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MODERATE EARTHQUAKES ALONG GEOMAGNETIC EQUATOR

EARTHQUAKE SUMMARY FOR JULY 12, 2024

A series of moderately large earthquakes occurred today near the geomagnetic equator. These were of M 5.5-5.6 in Chile, Bolivia and New Guinea and may reflect upcoming enhancement of seismicity in this zone with a strong geomagnetic storm beginning today through July 14, 2024.

The strongest earthquake in the world today was an M 5.6 in Southern Peru. NEIC

reported this event was felt with intensity up to IV in Tarata, Peru. EMSC reported moderate to strong shaking in Bolivia, Peru and Chile. The earthquake was felt with moderate shaking in Tacna, Peru, Arica with reports from Parinacota, Iquique, Alto Hospicio, Chile, La Paz. Bolivia. While not a classical aftershock of the M 7.2 about 500 km northwest of today's epicenter, this event was probably promoted by stress redistribution following the June 28 mainshock and is a regional aftershock of that event.

The earthquake in Bolivia is the strongest reported in that country since an

M 6.3 on January 21, 2018. At the time this summary noted:

"A strong earthquake of M 6.3 hit the region of northern Chile near Tarapaca today. NEIC reported maximum intensity from this intermediate focus event was felt in Arica, Tarapaca, Chile with intensity IV in Iquique, Chile and Arequipa, Peru. Intensity II-III was reported from Moquegua, Peru; La Paz, Bolivia; and Antofagasta, Chile. CSN reported this earthquake was felt with intensity VII in Arica, VI Cuya, Pocon Chile, Putre,; V Camina, Huara, La Tirana, Pisagua, Quillagua; IV Tocopilla, Pozo Almonte, Pica, Mamina, Iquique, Alto Hospicio, III Alcerreca, Viviri, Maria Elena; II Calama, Chungara-Complejo, Sierra Gorda. Felt in Parinacota, Tarapaca and Antofagasta, Chile. Due to the depth near 110 km no damage was reported on the surface and no tsunami was generated nor expected from this earthquake. An earthquake of M 6.3 also hit north of this epicenter by about 40 km on October 10, 2017. The last event in the region of larger magnitude was an M 8.2 about 100 km to the south on April 1, 2014 followed by

and M 7.6 on April 3, 2014." (January 21, 2018)

Forecast 164687 had expected today's epicenter would be active in Bolivia within about 50 km of today's epicenter around July 15.

O: 12JUL2024 18:19:04 17.4S 69.5W MW=5.6 EMSC LA PAZ, BOLIVIA

P: 15JUL2024 164687 18.0S 69.0W 4.0-5.5 BAAAA So. Peru/Bolivia

A true aftershock of that event also occurred today with M 5.6-5.7 earlier in the day. NEIC reported it was felt with intensity up to VI near Acari, Peru.

Forecast 164678 had expected enhanced aftershocks around July 11 in Peru.

O: 12JUL2024 09:30:32 15.6S 74.7W MW=5.7 EMSC NEAR COAST OF SOUTHERN PERU

O: 13JUL2024 03:35:41 15.9S 74.6W mb=4.6 EMSC NEAR COAST OF SOUTHERN PERU

O: 12JUL2024 18:55:00 16.0S 74.8W mb=4.8 EMSC NEAR COAST OF SOUTHERN PERU

P: 11JUL2024 164678 14.0S 76.0W 4.0-6.0 ABAAA Central Peru

A similar M 5.6 occurred today in the area of Papua New Guinea. NEIC reported it was felt with intensity up to V in the area of Rabaul, PNG. The last earthquake of larger magnitude in the New Ireland region was an M 5.7 on May 18, 2024 and this may be an aftershock of that mainshock. At the time this summary noted:

"The largest earthquake in the world today was an M 5.7 in Papua New Guinea. NEIC reported it was felt with intensity up to V in Rabaul, New Guinea. This event occurred within minutes of local solar midnight and was probably promoted by tidal and geomagnetic stresses which maximize near this hour. This appears to be a regional aftershock of an M 5.4 on May 16, 2024. At the time this summary noted:

"As the geomagnetic storm reduced in intensity today, moderately enhanced seismicity began to appear along the geomagnetic equator. Most notably this occurred in New Guinea in the area of New Ireland with the strongest earthquake of the day and in eastern New Guinea with an M 5.2 three hours earlier. This is the type of seismicity which can be expected several days following major geomagnetic storms. The M 5.4 in New Ireland since an M 5.5 on November 18, 2023 - an aftershock of an M 5.9 and M 6.1 on November, 12 and 13, 2023." (May 16, 2024, May 19, 2024)

Forecast 164477 had expected enhanced seismicity within about 150 km of this epicenter was likely around July 13.

O: 12JUL2024 17:12:48 3.8S 151.4E MW=5.6 EMSC NEW IRELAND REGION, P.N.G.

P: 13JUL2024 164477 5.0S 152.0E 4.0-5.4 ABAAA New Britain

The strongest earthquake in the U.S. or Canada today was an M 4.8 aftershock of the M 6.4 near Vancouver Island yesterday. Today's event was reported by NEIC to have been felt with intensity up to III in Tofino, Canada. Previous issues of this summary have noted this swarm in detail. Readers are referred to the past three issues for more details.

Forecast 164642 had expected today's activity was likely within about 25 km around July 12, 2024.

O: 12JUL2024 08:20:28 48.9N 128.7W MB=4.6 ECAN OF PORT HARDY, BC

O: 12JUL2024 08:20:31 49.0N 128.4W MW=4.8 EMSC VANCOUVER ISLAND, CANADA REGIO

P: 12JUL2024 164642 48.7N 129.0W 2.8-5.1 AAAAA Vancouver Island area

An earthquake of M 4.6 also occurred in the Unimak Island region of Alaska today. It was not reported felt in this remote area. The last earthquake of larger magnitude in the Unimak Island area was an M 4.7 on May 23, 2024.

Forecast 164661 had expected today's event was likely within about 50 km of today's epicenter around July 11.

O: 13JUL2024 01:57:51 53.5N 164.8W ML=3.6 EMSC UNIMAK ISLAND REGION, ALASKA

O: 13JUL2024 02:28:52 53.5N 164.8W MB=4.6 EMSC UNIMAK ISLAND REGION, ALASKA

P: 11JUL2024 164661 54.1N 164.4W 3.5-4.9 AAAAA Unimak Islands, Aleutians

STRONG EARTHQUAKE RATTLES VANCOUVER ISLAND AREA, BRITISH COLUMBIA, CANADA

EARTHQUAKE SUMMARY FOR JULY 11, 2024

The strongest earthquake in the world today was an M 6.4 in the series in Vancouver Island, British Columbia which began July 4, 2024. NEIC reported it was lightly felt with moderate intensity up to IV in Tofino, Canada. EMSC reported light shaking in Chilliwack, Canada. Several moderate aftershocks – including an M 5.4 - were also felt in this region. This summary has extensively

covered this swarm in previous issues as in the last summary which noted:

"This epicenter (in Mindanao, Philippines) is near 100 degrees from the M 6.7 yesterday south of Africa and at the same distance from the continuing swarm of earthquakes in the Vancouver Island area of British Columbia, Canada. With an earthquake at this depth these areas are at the shadow zone boundary for S- and P-waves (normally 102-103 degrees distance for earthquakes that occur near the surface. Thus the event today in Mindanao is considered a triggered earthquake from the M 6.7 South of Africa yesterday. Further activity (perhaps) a strong earthquake in Vancouver is also likely at this time due to the concentration of energy from the area south of Africa. A further complication perhaps leading to additional enhancement in Vancouver, B.C. is the track of Hurricane Beryl. The remnants Hurricane Beryl is now located over the northeastern U.S. where it has dropped large reserves of water over the past two days. This summary has long been a proponent of the theory that effects of strong meteorological events (nor'easters and hurricanes, for example) affecting the Northeast U.S. can trigger strong earthquakes on the Pacific-North American plate boundary in particular from California north to Alaska. This was outlined in the previous issue of this summary as:

"Today's epicenter (south of Africa) is near the antipode of the Alaska Peninsula and the Unimak Island area of Alaska - an active region - where antipodal triggering possible following this earthquake in the next week. With a strong solar flare, this could reach strong magnitude levels. This possibility was emphasized when a light earthquake occurred two days ago in western South Dakota, often a precursor to a strong event along the North American- Pacific boundary." (July 9, 2024)

and

"The tidal effects will linger for several more days as the new moon arrives. Due to this, this series could intensify and possibly include a moderate to moderately large event in the next three days in the Vancouver Island area." (July 4-5, July 9, 2024)

and with additional tidal stresses with the upcoming full moon as:

"The full moon will arrive on July 21, 2024 at 10:17 UT. Longitudes which are at local solar noon at this time are located near 30 East longitude while those at local solar midnight are near 150 West longitude. In the west these include Hawaii and areas of eastern and southern Alaska and western Canada and to a lesser extent areas off the coast of Oregon and California while in the east they include Eastern Turkey and Greece and Romania as well as Ethiopia and areas off southern Africa and eastern Europe. These and surrounding areas are the most likely to see tidally enhanced seismicity at this time. A large to major earthquake is considered moderately likely in the period July 17-25, 2024." (July 8, 2024, July 11, 2024)

Today's event of M 6.4 in the Vancouver Island area is the strongest within about 200 km of this epicenter since an M 6.5 and 6.8 on October 22, 2018. At the time this summary noted in this regard:

"A strong earthquake of M 6.6 hit off the southwest coast of Vancouver Island, British Columbia, Canada today. It was reported by Earthquakes Canada and NEIC to have been felt lightly in British Columbia at Port MacNeil, Ucluelet, Nanaimo, Sooke, Sidney, Victoria, Vancouver, and Whistler and in Washington State at Sequim and Hoquiam among others. Earthquakes Canada reported this earthquake of M 6.5 southwest of Vancouver Island, B.C, Canada was felt with intensity II-III in the epicentral area. No tsunami was generated and no damage was expected. This epicenter is located at 103 degrees from the last major earthquake in the world - the M 7.6 in Minahasa, Indonesia which killed thousands in the earthquake and tsunami on September 28, 2018. This summary has long established that seismic energy from large earthquakes, concentrated by reflection and refraction off the core-mantle boundary and reflected to the surface near 103 degrees can promote further seismicity in this distance range. When the Minahasa event occurred this summary had noted at the time the relation between Minahasa and Vancouver Islands in the issue of October 2 as:

...

This epicenter is at 102 degrees from the Minahasa quake of M 7.5 of September 28 and probably was enhanced by concentrated seismic energy from that event." (October 2, 2018)

Another factor which probably encouraged the occurrence of the Vancouver event at this time was the massive Hurricane Willa which hit off the coast of western Mexico with winds up to 170 kts today. Strong hurricanes pushing North America to the east have often been cited in this summary as promoters of strong earthquakes in the Vancouver or Queen Charlotte Islands area of Canada. This summary had noted Hurricane Willa in previous summaries as:

"Hurricane Willa continued today south of Jalisco, Mexico with winds up to 170 kts. It is expected to track to the north making landfall around October 24 near Mazatlan, Mexico. Enhanced seismicity in the region is likely with landfall. The storm reached maximum as it hit the coast of Mexico today with winds up to 170 kts (category 5). Motions imparted to North America with this landfall reduced normal friction across faults near the North American rim and probably helped bring on the M 6.6 today in Vancouver, British Columbia." (October 20-21, 2018)

The region may have also been set up for strong seismicity at this time due to effects on North America from the landfall of Hurricane Michael. This had been noted in this summary as:

"Seismicity along the coast of California may be enhanced at this time as Hurricane Michael makes landfall on the Florida panhandle with winds up to 145 kts, the strongest storm ever to have hit this area. This will tend to push the North American plate to the northeast loosening the normal friction on Faults in the west." (October 9-10, October 13, 2018)

Today's earthquake of M 6.6 is the largest in the Vancouver Island area of Canada since an M 6.6 on April 24, 2014. Other such quakes occurred in the past 30 years with M6.5-6.6 on April 6, 1992; November 2, 2004 and January 5, 2008.

Forecast 120595 had expected today's event within about 100 km of the epicenter most likely to occur around October 21.

The last such event in Vancouver in April 2014 was also associated with a storm not unlike Hurricane Michael as noted at the time:

"a strong spring storm was racing up the Atlantic coast of the U.S. at the time of this earthquake in Vancouver. This is a situation very much like that which preceded the M 7.7 in the Queen Charlotte Islands in October, 2012 as Hurricane Sandy did massive damage to the central east coast of the U.S. This summary has documented this relation with strong storms and major earthquakes in the British Columbia region on many previous occasions." (April 24, 2014, October 22, 2018)

Forecast 164642 had expected today's activity near Vancouver within about 25 km was likely around July 12, 2024. This epicenter is at 98 degrees from the M 7.1 in Mindanao of July 11, 2024 and may have been promoted by energy from that source and other major earthquakes in Mindanao of recent months.

O: 11JUL2024 17:34:28 48.9N 128.5W Mw=4.7 EMSC VANCOUVER ISLAND, CANADA REGION

O: 11JUL2024 16:17:26 49.0N 128.1W Mw=5.4 EMSC VANCOUVER ISLAND, CANADA REGION

O: 12JUL2024 08:20:28 48.9N 128.7W MB=4.6 ECAN OF PORT HARDY, BC

O: 11JUL2024 20:00:44 48.9N 128.6W MB=3.3 ECAN OF TOFINO, BC

O: 11JUL2024 17:48:30 48.6N 128.7W MB=3.6 ECAN OF TOFINO, BC

O: 11JUL2024 17:41:27 48.8N 128.6W MB=3.6 ECAN OF TOFINO, BC

O: 11JUL2024 17:34:26 48.8N 128.7W MB=5.1 ECAN OF TOFINO, BC

O: 11JUL2024 17:12:40 48.9N 128.5W MB=3.2 ECAN OF TOFINO, BC

O: 11JUL2024 16:41:05 48.7N 128.7W MB=3.4 ECAN OF PORT HARDY, BC

O: 11JUL2024 16:17:20 48.8N 128.6W MB=5.2 ECAN OF TOFINO, BC

O: 11JUL2024 16:12:58 49.1N 128.3W MB=2.1 ECAN OF PORT ALICE, BC

O: 11JUL2024 15:35:43 48.9N 128.7W MB=4.0 ECAN OF TOFINO, BC

O: 11JUL2024 15:08:46 48.7N 128.8W MB=6.4 ECAN OF PORT HARDY, BC

O: 11JUL2024 15:08:50 48.9N 128.5W MW=6.4 EMSC VANCOUVER ISLAND, CANADA REGIO

P: 12JUL2024 164642 48.7N 129.0W 2.8-5.1 AAAAA Vancouver Island area

An M 5.4 was also felt in Guam, Mariana Islands today. NEIC reported it was felt with intensity up to IV in Guam at Merizo Village. This is the strongest earthquake in Guam since an M 5.5 on April 16, 2024.

Forecast 164522 had expected today's event in Guam was likely within about 100 km of this epicenter around July 12, 2024.

O: 11JUL2024 09:27:35 12.3N 144.1E MB=5.4 EMSC GUAM REGION

P: 12JUL2024 164522 12.0N 145.0E 4.0-5.5 AAAAA So. Marianas/Guam

A moderately large M 5.8 also occurred in the central East Pacific Rise today. It was not reported felt in this remote area. It was followed by an M 4.6 aftershock. This is the strongest earthquake in the Central East Pacific Rise within about 250 km of today's epicenter since an M 6.0 on September 20, 2023. At the time this summary noted:

"The largest earthquake in the world today was an M 6.0 in the northern East Pacific Rise south of Oaxaca, Mexico where was reported felt with intensity II. It was followed by a strong aftershock of M 5.7 and a moderate event of M 4.6 and preceded by an M 4.6 foreshock and an M 5.2 foreshock seconds before the mainshock. The last earthquake of M>=6 within about 200 km of today's epicenters occurred as an M 6.1 on March 22, 2020 and a similar event of M 6.0-6.1 on September 11, 2013. The only event of M>=6.0-6.1 in the area in the past 35 years was an M 6.33 on August 15, 1997. At the time of the event of March 22, 2020, this summary noted:

"The strongest earthquakes in the world today were an M 6.1 in the Central East Pacific Rise and an M 5.6 in the Central Mid-Atlantic Ridge. Neither of these were reported felt in these remote areas. The event in the Central East Pacific Rise is the largest within about 250 km of that epicenter since an M 6.1 on September 11, 2013 and a similar M 6.1 on August 4, 2007. The maximum sized earthquakes in the region in the past 30 years have been about M 6.1." (March 22, 2020, September 20, 2023)

Forecast 164482 had expected today's event within about 50 km was likely

around July 13.

O: 12JUL2024 05:47:09 4.0S 104.5W MB=4.6 EMSC CENTRAL EAST PACIFIC RISE

O: 12JUL2024 00:19:44 4.5S 104.8W MW=5.8 EMSC CENTRAL EAST PACIFIC RISE

P: 13JUL2024 164482 5.0S 105.0W 4.0-5.7 AAAAA No. East Pacific Rise

MAJOR DEEP FOCUS EARTHQUAKE IN SOUTHERN PHILIPPINES

EARTHQUAKE SUMMARY FOR JULY 10, 2024

A major earthquake hit at a deep focus (620 km) in beneath eastern Mindanao today with M 7.1. NEIC reported it was felt with intensity up to VI at the surface at Sangay, Philippines. EMSC reported light shaking in the Philippines at General Santos City, Davao City, and in Indonesia at Manado, Mapanget, Wenang, in Malaysia t Kota Kinabalu. PHIVOLCS reported this earthquake was felt with intensity IV in Jose Abad Santos, Davao Occidental; and III in the City of Cebu, Davao Occidental, Davao Oriental, Sultan Kudarat, and II in City of Iloilo, Davao de Oro, Davao del Norte, Catabato, Sarangani, City of General Santos with lesser regional shaking.

This epicenter is near 100 degrees from the M 6.7 yesterday south of Africa and at the same distance from the continuing swarm of earthquakes in the Vancouver Island area of British Columbia, Canada. With an earthquake at this depth these areas are at the shadow zone boundary for S- and P-waves (normally 102-103 degrees distance for earthquakes that occur near the surface. Thus the event today in Mindanao is considered a triggered earthquake from the M 6.7 South of Africa yesterday. Further activity (perhaps) a strong earthquake in Vancouver is also likely at this time due to the concentration of energy from the area south of Africa. A further complication perhaps leading to additional enhancement in Vancouver, B.C. is the track of Hurricane Beryl. The remnants Hurricane Beryl is now located over the northeastern U.S. where it has dropped large reserves of water over the past two days. This summary has long been a proponent of the theory that effects of strong meteorological events (nor'easters and hurricanes, for example) affecting the Northeast U.S. can trigger strong earthquakes on the Pacific-North American plate boundary in particular from California north to Alaska. This was outlined in the previous issue of this summary as:

and

and with additional tidal stresses with the upcoming full moon as:

The last earthquake within about 200 km of today's epicenter in the Philippines was an M 7.3, 7.4 and 7.6 on July 23, 2010. At the time this summary noted:

"A series of three major earthquakes hit in the Moro Gulf of Mindanao, Philippines today at the great depth of around 600 km. As is typical of major earthquakes at great depth, these events were felt widely on the surface with light to moderate shaking. NEIC reported intensity IV in Abucay, Bicol, Philippines and Purikay, Central Mindanao and Tanauan, Eastern Visayas, 500 km to the north of the epicenter. Intensity II-III was felt in Mindanao at Alabel, Cagayan, Davao, Korondal, Manila, Palo, Panabo, and Tagbilaran. The largest event was felt with intensity V in Tagum, Cotabato and Purikay and IV in Recodo, Digos and III in Polomolok, Mati, Philippines as as far as 2000 km to the north in Taiwan. The earthquakes were also felt in Brunei, Malaysia, and Indonesia with intensity II-III. No damage or injuries were reported with these events and no tsunami occurred due to the great depth. Major earthquakes at great depth seldom occur in pairs and it is quite uncommon for them to occur in groups of 3-4 with a strong aftershock sequence. This is due to the nature of the brittleness of the earth in the great heat at 600 km depth. A strong foreshock of M 6.0 hit the Moro Gulf region on May 31. These are the strongest earthquakes in the Moro Gulf since an M 8.1 in August, 1976 which killed more than 5000 people. Shallow earthquakes hit on March 5, 2002 and on January 1, 2001 with M 7.5. The event in 2002 killed 15 and injured 100 while damaging or destroying 800 buildings in southern Mindanao.

...

In the past week we have warned of the possibility of a major event in the Philippines at this time. This was partially based on the paths of two typhoons which passed over the central Philippines over the past week.

...

Because the full moon alignment occurs tomorrow, there may also be a tidal component to the triggering of these earthquakes at this time. Deep earthquakes have been shown to often occur at the time of the new moon, or on the moon at the time of the new earth." (July 23, 2010)

Forecasts 164187 and 164456 had expected enhanced seismicity in this region of the Moro Gulf, Mindanao was likely within about 150-200 km of this epicenter in mid-July.

O: 11JUL2024 02:13:17 6.1N 123.2E mw=7.1 ANSS WSW of Sangay Philippines

O: 11JUL2024 02:13:17 6.1N 123.1E MW=7.1 EMSC MORO GULF, MINDANAO, PHILIPPIN

P: 8JUL2024 164187 6.0N 125.0E 4.0-5.4 BABAA Mindanao, Philippines

P: 17JUL2024 164456 7.0N 124.0E 4.0-5.6 CAAAA Central Philippines

A moderate earthquake of M 5.4-5.8 also occurred today in the area southwest

of Sumatra, Indonesia. BMG reported this earthquake of M 5.8 in Bengkulu, Indonesia at Enggano was felt with intensity up to III in the area(s) of Bengkulu and II in Musi Rawas Empat Lawang, Rejang Lebong, Seluma, Kepahiang, Bogor, Sukabumi at Sukuraga among others. The last earthquake within about 200 km of today's epicenter with M>=5.4 was an M 5.6 on June 6, 2024. At the time this summary noted:

"The strongest earthquake in the world today was an M 5.7-5.8 in Northern Sumatra. BMG reported this event was felt with intensity III in Kepulauan Mentawi at Pagai and in Muko at Ipuh and Air Dikit and with intensity II in Kab. Pesisir, Kerinci, Merangin, Sarolangun, Bungo, Tebo, Sungai Oetah, Musi Rawas, Rejang Leband, Bengkulu and Seluma among others." (June 5, 2024)

Today’s event occurred near local solar midnight and may have been promoted by tidal stresses which maximize near this hour.

Forecast 164490 expected today's event in Sumatra was likely in mid-July.

O: 10JUL2024 21:00:57 5.3S 101.1E Mw=4.8 EMSC SOUTHWEST OF SUMATRA, INDONESIA

O: 10JUL2024 17:18:42 5.5S 101.0E mb=4.4 EMSC SOUTHWEST OF SUMATRA, INDONESIA

O: 10JUL2024 15:32:44 5.3S 101.1E MW=5.4 EMSC SOUTHWEST OF SUMATRA, INDONESI

P: 18JUL2024 164490 5.0S 102.0E 4.0-5.4 CAAAA So. of Sumatera

STRONG EARTHQUAKE SOUTH OF AFRICA

EARTHQUAKE SUMMARY FOR JULY 9, 2024

The strongest earthquake in the world today was an M 6.7 south of Africa. This event was not reported felt in this remote area and is the second strongest in the world since an M 7.2 in Taiwan on April 2, 2024; an M 6.7 in the northern Marianas on April 5, 2024 and a similar M 7.2 in Southern Peru on June 28, 2024. This is the strongest earthquake in this region south of Africa in more than 35 years. Smaller events in the region east of this epicenter occurred with M 6.1 on December 22, 2023; September 28, 2004 (M 6.4) and March 11, 1991 (M 6.4. At the time of the M 6.1 on December 22, 2023 this summary noted:

"The strongest earthquake in the world today was an M 6.1 south of Africa. NEIC reported it may have been felt lightly in South Africa. This earthquake is antipodal to the Alaska Peninsula. An M 6.1 occurred yesterday in the Andreanof Islands west of this yesterday and may have helped trigger today's M 6.1 south of Africa by energy that was antipodally focused.

The last earthquake of M>=6.1 within about 250 km of today's event of M 6.1 was an M 6.4 on September 28, 2004. The only other event in this area of M>=6.1 was recorded was an M 6.4 on March 11, 1991. The event in September, 2004 was coincident with an M 6.0 in Parkfield, California on the same date. At the time this summary lended some context to events south of Africa as:

"A series of moderate to large earthquakes occurred today in the world's Ocean Ridge systems. The strongest of these has been located from an area South of Africa to the Prince Edward Islands area to the northwest of this epicenter with magnitude 5.9-6.3. A foreshock to this event occurred on Sept. 21 with M 5.0. Only two other events have been recorded in the Preliminary Determination of Epicenters (PDE) catalog with M>=6.3 in the region 50-60S 20-50E. These occurred on March 11, 1991 with M 6.3 and on Nov. 11, 1980 with M 6.8. The last earthquake of M>6 in the region within 1000 km north of this occurred on May 9, 2003 with M 6.3." (September 28, 2004, December 22, 2023)

Today's epicenter is near the antipode of the Alaska Peninsula and the Unimak Island area of Alaska - an active region - where antipodal triggering possible following this earthquake in the next week. With a strong solar flare, this could reach strong magnitude levels. This possibility was emphasized when a light earthquake occurred two days ago in western South Dakota, often a precursor to a strong event along the North American- Pacific boundary.

The possibility of a strong earthquake in this region in association with the upcoming full moon had been noted in the "Update" section of this summary in the previous issue.

"The full moon will arrive on July 21, 2024 at 10:17 UT. Longitudes which are at local solar noon at this time are localed near 30 East longitude while those at local solar midnight are near 150 West longitude. In the west these include Hawaii and areas of eastern and southern Alaska and western Canada and to a lesser extent areas off the coast of Oregon and California while in the east they include Eastern Turkey and Greece and Romania as well as Ethiopia and areas off southern Africa and eastern Europe. These and surrounding areas are the most likely to see tidally enhanced seismicity at this time. A large to major earthquake is considered moderately likely in the period July 17-25, 2024." (July 8, 2024)

and prior to this with the new moon of July 5 as:

"The new moon arrived on July 5, 2024 at 22:57 UT. Longitudes which are at local solar midnight at this time are located at about 15 East while those at local solar noon are near 165 West. In the east these include most of western Europe and Iceland while in the west areas of the western Aleutians, Alaska, Hawaii, Tonga/Fiji/New Zealand and portions of the Pacific-Antarctic Ridge are included. These are the most likely areas to see significant tidal triggering with this new moon. Other areas may also see tidal promotion in the next week especially at times of large solar flares and near local solar midnight and solar noon. The likelihood of a strong associated earthquake with this new moon are considered moderate to high in the next week (July 1-10, 2024).

Forecasts 164450 and 164726 had expected today's activity south of Africa in this area was likely enhanced around July 4-16. Today's event in the area south of Africa is at 103 degrees from major events in Mindanao, Philippines including an M 7.0 in Xinjiang, China of January 22, 2024, the M 7.6 on December 2, 2023 and from the M 6.9 in New Guinea of March 23, 2024 and may have been promoted by energy from those sources.

O: 10JUL2024 04:55:45 53.3S 25.5E MW=6.7 EMSC SOUTH OF AFRICA

P: 4JUL2024 164450 51.0S 29.0E 4.0-5.6 CBBAA Atlantic-Indian Ridge

P: 16JUL2024 164726 51.0S 29.0E 4.0-5.6 CBBAA Atlantic-Indian Ridge

MODERATE AFTERSHOCKS IN SOUTHERN PERU; VANCOUVER

EARTHQUAKE SUMMARY FOR JULY 8, 2024

An M 5.4 earthquake was felt in southern Peru today. This appears to be an aftershock of the M 7.2 in the region of June 28, 2024. Today's event was reported with intensity up go IV in Atiquipa, Peru. It followed an M 5.3 felt in Atiquipa, Peru an hour earlier. At the time of the June 28, 2024 event this summary noted in the "UPDATE" section in regard to the mainshock:

"A major M 7.2 earthquake occurred today off the west coast of Southern Peru. NEIC reported it was felt with intensity up to IX in Atiquipa, Peru. EMSC reported strong to damaging intensity in Southern Peru at Ica, Arequipa, Jose Luis Bustamante y Rivero, Pilcomayo, Villa El Salvador, Chorrilos, Surquillo, San Isidro, Jesus Maria, Magdalena Del Mar, Lima, Independencia, San Martin de Porres, Ventanilla, Alto Hospicio, and possible as far the north as Ecuador.

CENSIS reported intensity VI in Yauca, Caraveli, Arequipa, Peru. At least five were injured in this earthquake according to on-line news sources. Power and Telephone service was out in some portions of southern Peru. This is the strongest earthquake within about 250 km of this epicenter since an M 8.4 on June 23, 2001 - an event closely associated with a total solar eclipse on June 21, 2001 - and an M 7.7 on November 12, 1996 - the only such regional events in the past 35 years. The earthquake in Peru today occurred 23 years after the event of June 23, 2001 and was reviewed in the "HISTORY" section of this summary on June 23, 2023 (and June 23, 2024) as:

"The earthquake killed at least 75 including at least 26 by a tsunami. Nearly 18,000 homes were destroyed and more than 35,000 damaged in Arequipa, Camana and Tacna while injuring nearly 2700. Besides the 26 killed by the tsunami an additional 64 were missing. Many historic buildings were damaged or destroyed at Arequipa. Landslides blocked many highways. The earthquake followed by several days a total eclipse of the sun in the area. A tsunami was generated with maximum height to 7 meters and inundated up to 1 km inland." (June 23, 2023)

Today's earthquake of M 7.2 is the strongest in the world in nearly 3 months - following an M 7.4 in Taiwan on April 2, 2024. A tsunami warning was issued and minor tsunami waves were observed in the area. This earthquake occurred within minutes of local solar midnight and was probably promoted by strong tidal stresses with the full moon of May 23, 2024.

"The full moon will arrive at 13:53 UT on May 23, 2024. Longitudes which are sub-solar at this time are near 30 West and 150 East. These include the central Atlantic in the west and Japan and much of the eastern Pacific Rim from Kamchatka to New Guinea in the east. These areas may see moderate seismic enhancement over the next seven days to enhanced tidal stresses but other tidally stressed areas may also see increased seismicity at this time." (May 20-24, 2024)

This summary has followed local seismicity in this area over the past month after a major earthquake at this location was forecast in this summary in late May, 2024. This was followed by an M 6.0 two weeks ago on June 16, 2024. At the time this summary noted:

A strong geomagnetic storm occurred today starting at about 14:00 UT and peaking at about 14:50 UT the GOES 15 magnetometer registered a change in the field strength beginning at about 80 NT and ending at about 130 nT (nanoTesla) 15 minutes later as this geomagnetic storm hit. A strong earthquake of M 6.0 occurred with this storm on the geomagnetic equator in Southern Peru at 16S 74W. This was an epicenter which this summary had expected to see a strong earthquake at this time associated with geomagnetic disturbances as noted in a previous issue of this summary, for example on May 26 as:

"A recent series of moderately large earthquakes near the geomagnetic equator in Indonesia and New Britain/New Ireland/New Guinea raises concern about triggered earthquakes associated with the major geomagnetic storm of mid-May. The area of central Peru has been surprisingly quiet during this period. It lies near the geomagnetic equator, and like Indonesia, can be triggered by strong geomagnetic storms. It is possible that this area could see a strong to major earthquake in the next week. If this should occur, it is most likely off the coast near 15S-17S 70W-80W on the subduction zone boundary. An unusual earthquake west of North Island, New Zealand could be a precursor to such an event. Seismicity in the area of Indonesia, New Guinea and Vanuatu is also expected to continue to be enhanced in the next week with a strong earthquake likely in this region." (May 24, 2024)

EMSC reported today's event was felt with moderate to strong intensity in Peru at Ica, Arequipa, Jose Luis Bustamante y Rivero, Chorrilos, Los Olivos, Lima.

NEIC reported the quake with intensity up to VII in Atiquipa, Peru.

Today's event in Peru was also coincident with the maximum output of Solar Flare 2280 of C3.2 and may have been triggered by SFE from that source. Following are the parameters from SWPC for this flare:

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

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

2280 1432 1439 1449 C3.2 (June 16, 2024) 2.5E-03

Southern Peru M 6.0 14:47 UT

A similar M 6.0-6.2 quake hit this region on December 20, 2023 about 200 km east of today's epicenter but the last event of larger magnitude within about 200 km of this epicenter with equal or larger magnitude was an M 7.1 on January 14, 2018. Today's event appears to be the strongest aftershock to date of this mainshock. At the time this summary noted:

"A major earthquake of M 7.1 hit the area of south-Central Peru today. It caused

major damage at Acari, Arequipa where intensity IX was reported by NEIC.

Damage at intensity VII was also reported from Nazca, Ica, Peru with intensity VI at Coracora, Ayacucho and Vista Alegre, Ica, Peru and within about 200 km of the epicenter. Shaking at IV-V levels was relt in Ica, at Ica, Los Aquijes, Santiago, Puquio; in Arequipa at Arequipa about 350 km from the epicenter; in the Lima Provinces at Quilmana, Mala, Chilca, Chosica. Lesser shaking of intensity II-III was felt within about 500 km of the epicenter including at Ayacucho, Chincha Alta, Mollendo, San Vicente de Canete, Cusco, Matucana, Nicolas de Pierola, San Luis, Santa Maria, Lima. It was also felt in Arica and Tarapaca, Chile with light intensity around 600 km from the epicenter. It is likely this earthquake was promoted by tidal stresses associated with the upcoming new moon as well as by stress redistribution following the M 7.6 north of Honduras on January 10. The last earthquake of M>=7.1 in southern Peru within about 300 km of this epicenter occurred on August 15, 2007 more than 10 years ago with M 8.0. Other events of M>=7.1 occurred June 23, 2001 (M 8.4) and November 12, 1996 (M 7.7)." (January 14, 2018)

"The M 7.1 in Southern Peru early on January 14 occurred with the strongest geomagnetic storm since December 17, nearly a month. The KP (3-hour average) reached 5 at 03-06 UT for the first time since December 17. The earthquake in Peru occurred on the geomagnetic equator in an area commonly triggered by strongly changing geomagnetic conditions. It is likely that this quake was promoted by the geomagnetic storm which preceded and accompanied it.

CSN reported this earthquake was felt with intensity IV in Arica, Codpa, Cuya, III Pocon Chile, Huara, La Tirana; II Camina, Felt in Chile at Arica, Parinacota and Tarapaca." (January 14, 2018)

A pair of aftershocks 12 hours later occurred near local solar midnight with M 4.2 and M 4.5. The mainshock was near local solar noon. These events appear to have been promoted by SFE as well as by strong tidal stresses which maximize near this hour." (June 16, 2024, June 28, 2024)

Like the mainshock today's events were also closely associated with a strong solar flare (#8900) as the M 5.4 occurred at the same time as this flare was officially (SWPC) beginning. Flare data for this event follows:

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

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

8900 1934 1941 1945 C3.2 (July 8, 2024) 1.8E-03

Southern Peru M 5.4 19:33 UT

Forecast 164406 expected today's events in Southern Peru were expected as enhanced seismicity within about 100 km of this epicenter around July 8.

O: 08JUL2024 19:33:29 16.0S 74.8W Mw=5.4 EMSC NEAR COAST OF SOUTHERN PERU

O: 08JUL2024 18:22:30 16.1S 74.8W ML=4.1 EMSC NEAR COAST OF SOUTHERN PERU

O: 08JUL2024 23:15:35 16.1S 75.1W ML=4.0 EMSC OFF COAST OF SOUTHERN PERU

O: 09JUL2024 00:10:17 16.1S 75.0W mb=4.5 EMSC NEAR COAST OF SOUTHERN PERU

O: 09JUL2024 02:06:40 16.1S 75.2W ML=4.2 EMSC OFF COAST OF SOUTHERN PERU

O: 8JUL2024 14:03:32 15.9S 74.9W MW=5.3 EMSC NEAR COAST OF SOUTHERN PERU

P: 8JUL2024 164406 15.0S 75.0W 4.0-5.8 AAAAA Central Peru

The strongest earthquake in the U.S. or Canada today was an M 5.2 in the current swarm in the Vancouver, British Columbia, Canada area. This event was reported by NEIC to have been felt with intensity III in Tofino, Canada.

The series of moderate to moderately strong earthquakes in Vancouver has been followed in this summary. For example in the July 5 issue it was noted:

"The strongest earthquake in the world today was an M 5.7 in the Vancouver, B.C., Canada region. This event was reported felt in British Columbia near Vancouver Island with intensity up to III in Tofino, Canada. It was accompanied by a strong series of moderate foreshocks and aftershocks near local solar noon and may have been promoted by tidal stresses with today's new moon as reported in previous issues of this summary:

"The new moon will arrive on July 5, 2024 at 22:57 UT. Longitudes which are at local solar midnight at this time are located at about 15 East while those at local solar noon are near 165 West. In the east these include most of western Europe and Iceland while in the west areas of the western Aleutians, Alaska, Hawaii, Tonga/Fiji/New Zealand and portions of the Pacific-Antarctic Ridge are included. These are the most likely areas to see significant tidal triggering with this new moon. Other areas may also see tidal promotion in the next week especially at times of large solar flares and near local solar midnight and solar noon. The likelihood of a strong associated earthquake with this new moon are considered moderate to high in the next week (July 1-10, 2024)." (July 1-4, 2024)

In the previous issue of this summary it had been noted in regard to this swarm:

"A series of moderate sized earthquakes hit the Vancouver, B.C. area of Canada today. These were the largest in the U.S. or Canada today. NEIC reported these events of M 4.0, 4.2 and 4.4 were felt with light intensity up to II in Tofino, Canada. This earthquake series began with an M 4.6 and 4.6 within a few minutes of local solar noon and were probably triggered by strong tidal stresses at this hour with the coming new moon as noted in this summary.

…

The tidal effects will linger for several more days as the new moon arrives. Due to this, this series could intensify and possibly include a moderate to moderately large event in the next three days in the Vancouver Island area." (July 4-5, 2024)

Like the M 5.4 in Peru this earthquake in Vancouver was also closely associated with a strong solar flare - occurring at the peak of flare 8860. Flare data from SWPC follows for this flare.

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

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

8860 1458 1506 1514 C4.2 (July 8, 2024) 1.4E-03

Vancouver M 5.2 15:06 UT

Forecast 164361 had expected a moderate increase in aftershocks in Vancouver

Island area was likely around July 7.

O: 08JUL2024 17:06:00 48.9N 128.3W mb=4.5 EMSC VANCOUVER ISLAND, CANADA REGION

O: 08JUL2024 17:05:53 48.6N 128.9W MB=4.4 ECAN OF PORT HARDY, BC

O: 08JUL2024 15:06:44 48.6N 129.0W MB=5.2 ECAN OF PORT HARDY, BC

O: 8JUL2024 15:06:49 48.9N 128.8W MW=5.2 EMSC VANCOUVER ISLAND, CANADA REGIO

P: 7JUL2024 164361 49.3N 129.0W 2.8-5.1 AAAAA Vancouver Island area

STRONG EARTHQUAKE SHAKES BONIN ISLANDS, JAPAN

EARTHQUAKE SUMMARY FOR JULY 7, 2024

The strongest earthquake in the world today was an M 6.2 in the Bonin Islands of Japan. NEIC reported this deep focus earthquake was felt lightly in the Bonin Islands. This deep focus earthquake was not widely felt at the surface. An M 6.5 hit the Bonin Islands about 100 km north of today's epicenter and may have helped promote today's event as a regional aftershock. At the time of the April event this summary noted:

"The strongest earthquake in the world today was a deep focus M 6.5 in the Bonin Islands, Japan. NEIC reported light shaking at intensity II at the surface in the Bonin Islands. This is the largest earthquake reported in the Bonin Islands within about 200 km of today's epicenter since an M 6.6 on April 18, 2020." (April 27, 2024)

Forecast 164527 had expected today's event within about 100 km was likely

around July 12.

O: 7JUL2024 20:01:14 26.9N 138.8E MW=6.2 EMSC BONIN ISLANDS, JAPAN REGION

P: 12JUL2024 164527 28.0N 139.0E 4.0-5.4 BBAAA Bonin Islands

Two earthquakes of M 5.5 each occurred in the Kamchatka region of Russia today.

EMSC reported this earthquake of M 5.5 in Kamchatka, Russia was felt with intensity up to IV in the area(s) of Kamchatka, Russia in Ust-Kamchatskoye, Petropavlovsk-Kamchatsky. The second of these occurred 14 minutes after the M 6.2 in the Bonin Islands at a distance of 33 degrees from that epicenter. The surface wave and the ScS seismic phase from the Bonin Islands event were passing through the Kamchatka epicenter when the M 5.5 occurred. It is likely that it was triggered by the surface wave from the Bonin Islands. The last earthquake in Kamchatka within about 200 km of this epicenter with M>=5.5 occurred as an M 6.6 on March 16, 2021.

Forecast 164377 had expected enhanced seismicity in this area was likely around July 2.

O: 07JUL2024 20:15:48 55.6N 162.1E mb=5.5 EMSC NEAR EAST COAST OF KAMCHATKA

O: 7JUL2024 11:55:33 55.6N 162.0E MW=5.5 EMSC NEAR EAST COAST OF KAMCHATKA

P: 2JUL2024 164377 55.0N 163.0E 4.0-5.7 BAAAA Komandorsky Isl

A series of light earthquakes appears to have re-started in Southern Texas. This began upon landfall of Hurricane Beryl near these epicenters yesterday and today. It is likely they were promoted by stresses associated with that landfall as noted in this and previous issues of this summary:

"Hurricane Beryl continued today in the area of southern Texas with winds up to 40 kts. This system is expected to track to the north and west over the next three days in Southern Texas, Arkansas, Missouri and onto the great Lakes of Erie and Ontario. It could help promote enhanced seismicity the area of eastern Mexico and southern coastal Texas and central U.S. including the possibility of a strong regional earthquake as it moves north of this area. Enhanced seismicity is also likely with substantial flooding in southern Texas and central U.S. at the beginning of the week and following the pat to the northeast through the rest of the week. An active seismic center near 28N 98W could be activated at this time." (July 7-8, 2024)

Forecast 164250 had expected this activity in Southern Texas was likely in early July.

O: 6JUL2024 22:35:07 29.0N 97.9W ML=2.2 EMSC SOUTHERN TEXAS

O: 8JUL2024 00:32:54 29.0N 97.9W ML=2.2 EMSC SOUTHERN TEXAS

P: 4JUL2024 164250 28.0N 98.0W 3.0-4.5 BAAAA Northern Mexico

An earthquake of M 4.5 also occurred today in northern Venezuela. Hurricane Beryl made landfall near this epicenter and today's event may have been promoted by energy associated with that storm.

Forecast 164241 had expected this activity was likely in early 2024.

O: 7JUL2024 07:07:54 10.9N 62.5W MB=4.5 EMSC OFFSHORE SUCRE, VENEZUELA

P: 2JUL2024 164241 10.0N 63.0W 3.4-5.1 BAAAA Windward Islands

An unusual earthquake of M 2.6 occurred in western South Dakota today. The area has seen several such earthquakes in the past two months including an M 2.8 on June 16, 2024 and an M 3.7 on May 30, 2024. At that time this summary noted:

"An unusual earthquake of M 3.7 occurred today in western South Dakota. NEIC reported this earthquake was felt with intensity V in Pierre, South Dakota. Earthquakes in this region often precede strong to major earthquake along the North American-Pacific rim within several days and this could occur in this case especially if a major solar storm or X-class solar flare occurs in this time period. Nevertheless this event may precede enhanced seismicity in California in the next five days.

The last earthquake with M>=3.7 in western South Dakota within about 200 km of this epicenter occurred on May 25, 2003 of M 4.0. At the time this summary noted:

"The earthquake in South Dakota was the most unusual of the two events. It was felt from Chadron on the west to Valentine, Nebraska on the east and northward towards Rapid City, South Dakota. This is probably the strongest earthquake within South Dakota since March 4, 1983 when an event of M 4.6 occurred in the eastern portion of the state." (May 25, 2003, May 30, 2024)

O: 7JUL2024 10:02:18 43.0N 101.7W ML=2.6 EMSC SOUTH DAKOTA

MODERATELY STRONG QUAKE IN NORTHERN PHILIPPINES

EARTHQUAKE SUMMARY FOR JULY 6, 2024

The strongest earthquake in the world today was an M 5.5 in northern Philippines. NEIC reported it was felt with intensity up to V in Namuac. PHIVOLCS reported this earthquake of M 5.1 in Northern Philippines was felt with intensity up to III in the area(s) of Northern Philippines in Cayagan at Claveria and II in Lasam, Philippines. This epicenter is at a latitude at which the sun was directly overhead at noon. This summary has argued that enhanced vertical tidal effects occur on this date at this latitude. An M 4.1-4.4 in Hawaii today (see below) also occurred at this latitude (19.3N). Other enhanced seismicity occurred at this latitude today in Colima, Jalisco and Michoacan, Mexico, Haiti; and the northern Caribbean. The last earthquake with M>=5.5 within about 200 km of today's epicenter in northern Philippines occurred on October 4, 2023 with M 5.7. At the time this summary noted:

"A moderately strong earthquake of M 5.7 also occurred today in northern Philippines. This event was reported by NEIC to have been felt with intensity II in Tuguegarao, Cagayan Valley and in Bontoc, Cordillera, Philippines.

…

This earthquake was probably promoted by passage of Typhoon Koinu which made landfall today near this epicenter as expected ..." (October 4, 2023)

Forecast 164254 had expected a moderately large event in this region was likely around July 4.

O: 6JUL2024 10:29:32 19.2N 121.1E MW=5.5 EMSC BABUYAN ISL REGION, PHILIPPINE

P: 4JUL2024 164254 20.0N 123.0E 4.0-5.9 AABAA Taiwan

The strongest earthquake in the U.S. or Canada today was an M 4.1-4.4 in Hawaii. NEIC reported it was felt with intensity up to V in Fern Forest, Hawaii. EMSC reported moderate shaking in Hawaii at Pahoa, Mountain View (with earthquake noise), Keaau, Pepeekeo, Captain Cook. This continues elevated seismicity in Hawaii of the past week and may indicate a new upcoming eruption at Kilauea, which is common in summer as the sun is directly over head and tidal stresses are maximized on this day of the year. The last earthquake in Hawaii within about 100 km of this epicenter of larger magnitude than M 4.4 was recorded by NEIC on February 9, 2024 with M 5.7. At the time this summary noted:

"The strongest earthquake in the U.S. or the world today was an M 5.7 in the Mauna Loa region of Hawaii (initially given as M 6.3). NEIC reported it was felt as far as Honolulu and throughout the island of Hawaii with intensity up to VII. Foreshocks of M 2.9 and 3.0 were also reported felt in Pahala, Hawaii with intensity up to IV. ….Minor damage which included items being thrown from shelves and minor damage to structures was reported which included cracked walls. This is the strongest earthquake in Hawaii since an M 6.2 on October 10, 2021 and an M 6.9 on May 4, 2018 - the largest in Hawaii in the past 35 years. the only other event in Hawaii with M>=6.2 in this time period was an M 6.7 on October 15, 2006." (February 9, 2024)

Forecast 164505 had expected today's event was likely within about 25 km around July 11.

O: 7JUL2024 06:47:45 19.3N 155.1W MB=4.4 EMSC ISLAND OF HAWAII, HAWAII

P: 11JUL2024 164505 19.3N 155.3W 3.0-4.4 BAAAA Hawaii

The most widely felt earthquake in the world today was an M 4.9 in Southern Greece. NEIC reported it was felt with intensity up to V in Arkoudi, Greece.

EMSC reported moderate shaking in southern Greece in Lygia, Loutra Kyllinis, Kalamia, Kyllini, Amaliada, Lechaina, Dounaiika, Vasilikos, Zakynthos among others. The last earthquake in southern Greece of greater magnitude and within about 200 km of today's epicenter occurred with M 5.8 on March 29, 2024. At the time this summary noted:

"The strongest earthquake in the world today was an M 5.8-5.9 in Greece. NEIC reported it was felt with intensity up to VII in Filiatra, Greece.

…

No major damage was reported. A foreshock a minute before the mainshock was felt with moderate intensity in Greece at Filiatra, Tholo, Epitalio, Schinolakka, Pylos, Dounmaiika, Vasilikos, Amaliada, Pantokratoras, Xifytas and as far as 400 km from the epicenter in Athens and Heraklion. This is the strongest earthquake to occur in southern Greece within about 200 km of today's epicenter since an M 6.8 on October 24, 2018 and a series of event of M 6.7 on February 14, 2008; M 6.1 on February 20, 2008 and June 8, 2008." (March 29, 2024)

Forecast 164283 had expected today's event in this area of Greece was likely around July 5.

O: 6JUL2024 17:34:31 37.8N 21.2E ML=4.9 EMSC SOUTHERN GREECE

P: 5JUL2024 164283 37.0N 22.0E 3.0-4.8 AAAAA No. Greece

An unusually large earthquake of M 3.9 also occurred today in the area north of Mammoth Lakes, California. The last earthquake within about 100 km of this epicenter in Nevada of M>=3.9 occurred as an M 4.3 on January 22, 2022. At the time this summary noted:

"The strongest earthquake in the U.S. or Canada today was an M 4.3 in western Nevada near the California border. It was followed by a series of light aftershocks. NEIC reported this earthquake of M 4.3 in Nevada was felt with intensity II-III in the area(s) of Nevada at Luning, Hawthorne, and in California in Mammoth Lakes, Bridgeport, Coleville and Bishop. This is the strongest earthquake within about 100 km of this epicenter since an M 4.4 on March 30, 2021. More recent stronger events occurred as an M 6.0 about 100 km to the northwest of this on July 8, 2021 and about 100 km to the southeast with M 4.8 on January 6, 2022." (January 22, 2022)

Forecast 164263 had expected today's event within about 10 km was likely around

July 6.

O: 6JUL2024 11:14:53 38.2N 118.8W MW=3.9 EMSC NEVADA

O: 6JUL2024 22:07:19 38.3N 117.9W ML=2.1 EMSC NEVADA

P: 6JUL2024 164263 38.2N 118.8W 2.5-4.9 AAAAA California/Nevada area

P: 6JUL2024 164264 38.4N 118.7W 2.5-4.9 AAAAA California/Nevada area

UNUSUAL QUAKE IN NORTHERN MONTANA

EARTHQUAKE SUMMARY FOR JULY 5, 2024

The strongest earthquake in the world today was an M 5.3 in the current

swarm in the Vancouver Island region of Canada. NEIC reported this earthquake of M 5.0-5.3 in Vancouver, Canada was felt with intensity up to III in the area(s) of Vancouver, Canada in Tofino. This swarm has now continued for two days and had been noted in the previous two issues of this summary as:

In the previous issue of this summary it had been noted in regard to this swarm:

Forecasts 164361 had expected today's activity was likely within about 25 km around July 3 and 7, 2024.

O: 05JUL2024 09:05:13 48.7N 128.7W mb=4.0 EMSC VANCOUVER ISLAND, CANADA REGION

O: 06JUL2024 11:01:06 48.4N 128.8W MB=3.9 ECAN WSW OF TOFINO, BC

O: 05JUL2024 16:34:05 48.6N 129.0W MB=5.3 ECAN OF PORT HARDY, BC

O: 05JUL2024 15:51:51 48.6N 129.0W MB=3.9 ECAN OF PORT HARDY, BC

O: 05JUL2024 12:29:11 48.6N 128.9W MB=3.0 ECAN OF PORT HARDY, BC

O: 05JUL2024 09:05:13 48.5N 128.9W MB=3.4 ECAN OF PORT HARDY, BC

O: 05JUL2024 08:53:14 48.7N 129.0W MB=3.4 ECAN OF PORT HARDY, BC

O: 05JUL2024 08:51:00 48.7N 129.0W MB=3.0 ECAN OF PORT HARDY, BC

O: 5JUL2024 16:34:04 48.6N 129.1W MB=5.0 EMSC VANCOUVER ISLAND, CANADA REGIO

P: 7JUL2024 164361 49.3N 129.0W 2.8-5.1 AAAAA Vancouver Island area

An unusually large earthquake occurred today in northern Montana. This event of M 3.9-4.2 was reported by NEIC to have been felt with intensity IV in Seeley Lake, Montana. EMSC reported moderate shaking in Missoula, Montana. The last earthquake in northwestern Montana within about 150 km of this epicenter with M>=4.2 was reported by NEIC to have occurred as an M 4.2 on October 19, 2017, an aftershock of an M 5.8 exactly seven years ago on July 6, 2017. At the time this summary noted:

"The earthquake in Montana was a near-midnight event and may also have been triggered by earth tides which are maximized at this hour. The area often is active in summer months as water becomes more accessible but it has been some time since a large earthquake hit the area. It is possible that the Yellowstone Wyoming/Montana swarm of the past month helped set the area up for this large earthquake which is about 250 km north of that swarm.

The mainshock of M 5.8 was felt throughout the northwestern U.S. and southwestern Canada. States reporting light to moderate shaking included, Montana, Idaho, Washington, Utah, Wyoming, Oregon and in Canada, British Columbia, Saskatchewan and Alberta. Light shaking was reported from up to 800 km from the epicenter at Portland and Beaverton, Bend, The Dalles, Oregon and in Washington at Walla Walla, Prescott, Valley, Metaline Falls, Chewelah, Sprague, Ione, Reardan, Ford, Cusick, Koon Lake, Endicott, Clayton, Medical Lake, Nine Mile Falls, Usk, Fairchile AFB, Deer Park, Cheney, Airway Heights, Spokane, Saint John, Newport, Colbert, Elk, Chattaroy, Clarkston, Colfax, Mead, Valleyford, Veradale, Otis Orchards, Newman Lakes, Fairfield, Pullman, Rockford, Uniontown, Twisp, Wenatchee, Quincy, Omak, Okanogan, Richland, Moses Lake, Keller, Incheliun, Kettle Falls, Prescott, Addy, Colville, Seattle, Lynnwood, Marysville, Auburn, Everett, Bellevue, Shelton, Port Townsend, Brush Prairie, and Yelm.

In Montana the mainshock was felt with intensity VI in Canyon Creek and Lincoln, Montana with possible light to moderate damage in the epicentral area about 25-30 km from these communities. Intensity IV-V in Montana included reports from Garrison, Helena, Augusta, Deer Lodge, Ovando, Clancy, East Helena, Bonner, Drummond, Cascade, Boulder, Winston, Anaconda, Seeley Lake, Clinton, Fairfield, Philipsburg, Fort Shaw, Sun River, Missoula, Butte, Townsend, Condon, Vaughn, Choteau, Great Falls, Stockett, Arlee, Stevensville, Power, Divide, Saint Ignatius, Great Falls, Corvallis, Florence, Black Eagle, San Coulee, Frenchtown, White Sulphur Springs, Malmstrom AFB, Dutton, Three Fors, Ronan, Lolo, Victor, Belt, Dixton, Hamilton, Floweree, Bigfork, Wisdom, Huson, Raynesford, Belgrade, Manhattan, Polson, Valier, Highwood, Big Arm, Sheridan, Conner, Dayton, Rollins, Darby, Lakeside, Plains, Kila, Gallatin Gateway, Virginia City, Chester, and within about 200 km of the epicenter. Intensity II-III in Montana was reported from areas up to 350 km from the epicenter including at Billings, Winnett, Joliet, Troy, Roundup, Park City, Creston, Cranbrook,

In Utah it was felt with intensity II-IV in Salt Lake City, and in Idaho at Twin Falls, Preston, Kuna, Meridian, Boise, Gooding, Eagle, Garden City, Fairfield, Garden Valley, Hailey, Arco, Ketchum, Bonners Ferry, Donnelly, Priest River, Oldtown, Blanchard, Rexburg, Spirit Lake, Rathdrum, Post Falls, Sandpoint, Lewiston, Moore, Worley, Sagle, Moscow, Genesee, Potlatch, Coeur D;Alene, Athol, Tensed, Harrison, McCall, Hayden, Saint Anthony, Clark Fork, Saint Maries, Challis, Kendrick, Deary, Kingston, Grangeville, Pinehurst, Nezperce, Island Park, Smelterville, Kellogg, Kamiah, Weippe, Leadore, Mullan, Kooskia, Pierce, Wallace, Orofino, Elk City, Salmon, Carmen, and within about 400 km of the epicenter. It was also reported felt in Wyoming in Yellowstone National Park, Dubois, among others.

Canada felt the earthquake with intensity II-III with reports from British Columbia at White Rock, Kamloops, Kelowna, Lumby, Golden, Cranbrook, Penticton, Grand Forks, Chilliwack, Castlegar, Trail, Nelson, and Walnut Grove up to 800 km from the epicenter. It was also felt in Saskatoon, Saskatchewan; in Alberta at Beaumont, Drumheller, Calgary, Chestermere, Brooks, Medicine Hat, Claresholn, Bow Island, Fort MacLeod, Coalhurst, Coaldale, Lethbridge, Magrath, Cardston.

NEIC reported a number of moderate aftershocks of M 3.9-5.0 in the first several hours after the mainshock in Montana. These were reported felt with intensity II-III within about 150 km of the epicenters, in Montana at Helena, Great Falls, Missoula, Manilton, Kalispell, Polson, Whitefish, and in Idaho at Wallace, Coeur D'Alene, Post Falls and Boise among others. A foreshock of M 2.3 also occurred at the epicenter of the mainshock about a day earlier. There were no obvious triggers to the foreshock that would have immediately put the area on alert for a larger event.

The last earthquake with M>=5.8 in western Montana within about 250 km of today's event occurred on October 28, 1983 with M 7.3 near Challis, Idaho; in Yellowstone as M 6.1 on June 30, 1975 and as the Hebgen Lake earthquake of August 18, 1959 of M 7.7. A series of earthquake within about 50 km of today's epicenters hit the area in October, 1935 with maximum magnitude M 6.3 on October 19, 1935 and October 31, 1935. These followed an M 5.9 foreshock on October 12, 1935. Given this regional history it appears likely that strong or moderately strong aftershocks of today's event are likely in the next two weeks. This summary had noted the damage from these earthquakes 82 years ago as:

"The main earthquake in a series of earthquakes in Montana in 1935. Two were killed by falling bricks. Damage estimated at $3 million. 300 buildings were damaged and up to 200 chimneys were destroyed. Severe damage at Helena at the High School, City Hall, Kessler Brewery and St. Joseph's Orphanage. Tombstones twisted and overturned. Ground cracks were common especially in allugial material where water flowed from the cracks. Changes in water flow in wells and springs occurred." (October 19, 2016)

The only other event of M>=5.8 within about 100 km of today's event that has been recorded occurred on June 28, 1925 with M 6.8 about 100 km southeast of today's epicenter. The historical account in this summary of this event read:

"This earthquake occurred east of Helena, Montana with violent shaking over 600 square miles over a felt area of about 300,000 square miles with intensity VIII. The greatest damage occurred at Manhattan where a large schoolhouse was destroyed. Some reinforeced concrete buildings survived. Many chimneys fell in all directions. Rockfalls and landslides destroyed sections of railroad track. At Three Forks similar damage was observed. A church with high unsecured walls was strongly damaged. Cracks appears in Masonry building however frame buildings were relatively undamaged. Cracks formed in the roads. Felt throughout Montana, North Dakota, Washington and Wyoming." (June 28, 2017)

Water is important in promotion of seismicity in this region and the concentration of many of the important regional historical events towards the end of June or in early July is probably not coincidental but may be related to regional weather patterns. While regional earthquake activity is expected to be promoted, it is also likely that changes in groundwater and wells will be noted in the next several days as occurred in 1935." (July 6, 2017)

Forecasts 164334 and 164367 had expected regional seismic enhancement was likely in early July in this area.

O: 05JUL2024 10:50:18 47.3N 113.2W ML=2.5 EMSC WESTERN MONTANA

O: 05JUL2024 10:53:22 47.3N 113.2W ML=2.0 EMSC WESTERN MONTANA

O: 05JUL2024 10:46:38 47.3N 113.2W mb=3.9 ANSS Seeley Lake Montana

O: 5JUL2024 10:46:38 47.3N 113.2W ML=4.2 EMSC WESTERN MONTANA

P: 4JUL2024 164334 45.7N 112.1W 2.0-4.0 ABAAA Montana/Idaho

P: 7JUL2024 164367 46.4N 111.4W 2.0-4.2 AABAA Yellowstone/Wyoming

MODERATELY STRONG EARTHQUAKE NEAR VANCOUVER ISLAND, CANADA

EARTHQUAKE SUMMARY FOR JULY 4, 2024

The strongest earthquake in the world today was an M 5.7 in the Vancouver, B.C., Canada region. This event was reported felt in British Columbia near Vancouver Island with intensity up to III in Tofino, Canada. It was accompanied by a strong series of moderate foreshocks and aftershocks near local solar noon and may have been promoted by tidal stresses with today's new moon as reported in previous issues of this summary:

In the previous issue of this summary it had been noted in regard to this swarm:

…

The last earthquakes of M>=4.7 in this area of Vancouver Island were an M 5.0 on May 3, 2024 and an M 6.0 on April 13, 2023. At that time this summary noted:

"The strongest earthquake in the world today was an M 6.0 off the western coast of Vancouver Island, British Columbia, Canada. NEIC reported intensity I-III in British Columbia at Port Hardy, Port MacNeill, Nanaimo, Sidney, Vancouver, White Rock and in Washington State at Friday Harbor, Eastsound, Ferndale and Port Townsend among others. The last earthquake in the Vancouver Island area within about 150 km of this epicenter with M>=6 was an M 6.3 on December 25, 2019 and an M 6.0 on December 23, 2019 But the last earthquake within about 100 km of this epicenter with M>=6 was an M 6.5 on October 22, 2018." (April 13, 2023)

Forecast 164361 had expected today's activity was likely within about 25 km around July 3, 2024.

O: 04JUL2024 17:43:17 48.7N 129.1W mb=4.4 EMSC VANCOUVER ISLAND, CANADA REGION

O: 05JUL2024 01:48:48 48.7N 128.4W mb=4.4 EMSC VANCOUVER ISLAND, CANADA REGION

O: 04JUL2024 16:00:24 48.8N 128.6W mb=4.3 EMSC VANCOUVER ISLAND, CANADA REGION

O: 04JUL2024 18:31:24 48.8N 129.1W mb=4.3 EMSC VANCOUVER ISLAND, CANADA REGION

O: 04JUL2024 21:20:23 48.8N 128.5W mb=4.4 EMSC VANCOUVER ISLAND, CANADA REGION

O: 04JUL2024 13:18:07 48.9N 129.0W mb=4.6 EMSC VANCOUVER ISLAND, CANADA REGION

O: 04JUL2024 16:15:13 48.9N 128.7W Mw=5.7 EMSC VANCOUVER ISLAND, CANADA REGION

O: 05JUL2024 02:09:08 49.1N 128.3W mb=4.7 EMSC VANCOUVER ISLAND, CANADA REGION

O: 4JUL2024 23:13:32 48.6N 129.0W MB=4.7 EMSC VANCOUVER ISLAND, CANADA REGIO

P: 3JUL2024 164361 48.7N 129.0W 2.8-5.1 AAAAA Vancouver Island area

MODERATE SERIES BEGINS IN VANCOUVER, BRITISH COLUMBIA, CANADA

EARTHQUAKE SUMMARY FOR JULY 3, 2024

A series of moderate sized earthquakes hit the Vancouver, B.C. area of Canada today. These were the largest in the U.S. or Canada today. NEIC reported these events of M 4.0, 4.2 and 4.4 were felt with light intensity up to II in Tofino, Canada. This earthquake series began with an M 4.6 and 4.6 within a few minutes of local solar noon and were probably triggered by strong tidal stresses at this hour with the coming new moon as noted in this summary:

"The new moon will arrive on July 5, 2024 at 22:57 UT. Longitudes which are at local solar midnight at this time are located at about 15 East while those at local solar noon are near 165 West. In the east these include most of western Europe and Iceland and the Atlantic Ridge while in the west areas of the western Aleutians, Alaska, Hawaii, Tonga/Fiji/New Zealand and portions of the Pacific-Antarctic Ridge are included. These are the most likely areas to see significant tidal triggering with this new moon. Other areas may also see tidal promotion in the next week especially at times of large solar flares and near local solar midnight and solar noon. The likelihood of a strong associated earthquake with this new moon are considered moderate to high in the next week (July 1-10, 2024)." (July 3-4, 2024)

The last earthquakes of M>=4.7 in this area of Vancouver Island were an M 5.0 on May 3, 2024 and an M 6.0 on April 13, 2023. At that time this summary noted:

"The strongest earthquake in the world today was an M 6.0 off the western coast of Vancouver Island, British Columbia, Canada. NEIC reporte intensity I-III in British Columbia at Port Hardy, Port MacNeill, Nanaimo, Sidney, Vancouver, White Rock and in Washington State at Friday Harbor, Eastsound, Ferndale and Port Townsend among others. The last earthquake in the Vancouver Island area within about 150 km of this epicenter with M>=6 was an M 6.3 on December 25, 2019 and an M 6.0 on December 23, 2019 But the last earthquake within about 100 km of this epicenter with M>=6 was an M 6.5 on October 22, 2018." (April 13, 2023)

Forecast 164361 had expected today's activity was likely within about 25 km around July 3.

O: 03JUL2024 20:25:12 48.4N 129.2W mb=4.6 EMSC VANCOUVER ISLAND, CANADA REGION

O: 03JUL2024 19:59:17 48.5N 128.7W mb=4.4 EMSC VANCOUVER ISLAND, CANADA REGION

O: 03JUL2024 21:14:22 48.5N 128.7W mb=4.0 EMSC VANCOUVER ISLAND, CANADA REGION

O: 03JUL2024 20:21:42 48.6N 128.8W mb=4.5 EMSC VANCOUVER ISLAND, CANADA REGION

O: 03JUL2024 20:23:46 48.6N 128.6W mb=4.3 EMSC VANCOUVER ISLAND, CANADA REGION

O: 04JUL2024 05:01:26 48.6N 128.6W mb=4.3 EMSC VANCOUVER ISLAND, CANADA REGION

O: 3JUL2024 20:18:14 48.3N 129.4W MB=4.7 EMSC VANCOUVER ISLAND, CANADA REGIO

P: 3JUL2024 164361 48.7N 129.0W 2.8-5.1 AAAAA Vancouver Island area

A moderate M 5.3 was also felt today in the Gulf of California. NEIC reported it was felt with intensity up to III in Loreto, Mexico. This is the strongest earthquake within about 150 km of this epicenter in the Gulf of California since an M 5.6 on April 19, 2024 and is probably an aftershock of that event of M 5.6. At the time this summary noted:

"The earthquake of M 5.6 in the Gulf of California was the largest event to date in a swarm which began after the total solar eclipse of April 8, 2024 which was visible in this epicentral area around 18:20 UT. While not total at this epicenter, the maximum of this eclipse occurred about 400 km south of this epicenter over Jalisco, Mexico. It is likely that strong tidal stresses from that alignment helped promote today's moderate earthquake in the area." (April 18, 2024)

Forecast 164246 had expected this area to see enhanced seismicity around July 6, 2024.

O: 3JUL2024 11:44:27 26.6N 111.0W MW=5.3 EMSC GULF OF CALIFORNIA

P: 6JUL2024 164246 25.0N 113.0W 3.5-4.9 BBBAA Gulf of California

The M 5.3 in the Gulf of California was accompanied by a strong swarm of events in northern Baja California, Mexico. Much of this occurred near local solar noon and may have been promoted by the new moon tidal effects. The new moon arrives on July 5 as noted in this summary:

"The new moon will arrive on July 5, 2024 at 22:57 UT. Longitudes which are at local solar midnight at this time are located at about 15 East while those at local solar noon are near 165 West. In the east these include most of western Europe and Iceland and the Atlantic Ridge while in the west areas of the western Aleutians, Alaska, Hawaii, Tonga/Fiji/New Zealand and portions of the Pacific-Antarctic Ridge are included. These are the most likely areas to see significant tidal triggering with this new moon. Other areas may also see tidal promotion in the next week especially at times of large solar flares and near local solar midnight and solar noon. The likelihood of a strong associated earthquake with this new moon are considered moderate to high in the next week (July 1-10, 2024)." (July 3-4, 2024)

This swarm is expected to continue for several days. Forecast 164246 had regional seismic enhancement was likely in the area around July 5.

O: 03JUL2024 20:29:51 31.1N 115.1W ML=3.2 EMSC BAJA CALIFORNIA, MEXICO

O: 03JUL2024 20:36:24 31.1N 115.1W ML=3.1 EMSC BAJA CALIFORNIA, MEXICO

O: 03JUL2024 21:10:13 31.1N 115.1W ML=3.2 EMSC BAJA CALIFORNIA, MEXICO

O: 03JUL2024 10:32:37 31.4N 115.5W ML=3.2 EMSC BAJA CALIFORNIA, MEXICO

O: 03JUL2024 10:38:14 31.4N 115.5W ML=3.1 EMSC BAJA CALIFORNIA, MEXICO

O: 03JUL2024 20:28:22 31.4N 115.5W ML=3.0 EMSC BAJA CALIFORNIA, MEXICO

O: 03JUL2024 22:27:35 31.4N 115.5W ML=3.2 EMSC BAJA CALIFORNIA, MEXICO

O: 03JUL2024 12:21:47 31.5N 115.6W ML=2.1 EMSC BAJA CALIFORNIA, MEXICO

O: 03JUL2024 16:23:17 31.5N 115.6W ML=2.8 EMSC BAJA CALIFORNIA, MEXICO

O: 03JUL2024 21:35:10 31.5N 115.5W ML=3.2 EMSC BAJA CALIFORNIA, MEXICO

O: 3JUL2024 08:47:23 30.6N 115.9W ML=3.3 EMSC BAJA CALIFORNIA, MEXICO

P: 5JUL2024 164246 29.0N 114.0W 3.5-4.9 ABBAA Gulf of California

A pair of near-antipodal earthquakes occurred today in the Southern Mid-Atlantic Ridge and in the Andreanof Islands with M 5.2 and M 3.7. This is not unusual activity for the areas and these events were not reported felt.

O: 3JUL2024 07:17:29 54.1S 2.4W MB=5.2 EMSC SOUTHERN MID-ATLANTIC RIDGE

O: 3JUL2024 18:34:55 51.4N 178.8W ML=3.7 EMSC ANDREANOF ISLANDS, ALEUTIAN IS

P: 6JUL2024 164370 51.3N 176.8W 3.5-4.9 BABAA Andreanoff Isls, Aleutians

A moderate earthquake occurred today in the Leeward Islands of the Caribbean with M 4.3. This is the strongest earthquake in the area of Martinique since an M 4.4 on September 1, 2023 but the last of significantly larger magnitude in the area occurred as an M 5.1 on January 8, 2020. Hurricane Beryl passed over this epicenter two days ago and probably helped trigger today's event. At the time this summary noted:

"Hurricane Beryl continued today in the area west of the Windward Islands and south of Puerto Rico with winds up to 165 kts (category 5). This is the earliest a category 4-5 hurricane has hit the Caribbean in modern history. Considerable damage was done in the Windward and Trinidad and Tobago areas upon landfall. This system is expected to track to the north and west over the next week. It could help promote enhanced seismicity the area of Nicaragua, El Salvador, Guatemala and eastern Mexico including the possibility of a strong regional earthquake as it moves north of this area." (July 2, 2024)

Forecast 164226 had expected today's enhanced seismicity near Martinique was likely around July 5.

O: 4JUL2024 05:10:24 15.0N 61.4W MB=4.3 EMSC MARTINIQUE REGION, WINDWARD IS

P: 5JUL2024 164226 17.0N 62.0W 3.0-5.3 ABAAA Leeward Islands

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