1S  169.5E mb=4.4  EMSC   VANUATU                      

P: 10MAY2017 107262    19.0S  170.0E 4.0-5.5 BAAAA  Vanuatu Islands            

 

O:  8MAY2017 06:30:47  20.5S  169.4E mb=4.9  EMSC   VANUATU                      

P: 11MAY2017 107274    20.0S  169.0E 4.0-5.4 BAAAA  Vanuatu Islands            

 

O:  7MAY2017 09:52:52  22.1S  171.6E mb=4.5  EMSC   SOUTHEAST OF LOYALTY ISLANDS 

P:  8MAY2017 107265    22.0S  171.0E 4.0-5.6 AAAAA  Loyalty Islands            

 

The strongest earthquake in the world today was an M 5.0 in the area south of the Kermadec Islands. This is a remote area and this event was not reported felt among the sparse population of these islands. It is the strongest earthquake in the area south of the Kermadec Islands within about 200 km of this epicenter since an M 5.3 on March 19, 2017; and prior to that, an M 5.0 on January 21, 2017 and December 30, 2016 also with M 5.0. Forecast 107281 had expected this activity was likely around May 9.

 

O:  7MAY2017 05:29:05  34.3S  179.8W mb=5.0  EMSC   SOUTH OF KERMADEC ISLANDS    

P:  9MAY2017 107281    33.0S  179.0W 4.0-5.5 ABAAA  So. Kermadec Islands       

 

The most unusual earthquake of the day was an M 4.6 in the Red Sea. NEIC reported this earthquake of M 4.6 in the Red Sea was felt with intensity II-III in the area(s) of Saqra, Riad, Saudi Arabia. The last event in the Red Sea within about 300 km of today's epicenter occurred on March 7, 2016 with M 4.8 and prior to that the last event in the region of larger magnitude occurred as an M 5.3 on December 23, 2013. Earthquakes in this region often are associated with strong solar flares and with swarms in Baja California.  Forecast 107110 had expected an event in this region was likely around March 6.

 

O:  7MAY2017 14:23:32  17.7N   40.1E mb=4.6  EMSC   RED SEA                      

P:  6MAY2017 107110    19.0N   39.0E 3.0-5.1 ABAAA  Sudan                      

 

In the U.S. and Canada, the most active area continued to be the region of Alaska. The strongest events in this area were a pair of M 4.0 quakes in the western Andreanof Islands, Aleutians, where they were not felt. The strongest earthquake in the region which was felt occurred in northern Alaska near Fairbanks with M 3.8. NEIC reported this earthquake of M 3.8 in Central Alaska was felt with intensity  II-III in the area(s) of Fairbanks, Fort Wainwright, and North Pole, Alaska. This is the strongest earthquake in Northern Alaska during the year 2017. The last such event within about 150 km of this epicenter was recorded on October 21, 2014 with M 4.6. Forecast 107235 had expected regional activity around May 10. Earthquakes in Alaska were also felt in the Skagway, Alaska and Whitehorse, NT, Canada with the maximum of these aftershocks of the two M 6.2 mainshocks of May 1 at M 3.8 today.

 

O:  8MAY2017 05:09:02  65.3N  146.9W Ml=3.8  EMSC   NORTHERN ALASKA              

P: 10MAY2017 107235    63.2N  151.4W 3.2-5.1 ACBAA  Central Alaska