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STRONG SERIES IN GULF OF ADEN AND ETHIOPIA WITH SOLAR FLARES

EARTHQUAKE SUMMARY FOR JUNE 3, 2023

The strongest earthquake in the world today was an M 5.9 north of Somalia in the Gulf of Aden. NEIC did not note any felt reports with this earthquake. It was accompanied by a series of smaller aftershocks as well as regional shocks in Ethiopia and the Gulf of Aden. In the previous issue of this summary the foreshocks to this event had been noted as:

"A strong series of earthquakes also continued today in the Gulf of Aden east of

Sudan and Ethiopia. An earthquake of M 5.7 hit this area on May 19, 2023 and this may be aftershocks of that event. Forecast 153672 had expected today's activity was likely in this area around June 2." (June 3, 2023)

Earthquakes in the Gulf of Aden, Eritrea and Ethiopia are closely related to

solar flare activity as they occur on the geomagnetic equator. For example, when an M 5.5 occurred in this area on December 26, 2022 this summary noted in this regard:

"An earthquake of M 5.5 also hit the region of Ethiopia today. It was not immediately reported felt in this remote area. This earthquake may also have been promoted by several moderate solar flares which occurred at or near the time of today's activity. This possibility had been previously noted and expected at this time in past summaries. For example on October 31, 2022 this summary pointed at this possibility as:

"Times of high solar and geomagnetic activity often coincide with renewed seismicity in the region of Ethiopia. Strong flares appear to trigger enhanced seismicity in this area, in particular. So an M 4.4 in the Eritrea and Ethiopia region today is not surprising as it lies on the geomagnetic equator at a time of strong geomagnetic activity. This is the strongest earthquake in Ethiopia within about 200 km of this epicenter since an M 4.6 on June 5, 2022. At the time this summary noted:

"This has been an active area especially during periods of active solar and geomagnetic periods, often showing synchronicity with major solar flares. During the current solar quiet period, however the area has seen little moderate seismicity. The last earthquakes of M>=4.6 within about 300 km of this epicenter occurred September 11, 2019 and August 13, 2018. The last event of M>5 in this area was an M 5.6 on July 8, 2013." (June 5, 2022, October 31, 2022, December 26, 2022)

The mainshock today occurred at the maximum of flare 9370 while the strongest aftershock (M 5.5) occurred at the beginning of flare 9470. More details are available in the Solar Flare lists below. Note that another event in Southern Peru today of M 4.7, also on the geomagnetic equator was synchronous with flare 9370.

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

9370 0709 0716 0723 C2.0 (June 3, 2023) 1.5E-03

Gulf of Aden M 5.8 07:17 UT

Gulf of Aden M 4.7 07:05 UT

Southern Peru M 4.7 07:17 UT

9470 1401 1409 1414 C2.2 (June 3, 2023) 1.6E-03

Gulf of Aden M 5.5 13:58 UT

Gulf of Aden M 4.8 14:10 UT

Forecast 153672 had expected enhanced seismicity in the Gulf of Aden was likely around June 2 and forecast 153670 had expected the event in Ethiopia around June 2.

O: 03JUN2023 07:04:26 12.5N 48.2E mb=4.7 EMSC GULF OF ADEN

O: 03JUN2023 10:32:07 12.5N 48.1E mb=4.8 EMSC GULF OF ADEN

O: 03JUN2023 10:53:53 12.5N 48.1E mb=4.4 EMSC GULF OF ADEN

O: 03JUN2023 14:10:36 12.5N 48.1E mb=4.8 EMSC GULF OF ADEN

O: 03JUN2023 07:17:48 12.6N 47.9E Mw=5.8 EMSC GULF OF ADEN

O: 03JUN2023 08:56:04 12.6N 47.9E mb=4.5 EMSC GULF OF ADEN

O: 03JUN2023 10:45:33 12.7N 48.0E mb=4.5 EMSC GULF OF ADEN

O: 03JUN2023 13:58:06 12.7N 48.0E Mw=5.5 EMSC GULF OF ADEN

O: 03JUN2023 09:43:38 13.0N 47.8E mb=4.6 EMSC GULF OF ADEN

O: 3JUN2023 10:15:55 12.4N 48.0E mb=4.8 EMSC GULF OF ADEN

P: 2JUN2023 153672 13.0N 51.0E 3.5-5.1 AACAA Gulf of Aden

O: 4JUN2023 04:14:48 14.5N 40.0E mb=4.7 EMSC ERITREA-ETHIOPIA BORDER REGION

P: 2JUN2023 153670 12.0N 40.0E 3.5-5.0 ACAAA Ethiopia

The strongest earthquake in the U.S. or Canada today was an M 4.5 in the Geysers region of Northern California. NEIC reported it was felt with maximum intensity IV in Kelseyville and Middletown with intensity II-III in Geyserville, Healdsburg, Hidden Valley Lake, Cloverdale, Lower Lake, Calistoga, Windsor and as far to the south as San Francisco, California. This is an area where fluid flow often controls seismicity. Strong tidal stresses can be an effective means to move fluids. So it is not surprising that this earthquake occurred in conjunction with today's full moon as noted in this and previous issues of this summary:

"The full moon will arrive on June 4, 2023 at 03:42 UT. Longitudes at local solar noon are near 126 East and those at local solar midnight are near 55 West longitude. In the west these include the northern and Eastern Caribbean as well as areas of western South America while in the East longitudes near 126 E are located in the Philippines, Taiwan, Japan, and Indonesia among others. These are the most likely areas to see tidal triggering at this time, but other areas could see significant enhancement in seismicity in the next several days. These would most likely see seismic enhancement near local solar noon or midnight. A strong to major earthquake is considered likely with this new moon before May 25, 2023." (June 2-4, 2023)

Today's earthquake is the strongest event in the Geysers area since an M 5.0 on December 14, 2016. That earthquake was likely the strongest recorded in the Geysers region of California as reported at the time in this summary:

"While smaller earthquakes in the Geysers, California are nearly continuous, events of larger magnitude are uncommon. Today's earthquake may be the largest ever recorded in the Geysers area, in fact. An M 5.0 was recorded on May 7, 1955 but magnitudes were not well determined at the time. No other events in the Geysers area have reached M>=5.0 until today." (December 14, 2016)

Like today's event this earthquake in 2016 occurred with the full moon of December 14, 2016 and was probably promoted by tidal stresses.

A similar M 4.4 hit in the Geysers area of Northern California on April 12, 2023. At the time this summary noted in this regard:

"While current seismic conditions remain at very quiet levels, mid-April often sees a rash of increased seismicity. One area where a combination of tidal and geomagnetic/solar effects may produce significant events at this time of year is Central California. The peak of seismicity in this region generally occurs in mid-April and can include moderate to large earthquakes such as the M 8.0 in San Francisco of April 18, 1906. This is a good time to check your emergency kit and rations for the possibility of a significant regional event as the sun becomes active again after a period of quiet over the past several weeks. A further triggering factor may be the solar eclipse of April 20. Tidal effects during solar eclipses have been known to trigger significant seismicity - especially when combined with strong X-class solar flares." (April 9, 2023)

Forecast 153717 had expected today's event was likely within about 10 km of this epicenter around June 5.

O: 03JUN2023 12:02:39 38.8N 122.8W Md=2.9 EMSC NORTHERN CALIFORNIA

O: 03JUN2023 12:07:20 38.8N 122.8W Md=2.5 EMSC NORTHERN CALIFORNIA

O: 03JUN2023 12:10:25 38.8N 122.8W Md=2.2 EMSC NORTHERN CALIFORNIA

O: 3JUN2023 12:01:19 38.8N 122.8W Mw=4.4 EMSC NORTHERN CALIFORNIA

P: 5JUN2023 153717 38.9N 122.8W 2.5-4.6 AAAAA Central California

The strongest seismicity in the U.S. or Canada today was a series including events of M 4.9, 4.9 and 4.7 in the Unimak Island region of the Alaskan Aleutians. These events were not reported felt in this remote area. A foreshock of M 4.6 and 3.8 hit the Unimak Island area on May 5, 2023. At the time this summary noted:

"The strongest earthquake in the U.S. or Canada today was an M 4.6 in Unimak Island area, Alaska. It was not reported felt in this remote area. The last earthquake in the Unimak Island area of Alaska with M>=4.6 occurred on January 21, 2023 with M 4.6, part of a series that stated on January 19 with an M 4.8." (May 5, 2023)

The last earthquake of larger magnitude than M 4.9 in the Unimak area was an M 5.1 on September 9, 2021. Events of M4.9-5.0 also occurred in the area on November 4, 2020 and January 11, 2021. Forecast 153828 had expected this activity was likely in the Unimak Island area around May 31.

O: 03JUN2023 15:24:56 53.5N 163.2W mb=4.9 EMSC UNIMAK ISLAND REGION, ALASKA

O: 03JUN2023 15:37:21 53.5N 163.2W ml=3.6 EMSC UNIMAK ISLAND REGION, ALASKA

O: 03JUN2023 22:49:24 53.6N 163.3W mb=4.7 EMSC UNIMAK ISLAND REGION, ALASKA

O: 04JUN2023 00:54:51 53.6N 163.5W mb=4.9 EMSC UNIMAK ISLAND REGION, ALASKA

O: 3JUN2023 20:42:40 53.4N 163.0W mb=3.9 EMSC SOUTH OF ALASKA

P: 31MAY2023 153828 54.0N 164.9W 3.5-5.1 BAAAA Unimak Islands, Aleutians

MODERATE QUAKE SHAKES SOUTHERN PERU

EARTHQUAKE SUMMARY FOR JUNE 2, 2023

A moderate earthquake of M 5.5 shook the area of Southern Peru north of Arequipa today. It was strongly felt with intensity VIII in Arequipa at Chivay and IV in Arequipa. An aftershock of M 5.1 was felt with intensity VIII in Lluta, Arequipa, Peru. It was followed by aftershocks of M 5.0 and 5.1. This is the strongest earthquake in Southern Peru within about 150 km of this epicenter since an M 5.5 on July 12, 2022. A major earthquake about 200 km northeast of today's epicenter of M 7.2 occurred in the area a year ago on May 26, 2022. At the time this summary noted:

"Only one other earthquake of equal or larger magnitude has occurred in Southern

Peru within about 300 km of today's epicenter - an M 7.5-7.6 on July 7, 2001." (May 26, 2022)

A strong M 6.0 was also recorded in the area on May 31, 2020.

Forecast 153853 had expected today's events within about 100 km were likely around June 6, 2023. This epicenter is at 103 degrees from the M 7.7 in the Loyalty Islands of May 19 and may have been promoted by energy from that source.

O: 03JUN2023 02:27:39 15.9S 71.9W Mw=5.1 EMSC SOUTHERN PERU

O: 03JUN2023 02:48:12 15.9S 72.0W mb=5.0 EMSC SOUTHERN PERU

O: 3JUN2023 01:49:14 15.7S 71.5W Mw=5.5 EMSC SOUTHERN PERU

P: 6JUN2023 153853 17.0S 72.0W 4.0-5.5 BBAAA So. Peru/Bolivia

A strong series of earthquakes also continued today in the Gulf of Aden east of Sudan and Ethiopia. An earthquake of M 5.7 hit this area on May 19, 2023 and this may be aftershocks of that event. Forecast 153672 had expected today's activity was likely in this area around June 2.

O: 3JUN2023 06:49:04 12.2N 48.2E mb=4.6 EMSC GULF OF ADEN

O: 03JUN2023 06:23:33 12.4N 48.2E Mw=5.0 EMSC GULF OF ADEN

O: 03JUN2023 06:29:04 12.4N 48.4E mb=4.9 EMSC GULF OF ADEN

O: 03JUN2023 06:37:57 12.5N 48.2E mb=4.9 EMSC GULF OF ADEN

P: 2JUN2023 153672 13.0N 51.0E 3.5-5.1 AACAA Gulf of Aden

The strongest earthquake felt in the U.S or Canada today was an M 3.9 in Wyoming. NEIC reported this earthquake of M 3.9 in Southern Wyoming was felt with intensity II-III in the area(s) of Southern Wyoming in Saratoga, Encampment, Laramie, and in Fort Collins, Colorado. NEIC reported an aftershock of M 3.2 in Wyoming was felt with intensity II-III in the area(s) of Wyoming in Saratoga. This is the strongest earthquake within Wyoming within about 150 km of this epicenter since an M 3.9 on October 1, 2005 and an M 4.3 on January 31, 2002. Forecast 153770 had expected this event within about 100 km was likely around June 8, 2023.

O: 2JUN2023 08:14:47 41.4N 106.8W mb=3.9 EMSC WYOMING

P: 8JUN2023 153770 40.6N 106.6W 2.0-4.4 CAAAA Colorado area

An M 4.1 also occurred as an aftershock in the Andreanof Islands, Aleutians, Alaska today. It was not reported felt in this remote area. The mainshock occurred earlier on June 3 and was described in the previous issue of this summary as:

"The last earthquake of significantly larger magnitude in this area of the

Andreanof Islands occurred on March 11, 2023 with M 4.6 and April 12, 2022 with M 4.9. The strongest earthquake in the area in the past 3 years was an M 6.1 on September 24, 2021 and an M 6.1 on January 3, 2021. Today's event may have been promoted by the M 5.7 South of Africa" (June 2, 2023)

Forecast 153809 had expected this event about 150 km southwest of today's epicenter was likely in the Andreanof Islands around June 5.

O: 3JUN2023 04:51:11 52.3N 178.7W mb=4.1 EMSC ANDREANOF ISLANDS, ALEUTIAN IS

P: 5JUN2023 153809 50.6N 179.2W 3.5-5.1 ABAAA Andreanoff Isls, Aleutians

ODERATE EARTHQUAKE IN GUAM TRIGGERED BY TYPHOON MAWAR

EARTHQUAKE SUMMARY FOR JUNE 1, 2023

One of the largest earthquakes in the world today was an M 5.3 in the area of Guam. NEIC did not report it as felt. This earthquake follows the passage of Typhoon Mawar over this epicenter several days ago and probably indicates a causal relationship. This has been previously noted in the relation between Typhoons in Guam in this summary and elsewhere. When Guam was approached by Typhoon Mawar noted in this regard:

"Typhoon Mawar (02W) continued today in the area of Guam with winds up to 165 kts. It is expected to track to the northwest passing over Guam around March 24-25, 2023 as a typhoon with winds up to 165 kts. It is likely that a moderate to strong earthquake could occur near Guam with this storm in the next week. This appears to be the strongest typhoon to hit Guam in the past two decades." (May 25, 2023)

While an M 5.4 hit near this epicenter on May 12, 2023, the last event of significantly larger magnitude in the Guam region was an M 5.7 on August 29, 2022. This was also accompanied by a super-typhoon as noted in this summary at the time:

"The strongest earthquake felt in the world today was an M 5.7 in the area of Guam. NEIC reported it was felt with maximum intensity V in Guam at Barrigada, IV in Dededo, Yigo, Tamuning, Hagatna,Mangilao, Mongmong, Sinajana. An M 4.7 foreshock several hours earlier than the mainshock was not reported in felt in the area. This activity may have been promoted by a super-typhoon which passed north of Guam yesterday and is nearing southern Japan today. The M 5.7 is the strongest earthquake in the region of Guam since an M 5.9 on June 23, 2020 and an M 5.8 on September 23, 2018. Strong activity near Guam is often associated with strong ocean storms." (August 29, 2022)

Forecasts 153688 and 153409 had expected enhanced seismicity in Guam at the end of May or in early July, 2023.

O: 2JUN2023 05:25:37 12.5N 144.8E mb=5.2 EMSC GUAM REGION

O: 2JUN2023 05:25:37 12.5N 144.8E mb=5.3 ANSS GUAM REGION

P: 7JUN2023 153688 12.0N 144.0E 4.0-5.4 BAAAA So. Marianas/Guam

P: 28MAY2023 153409 13.0N 144.0E 4.0-5.4 BAAAA So. Marianas/Guam

NEIC reported an earthquake of M 4.0 in Nevada was felt with intensity II-III in the area(s) of Nevada in Reno (IV) and Sparks and in Loyalton, California. An aftershock of M 3.1 was also felt lightly in Reno, Nevada. This appears to be the strongest earthquake within about 100 km of this epicenter since an M 4.2 on May 28, 2021 and an M 4.7 on May 7, 2021. Today's activity may be related to the M 5.5 in Northern California about 150 km northwest of this which occurred on May 11, 2023 and has seen an M 5.6 off the coast of northern California on May 21 among others. The area has seen enhanced seismicity since that time and further moderate earthquakes appear likely in Northern California in the next several days, possibly related to the events of May 11 and May 21. Forecasts 153768 and 153438 had expected this enhanced seismicity in this area was likely around May 27 to June 2, 2023.

O: 02JUN2023 00:28:07 39.6N 120.0W ML=3.0 EMSC NEVADA

O: 02JUN2023 00:28:07 39.6N 120.0W ML=3.1 ANSS NEVADA

O: 02JUN2023 01:41:34 39.6N 120.0W ml=2.2 EMSC NEVADA

O: 2JUN2023 00:23:05 39.6N 120.0W Mw=3.8 EMSC NEVADA

O: 2JUN2023 00:23:05 39.6N 120.0W Mw=4.0 ANSS NEVADA

P: 2JUN2023 153768 40.2N 119.6W 2.5-4.4 AAAAA California/Nevada area

P: 27MAY2023 153438 39.3N 120.0W 2.5-4.5 BAAAA California/Nevada area

The strongest earthquake in the U.S. or Canada today was an M 4.5 in the Andreanof Islands, Aleutians, Alaska. It was not reported felt in this remote area. The last earthquake of significantly larger magnitude in this area of the

"The earthquake of M 5.7 South of Africa today is near the antipode of the Andreanof Islands, Alaska at 53N 170W. A moderate far-field earthquake in the

Andreanof Islands near the this antipode is likely in the next several days." (May 29, 2023)

Forecast 153809 had expected today's event within about 100 was likely in early

June, 2023.

O: 1JUN2023 11:47:15 51.2N 178.5W mb=4.5 EMSC ANDREANOF ISLANDS, ALEUTIAN IS

P: 5JUN2023 153809 50.6N 179.2W 3.5-5.1 BAAAA Andreanoff Isls, Aleutians

MODERATELY STRONG QUAKE IN MYANMAR

EARTHQUAKE SUMMARY FOR MAY 31, 2023

The strongest earthquake in the world today was an M 5.8 in Myanmar. NEIC reported it was felt with intensity V in Myanmar at Katha Sagaing and III in Mandalay with II in Dulia Gaon, Assam, India. This is the strongest earthquake in Myanmar within about 200 km of this epicenter since an M 5.8 on May 23 and an M 5.9 nine years ago on May 30, 2014.

Forecast 153420 had expected this event within Myanmar within about 100 km was likely around May 26, 2023. A strong tropical storm passed over this epicenter in May, 2023 and may have helped set this earthquake up. In the previous issue of this summary this had been alluded to as:

"Another recent typhoon landfall has occurred in the Bay of Bengal in the area of India and Myanmar. This Tropical Cyclone was described in past issues of this summary as:

"TC Mocha (01B) formed today in the area south of Myanmar and Bangladesh in the Gulf of Bengal with winds up to 130 kts. It is expected to continue north and to make landfall in the next two days in India, Bangladesh and Myanmar. Considerable damage is expected with winds up to 130 kts. Seismicity in Southeast Asia is likely to be enhanced while this storm is active." (May 15-16, 2023)

It is possible this area of Assam, India and Myanmar could still see a weather-related moderate event in the next several days. A series of moderate events have occurred in Assam, India in the past week perhaps indicating a larger event is possible." (May 30, 2023)

O: 31MAY2023 11:20:16 25.1N 96.2E Mw=5.8 EMSC MYANMAR

P: 26MAY2023 153420 25.0N 95.0E 4.0-5.4 BAAAA Myanmar

An M 5.5 was also lightly felt in Kamchatka today. This continues a series of moderate quakes in Kamchatka that began in early to mid-April, 2023 with an M 6.7 on April 3 and an M 5.6 on April 18 but is to the northeast of those epicenters by about 400 km. The only earthquake within about 250 km of today's epicenter with equal or greater magnitude was an M 6.6 about 100 km south of this on March 16, 2021. Forecast 153542 had expected today's event within about 50 km was likely around May 27.

O: 31MAY2023 14:01:46 55.4N 163.2E Mw=5.5 EMSC OFF EAST COAST OF KAMCHATKA

P: 27MAY2023 153542 55.0N 163.0E 4.0-5.7 BAAAA Komandorsky Isl

An earthquake of M 3.9 occurred today off the coast of Northern California. NEIC reported it was felt with intensity II in Fortuna, Eureka and Arcata, California. This appears to be an aftershock of the M 5.6 off northern California of May 21, 2023. At the time this summary noted in this regard:

"The strongest earthquake in the U.S. or Canada today was an M 5.6 off the coast of Northern California. NEIC reported it was felt with maximum intensity VI in California at Petrolia and II-III in Ferndale, Loleta, Rio Del, Fortuna, Samoa, Hydesville, Eureka, Scotia, and as far as the coast of Oregon and Central California. This is near the antipode of the M 6.8 in the Prince Edward Islands which occurred several hours earlier in the day. Triggering associated with that event possible. This event is near the fourth node (90 degrees) from the major activity in the Loyalty Islands of the past three days and continues a regional activation of seismicity in California associated with the Loyalty Islands near the fourth node" (May 21, 2023)

Today's earthquake occurred with minutes of local solar noon and was probably promoted by tidal stresses which maximize near this hour.

Forecasts 153518 had expected today's event was likely within about 25 km around

May 29.

O: 01JUN2023 00:25:27 40.5N 124.9W Md=2.2 EMSC OFFSHORE NORTHERN CALIFORNIA

O: 31MAY2023 19:59:39 40.4N 125.6W Mw=3.9 EMSC OFFSHORE NORTHERN CALIFORNIA

P: 29MAY2023 153518 40.5N 125.8W 2.5-4.4 AAAAA Off Coast of No. Calif

STRONG QUAKE SOUTH OF NEW ZEALAND IN SNARES ISLAND

EARTHQUAKE SUMMARY FOR MAY 30, 2023

The largest earthquake in the world today was an M 6.1-6.2 in Auckland, New Zealand. NEIC reported it was lightly felt with intensity II in New Zealand in Southland at Riverton, Invercargill and Gore. GEONET reported this earthquake in Snares Island, New Zealand was felt by 1 with 1 reporting weak intensity and 0 light intensity. This earthquake occurred new local solar noon and may have been promoted by tidal stresses which maximize near this hour. The last earthquake in the Snares Island within about 200 km of today's epicenter with larger or equal magnitude occurred on July 11, 2017 with M 6.6. At the time this summary noted in this regard:

"The last earthquake with M>=6.5 in the region occurred on September 30, 2007 with an M 7.4 and 6.6 ten years ago. A great earthquake hit the region December 23, 2004, two days before the great tsunamigenic Sumatra earthquake which caused more than 200,000 deaths around the Indian Ocean." (July 11, 2017) ...

Forecast 153885 had expected this event in this region was likely around June 1, 2023. This epicenter is located near 144 degrees from the M 7.7 in Turkey of February 6, 2023 at 104 degrees from the M 6.7 in Ecuador of March 18 and may have been promoted by energy from those sources.

O: 31MAY2023 02:21:19 49.9S 163.9E ML=6.1 GEONET Snares Island, New Zealand

O: 31MAY2023 02:21:21 49.6S 163.9E Mw=6.2 EMSC AUCKLAND ISLANDS, N.Z. REGION

O: 31MAY2023 02:21:21 49.6S 163.9E Mw=6.2 ANSS AUCKLAND ISLANDS, N.Z. REGION

P: 1JUN2023 153885 47.0S 164.0E 3.0-5.0 ACAAA So. Island, N.Z.

A moderate earthquake was also felt in northern Chile today. NEIC reported this earthquake of M 5.5 in Northern Chile was felt with intensity II-III in the area(s) of Northern Chile in Iquique with V, and in Arica and in Tocopilla, Antofagasta. The last earthquake in Tarapaca, Chile with M>=5.4 within about 200 km of today's epicenter occurred as an M 6.1 on December 6, 2020, the only such event in this area in at least three years. Today's event occurred within minutes of local solar noon and was probably promoted by tidal stresses which maximize near this hour. The M 6.1 on December 6, 2020 shared this timing occurring at 16:48 UT at solar noon as noted in this summary on that date:

"The strongest earthquake in the world today was an M 6.1 in northern Chile. It was reported with maximum intensity VI in Iquique, Tarapaca and V in Tocopilla, Antofagasta and IV in Calama and Arica, Antofagasta and Arequipa. ... This continues strong activity in the region over the past week. The last earthquakes in northern Chile of M>=6.1 occurred on September 11, 2020 and prior to that on November 1, 2018. A major event of M 7.6 hit the area on April 3, 2014 after an M 8.2 to the north on April 1, 2014. Today's event is about 150 km east of those epicenters. This event occurred within several minutes of local solar noon and was probably promoted by high tidal stresses which maximize at this hour." (December 7, 2020)

Forecasts 153870, 153588 and 153863 had expected today's event within about

100 km was likely at the end of May or in early June, 2023. This epicenter is at 144 degrees from the M 7.2 in Tajikistan of February 23, and at 105 degrees from the M 7.7 in the Loyalty Islands of May 19, 2023 and may have been promoted by energy from those sources.

O: 30MAY2023 16:51 20.7S 70.6W mb=5.4 GUC Tarapaca at Alto Hospicio and

O: 30MAY2023 16:51:37 20.7S 70.5W Mw=5.5 EMSC OFFSHORE TARAPACA, CHILE

P: 1JUN2023 153870 20.0S 69.0W 4.0-6.1 AAAAA So. Peru/Bolivia

P: 30MAY2023 153588 21.0S 69.0W 4.0-5.8 AAAAA Coast No. Chile

P: 30MAY2023 153863 21.0S 69.0W 4.0-5.8 AAAAA Coast No. Chile

An unusual M 5.1 earthquake also shook the area of Turkmenistan today. The is the strongest earthquake within about 200 km of this epicenter in Turkmenistan since an M 5.1 on March 22, 2023 with the last of larger magnitude an M 5.3-5.4 on May 16 and again on 17, 2021. Forecast 153777 had expected this event was likely within about 25 km around June 1, 2023.

O: 31MAY2023 04:04:49 39.7N 55.0E mb=5.1 EMSC TURKMENISTAN

P: 1JUN2023 153777 40.0N 55.0E 4.0-5.4 AAAAA Kazakhstan

MODERATE QUAKES SHAKE AREAS SOUTH OF AFRICA AND VOLCANO ISLANDS, JAPAN

EARTHQUAKE SUMMARY FOR MAY 29, 2023

The strongest earthquakes of the day occurred as an M 5.7 Southwest of Africa

and as an M 5.8-5.9 in the Volcano Islands of southeastern Japan. The only earthquake in the Volcano Islands of similar magnitude occurrred about 200 km north of today's epicenter as an M 5.7 on November 7, 2020. The last earthquake in the Volcano Islands of M>=5.8 occurred on August 16, 2018. At the time this summary noted the importance of Tropical Cyclone Soulik in triggering this event as:

“A pair of strong earthquakes in the Volcano Islands of M 6.0 and 6.3-6.4 today were likely triggered by the passage of Typhoon Soulik over the epicenter today. Typhoon Soulik has winds up to 80 kts. This storm is expected to pass to the northwest over the next several days reaching Kyushu, Japan around August 21. This is a classic example of weather-related seismic triggering. ...

The last earthquake of M>=6.3 in the Volcano Islands within about 200 km of today's epicenters occurred as an M 7.5 on September 18, 2007 and prior to that on July 3, 2001. Earthquakes also hit the region with M 7.6 on March 28, 2000 and January 1, 1998 (M 6.6)." (August 17, 2018)

The Volcano Islands are located north of Guam which was hit by a super-typhoon (Mawar) over the past two days. The earthquake in the Volcano Islands occurred as Super-Typhoon Mawas passed through the region and may have been promoted by energy associated with that storm, the strongest in the region in the past two decades as noted in this and previous issues of this summary as:

"Typhoon Mawar (02W) continued today in the area East of Taiwan and northern Philippines. It is expected to track to the northwest reaching Taiwan around May 31 as a typhoon with winds up to 135 kts. It is likely that a moderate to strong earthquake could occur near northern Philippines or Taiwan with this storm in the next week. This appears to be the strongest typhoon to hit Guam in the past two decades." (May 30, 2023)

Forecasts 153428 and 153693 had expected this activity in the Volcano Islands was likely at the end of May or early June, 2023.

O: 30MAY2023 00:52:08 24.0N 143.0E Mw=5.8 EMSC VOLCANO ISLANDS, JAPAN REGION

P: 1JUN2023 153693 26.0N 144.0E 4.0-5.6 ABAAA Bonin Islands

P: 26MAY2023 153428 22.0N 145.0E 4.0-5.4 BBBAA Volcano Islands

The earthquake of M 5.7 South of Africa today is near the antipode of the Andreanof Islands, Alaska at 53N 170W. A moderate far-field earthquake in the

Andreanof Islands near the this antipode is likely in the next several days. This earthquake in the area southwest of Africa was not reported felt in this remote oceanic area. This event occurred west of the M 6.8 south of Africa in the Prince Edward Islands of May 21, 2023 and may have been promoted by strong regional stress redistribution from that event. Equal or larger events within about 300 km of today's epicenter occurred as an M 5.9 on August 9, 2020 and an M 6.6 on January 28, 2018. This earthquake is located near 103 degrees from the M 7.3 in Tajikistan of February 23, 2023 and may have been promoted by energy from that source. Other activity at this distance from Tajikistan today occurred in Central California, New Madrid and Kentucky. It is also at 102 degrees from the Loyalty Islands where a series of major earthquakes occurred around May 19 and was probably promoted by energy from that source as well.

O: 29MAY2023 21:52:05 53.0S 10.4E Mw=5.7 EMSC SOUTHWEST OF AFRICA

Another recent typhoon landfall has occurred in the Bay of Bengal in the area of India and Myanmar. This Tropical Cyclone was described in past issues of this summary as:

An earthquake of M 5.2 also occurred in the Drake Passage north of Antarctica and south of South America today. It was not reported felt in this remote oceanic area. The only even of M>5.1 in the Drake Passage in the past three years was an M 5.4 about 500 km southeast of this epicenter on June 23, 2021. Forecast 153890 had expected seismic enhancement in this area was likely at the end of May or in early June, 2023.

O: 30MAY2023 04:35:01 56.7S 69.4W ML=5.1 EMSC DRAKE PASSAGE

P: 1JUN2023 153890 55.0S 64.0W 3.0-5.4 ABCAA So. So. America

The most unusual earthquake in the U.S. or Canada today occurred in western

Kentucky. This event of M 3.3 was followed by an M 2.4 aftershock. NEIC reported this earthquake of M 3.0-3.3 in Western Kentucky was felt with intensity IV in the area(s) of Western Kentucky in Calhoun, Rumsey, Sacramento, Hanson; III in Livermore, Madisonville, Benton and Louisville and in Indiana at Newburgh and Evansville. The last earthquake of M>2 in western Kentucky was recorded about 150 km west of today's epicenter with M 2.0 on April 4, 2021 and January 18, 2021. The last earthquake of M>=3.3 within about 150 km of this epicenter in Kentucky occurred as an M 3.8 on September 19, 2017. This event occurred several hours before a great earthquake in Chiapas and several major solar flares. Forecast 153458 had expected today's event was likely within about 150 km around May 26. This epicenter is located at 144 degrees from the M 7.0 in Java of April 14 and the M 7,3 in Nias, Sumatra, Indonesia of April 24 and at 103 degrees from the M 7.2 in Tajikistan of February 23, 2023 and may have been promoted by energy from those sources.

O: 30MAY2023 02:49:42 37.5N 87.4W Md=2.4 EMSC WESTERN KENTUCKY

O: 30MAY2023 02:45:21 37.5N 87.3W mb=3.3 EMSC WESTERN KENTUCKY

P: 26MAY2023 153458 38.0N 89.0W 2.0-4.1 BABAA New Madrid area

UNUSUAL EARTHQUAKE SHAKES VICTORIA, AUSTRALIA

EARTHQUAKE SUMMARY FOR MAY 28, 2023

An unusual earthquake of M 3.6 was widely felt in Victoria, Australia today. NEIC reported it was felt with maximum intensity IV in Craigieburn and II-III in Sunbury, Melbourne, Melton, Baccus Marsh, Healesville, Clifton Springs, Pakenham and Leopold. The last earthquake of equal or larger magnitude within about 200 km of today's epicenter was an M 4.6 about 200 km southeast of this on July 20, 2012 - an aftershock of an M 5.4 on June 19, 2012. The only earthquakes within about 150 km of today's epicenter in the past 35 years were both of M 3.6 - on November 8, 1992 and August 21, 2001. When the M 5.4 hit southeast of this on June 19, 2012 this summary noted in this regard:

"A moderate earthquakes of M 5.2 occurred off the southeastern coast of Australia today and was widely felt in Victoria, New South Wales and Canberra.

....

This is the largest earthquake to hit Victoria in decades. Because it was offshore, damage was minimized occurring as cracked walls and as damage to items which fell from shelves in supermarkets and other stores. It is the largest since 1982 and the third largest in the past 100 years in the region of Victoria. Damage was done to supermarkets and pharmacies in Moe, Newborough, Trafalgar and Morwell and in some cases shelves collapsed. The shaking lasted for about 40 seconds. No damage occurred to infrastructure such as roads, rail, dams and power supply. An earthquake of M 5.5 hit near this on June 16, 1981 with the largest in modern times an M 6.0 on June 20, 1969 exactly 43 years ago today. (the two events both occurred at about 1100 UT as well). With the three largest events occurring near the summer solstice there could be a seasonal seismic factor involved in this timing as well." (June 19, 2012)

Today's epicenter is at 101 degrees from the M 7.2 in Tajikistan of February 23, 2023 and may have been promoted by energy from that source.

O: 28MAY2023 13:41:51 37.6S 144.8E mb=3.6 EMSC NEAR S.E. COAST OF AUSTRALIA

The strongest earthquake in the world today was an M 5.3 in Northern Colombia. NEIC reported it was felt in Santander, Colombia at Barichara, Floridablaca, Bucaramanga; in Tunja Boyaca and in Chiquinquira and in Cundinamarca at Chia, Cota, La Calera, Funza and in Bogota, Colombia. This appears to be part of a general seismic activation period in Colombia which included, but has not been limited to the epicenter of an M 6.6 on May 25, 2023. In the past week six distinct epicenters in Colombia have see earthquakes of M>=4 but today's event is the strongest besides the M 6.6 on May 25. This could be due to regional stress redistribution or to the far-field effects of recent major earthquakes as noted in previous issues of this summary. For example on May 25 it was noted:

"... of Colombia. This epicenter is also at 103 degrees from the M 7.8 in Turkey of February 6, 2023 and the M 7.2 in the Kermadec Islands of April 24, 2023 and near this distance from the M 7.6 in Tonga of May 10 and the M 7.8 in the Loyalty Islands of May 19 and may have been promoted by energy from those sources." (May 25, 2023)

The only events of M>=5.3 within about 200 km of today's epicenter in Northern

Colombia in the past three years occurred as an M 5.5 on February 23, 2022 and an M 5.4 on March 10, 2023. Forecast 153352 had expected today's event was likely within about 25 km in Colombia around May 25, 2023.

O: 28MAY2023 15:45:57 6.7N 73.0W Mw=5.3 EMSC NORTHERN COLOMBIA

P: 25MAY2023 153352 7.0N 73.0W 4.0-5.9 BAAAA Colombia

MODERATE QUAKES IN SOLOMON IS; AFGHANISTAN AND SOUTH SANDWICH ISLANDS

EARTHQUAKE SUMMARY FOR MAY 27, 2023

It was a relatively quiet day in global seismicity. Moderate quakes occurred in the South Sandwich Islands (M 5.5) and felt in Pakistan (M 5.2) and the Solomon Islands (M 5.6) but no damaging quakes were observed. The geomagnetic field was quiet and solar flare activity was minimal. Tidal effects were also minimal mid-way between new and full moons. Typhoon Mawar which may have helped trigger one of the largest earthquakes in the region of southeastern Honshu, Japan yesterday remained a threat to Taiwan and Japan as it continued on its westward track.

A moderate earthquake shook regions of Pakistan, Hindu Kush, Afghanistan and Kashmir, India today. This event of M 5.2 was reported with maximum intensity V in Abottabad, Pakistan and Badgam, Jammu and Kashmir, Intia and IV in Pakistan at Haripur, Taxila, with lesser shaking in Peshawar, Wah, Punjab, Rawalpindi, Lahore, Sharqpur and Udhampur, India. A foreshock of M 4.3 was felt in Rawalpindi, Punjab, Pakistan with III and in Badgam, Jammu and Kashmir, India with intensity IV. This is likely an aftershock of the M 6.5 of March 21, 2023, the strongest to date. A similar M 5.2-5.3 shook the Hindu Kush area on May 3, 2023 and was reported in this summary as:

"NEIC reported this earthquake of M 5.3 in Hindu Kush, Afghanistan was felt with intensity II-III in the area(s) of Hindu Kush, Afghanistan in Kabul and in Tashkent, Uzbekistan." (May 3, 2023)

Forecast 153450 had expected today's activity in Afghanistan was likely around May 24, 2023 within about 100 km of the epicenter.

O: 28MAY2023 05:49:56 36.6N 71.2E Mw=5.2 EMSC HINDU KUSH REGION, AFGHANISTAN

O: 27MAY2023 19:24:53 36.9N 71.4E mb=4.3 EMSC HINDU KUSH REGION, AFGHANISTAN

P: 24MAY2023 153450 36.0N 71.0E 3.8-5.4 BAAAA Hindu Kush/Pakistan

A moderate earthquakes also shook the region of Guadalcanal, Solomon Islands today where NEIC reported it was felt with intensity IV in Honiara. This appears to be an aftershock of an M 6.1 of May 21, 2023. At the time this summary noted in this regard:

"A strong M 6.1 was also felt in the Solomon Islands today. NEIC reported it was felt with intensity V in the Solomon Islandsa at Kirakira Makira and Ulawa and in Honiara, Guadalcanal. This is part of a regional enhancement of seismicity following the M 7.7 and 7.2 events in the Loyalty Islands of the past two day which occurred about 15 degrees south east of this epicenter in the Solomon Islands. Today's event of M 6.1 is the strongest in the Solomon Islands within about 200 km since an M 6.3 on January 27, 2020 and an M 6.5 on September 9, 2018." (May 21, 2023)

Forecast 153574 had expected today's activity in the Solomon Islands was likely towards the end of May within about 100 km of this epicenter.

O: 28MAY2023 03:29:54 10.1S 161.2E Mw=5.6 EMSC SOLOMON ISLANDS

P: 22MAY2023 153574 10.0S 160.0E 4.0-5.6 CAAAA No. of Santa Cruz Islands

A moderate earthquake of M 5.5 also occurred today in the South Sandwich Islands. It was not reported felt in this remote area. The last earthquake of M>=5.5 in the South Sandwich Islands was on April 28, 2023 when an M 5.6 was recorded. This and a second M 5.6 on April 24, 2023 are the strongest events in the South Sandwich Islands in the past three months. Today's event occurred near local solar noon and may have been promoted by tidal stresses which maximize near this hour. Forecast 153618 had expected this activity was likely within about 100 km of this epicenter around May 28.

O: 27MAY2023 15:21:47 58.0S 25.7W Mw=5.5 EMSC SOUTH SANDWICH ISLANDS REGION

P: 28MAY2023 153618 59.0S 26.0W 4.0-6.1 AAAAA So. Sandwich Islands

The largest earthquake in the U.S. or Canada today was an M 4.6 in Southern Alaska. It was followed by an M 4.4 aftershock. NEIC reported this activity was felt with intensity II-III in Alaska in the West Kenai Peninsula, Anchor Point, Homer, Kenai and Anchorage. This is the strongest earthquake within about 150 km of this epicenter since an M 5.0 on February 2, 2023 and prior to that an M 4.7 on March 23, 2022. Earthquakes in this area generally occur at intermediate depths and are not destructive at the earth's surface. Forecast 153555 had expected this event was likely within about 10 km around May 25, 2023.

O: 27MAY2023 16:49:22 60.3N 153.0W mb=4.6 EMSC SOUTHERN ALASKA

P: 25MAY2023 153555 60.3N 153.0W 3.2-5.1 AAAAA Central Alaska

STRONG EARTHQUAKE SHAKES AREA NEAR TOKYO, JAPAN

EARTHQUAKE SUMMARY FOR MAY 26, 2023

An M 6.1-6.2 earthquake shook the area of Japan near Tokyo today. NEIC reported it was felt with maximum intensity VI in Chiba, IV in Ibaraki, Saitama, Kanagawa, Tokyo, with lesser shaking in Gunma, Tochigi, Shizuoka, Miyagi, Niigata, Aichi Prefectures. JMA reported intensity IV (Japanese scale) throughout much of the area of southeastern Honshu, Japan. An aftershock of M 4.9 was reported by NEIC to have been felt with intensity III in Chiba and IV in Kochi Prefectures, Japan. This forced a number of bullet trains to stop operations temporarily. A series of earthquakes have occurred in this region of Japan in the past two weeks of M 5.0-5.5 and may have been precursory to today's event. This included an M 5.2 in Chiba Prefecture of May 11, 2023 which injured at least five elderly people in Chiba and two others in Kanagawa Prefecture while doing minor damage to buildings and roofing. At the time this summary noted in this regard:

"A moderate earthquake of M 5.2 was widely felt in the region of Tokyo, Japan today. NEIC reported maximum intensity V in Chiba and Kanagawa Prefectures with IV in Tokyo, Saitama, and lesser shaking in Ibaraki and Shizuoka Prefectures, Japan. It caused several injuries to elderly people and minor damage to buildings. The last earthquake within about 200 km of this epicenter near Tokyo, Japan with M>=5.2 was an M 5.0 on October 7, 2021. At the time this summary note in this regard:

"Today's event is the first within about 150 km of Tokyo, Japan with M>=5.9 in more than an year - since an M 5.9 on June 24, 2020. The last event of larger magnitude in this area was an M 6.2 five years ago on September 23, 2016." (October 7, 2021)

... This activity is located at the seventh node (51.5 degrees) from the major earthquake in Tajikistan of M 7.2 on February 23, 2023 and may have been promoted by energy from that source." (May 11, 2023)

Typhoon Mawar is currently south of this epicenter. Mawar is the strongest typhoon to hit the region of Guam and the Mariana Islands in more than two decades and could have influenced the timing of today's earthquake in Japan. In previous issues this summary had noted in this regard:

"Typhoon Mawar (02W) continued today in the area of west of Guam with winds up to 165 kts. It is expected to track to the northwest reaching Taiwan around May 31 as a typhoon with winds up to 165 kts. It is likely that a moderate to strong earthquake could occur near Guam or Taiwan or Southern Japan with this storm in the next week. This appears to be the strongest typhoon to hit Guam in the past two decades." (May 25-27, 2023)

Today's earthquake of M 6.1 is the strongest to hit the region within about 150 km of Tokyo since an M 6.2 on September 23, 2016 an event also accompanied by a strong typhoon. The last of M>6.2 in this region occurred as aftershocks of the M 7.9-9.3 earthquake and tsunami of March 11, 2011. On September 23, 2016 this summary noted:

"This area has been relatively quiet at M>=6 since the great earthquakes of March, 2011, but did not rupture in those events and probably is still capable of a major earthquake. The last earthquake of M>=6.3 within about 150 km of this epicenter was an M 6.4 on January 19, 2005 and prior to that an M 6.3 on May 29, 2004, the only such earthquakes in the area in the past 25 years, making this a regionally significant earthquake." (September 23, 2016)

A great earthquake with M>9 hit near this epicenter on May 27, 1293 - 830 years ago today. It, and an accompanying tsunami reportedly killed more than 22,000 (See HISTORY section of this summary).

Forecast 153465 had expected today's event was likely within about 150 km of this epicenter around May 22, 2023. This epicenter is located at the third node (120 degrees) from the M 6.8 in the Prince Edward Islands of May 21, 2023 and at the seventh node (52 degrees) from the M 7.3 in Sumatra of April 24, 2024 and the M 7.2 in Tajikistan of February 23, 2023 and may have been promoted by energy from those sources.

O: 26MAY2023 11:07:39 35.5N 140.7E mb=4.3 EMSC NEAR EAST COAST OF HONSHU, JAPAN

O: 26MAY2023 12:01:50 35.5N 140.8E mb=4.6 EMSC NEAR EAST COAST OF HONSHU, JAPAN

O: 26MAY2023 10:03:24 35.6N 140.5E Mw=6.1 EMSC NEAR EAST COAST OF HONSHU, JAP

O: 26MAY2023 10:03:24 35.6N 140.5E Mw=6.2 JMA NEAR EAST COAST OF HONSHU, JAP

O: 26MAY2023 10:03:24 35.6N 140.7E Mw=6.2 CENC NEAR EAST COAST OF HONSHU, JAP

P: 22MAY2023 153465 35.0N 142.0E 4.0-5.5 BAAAA Off East Coast Honshu

Moderately large to large earthquakes also occurred in the West Chile Rise and in the Tonga Islands with M 5.9 and 6.0 today. These events were lightly felt in their respective epicentral area but did not do any damage that was reported.

The last similar earthquake in the West Chile Rise was an M 5.8 on October 31, 2022. This summary noted this event at the time as:

"The strongest earthquake in the world today was an M 5.8-6.0 in the West Chile Rise. It was not reported felt in this remote area. This is the strongest earthquake within about 250 km of this epicenter since an M 5.9 on May 20, 2010. The only other such event in the area in the past 30 years was an M 5.8-6.0 on June 5, 2008." (November 1, 2022)

The last earthquake with M>=5.9 in the West Chile Rise within about 300 km

of today's epicenter was an M 5.9-6.0 on June 5, 2008, the only such event in the area in the past 35 years. Forecast 153609 had expected enhanced seismicity in the Chile Rise was likely around May 27.

O: 26MAY2023 22:18:25 39.1S 91.5W Mw=5.9 EMSC WEST CHILE RISE

P: 27MAY2023 153609 43.0S 83.0W 4.0-5.7 ACCAA Chile Rise

The M 6.0 in Tonga today continued activation of that area which included an M 7.6 in northern Tonga near Samoa on May 10, 2023. It is the strongest earthquake within about 150 km of this epicenter since an M 6.3 a year ago on June 4, 2022 and an M 6.5 on April 24, 2021. Forecast 153581 had expected today's event within about 100 km was likely around May 29, 2023. This epicenter is at 145 degrees from the M 7.8 in Turkey of February 6, 2023 and at 100 degrees from the M 6.7 in Colombia of May 25, 2023 and at the fifth node (72 degrees) from the M 7.0 in Java of April 14, 2023 and may have been promoted by energy from those sources.

O: 27MAY2023 00:11:01 18.4S 175.3W Mw=6.0 EMSC TONGA

P: 29MAY2023 153581 18.0S 174.0W 4.0-5.6 AAAAA Tonga Islands

The strongest earthquake in the U.S. or Canada today was an M 4.1 aftershock in the region of Northern California. NEIC reported this earthquake of M 4.1 in Northern California was felt with intensity II-III in the area(s) of Northern California in Canyon Dam and Westwood (IV) and in Chester, Greenville, Crescent Mills, Mineral, Quincy, Meadow Valley and Magalia among others.

This is the strongest aftershock of the M 5.5 in Northern California of May 11, 2023 since the M 5.2 on May 12, 2023. Forecast 153516 had expected today's event within about 10 km was likely around May 28.

O: 26MAY2023 11:37:21 40.2N 121.2W Md=2.4 EMSC NORTHERN CALIFORNIA

O: 26MAY2023 12:19:20 40.2N 121.2W Md=2.2 EMSC NORTHERN CALIFORNIA

O: 26MAY2023 12:34:01 40.2N 121.2W Md=2.2 EMSC NORTHERN CALIFORNIA

O: 26MAY2023 17:51:28 40.2N 121.2W Md=2.2 EMSC NORTHERN CALIFORNIA

O: 27MAY2023 00:14:26 40.2N 121.1W MD=2.7 EMSC NORTHERN CALIFORNIA

O: 27MAY2023 04:35:26 40.2N 121.1W Md=2.3 EMSC NORTHERN CALIFORNIA

O: 26MAY2023 11:26:25 40.2N 121.2W ML=4.1 EMSC NORTHERN CALIFORNIA

P: 28MAY2023 153516 40.2N 121.2W 2.5-4.5 AAAAA Northern California

ODERATE AFTERSHOCKS CONTINUE IN LOYALTY ISLANDS

EARTHQUAKE SUMMARY FOR MAY 25, 2023

The strongest earthquakes in the world today was an M 5.5 aftershock in the Loyalty Islands. This earthquake was not reported felt in the epicentral area. It is an aftershock of the M 7.8 in the Loyalty Islands of May 19, 2023. It occurred within minutes of local solar midnight and may have been promoted by high tidal stresses which maximize near this hour. Forecast 153589 had expected today's event was likely around May 27.

O: 25MAY2023 12:59:14 22.8S 171.3E mb=4.7 EMSC SOUTHEAST OF LOYALTY ISLANDS

P: 27MAY2023 153589 23.0S 172.0E 4.0-5.5 AAAAA Loyalty Islands

EMSC reported an M 3.6 in Michigan today, but this could not be confirmed with NEIC data. The last earthquake to have occurred in the State of Michigan was an M 2.4 on July 11, 2022 about 500 km south of today's epicenter. The last earthquake within about 200 km of today's epicenter was an M 3.8 on August 5, 2014. At the time this summary noted:

"A light earthquake of M 3.8 in Ontario, Canada was also widely felt today. NEIC reported intensity II in Rochester, New York nearly 500 km from the epicenter. Intensity III was felt in Ontario at Onaping-Levack and Sudbury. The Sudbury Star (online) reported the larger event was preceded by an M 3.3 about 23 minutes earlier. The quake was felt across Sudbury but especially in the north. This is the strongest earthquake in the Sudbury area in at least 25 years. An M 3.1 hit the area on September 26, 2001. As these are genuine earthquakes, they compare in size with mining-related earthquakes four of which have reach M 3.8 in the area in the past 25 years. This is the first earthquake to reach this magnitude in this time however." (August 5, 2014)

Forecast 153246 had expected this event within this area was likely around

May 19.

O: 25MAY2023 19:07:57 46.0N 83.8W ML=3.6 EMSC MICHIGAN

P: 19MAY2023 153246 46.0N 81.0W 2.0-4.5 CABAA Ohio/Lake Erie

STRONG EARTHQUAKE SHAKES PANAMA AND COLOMBIA

EARTHQUAKE SUMMARY FOR MAY 24, 2023

The strongest earthquake in the world today was an M 6.6 on the Panama-Colombia border. NEIC reported it was felt in Colombia with maximum intensity IV in Acandi Choco and in Necocli, Antioquia and in Panama with VI in Meteti, Darien. Intensity V in Panama was felt in Las Cumbres with IV in Santa Fe, Darien. Intensity III was reported in Colombia at San Bernardo Viento Cordoba, Cartagena, Bolivar and in Panama at San Miguelito and Panama City among other communities. Residents of Medellin and Cali also reported feeling the earthquake. This earthquake is located in the Darien Gap where thousands of migrants congregate on their migration to the north. While the area is densely populated with migrants and is dense jungle, some damage and injuries may have been incurred in this quake. The antipode of this earthquake is in southern Sumatra, Indonesia at 7S 103E, an active seismic zone near the M 7.3 in Sumatra of April 24, 2023 and the M 7.0 in Java of April 14, 23 and this activity may have been promoted by energy from that source. In recent days the antipode south of Sumatra has been active and a triggered moderate to large earthquake in this area in the next several days is possible.

When the M 7.3 in Sumatra occurred a month ago on April 24, this summary contemplated the effect on the relation between seismicity in Colombia and Sumatra as:

"The M 8+ in Sumatra on September 13, 2007 followed an M 7.0 in Colombia the day before and was considered as an antipodal aftershock of that event." (April 24, 2023)

and prior to that:

"A moderate earthquake occurred in northern Colombia today with M 5.5. Moderately large earthquakes in Colombia are often associated with enhanced seismicity near the antipode in the region of Sumatra, Indonesia. A moderately large to large earthquake is likely in the next several days in that region due to antipodal triggering. This is most likely at local solar noon of local solar midnight with high earth tides which maximize near this hour." (February 23, 2022)

and following an M 6.8 in Sumatra of November 18, 2022 it was noted:

"... This earthquake is located at the antipode of the M 6.8 south of Panama of October 20, 2022 and was probably promoted by energy from that source focused at the antipode." (November 18, 2022)

Today's event occurred near local solar midnight and may also have been promoted by strong tidal stresses with the new moon of May 19 as noted in this summary:

"The new moon arrived on May 19, 2023 at 15:53 UT. Longitudes at local solar solar midnight were near 126 East and those at local solar noon are near 54 West longitude. In the west these include the northern and Eastern Caribbean as well as areas of western South America while in the East longitudes near 126 E are located in the Philippines, Taiwan, Japan, and Indonesia among others. These are the most likely areas to see tidal triggering at this time, but other areas could see significant enhancement in seismicity in the next several days. These would most likely see seismic enhancement near local solar noon or midnight. A strong to major earthquake is considered likely with this new moon before May 25, 2023. (May 18-24, 2023)

The last earthquake in Colombia within about 250 km of this epicenter with M>=6.6 occurred on October 17 and October 18, 1992 with M 6.7 and 7.2, the only such events in the area in the past 35 years. Forecast 153352 had expected today's event in this region was likely around May 27, 2023 in the area of Colombia. This epicenter is also at 103 degrees from the M 7.8 in Turkey of February 6, 2023 and the M 7.2 in the Kermadec Islands of April 24, 2023 and near this distance from the M 7.6 in Tonga of May 10 and the M 7.8 in the Loyalty Islands of May 19 and may have been promoted by energy from those sources.

O: 25MAY2023 03:05:34 8.9N 77.1W Mw=6.6 EMSC PANAMA-COLOMBIA BORDER REGION

O: 25MAY2023 03:14:59 8.9N 77.1W mb=4.9 EMSC PANAMA-COLOMBIA BORDER REGION

O: 25MAY2023 06:48:30 8.9N 77.1W mb=4.6 EMSC PANAMA-COLOMBIA BORDER REGION

O: 25MAY2023 03:16:26 8.6N 77.2W ML=4.1 EMSC PANAMA-COLOMBIA BORDER REGION

P: 27MAY2023 153352 7.0N 78.0W 4.0-5.9 ABAAA Colombia

A large earthquake also occurred today as an M 6.2 in the Banda Sea, Indonesia. NEIC reported it was felt with intensity III in Dili, East Timor and Pringsewu, Lampung, Indonesia and in Northern Territory, Australia with maximum intensity IV in Coonawarra and II-III in Darwin, Howard Springs, Humpty Doo-MacMinns Lagoon and Katherine. Like the earthquake in Colombia today, this epicenter at 130 East Longitude occurred at the longitude of maximum tidal stresses with the past new moon and may have been promoted by tidal energy associated with that tidal alignment (see above). This earthquake occurred near local solar midnight intensifying the tidal effect. This is the strongest earthquake in the Banda Sea within about 250 km of this epicenter since the M 7.6 on January 9, 2023 and is the largest aftershock to day of that event. Forecast 153382 had expected today's event within about 50 km was likely around May 24, 2023. This epicenter is located at the sixth node from the M 7.2 in Tajikistan of February 23, 2023 and at the fourth node (90 degrees) from the M 6.8 in the Prince Edward Islands of May 19 and may have been promoted by energy from those sources.

O: 24MAY2023 15:49:35 7.0S 129.5E Mw=6.2 EMSC BANDA SEA

P: 24MAY2023 153382 7.0S 130.0E 4.0-5.6 AAAAA West Irian, PNG

A moderate earthquake of M 5.5 also occurred today in the Pacific-Antarctic Ridge. It was not reported felt in this remote area. The last earthquake within about 300 km of this epicenter on the Pacific-Antarctic Ridge with M>=5.5 occurred on March 14, 2023 with M 5.5 and prior to that as an M 5.7 on June 24, 2022. This epicenter is near the seventh node (51 degrees) from recent major earthquakes in the Loyalty Islands. This epicenter is at 103-104 degrees from the M 7.3 in Sumatra of April 24, 2023 and at the fifth node (72 degrees) from the event of M 6.7 in Ecuador of March 18, 2023 and may have been promoted by energy from those sources as well.

O: 24MAY2023 10:33:23 57.0S 140.8W Mw=5.5 EMSC PACIFIC-ANTARCTIC RIDGE

MODERATE QUAKES IN MINDANAO, PHILIPPINES

EARTHQUAKE SUMMARY FOR MAY 23, 2023

It was a relatively quiet day in global seismicity. The strongest earthquake

in the world was an M 5.2 in southern Mindanao, Philippines. This event was accompanied by a series of lesser quakes of M 4.8, 4.2, 4.9 and 4.5. NEIC reported this earthquake of M 5.2 in Mindanao, Philippines was felt with intensity II-III in the area(s) of Mindanao, Philippines in Kiamba, Koronadal, Buayan, Tacurong. Foreshocks of M 4.8 and M 4.5 were felt with intensity II in Katangawan and Buayan, Mindanao. Forecast 153356 had expected this activity within about 100 km was likely around May 22.

O: 23MAY2023 18:23:04 5.7N 124.5E mb=4.8 EMSC MINDANAO, PHILIPPINES

O: 23MAY2023 18:30:16 5.7N 124.3E ML=4.2 EMSC MINDANAO, PHILIPPINES

O: 24MAY2023 00:44:06 5.7N 124.4E Mw=5.2 EMSC MINDANAO, PHILIPPINES

O: 23MAY2023 17:04:00 5.8N 124.6E mb=4.9 EMSC MINDANAO, PHILIPPINES

O: 23MAY2023 17:11:54 5.8N 124.6E mb=4.5 EMSC MINDANAO, PHILIPPINES

P: 22MAY2023 153356 5.0N 124.0E 4.0-5.8 AAAAA Mindanao, Philippines

The most unusual earthquake in the U.S. or Canada today was an M 2.6 in North Carolina. NEIC reported this earthquake of M 2.6 in North Carolina was felt with intensity II-III in the area(s) of North Carolina in Lake Junaluska, Clude, Waynesville, Canton, Leicester, Candler, Maggie Valley and Asheville among others. This is the largest earthquake in North Carolina within about 100 km of this epicenter since an M 2.7 on December 8, 2022. The last event of significantly larger magnitude in this area was an M 3.4 on March 5, 2019. Forecast 153453 had expected today's event within North Carolina within about 50 km of this epicenter was likely around May 23.

O: 23MAY2023 23:28:55 35.6N 82.9W mb=2.6 EMSC NORTH CAROLINA

P: 23MAY2023 153453 35.0N 83.0W 2.0-4.1 AAAAA Kentucky/Tennessee/NC

Two light earthquakes also occurred today in southern Texas of M 2.2 and 2.5. These occurred near local solar noon and may have been promoted by tidal stresses which maximize near this hour. Forecast 153422 had expected this activity within about 50 was likely around May 24. This activity is located at 102 degrees from the Loyalty Islands and may have been promoted by energy from that source. Other activity at this distance from the Loyalty Islands has been occurring in Tajikistan, Nepal, Prince Edward Islands, Colorado, Yukon Territory, Canada, and northern South and Central America and these areas could see continued seismic enhancement in the next several days.

O: 23MAY2023 19:23:26 28.6N 98.3W ML=2.2 EMSC SOUTHERN TEXAS

O: 23MAY2023 19:20:00 28.6N 98.3W mb=2.5 EMSC SOUTHERN TEXAS

P: 24MAY2023 153422 28.0N 98.0W 3.0-4.4 AAAAA Northern Mexico

UNUSUAL SEISMICITY CONTINUES IN EASTERN EUROPE AT 144 DEGREES FROM LOYALTY IS.

EARTHQUAKE SUMMARY FOR MAY 22, 2023

An unusual earthquake of M 4.5 shook western Romania today. NEIC reported it was felt with maximum intensity in Arad, Romania with V in Ghioroc, Arad and IV in Sevis with II-III shaking in Oradea and Cluj-Napoca and in Gyula, Hungary. This follows a series of unusual earthquakes in eastern Europe over the past several days as described in the previous issue of this summary:

"An unusual earthquake occurred today in the region of Belarus with M 4.2.

This event is located near the 144 degree distance from the Loyalty Islands major earthquakes of the past three days and may have been promoted by energy from those sources as noted in the previous issue of this summary:

"Other areas where FFA from the Loyalty Islands is still occurring include eastern Europe. Earthquakes of M 3.9 in Romania and M 4.5 in Crete, Greece occurred today around 144 degrees from the Loyalty Islands, a distance where seismic enhancement is expected with major global earthquakes as previously described in this summary:

"144 degrees: Loyalty Islands to Reykjanes Ridge, Dodecanese Is. Greece, Romania," (May 20, 2023)

This is the largest earthquake in Belarus within about 300 km of this epicenter in at least 35 years. NEIC has recorded no earthquakes of any size in this region since 1990, so this is a significant event and should be examined in detail." (May 22, 2023)

The M 4.5 in western Romania was followed by an M 4.2 two hours later and by an

M 3.9 to the northwest in Poland about eight hours later. The M 4.5 in Romania is the strongest within about 150 km of that epicenter since an M 4.8 on March 24, 1996. An M 5.5 occurred about 100 km southwest of today's epicenter on December 2, 1991 - an aftershock of an M 5.6 on July 12, 1991. When an M 5.5 occurred about 200 km to the southeast of today's epicenter on February 14, 2023 this summary noted:

"No earthquakes of greater magnitude have occurred in southern Romania in at least 35 years. The last earthquakes of M 5.5-5.6 within about 200 km of today's epicenter hit west of this in Serbia on July 12 and 18, 1991. This activity is at 145-150 degrees from the strong earthquakes in the Tonga and Fiji areas in November and December, 2022" (February 14, 2023)

An aftershock in Romania occurred on March 20, 2023 with M 4.9 concurrent with an M 5.6 in Costa Rica and Panama of the same date. These areas are at the fourth node (90 degrees) from each other and nodal triggering may have occurred in these regions.

Forecast 153525 had expected today's activity was likely about 250 km to the southeast of this epicenter around May 27. The earthquakes in Romania are at 144-146 degrees from the M 7.6 in Tonga of May 10 and the Loyalty Islands of May 19 and were probably promoted by energy from those sources.

O: 22MAY2023 19:55:25 46.1N 21.5E ML=4.2 EMSC ROMANIA

O: 22MAY2023 17:46:41 46.1N 21.5E ML=4.5 EMSC ROMANIA

P: 27MAY2023 153525 45.0N 23.0E 3.0-5.3 BBAAA Romania/NW Turkey

O: 22MAY2023 22:31:34 45.3N 25.4E ML=3.2 EMSC ROMANIA

P: 23MAY2023 153526 46.0N 26.0E 3.0-4.9 AAAAA Romania/NW Turkey

The last earthquake of M>=3.9 in Poland was an M 3.9 on January 3, 2023 and an M 4.2 on September 14, 2022. This is a mining area and some of this activity may be due to rock fracture associated with mining. Forecast 153546 had expected today's activity in Poland was likely around May 22. This activity, like that in Romania is at 143-145 degrees from the Loyalty Islands. Aftershocks in Central Turkey also continued today following the mainshock there of M 7.8 on February 6, 2023. These events area also located at 144 degrees from the M 7.6 in Tonga. Forecast 153488 had expected enhanced seismicity in Turkey was likely around May 25.

O: 23MAY2023 03:21:00 51.6N 16.1E ML=3.9 EMSC POLAND

P: 22MAY2023 153546 51.0N 16.0E 3.0-4.8 AAAAA Poland

O: 22MAY2023 16:42:59 37.9N 36.3E Mw=4.3 EMSC CENTRAL TURKEY

O: 23MAY2023 01:12:46 37.9N 36.3E mb=4.0 EMSC CENTRAL TURKEY

O: 22MAY2023 16:06:58 37.9N 36.3E mb=4.6 EMSC CENTRAL TURKEY

P: 25MAY2023 153488 38.0N 36.0E 3.5-5.3 BAAAA Turkey

The strongest earthquake in the world today was an M 6.1 aftershock in the

Loyalty Islands. It was not reported felt. Forecast 153589 had expected continuing activity in the Loyalty Islands was likely around May 21.

O: 22MAY2023 21:45:56 22.9S 170.4E mb=5.0 EMSC SOUTHEAST OF LOYALTY ISLANDS

O: 23MAY2023 00:52:43 23.0S 171.0E mb=4.9 EMSC SOUTHEAST OF LOYALTY ISLANDS

O: 23MAY2023 06:42:00 23.0S 170.3E Mw=6.1 EMSC SOUTHEAST OF LOYALTY ISLANDS

O: 23MAY2023 06:22:13 23.2S 170.7E Mw=5.1 EMSC SOUTHEAST OF LOYALTY ISLANDS

O: 22MAY2023 22:59:56 23.3S 170.6E mb=4.9 EMSC SOUTHEAST OF LOYALTY ISLANDS

O: 22MAY2023 06:52:47 23.8S 171.8E Mw=5.5 EMSC SOUTHEAST OF LOYALTY ISLANDS

O: 22MAY2023 22:54:13 22.6S 170.0E mb=5.1 EMSC SOUTHEAST OF LOYALTY ISLANDS

P: 21MAY2023 153589 23.0S 171.0E 4.0-5.5 AAAAA Loyalty Islands

One of the few places where the major earthquakes in the Loyalty Island of recent days have been reported felt was the Norfolk Island region of Australia. An unusual earthquake of M 3.7 hit this area today. The only events in this region of any size in the past 3 years occurred in February, 2021 with a series of events of M 3.9, 3.8 and 4.1. These - like the current event - were concurrent with a M 7.7 in the Loyalty Islands of February 10, 2021. Regional stress redistribution is the likely cause of today's event in the Norfolk Island region. Today's event occurred within minutes of local solar noon and may have been promoted by tidal stresses which maximize at that time. It also occurred less than two minutes after an M 4.9 in the Loyalty Islands. This epicenter in the Norfolk Islands, Australia area is at 142 degrees from the M 7.8 in Turkey of February 6 and may have been promoted by energy from that source.

O: 23MAY2023 00:54:03 27.6S 172.8E ML=3.7 EMSC NORFOLK ISLAND, AUSTRALIA REGION

P: 27MAY2023 153589 23.0S 172.0E 4.0-5.5 BCAAA Loyalty Islands

Strong volcanic eruptions have been occurring in Mt. Etna, Italy and in Popocatepetl Volcano north of Mexico City. Both eruptions have included copious amount of emitted ash and lava and have briefly shut down tourism and air travel in these areas. The eruption in Popocatepetl is being carefully monitored as it is near Mexico City, a major metropolitan area. Both volcanoes have frequent smaller eruptions. A volcano is also active and spewing lava in the Congo at this time. This activity may be related to strong solar flares and geomagnetic storms of the past several days.

M 6.8 IN PRINCE EDWARD ISLANDS PRECEDES M 5.6 OFF NO. CALIFORNIA NEAR ANTIPODE

EARTHQUAKE SUMMARY FOR MAY 21, 2023

The strongest earthquake in the world today was an M 6.8 in the Prince Edward Islands of the South Indian Ocean. It was not reported felt in this remote area. This is the strongest earthquake in the Prince Edward Islands region within about 300 km of these epicenters in at least 35 years. The largest previous earthquake in this time frame in this area was an M 6.3 exactly 25 years ago today on May 21, 1998 within about 200 km of today's epicenter. This epicenter is located at the fifth node (72 degrees) from the M 7.0 in Java of April 14, 2023 and at 100 degrees from the Loyalty Islands events of the past three days and may have been promoted by energy from those sources.

The antipode of this event is off the coast of Northern California and Oregon at

43N 140W, near an area of active seismicity which could be promoted by antipodal focusing of seismic energy. It also preceded an M 6.1 in the Solomon Islands by less than an hour. The distance between these is 103-104 degrees, a distance at which triggering is expected following large earthquakes.

O: 21MAY2023 14:56:46 43.4S 39.3E Mw=6.8 EMSC PRINCE EDWARD ISLANDS REGION

O: 21MAY2023 17:23:21 43.9S 39.5E mb=5.1 EMSC PRINCE EDWARD ISLANDS REGION

P: 22MAY2023 153611 41.0S 43.0E 4.0-5.8 ACBAA So. Indian Ocean

The strongest earthquake in the U.S. or Canada today was an M 5.6 off the coast of Northern California. NEIC reported it was felt with maximum intensity VI in California at Petrolia and II-III in Ferndale, Loleta, Rio Del, Fortuna, Samoa, Hydesville, Eureka, Scotia, and as far as the coast of Oregon and Central California. This is near the antipode of the M 6.8 in the Prince Edward Islands which occurred several hours earlier in the day. Triggering associated with that event possible. This event is near the fourth node (90 degrees) from the major activity in the Loyalty Islands of the past three days and continues a regional activation of seismicity in California associated with the Loyalty Islands near the fourth node as noted in the previous issue of this summary:

"A series of moderate earthquakes shook the region of California today. These included unusual earthquakes of M 4.2 near the California-Nevada border and an M 4.1 off the coast of Baja California. An M 3.3 was also widely felt south of Los Angeles. These epicenters are all located within about a degree of the fourth node (90 degrees) of the M 7.7 in the Loyalty Islands of May 20-21 and are probably far-field aftershocks of those mainshocks

...

This includes area throughout much of California as far to the north as areas off the coast of northern California and could include more such seismicity in the coming days." (May 21, 2023)

Earthquakes of equal or larger magnitude in this area of California have most recently occurred as an M 6.2 on December 20, 2021, an M 5.8 on March 9, 2020 and an M 5.8 on January 25, 2018. Forecast 153518 had expected this activity off the coast of Northern California within about 25-100 km was likely in late May, 2023. Today's event is at the fifth node (72 degrees) from the M 7.6 in Tonga of May 10 and may have been promoted by energy from that source. Other earthquakes at 72 degrees from Tonga today included an M 5.5 in the northern Ryukyu Islands, Japan and the swarm off the coast of Baja California.

O: 21MAY2023 18:44:02 40.4N 125.4W Mw=5.6 EMSC OFFSHORE NORTHERN CALIFORNIA

O: 21MAY2023 18:44:02 40.4N 125.4W Mw=5.5 ANSS OFFSHORE NORTHERN CALIFORNIA

P: 22MAY2023 153518 40.9N 124.3W 2.5-4.4 AAAAA Off Coast of No. Calif

P: 29MAY2023 153518 40.5N 125.8W 2.5-4.4 CAAAA Off Coast of No. Calif

A strong M 6.1 was also felt in the Solomon Islands today. NEIC reported it was felt with intensity V in the Solomon Islands at Kirakira Makira and Ulawa and in Honiara, Guadalcanal. This is part of a regional enhancement of seismicity following the M 7.7 and 7.2 events in the Loyalty Islands of the past two day which occurred about 15 degrees south east of this epicenter in the Solomon Islands. Today's event of M 6.1 is the strongest in the Solomon Islands within about 200 km since an M 6.3 on January 27, 2020 and an M 6.5 on September 9, 2018.

Forecast 153574 had expected today's epicenter would be active within about

150 km of this around May 22, 2023. This epicenter is located at 104 degrees from the M 6.8 in the Prince Edward Islands today and may have been promoted by energy from that source which occurred less than an hour earlier.

O: 21MAY2023 15:45:13 10.3S 161.4E Mw=6.1 EMSC SOLOMON ISLANDS

P: 22MAY2023 153574 10.0S 160.0E 4.0-5.6 AABAA No. of Santa Cruz Islands

An unusual earthquake occurred today in the region of Belarus with M 4.2. This event is located near the 144 degree distance from the Loyalty Islands major earthquakes of the past three days and may have been promoted by energy from those sources as noted in the previous issue of this summary:

"144 degrees: Loyalty Islands to Reykjanes Ridge, Dodecanese Is. Greece, Romania," (May 20, 2023)

O: 21MAY2023 08:02:53 53.8N 25.7E ML=4.2 EMSC BELARUS

P: 30MAY2023 153546 50.0N 19.0E 3.0-5.0 CCCAA Poland

MODERATE QUAKES IN CALIFORNIA MAY BE FAR-FIELD EVENTS FROM LOYALTY ISLANDS

EARTHQUAKE SUMMARY FOR MAY 20, 2023

A series of moderate earthquakes shook the region of California today. These included unusual earthquakes of M 4.2 near the California-Nevada border and an M 4.1 off the coast of Baja California. An M 3.3 was also widely felt south of Los Angeles. These epicenters are all located within about a degree of the fourth node (90 degrees) of the M 7.7 in the Loyalty Islands of May 20-21 and are probably far-field aftershocks of those mainshocks as previously discussed in this summary:

"Far field triggering from the activity in the Loyalty Islands is expected to be robust. This is due, not only to the great size of the mainshock but also to the regions which are near 103 degrees from this epicenter. ... Other areas subject to seismic promotion include ... Southern and Central California, ... (node 4, 90 degrees) ...

90 degrees: Loyalty Islands to Ridgecrest, Southern California," (May 20, 2023)

This includes area throughout much of California as far to the north as areas off the coast of northern California and could include more such seismicity in the coming days.

The strongest earthquake felt in the U.S. or Canada today was an M 4.2 near the California-Nevada border. NEIC reported it was felt with intensity II-III in Clovis, Yucca Valley and Ontario, California. The last earthquake within about 75 km of this epicenter with M>=4.2 in Central California occurred on January 6, 2022 with M 4.8 and before that an M 4.8 on February 14, 2015. The largest earthquake in this area in the past 30 years was an M 5.7 on August 1, 1999. At the time of the January, 2022 event this summary noted:

"earthquakes on the border between Central California and Nevada were reported felt with maximum intensity VI in California at Big Pine and III in Independence, Bishop, Benton, Kings Canyon National Park and in Nevada at Silverpeak, Goldfield and II in Mammoth Lakes, Shaver Lake and Dunlap, California. An M 2.2 foreshock occurred near local solar noon within about 25 km of this epicenter. The last earthquake of M>=4.8 within about 50 km of this epicenter occurred on February 14, 2015 about 30 km to the south of today's epicenter on February 14, 2015, the only such earthquake in the area in the past 30 years. An M 5.7 about 100 km northeast of today's M 4.8 occurred on August 1, 1999." (January 6, 2022).

The event in January 6, 2022 was also accompanied by an M 4.6 off the coast of Northern California about an hour earlier. Today's event follows moderate quakes in Northern California of M 5.5 and 5.2 and could have been promoted by that activity. An event in the area off the coast of Northern California is anticipated at this time due to this area's distance from the M 7.6 in Tonga of April 24 and the M 7.7, 7.2 and 7.2 in the Loyalty Islands (90 degrees - node 4) of May 20. Such an event may occur near the current new moon. A strong series of aftershocks off the coast of Baja California today also suggests this area is likely to be experiencing strong far-field triggering from the Loyalty Islands.

Forecast 153433 had expected this activity was likely within about 25 km of these events around May 21, 2023.

O: 21MAY2023 03:06:38 37.3N 117.6W ML=2.8 EMSC CENTRAL CALIFORNIA

O: 21MAY2023 03:26:29 37.3N 117.6W mb=4.2 EMSC CENTRAL CALIFORNIA

O: 21MAY2023 03:35:54 37.3N 117.6W ML=3.1 EMSC CENTRAL CALIFORNIA

O: 21MAY2023 03:53:31 37.3N 117.6W ML=2.7 EMSC CENTRAL CALIFORNIA

O: 21MAY2023 03:58:38 37.3N 117.6W ml=2.1 EMSC NEVADA

O: 21MAY2023 04:01:41 37.3N 117.6W ml=2.0 EMSC NEVADA

P: 21MAY2023 153433 37.2N 117.3W 2.5-4.8 AAAAA California/Nevada area

Earthquakes of M 3.4 and 2.7 were also widely felt today in Southern California. NEIC reported the maximum intensity was felt with IV in California at Warner Springs with II-III in Pala, Pauma Valley, Aguanga, Valley Center, Temecula, Santa Ysabel, Escondido among others as far to the north as Los Angeles and Ludlow. Forecast 153473 had expected this activity within about 25 km was likely around May 22.

O: 20MAY2023 08:20:51 33.4N 116.9W ML=2.6 EMSC SOUTHERN CALIFORNIA

O: 20MAY2023 08:18:15 33.4N 116.9W ML=3.3 EMSC SOUTHERN CALIFORNIA

P: 22MAY2023 153473 33.4N 116.7W 2.5-4.8 AAAAA So. California

The earthquakes off Baja California today continued the strong aftershock sequence of the November 22, 2022 mainshock. This has been a very active series of events throughout the past six months and is highly abnormal for aftershock sequences in general as it does not appear to be diminishing in strength, so there may be other factors involved not normal to general aftershock sequences which remain unknown. Due to the unusual nature of this series, the area should be closely monitored for signs of other seismic activity. The largest event in today's series was an M 4.1 near local solar noon. Aftershocks of M 3.5-4.0 have been common for the past six months but events of M>=4 within about 50 km of the mainshock of November, 2022 have been rare. Only three events of M>=4.1 had hit this region since November, 2022 - an M 4.5 and 4.3 on May 14 and 15, 2023 and an M 4.4 on December 10, 2022. The only other event in this region in the past 35 years of M>=4.1 was an M 4.2 on December 2, 1992. Forecasts 153190 and 153468 had expected today's activity between May 16-24, 2023.

O: 20MAY2023 22:23:31 30.7N 116.4W ML=3.4 EMSC OFFSHORE BAJA CALIFORNIA, MEXICO

O: 20MAY2023 22:50:53 30.7N 116.2W ML=3.1 EMSC OFFSHORE BAJA CALIFORNIA, MEXICO

O: 20MAY2023 21:52:30 30.8N 116.3W ML=3.7 EMSC OFFSHORE BAJA CALIFORNIA, MEXICO

O: 20MAY2023 22:10:51 30.8N 116.2W ML=3.4 EMSC OFFSHORE BAJA CALIFORNIA, MEXICO

O: 20MAY2023 23:00:35 30.8N 116.2W ML=3.6 EMSC OFFSHORE BAJA CALIFORNIA, MEXICO

O: 20MAY2023 09:37:00 30.9N 116.2W ML=3.4 EMSC OFFSHORE BAJA CALIFORNIA, MEXICO

O: 20MAY2023 10:46:38 30.9N 116.1W ML=3.4 EMSC BAJA CALIFORNIA, MEXICO

O: 20MAY2023 16:42:08 30.9N 116.2W ML=3.6 EMSC OFFSHORE BAJA CALIFORNIA, MEXICO

O: 20MAY2023 21:42:44 30.7N 116.4W ML=4.1 EMSC OFFSHORE BAJA CALIFORNIA, MEXI

P: 16MAY2023 153190 30.8N 116.1W 2.0-4.2 BAAAA SW U.S.A

P: 24MAY2023 153468 30.8N 116.3W 2.0-4.1 BAAAA SW U.S.A

The strongest unfelt earthquake in the U.S. today was an M 4.8 in the Near Islands, Aleutians, Alaska. This is the largest earthquake in the Near Islands since an M 4.8 on December 25, 2022. The last earthquake of larger magnitude in this area was an M 5.2 more than a year ago on March 1trongest earthquake within about 300 km of today's event in the Near Islands in the past three years was an M 5.7 on December 29, 2021. 2022. Forecast 153273 had expected this earthquake in the Near Islands was likely around May 17, 2023.

O: 20MAY2023 19:00:05 51.2N 172.8E mb=4.8 EMSC NEAR ISLANDS, ALEUTIAN ISLANDS

P: 17MAY2023 153273 53.0N 170.0E 4.0-6.0 BBBAA Near Islands

Other areas where FFA from the Loyalty Islands is still occurring include eastern Europe. Earthquakes of M 3.9 in Romania and M 4.5 in Crete, Greece occurred today around 144 degrees from the Loyalty Islands, a distance where seismic enhancement is expected with major global earthquakes as previously described in this summary:

"144 degrees: Loyalty Islands to Reykjanes Ridge, Dodecanese Is. Greece, Romania," (May 20, 2023)

These events had been anticipated in forecasts 153430, 153251 and 153526 to occur around May 20-25, each within about 100 km of their respective epicenters.

NEIC reported the earthquake of M 4.5 in Crete, Greece was felt with intensity II-III in the area(s) of Crete, Greece in Timbakion, Iraklion.

O: 21MAY2023 04:36:05 35.0N 24.8E mb=4.5 EMSC CRETE, GREECE

P: 25MAY2023 153430 36.0N 25.0E 3.0-4.7 BAAAA Aegean Sea

O: 20MAY2023 07:36:19 45.4N 26.2E ML=3.9 EMSC ROMANIA

P: 17MAY2023 153251 46.0N 26.0E 3.0-5.0 BAAAA Romania/NW Turkey

P: 23MAY2023 153526 46.0N 26.0E 3.0-4.9 BAAAA Romania/NW Turkey

The strongest earthquake in the world today was an M 5.8 in eastern Tonga. This continued enhanced seismicity in this region following the M 7.6 in Tonga of April 24, 2023. Today’s event was not reported felt in this remote area. It is probably an aftershock - the largest to date - of the M 7.3 in the area on November 11, 2022. At the time this summary noted in this regard:

"The M 7.3 was widely felt throughout Tonga and Samoa. NEIC reported it was felt with intensity Vin Tonga at Neiafu, Haveloloto, and IV in Mu'a, Nuku'alofa, American Samoa and in Niue at Avatele, Alofi, Hakupu, with lesser intensity in Upolo, Samoa and Tongatapu, Tonga. The event of M 7.3 is the strongest in the world in nearly two months – following an M 7.6 in Michoacan, Mexico of September 19, 2022. It is the strongest earthquake in Tonga within about 250 km of this epicenter since an M 7.9-8.0 about 250 km to the southwest of today's epicenter on May 3, 2006." (November 11, 2022)

Forecast 153581 had expected today's event in Tonga was likely within about 50 km around May 22, 2023. This epicenter is located near 144 degrees from the earthquakes of February 6, 2023 in Turkey and the third node (120 degrees) from the M 7.2of February 23, 2023 and may have been promoted by energy from those sources.

O: 21MAY2023 05:23:15 19.3S 173.9W Mw=5.8 EMSC TONGA

P: 22MAY2023 153581 19.0S 174.0W 4.0-5.6 AAAAA Tonga Islands

Aftershocks in the Loyalty Islands continued today with at least 10 of M>=4.7. These were not reported felt in this area. Forecast 153589 had expected this activity was likely around May 21 within about 50 km.

O: 20MAY2023 11:36:12 23.0S 170.6E mb=5.2 EMSC SOUTHEAST OF LOYALTY ISLANDS

O: 20MAY2023 07:55:42 23.1S 170.1E mb=4.7 EMSC SOUTHEAST OF LOYALTY ISLANDS

O: 20MAY2023 13:27:17 23.1S 170.8E mb=5.1 EMSC SOUTHEAST OF LOYALTY ISLANDS

O: 20MAY2023 13:29:27 23.1S 170.9E mb=5.2 EMSC SOUTHEAST OF LOYALTY ISLANDS

O: 20MAY2023 13:50:20 23.2S 170.6E mb=4.7 EMSC SOUTHEAST OF LOYALTY ISLANDS

O: 20MAY2023 09:41:59 23.3S 171.6E mb=4.8 EMSC SOUTHEAST OF LOYALTY ISLANDS

O: 20MAY2023 16:14:00 23.3S 171.2E mb=4.8 EMSC SOUTHEAST OF LOYALTY ISLANDS

O: 20MAY2023 22:08:45 23.5S 171.7E mb=5.1 EMSC SOUTHEAST OF LOYALTY ISLANDS

O: 20MAY2023 18:07:42 22.8S 170.9E mb=5.0 EMSC SOUTHEAST OF LOYALTY ISLANDS

P: 21MAY2023 153589 23.0S 171.0E 4.0-5.5 AAAAA Loyalty Islands

MAJOR AFTERSHOCKS CONTINUE IN LOYALTY ISLANDS

EARTHQUAKE SUMMARY FOR MAY 19, 2023

The strongest earthquakes in the world today were aftershocks of the M 7.7 in the Loyalty Island reported in this summary in the previous issue. Today's largest quakes were of M 7.2 and 6.5. NEIC reported this activity was felt with intensity II-III in New Caledonia at Vao, Tadine Iles, We, Noumea and in Norfolk Island, Australia. The mainshock occurred early on May 19 and was briefly described in the previous issue of this summary as:

"A major to great earthquake occurred today in the region of New Caledonia and the Loyalty Islands. NEIC reported this earthquake was felt with intensity II-III in New Caledonia at We Iles, Noumea, Paita, Norfold Island, Suva, Fiji and Sydney, New South Wasles, Australia. This earthquake occurred at the peak of an M2.3 solar flare but was probably triggered by an M8.0 flare which maximized within a couple of minutes of local solar noon at the epicenter an hour earlier. Solar Flare Effects (SFE) on seismicity is most prominent at local solar noon when the epicenter is directly beneath the sun. The second flare appears to have triggered the actual earthquake of M 7.7. ... " (May 19, 2023)

Aftershocks today were also closely related to solar flares which continued to increase in magnitude (see flare list below). No tsunami was expected nor observed with today's M 7.2 aftershock. Today's M 7.2 occurred near, like the mainshock yesterday, near local solar noon and may have been promoted by strong tidal stresses as well as strong M-class solar flares (more details in the next issue of this summary).

Forecast 153319 had expected this activity was likely within about 100 km in mid to late May. This activity is at the fifth node (72 degrees) from the M 7.3 in Nias, Indonesia of April 24, 2023 and at the sixth node (60 degrees) from the M 7.0 in Java of April 14, 2023 and may have been promoted by energy from those sources.

O: 19MAY2023 08:27:26 22.7S 170.7E mb=5.3 EMSC SOUTHEAST OF LOYALTY ISLANDS

O: 20MAY2023 01:51:00 22.9S 170.6E Mw=7.1 EMSC SOUTHEAST OF LOYALTY ISLANDS

O: 20MAY2023 02:09:56 22.9S 170.7E Mw=6.5 EMSC SOUTHEAST OF LOYALTY ISLANDS

O: 20MAY2023 04:34:14 22.9S 170.4E mb=5.2 EMSC SOUTHEAST OF LOYALTY ISLANDS

O: 19MAY2023 07:13:40 23.0S 170.8E mb=5.5 EMSC SOUTHEAST OF LOYALTY ISLANDS

O: 19MAY2023 08:42:19 23.0S 170.0E mb=4.6 EMSC SOUTHEAST OF LOYALTY ISLANDS

O: 19MAY2023 11:02:21 23.0S 170.7E mb=4.9 EMSC SOUTHEAST OF LOYALTY ISLANDS

O: 19MAY2023 14:26:10 23.0S 170.6E mb=4.8 EMSC SOUTHEAST OF LOYALTY ISLANDS

O: 20MAY2023 02:20:22 23.0S 170.6E mb=5.4 EMSC SOUTHEAST OF LOYALTY ISLANDS

O: 20MAY2023 04:31:26 23.0S 170.4E mb=5.1 EMSC SOUTHEAST OF LOYALTY ISLANDS

O: 19MAY2023 08:10:41 23.1S 170.9E mb=4.7 EMSC SOUTHEAST OF LOYALTY ISLANDS

O: 19MAY2023 09:41:16 23.1S 170.6E mb=4.9 EMSC SOUTHEAST OF LOYALTY ISLANDS

O: 19MAY2023 09:55:09 23.1S 170.5E mb=4.7 EMSC SOUTHEAST OF LOYALTY ISLANDS

O: 19MAY2023 10:22:10 23.1S 170.9E mb=4.9 EMSC SOUTHEAST OF LOYALTY ISLANDS

O: 19MAY2023 17:14:52 23.1S 171.1E mb=5.0 EMSC SOUTHEAST OF LOYALTY ISLANDS

O: 19MAY2023 22:04:00 23.1S 170.7E mb=5.1 EMSC SOUTHEAST OF LOYALTY ISLANDS

O: 20MAY2023 02:06:36 23.1S 170.4E mb=5.1 EMSC SOUTHEAST OF LOYALTY ISLANDS

O: 20MAY2023 02:17:49 23.1S 170.7E mb=5.4 EMSC SOUTHEAST OF LOYALTY ISLANDS

O: 20MAY2023 03:46:54 23.1S 170.8E mb=5.1 EMSC SOUTHEAST OF LOYALTY ISLANDS

O: 20MAY2023 04:41:24 23.1S 170.4E mb=4.9 EMSC SOUTHEAST OF LOYALTY ISLANDS

O: 20MAY2023 04:56:03 23.1S 170.6E mb=4.5 EMSC SOUTHEAST OF LOYALTY ISLANDS

O: 20MAY2023 05:15:03 23.1S 171.0E mb=4.8 EMSC SOUTHEAST OF LOYALTY ISLANDS

O: 19MAY2023 07:02:11 23.2S 171.0E mb=5.0 EMSC SOUTHEAST OF LOYALTY ISLANDS

O: 19MAY2023 10:04:20 23.2S 170.7E mb=4.8 EMSC SOUTHEAST OF LOYALTY ISLANDS

O: 19MAY2023 10:44:12 23.2S 170.8E mb=5.1 EMSC SOUTHEAST OF LOYALTY ISLANDS

O: 19MAY2023 11:23:44 23.2S 170.9E mb=4.9 EMSC SOUTHEAST OF LOYALTY ISLANDS

O: 19MAY2023 20:48:20 23.2S 170.6E mb=4.9 EMSC SOUTHEAST OF LOYALTY ISLANDS

O: 19MAY2023 10:15:46 23.3S 170.8E mb=5.0 EMSC SOUTHEAST OF LOYALTY ISLANDS

O: 19MAY2023 10:46:33 23.3S 171.6E mb=5.2 EMSC SOUTHEAST OF LOYALTY ISLANDS

O: 19MAY2023 11:37:05 23.3S 171.5E mb=4.9 EMSC SOUTHEAST OF LOYALTY ISLANDS

O: 19MAY2023 14:50:56 23.3S 170.8E mb=4.8 EMSC SOUTHEAST OF LOYALTY ISLANDS

O: 19MAY2023 07:23:49 23.4S 171.3E mb=4.8 EMSC SOUTHEAST OF LOYALTY ISLANDS

O: 19MAY2023 20:20:05 23.4S 171.1E mb=4.9 EMSC SOUTHEAST OF LOYALTY ISLANDS

O: 20MAY2023 02:56:26 22.6S 170.8E mb=5.3 EMSC SOUTHEAST OF LOYALTY ISLANDS

P: 15MAY2023 153319 22.0S 170.0E 4.0-5.6 BAAAA Loyalty Islands

P: 17MAY2023 153319 23.0S 172.0E 4.0-5.6 BAAAA Loyalty Islands

P: 21MAY2023 153589 23.0S 171.0E 4.0-5.5 AAAAA Loyalty Islands

A light earthquake of M 2.6 was widely felt in the area of Toledo, Ohio today. NEIC reported it with intensity III in Ohio at Walbridge, Millbury, Northwood, Rossford, Perrysburg, Genoa, Luckey, Toledo, Oregon, and possibly as far as Michigan, Pennsylvania, Virginia, New York, Missouri and Massachusetts. No damage was reported with this event. The last earthquake within about 100 km of this epicenter in Ohio with M>=2.6 was an M 3.2 on August 21, 2020. It was discussed in the summary at the time as:

"An unusual earthquake of M 3.2 was widely felt in the area south of Detroit, Michigan today. NEIC reported maximum intensity IV in Michigan at Monroe, Luna Pier, South Rockwood and II-III in Newport, La Salle, Carleeton, Rockwood, Erie, Flat Rock. The earthquake was felt with light intensity as far as Ohio, Pennsylvania, Wisconsin, Illinois, New Jersey, New York, Tennessee, North Carolina, Massachusetts, Georgia, Connecticut and Missouri among other states in the eastern U.S. No major damage was reported. The last earthquake in the Detroit area occurred as an M 3.4 on April 20, 2018. The largest regional earthquake in the past 30 years was an M 4.2 on May 2, 2015. An M 2.0 also occurred when a meteor hit the earth near Detroit on January 16, 2018. Other recent quakes occurred as an M 4.0 near Kalamazoo on May 2, 2015. Today's earthquake did not affect operations at the area's two nuclear power plant." (August 21, 2020)

Forecast 153245 had expected today's seismic enhancement within about 150 km in Ohio around May 18.

O: 20MAY2023 00:17:36 41.6N 83.5W mb=2.6 EMSC OHIO

P: 18MAY2023 153245 40.0N 84.0W 2.0-4.2 ABAAA Ohio/Lake Erie

The strongest earthquake in the world today outside the Loyalty Islands was an M 5.7 in the Gulf of Aden east of Ethiopia and Eritrea. This epicenter is near the third node (120 degrees) from the Loyalty Islands and may have been promoted by energy from those sources. An M 5.5 hit near this epicenter on June 14, 2021 but the last event of magnitude greater than or equal to M 5.7 in the Gulf of Aden within about 200 km of this epicenter occurred more than 35 years ago. An M 5.9 last occurred about 300 km to the east on July 15, 2018 and on December 30, 2006 near that same epicenter (M 6.5). Forecast 153121 had expected today's event within about 150 km was likely around May 17 in the Gulf of Aden. This epicenter is at the seventh node (51 degrees) from the M 7.3 in Indonesia of April 24, 2023 and the M 6.7 in Ecuador of March 18, 2023 and may have been promoted by energy from those sources.

O: 19MAY2023 15:15:04 12.8N 49.2E Mw=5.7 EMSC GULF OF ADEN

P: 17MAY2023 153121 13.0N 51.0E 3.5-5.3 AABAA Gulf of Aden

The strongest earthquake in the U.S. or Canada today was an M 3.9 in Hawaii.

NEIC reported this earthquake of M 3.7-3.9 in Hawaii was felt with intensity II-III in the area(s) of Hawaii with IV in Holualoa and lesser shaking in Pahala, Naalehu, Captain Cook, Volcano, Hilo, Pahoa, Kailua and Pepeeleo. This earthquake occurred near local solar midnight and may have been promoted by strong tidal stresses which maximize near this hour. Forecast 153144 had expected this activity in mid-May within about 25 km of these epicenters. Hawaii is located at the seventh node from the Loyalty Islands M 7.7 of May 19 and the M 7.2 in the Kermadec Islands of April 24, 2023 and may have been promoted by energy from those sources.

O: 19MAY2023 13:20:19 19.2N 155.5W ML=3.2 EMSC ISLAND OF HAWAII, HAWAII

O: 19MAY2023 11:10:47 19.2N 155.5W ML=3.9 EMSC ISLAND OF HAWAII, HAWAII

O: 19MAY2023 21:07:48 19.4N 155.4W ML=3.2 EMSC ISLAND OF HAWAII, HAWAII

P: 14MAY2023 153144 19.3N 155.1W 4.0-5.6 BAAAA Hawaii area

AJOR M 7.7 EARTHQUAKE AND TSUNAMI HIT NEW CALEDONIA ISLANDS WITH NEW MOON

EARTHQUAKE SUMMARY FOR MAY 19, 2023

A major to great earthquake occurred today in the region of New Caledonia and the Loyalty Islands. NEIC reported this earthquake was felt with intensity II-III in New Caledonia at We Iles, Noumea, Paita, Norfold Island, Suva, Fiji and Sydney, New South Wales, Australia. This earthquake occurred at the peak of an M2.3 solar flare but was probably triggered by an M8.0 flare which maximized within a couple of minutes of local solar noon at the epicenter an hour earlier. Solar Flare Effects (SFE) on seismicity is most prominent at local solar noon when the epicenter is directly beneath the sun. The second flare appears to have triggered the actual earthquake of M 7.7. Flare data for these events follow:

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

#-----

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

XXXX 0040 0050 0200 M8.0 (May 19, 2023) 4.2E-02

New Guinea M 4.9 00:57 UT

Puerto Rico, M 3.8 0046 UT

Gulf of Aden M 4.5 01:58 UT

XXXX 0250 0300 0340 M2.2 (May 19, 2023) 2.2E-03

Loyalty Islands M 7.7 02:57 UT, M 5.9 03:06 UT, M 5.4 03:27 UT, M 5.5 03:10 UT,

Turkey M 4.6 03:14 UT

XXXX 0449 0500 0520 M2.5 (May 19, 2023) 2.6E-03

Loyalty Islands M 5.5 04:45 UT

Solar flares have been getting gradually larger over the past week. The largest today occurred with maximum output at 0050 UT with class around M8.0. Only two solar flares of high M-class have occurred in the current year (2023). These occureed as an M8.6 on February 28, 2023 and January 6, 2023 with M8.0. An X2.2 also occurred on February 17, 2023 and X2.1 on March 3, 2023.

A tsunami alert was in effect following this M 7.7 in the region of New Caledonia in New Caledonia May 2023. The warning was for waves up to 1 meter in Vanuatu with regional tsunami warnings for areas of Tonga north to Samoa. A 22 cm tsunami was observed near New Caledonia. Citizens have been warned to move to higher ground pending high tsunami waves. A tsunami was also expected in the Lord Howe Island area of Australia and the west coast of New Zealand and inhabitants have been warned there as well.

A similar M 7.7 hit in the area southeast of the Loyalty Islands on February 10, 2021. At the time this summary noted in this regard:

"Far field triggering from the activity in the Loyalty Islands is expected to be robust. This is due, not only to the great size of the mainshock but also to the regions which are near 103 degrees from this epicenter. Areas at 103 degrees from the Loyalty Islands include western Canada, Oklahoma in the U.S. Oaxaca, Chiapas, Mexico, Guatemala, Panama, Ecuador, Peru, Chile in South America, India, China, Afghanistan in Asia. Areas at 144 degrees from the Loyalty Islands include Turkey, Eastern Europe and Central Africa. These area may see enhanced seismicity in coming days. Other area subject to seismic promotion include Iran and the northern Caribbean (120 degrees node 3); Southern and Central California, Vancouver, southern Alaska, Myanmar, Mongolia (node 4, 90 degrees); East Pacific Rise, Sumatra, Taiwan, Hokkaido (node 5, 72 degrees); Izu Islands, Philippines, (node 6, 60 degrees) and Banda, Guam, New Guinea (node 5, 51 degrees) among others. (February 10, 2021)

Apparently triggered FFA activity from this event in the Loyalty Islands was recorded in this summary on April 15, 2021 as:

144 degrees: Loyalty Islands to Reykjanes Ridge, Dodecanese Is. Greece, Romania, Iceland, Egypt, North Sea, Poland, Turkey, Dodecanese Islands,

120 degrees: Loyalty Islands to Haiti, Baffin Bay, Quebec, Canada,

103 degrees: Loyalty Islands to Texas, Wyoming, Beaufort Sea, West Chile Rise, Kansas, South Georgia Rise, South of Africa, Oklahoma, Nebraska, Southern Peru, Southern Texas, Siberia, Carlsberg Ridge, Guatemala, Ecuador, El Salvador, Nicaragua, Oklahoma, Atacama, Chile, Guatemala,

90 degrees: Loyalty Islands to Mongolia, Western Mexico, Southern Alaska, Washington State, Ridgecrest, Southern California,

72 degrees: Loyalty Islands to Sumatra, Kuril Islands,

60 degrees: Loyalty Islands to South Indian Ridge, Tokyo, Japan,

52 degrees: Loyalty Islands to Sumbawa, Northern Mariana Islands,

Similar activity at far-field distances can be expected with today's M 7.7.

"A major quake of M 7.7 (on February 10, 2021) was preceded by a series of strong foreshocks and followed by a number of large aftershocks today. NEIC reported the mainshock was felt with intensity VII in Mont-Dore and V in Vao Sud, New Caledonia and in Shefa, Vanuatu with III. The mainshock of M 7.7 is the strongest earthquake in the Loyalty Islands within about 300 km of this epicenter since an M 7.7 on May 16, 1995. No larger events have hit the region in historical times (more than 100 years).

This activity occurred at a time when a number of stresses were enhancing seismicity in the region. These included the new moon tides, ... the strongest solar flare since mid-January...

Today's activity in the Loyalty Islands was likely promoted by strong tidal stresses associated with the new moon as noted in this summary in previous issues:

"The new moon will arrive at 19:06 on February 11, 2021. ...

This activity began with an M 6.0 at 12:24 UT in the Loyalty Islands on February 10. This is within about 10 minutes of local solar midnight, a time when tidal stresses are maximized. The major aftershocks of this event occurred within the next hour and were also probably enhanced by tidal stresses." (February 10, 2021)

Note that these conditions (new moon, solar flare etc) exactly parallel those described for the M 7.7 on February 10, 2021, conditions which probably led to the major event at this time. Even the time of these two events (13:19 UT on February 10, 2021 and 02:57 UT today) was nearly the same.

Forecast 153319 had expected this activity was likely within about 100 km in mid-May.

O: 19MAY2023 04:09:36 23.0S 171.9E mb=5.4 EMSC SOUTHEAST OF LOYALTY ISLANDS

O: 19MAY2023 04:22:40 23.1S 170.7E mb=5.3 EMSC SOUTHEAST OF LOYALTY ISLANDS

O: 19MAY2023 04:50:15 23.1S 170.7E mb=5.1 EMSC SOUTHEAST OF LOYALTY ISLANDS

O: 19MAY2023 05:06:08 23.1S 170.6E mb=5.2 EMSC SOUTHEAST OF LOYALTY ISLANDS

O: 19MAY2023 02:57:05 23.2S 170.8E Mw=7.7 EMSC SOUTHEAST OF LOYALTY ISLANDS

O: 19MAY2023 03:06:23 23.2S 170.8E mb=5.9 EMSC SOUTHEAST OF LOYALTY ISLANDS

O: 19MAY2023 03:27:53 23.2S 170.6E mb=5.4 EMSC SOUTHEAST OF LOYALTY ISLANDS

O: 19MAY2023 04:02:34 23.2S 171.1E mb=5.3 EMSC SOUTHEAST OF LOYALTY ISLANDS

O: 19MAY2023 04:54:06 23.2S 170.5E mb=5.5 EMSC SOUTHEAST OF LOYALTY ISLANDS

O: 19MAY2023 05:36:51 23.2S 170.7E mb=5.2 EMSC SOUTHEAST OF LOYALTY ISLANDS

O: 19MAY2023 06:34:21 23.2S 170.5E ML=5.2 EMSC SOUTHEAST OF LOYALTY ISLANDS

O: 19MAY2023 04:33:09 23.3S 170.6E mb=5.1 EMSC SOUTHEAST OF LOYALTY ISLANDS

O: 19MAY2023 05:25:53 23.3S 171.3E mb=5.2 EMSC SOUTHEAST OF LOYALTY ISLANDS

O: 19MAY2023 05:54:16 23.3S 171.0E mb=4.8 EMSC SOUTHEAST OF LOYALTY ISLANDS

O: 19MAY2023 06:08:21 23.3S 171.0E mb=5.1 EMSC SOUTHEAST OF LOYALTY ISLANDS

O: 19MAY2023 03:10:47 23.0S 170.4E mb=5.7 EMSC SOUTHEAST OF LOYALTY ISLANDS

P: 15MAY2023 153319 22.0S 170.0E 4.0-5.6 BAAAA Loyalty Islands

P: 17MAY2023 153319 23.0S 172.0E 4.0-5.6 AABAA Loyalty Islands

A moderate earthquake of M 4.8 was widely felt in the Dominican Republic today. NEIC reported it was felt with intensity V in Altamira and Montellano, Dominican Republic and IV in La Canela, Santiago, Villa Isabela, Sosua, Puerto Plata, Esperanza, La Canela and Villa Gonzalez Santiago and III in Jicome Valverde. This follows a strong activation of the region over the past several days. It was located near 103 degrees from the M 7.6 in the Tonga Islands of May 10 as noted in previous issues of this summary:

"A series of light earthquakes continued in the regions of Puerto Rico and the Dominican Republic today. This activity is near the 103 degree distance from the M 7.6 in Tonga and could see a larger event in the next several days." (May 14, 2023)

An earthquake of M 5.0 on February 1, 2023 was the only earthquake of larger magnitude than M 4.8 in the Dominican Republic within about 200 km of this epicenter in the past three years. Forecast 153134 had expected this earthquake was likely within this area within about 50 km around May 15, 2023.

O: 18MAY2023 18:09:33 19.6N 70.7W ML=3.0 EMSC DOMINICAN REPUBLIC

O: 19MAY2023 00:17:40 19.6N 70.7W ML=3.0 EMSC DOMINICAN REPUBLIC

O: 18MAY2023 09:07:37 19.7N 70.7W ML=3.3 EMSC DOMINICAN REPUBLIC

O: 18MAY2023 09:11:53 19.7N 70.7W ML=3.0 EMSC DOMINICAN REPUBLIC

O: 18MAY2023 21:35:18 19.7N 70.7W ML=3.0 EMSC DOMINICAN REPUBLIC

O: 18MAY2023 08:43:56 19.6N 70.8W Mw=4.8 EMSC DOMINICAN REPUBLIC

P: 15MAY2023 153134 19.0N 71.0W 3.4-5.0 BAAAA Puerto Rico

P: 18MAY2023 153133 18.0N 69.0W 3.4-5.0 AABAA Puerto Rico

This earthquake in the Loyalty Islands was also probably promoted by tidal stresses associated with today's new moon as it occurred near local solar noon with the new moon as noted in this summary:

The new moon will arrive on May 19, 2023 at 15:53 UT. Longitudes at local solar solar midnight are near 126 East and those at local solar noon are near 54 West longitude. In the west these include the northern and Eastern Caribbean as well as areas of western South America while in the East longitudes near 126 E are located in the Philippines, Taiwan, Japan, and Indonesia among others. These are the most likely areas to see tidal triggering at this time, but other areas could see significant enhancement in seismicity in the next several days. These would most likely see seismic enhancement near local solar noon or midnight. A strong to major earthquake is considered likely with this new moon before May 25, 2023.

The strongest earthquake in the U.S. or Canada today was a pair of events of M 4.6 each in the Andreanof Islands, Alaska. The last earthquake of equal or larger magnitude in the Andreanof Islands was an M 4.7 on April 22, 2023. Forecasts 153261 and 153263 had expected enhanced seismicity in this region was likely around May 16.

NEIC reported these earthquakes of M 4.6 in the Andreanof Islands, Alaska were felt with intensity II-III in the area(s) of the Andreanof Islands, Alaska in Adak. The first of these occurred near solar midnight and may have been promoted today's new moon.

O: 18MAY2023 13:13:19 52.7N 176.4W mb=4.6 EMSC ANDREANOF ISLANDS, ALEUTIAN IS.

O: 18MAY2023 21:08:23 51.7N 176.5W mb=4.6 EMSC ANDREANOF ISLANDS, ALEUTIAN IS

P: 14MAY2023 153263 51.9N 176.0W 3.5-5.2 BAAAA Andreanoff Isls, Aleutians

P: 16MAY2023 153261 50.3N 176.2W 3.5-5.1 ABAAA Andreanoff Isls, Aleutians

P: 16MAY2023 153263 51.7N 175.3W 3.5-5.0 AAAAA Andreanoff Isls, Aleutians

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