Because this summary is often behind schedule updates to the current date are being added here to make it more relEvAnt to current conditions

October 12, 2025

Notable earthquakes and events:

A moderate geomagnetic storm occurred today and lasted at its peak from about 0600 UT

to 1500 UT. It reached K-index at high latitudes of 6 around 0800 UT. Most of

the significant earthquakes of the day including those in

Ethiopia, Los Angeles California, Andreanof Islands, Alaska, Northern Mindanao,

Southern Mindanao, Leyte, Luzon, Philippines, Kuril Islands, and South Sandwich

Islands and Missouri occurred during the limited time this storm was maximized and may

have been promoted by geomagnetic stresses related to it.

A strong series of earthquakes occurred today in the region of Ethiopia. This

began with events of M 5.6 and M 5.3 but included a number of others of M>=4.5.

These earthquake were felt with intensity IV-VI in Ethiopia at Mek'ele and Addigrat, Tigray among others according to NEIC data.

The series ended as quickly as it began with an M 4.5 within minutes of local

solar midnight. The last earthquake in Ethiopia within about 200 km of these

epicenter occurred as an M 5.6 on August 1, 2023 about 200 km northeast of today's

epicenters. The only event of similar or larger magnitude within this 200

km radius in the past 35 years was an M 5.6 on August 10, 2002. At the time this summary noted it as:

"Over the past several days this report has been covering an unusual

sequence of earthquakes in the region of Ethiopia. The strongest in this

series occurred today with Mb 5.1. ... This was the strongest event within 200 km of this

epicenter since September 21, 1993 when a Mb 5.6 occurred about 200 km

south of today's epicenter.

...

A strong geomagnetic disturbance occurred last night from August 10

at about 18:00 UT to about 06:00 UT on August 11. This disturbance was

not strong enough to precipitate a seismic watch, but some effect is possible

on regions where seismicity is currently strongly active." (August 10, 2002)

Today's events in Ethiopia are located near the shadow zone boundary (102-107 degrees) from

the M 7.8 in the Drake Passage in an area which had been expected to see

enhanced seismicity at this time as noted in the previous issue of this

summary:

"Preliminary expectations for far field triggering from the Drake Passage earthquake of M 7.5 of August 22, 2025:

"P- and S- shadow zone edge and node 7 (101-110 degrees)

Drake Passage to Central, southern California, Nevada/Utah, Azores/Northern Mid-Atlantic Ridge, Gibraltar, Spain, New Guinea, New Britain, Hawaii, Ethiopia," (October 11, 2025)

These epicenters are located at 104-107 degrees from the South Geomagnetic

Pole and the M 7.8 in the Drake Passage of October 10 and at the fourth node

(90 degrees) from the eye of Typhoon Nakri and may have been promoted

with today's geomagnetic storm by energy from those sources.

O: 11OCT2025 21:41:28 13.8N 39.8E MB=4.5 NEIC ETHIOPIA

O: 11OCT2025 18:38:22 14.0N 39.7E MB=4.8 NEIC ETHIOPIA

O: 11OCT2025 21:23:13 13.9N 39.8E MB=4.3 NEIC ETHIOPIA

O: 11OCT2025 16:18:25 13.8N 39.9E MB=5.6 NEIC ETHIOPIA

O: 11OCT2025 16:01:59 13.9N 39.9E MB=5.3 NEIC ETHIOPIA

O: 11OCT2025 12:07:33 13.8N 39.8E MB=4.2 NEIC ETHIOPIA

Another seismic area which is near 103 degrees and at the shadow zone boundary

from the Drake Passage is in California most notably in southern California.

A set of two light earthquakes were felt in the Los Angeles, California area today.

An M 2.1 under the city center was reported by NEIC to have been felt with intensity III in Monterey Park and Los Angeles with II in Alhambra, Los Angeles.

This event occurred within minutes of local solar midnight and was probably

promoted by tidal and/or geomagnetic effects which maximize at this hour

in areas of high local stress. This epicenter is near 104 degrees from

the series of major earthquakes in Mindanao and Leyte, Philippines and

from the M 7.8 in the Drake Passage and may have been promoted by energy

from those sources.

O: 12OCT2025 08:24:33 34.1N 118.3W MB=2.1 NEIC LOS ANGELES, CALIFORNIA

Earthquakes of M 2.6 and M 2.3 were also felt today in eastern Los Angeles earlier in the day.

NEIC reported they were felt in California at Redlands, Mentone and Yucaipa with intensity II and II in Loma Linda and Victorville and in Riverside, California. The stronger of these

occurred within minutes of local solar midnight and the later event occurred

within several minutes of local solar noon and were probably promoted by

tidal and/or geomagnetic stresses following the strong geomagnetic storm

several days ago. A geomagnetic storm was in progress when this event occurred.

This epicenter, like the later event near local solar midnight was near 103-104

degrees from the Philippines and Drake Passage earthquakes of the past several

days and was probably promoted by energy from those sources.

O: 11OCT2025 19:56:20 34.1N 117.3W MB=2.3 NEIC GREATER LOS ANGELES, CALIFORNIA

O: 11OCT2025 09:05:00 34.0N 117.2W MB=2.6 NEIC GREATER LOS ANGELES, CALIFORNIA

These two earthquakes in Los Angeles illustrate that the area is under considerable

stress as it seem a minor tidal stress increase with an aligned sun is

able to to trigger the. The confluence of this along with the distance near

103 degrees from four major earthquakes (3 in the Philippines and one in the

Drake Passage) at the time of a building nor'easter on the east coast of the

U.S. suggest that this activity in California could continue for several

days and could include a moderate to large earthquake. The danger is not

limited to the area of Southern California as major far-field effects from

the Philippines and from the Drake Passage related to reflected and refracted

seismic waves from the core-mantle boundary near 103 degrees cover much of

California north to San Francisco and northeast to Idaho and Montana. All

these areas could see enhanced seismicity at this time.

The strongest earthquake in the U.S. or Canada today was an M 4.3 in western

Texas. NEIC reported it was felt with maximum intensity IV in Texas at Eola, Coaoma, Westbrook, Miles and III in Eldorado, Colorado City, San Angelo, Sterling City and Brady.

This event occurred within about half an hour of local solar midnight and

may have been promoted by tidal stresses. The last earthquake within about

200 km of this epicenter with M>=4.3 occurred on February 28, 2025 with M 4.8

about 100 km west of today's epicenter, the only such event in this region

of Texas in the past year. Today's epicenter is at the third node (120 degrees) from the

events in Mindanao and Leyte, Philippines of M 7.4 and M 7.6 and may have

been promoted by energy associated with those earthquakes.

A regional foreshock of M 2.7 was felt in Midland, Texas with intensity III.

This epicenter is located at the third node (120 degrees) from the major

earthquakes in the Philippines of the past two days and at the sixth node

(60 degrees) from the North Geomagnetic Pole and may have been promoted

during the geomagnetic storm today by energy from those sources.

O: 12OCT2025 06:08:59 32.3N 101.1W MB=4.3 NEIC WESTERN TEXAS

The strongest earthquake in the U.S. or Canada today was an M 4.5 in the

Andreanof Islands, Alaska. NEIC reported it may have been felt with light

intensity in the epicentral area. This is an active seismic zone but the

last earthquake in the western Andreanof Islands within about 150 km of

this epicenter with equal or larger magnitude at a shallow focus was an M 5.0

on June 21, 2024.

This epicenter is located at 145 degrees from the Drake Passage event of M 7.8

of October 10 and at the sixth node (60 degrees) from earthquake in Mindanao

and Leyte, Philippines of October 10 and was probably promoted by energy

from those sources. It may also have been promoted with the geomagnetic

storm today as it is located at the third node (120 degrees) from the South Geomagnetic

Pole and at the 10th node from the North Geomagnetic Pole (36.0 degrees).

O: 11OCT2025 13:51:19 51.0N 179.8W MB=4.5 NEIC ANDREANOF ISLANDS, ALASKA

The strongest earthquake in the world today was an M 6.0 in northern Mindanao, Philippines.

This earthquake was reported by NEIC to have been felt with intensity up to V in Caraga, Philippines at Carrascal, Calaitan, Butuan and Nabunturan ; with IV in Ourok, Panabo, Bunawan, Luna, and III in the Eastern Visayas at Abuyog and Lawaan.

EMSC reported it was felt strongly in the Philippines in Tandag, Basag, Butuan, Tungao, Libertad, General Luna, Libas, San Isidro and lightly in Surigao, Magugpo Poblacion, Binuangan, Jasaan, Bugo, Carmen, Panabo, Cagayan de Oro, Barra, Lumbia, Davao among others.

This is not a classical aftershock of either the events in Mindanao nor the

earlier events in Leyte, Philippines as it lies about 250 km from both these

areas but was probably triggered by stress redistribution

associated with those events of M 7.6 an 7.4 to the south and north.

This earthquake occurred near local solar midnight.

The last earthquake within about 200 km of this epicenter in Mindanao, Philippines

with M>=6 occurred as an M 6.8 and M 6.3 on August 2-3, 2024. These followed

a major M 7.6 near today's epicenter on December 2, 2023. Today's M 6.0 is

probably an aftershock of that major earthquake. At the time this summary noted:

"The strongest earthquake in the world today was an M 6.8 in Mindanao, Philippines. NEIC reported it was felt with intensity up to VII in Barcelona, Philippines. A strong aftershock of M 6.3 occurred in Mindanao, Philippines today. NEIC reported it was felt with intensity up to VI in Barcelona, and Santa Maria, Philippines.

EMSC reported strong but gentle swaying in Mindanao, Philippines at Butuan City, Panabo, Malaybalay City, Davao City, Digos City, Macrohon.

PHIVOLCS reporteed intensity up to V for the mainshock in Lingig, Hinatuan and City of Bislig, Surigao del Sur; Rosario, Agusan del Sur, Maco and Monkayo, Davao de Oro; IV in Nabuntura, Davao de Oro, City of Davao and III in Don Marcelino, Davao Occidental; Inabanga, Gohol; city of Baybey, Leyte and II in Camiguin; Sohof, Southern Leyte; City of Cotabo; Datu Odin Sinsuat, Maguindanao.

The M 6.3 was reported by EMSC to have been felt with strong intensity in Mindanao at Butuan City, Davao City, Philippines. Several moderate aftershocks were also reported felt in the Barcelona, Philippines area with intensity up to IV.

PHIVOLCS reported the M 6.3 was felt with intensity V in Mindanao at Lingig and City of Bislig, Surigao del Sur; IV in Hinatuan, Surigao del Sur; Monkayo, Davao de Oro; III in Marihatag, Surigao del Sur and in Misamis Oriental and the city of Cagayan de Oro with lesser intensity.

While a small tsunami is possible PTWC indicated a tsunami warning was not to be issued at this time.

The last earthquake of M>=6.8 within about 200 km of today's epicenter in Mindanao

occurred as an M 6.9 on December 3, 2023 - an aftershock of an M 7.6 on December 2, 2023

and today's event is probably a regional aftershock of that mainshock. It occurred following major geomagnetic

storms on the geomagnetic equator and had been expected with these storms

in the previous updates to this summary as:

"SFE promoted seismicity is most likely near local solar

midnight and noon and at high latitudes (Alaska and north) and near the geomagnetic

equator." (July 31, 2024)

At the time of the December 2, 2023 M 7.6 this summary noted in part:

"The mainshock occurred near local solar midnight at a location on the geomagnetic

equator as the strong geomagnetic storm was prevalent and was probably

triggered by effects associated with that storm.

...

The M 7.6 in Mindanao today is the strongest in the Philippines in the region

of Mindanao within about 300 km of today's epicenter since an M 7.6 on August 31, 2012, the only such event

in this area in at least 35 years. Other events of M >=7.5 hit somewhat further

to the south of today's epicenter on July 23, 2010, March 5, 2002 and January 1, 2001 (all with M 7.5)." (December 2, 2023, August 3, 2024)

Today's epicenter is located at the fifth node (72 degree) from the South

Geomagnetic Pole and the seventh node from Kamchatka and may have been promoted

by energy from those sources with today's geomagnetic storm.

O: 11OCT2025 14:32:58 8.9N 126.4E MW=6.0 NEIC NORTHERN MINDANAO, PHILIPPINES

O: 11OCT2025 14:32:58 9.0N 126.6E MW=6.0 PHIV NORTHERN MINDANAO, PHILIPPINES

A classical aftershock of M 5.5 occurred in southern Mindanao, Philippines today following the M 7.4 of October 10.

NEIC reported it was felt with intensity IV in Caraga at Lapinigan and in Mindanao at Davao and Lumbia and ins southern Mindanao at Lasang, Mawab, Digos and II in Libertad, Central Mindanao.

EMSC reported it was felt with intensity up to V in the Philippines at Manay, Mati, Magugpo Poblacion, Tagum, Kaputian, Davao, Ula, Tuli, Agusan, Cagayan de Oro.

PHIVOLCS reported it was felt with intensity IV in Cagwait and Carmen, Surigao del Sur; City of Cagayan De Oro, City of Davao, City of Butuan and III in Abuyyog, Leyte, Hinunangan, San Francisco, and Silago, Southern Leyte, Cabanglasan, Don Carlos, City of Malaybalay and San Fernando, Bukidnon, City of Bislig, Surigao del sur, City of Mati, Davao Oriental and II in Leyte, Samar, Bukidnon, Misamis Oriental and Surigao del Norte.

O: 11OCT2025 10:27:23 7.2N 126.8E MW=5.5 NEIC SOUTHERN MINDANAO, PHILIPPINES

Another non-conventional earthquake in the Philippines today occurred in the Central Visayas where it was felt

with intensity II and Minglanilla and M 4.5. This epicenter, like the one in northern Mindanao (see above)

does not fit neatly into any of the major aftershock zones at this time.

O: 11OCT2025 13:54:58 10.6N 125.2E MW=4.5 NEIC CENTRAL VISAYAS, PHILIPPINES

Also in the Philippines and M 4.9 was felt in the area north of Manila, Luzon.

NEIC reported it was felt with intensity III in Central Luzon at Subic and II in Urdaneta, Ilocos, Olongapo, Central Luzon and in Manila.

EMSC reported it was felt with strong intensity in the Philippines at Arayat, Bundoc, Cabangan, Olongapo. Gapan, Rosales, Santa Cruz, Del Monte, Manila, Calumpang, Pasay, Makati, Pateros.

O: 11OCT2025 09:32:16 15.2N 120.4E MW=4.9 NEIC LUZON, PHILIPPINES

O: 11OCT2025 09:32:13 15.2N 120.4E MW=5.0 EMSC LUZON, PHILIPPINES

An earthquake of M 5.5 also occurred today in the South Sandwich Islands area. NEIC reported it might have been felt with intensity up to IV

in the epicentral area. It occurred within an hour of local solar noon

and may have been promoted by energy associated with tides or geomagnetic

effects. A moderate geomagnetic storm reached its peak today about this hour.

This epicenter is located near the antipode of an M 5.8 in the Kuril Islands which occurred

42 minutes earlier (see below). SS seismic waves would have been in the

area and time of the South Sandwich Islands from that Kuril Islands event and could

could have helped trigger it. An earlier event of M 5.4 occurred near the

same epicenter.

Like an earthquake of M 5.3 in New Guinea today, this epicenter is located

at the sixth node from the South Geomagnetic pole and neart the antipode

of events in the Kurils and Kamchatka region and may have been promoted by

energy from those sources.

O: 11OCT2025 13:08:00 56.4S 26.6W MW=5.5 NEIC SOUTH SANDWICH ISLANDS REGION

O: 11OCT2025 08:06:43 56.2S 26.5W MW=5.4 NEIC SOUTH SANDWICH ISLANDS REGION

An unfelt earthquake was also located in New Guinea today with M 5.0-5.3.

This epicenter was likely promoted by today's geomagnetic storm as it is

located at the sixth node (60 degrees) from the South Geomagnetic Pole

and at the fourth node (90 degrees) from the North Geomagnetic pole. It is

also at the sixth node from Kamchatka and may have been promoted by energy from these sources.

O: 12OCT2025 03:00:35 2.7S 139.3E MW=5.0 NEIC PAPUA NEW GUINEA

O: 12OCT2025 03:00:34 2.5S 139.4E MW=5.3 BMG SARMI-PAPUA INDONESIAA

A moderately strong earthquake of M 5.8 was reported today in the Northern

Kuril Islands near local solar midnight. NEIC reported it may have been felt with

intensity up to IV in the epicentral area. EMSC reported moderate shaking

om Russia at Vilyuchinsk and Petropavlovsk-Kamchatsky. The last earthquake in the northern

Kurils within about 150 km of this epicenter with M>=5.8 occurred on

August 27. 2025 with M 6.0. These are aftershocks of an M 6.8 of August 3, 2025.

O: 11OCT2025 12:25:59 50.3N 156.7E MW=5.8 NEIC NORTHERN KURIL ISLANDS

NEIC reported an earthquake of M 4.4 in Northern Peru was felt with intensity up to II-III in the area(s) of Northern Peru in Piura.

EMSC reported light shaking in Pinas, Mida Nuevas and Zaruma, Ecuador.

NEIC reported an earthquake of M 2.9 in Missouri was felt with intensity up to II-III in the area(s) of Missouri with III in Hornerville, Steele; II in Jackson, Benton and Caruthersville. Also reported felt in Oakwood, Illinois.

The strongest earthquakes within about 100 km of this epicenter during

the year 2025 occurred as events of M 2.9-3.1 on September 6; August 1 and June 27, 2025.

Today's epicenter is located at the fifth node (72 degrees) from major earthquakes in

Kamchatka and at the third node (120 degrees) from earthquakes in central

Philippines of the past several days and may have been promoted by energy

from those sources.

O: 11OCT2025 08:28:34 36.1N 89.8W MW=2.9 NEIC SOUTHEASTERN MISSOURI

An M 4.8 in the Izu Islands, Japan today was note felt due to its depth of 433 km.

It occurred as Typhoon Nakri was passiing over this epicenter as noted in this summary:

"TYPH NAKRI 2025-10-12 00:00 UT 31.2N 138.3E 85 kts Izu Islands, Japan" (October 12, 2025)

Typhoon Nakri continued south of eastern Honshu in the Izu Islands today with winds up to 85 kts. It also made landfall October 8-9 the northern Ryukyu Islands and may promote seismicity in the Izu Islands at this time (an M 4.8 was recorded at 32N 138E today as this storm passed over that epicenter). The antipode is at 32S 42W in an area of the South Atlantic and is not seismic.

It is likely this event was promoted by stresses related to Typhoon Nakri.

This epicenter is also at 146 degrees from the M 7.8 in the Drake Passage

of October 10 and may have been promted by energy from that source.

O: 11OCT2025 03:22:00 30.3N 138.4E MW=4.8 EMSC IZU ISLANDS, JAPAN

EMSC reported an earthquake of M 2.3 in Spain was felt with intensity up to IV in the area(s) of Spain at Santa Pola, Guardamar del Segura, Elche, La Hoya, Los Montesinos.

This epicenter is near 108 degrees from recent major earthquakes in the

Philippines and the Drake Passage and may have been promoted by energy from those sources.

O: 11OCT2025 15:11:56 38.2N 0.6W MW=2.3 EMSC SPAIN

EMSC reported an earthquake of M 4.7 in Pakistan was felt with intensity up to IV in the area(s) of Pakistan at Karor, and Layyah.

TODAY'S MAP

Stippled white lines represent areas at nodal distances from the M 7.4 in Mindanao, Philippines of October 10, 2025.

Stippled lavender lines represent areas at nodal distances from the M 7.8 in the Drake Passage of October 10, 2025.

SEISMIC EFFECTS OF TROPICAL CYCLONES

TYPHOON NAKRI (29W)

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

TYPH NAKRI 2025-10-12 00:00 UT 31.2N 138.3E 85 kts Izu Islands, Japan

Typhoon Nakri continued south of eastern Honshu in the Izu Islands today with winds up to 85 kts. It also made landfall October 8-9 the northern Ryukyu Islands and may promote seismicity in the Izu Islands at this time (an M 4.8 was recorded at 32N 138E today as this storm passed over that epicenter - see above). The antipode is at 32S 42W in an area of the South Atlantic and is not seismic.

SOLAR FLARES

Following is the listing of C- M- or X-class flares from SWPC for the date

of October 11, 2025. These listings are published daily in this summary and at SWPC.

The main line gives details of flares. Subsequent lines identify some earthquakes

which are at or after the time of the flare and could have been affected by

immediate Solar Flare Effects (SFE). Some earthquakes occur at longitudes

which were at local solar noon or local solar midnight and may also have

been affected by SFE. These are not identified here.

SOLAR FLARES

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

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

7790 0537 0542 0546 C1.1 (October 11, 2025) 6.0E-04

7800 0754 0804 0815 C1.0 (October 11, 2025) 1.2E-03

South Sandwich Is. M 5.5 08:06 UT

7820 1031 1041 1047 C1.5 (October 11, 2025) 1.2E-03

Mindanao M 5.5 10:27 UT

Tabasco, Mexico M 3.9 10:46 UT

7830 1155 1204 1210 C1.7 (October 11, 2025) 1.3E-03

Ethiopia M 4.4 12:07 UT

Coast of Oregon M 2.7 12:05 UT

Botswana M 3.1 12:00 UT

7840 1905 1915 1927 C2.7 (October 11, 2025) 2.8E-03

Ethiopia M 4.9 19:30 UT

Reykjanes M 4.7 19:29 UT

Mindanao M 4.9 19:28 UT

Los Angeles M 2.3 19:56 UT

*indicates modified reading from NOAA GOES Graph

GEOMAGNETIC FIELD: unsettled October 12-14. Solar M-flare chance: 40% X-class: 10% proton storm: 10%

AP Indicies (global, high, mid-latitude, time of max AP, Max AP, Sunspot Number, Radio Flux) 17 30 15 09:00 6 108 131

October 11, 2025

Notable earthquakes and events:

A near-great earthquake of M 7.6-7.8 occurred in the Drake Passage south of

Western South America today. A tsunami warning was issued by PTWC but has

since been modified from a strong tsunami to a possible minor tsunami with

strong currents and sea level fluctuations. Readers along the coast of

South America should not be near the coastline at this time.

NEIC reported it may have been lightly felt in Ushuaia Tierra del Fuego, Argentina.

CSN (Chile earthquake network) reported intensity VI in Magallanes and Antartica, Chilena in Antarctici at Base Frei and IV in Base Fildes and Base Prat.

This earthquake occurred at the longitude of maximum tidal stress with

the full moon of October 7 (60 West longitude) at the opposite longitude 120-126 degrees longitude.

This easterly longitude saw a major M 7.4 and an aftershock of M 6.9 in

Mindanao, Philippines earlier in the day. This summary has hypothesized and still maintains tidal

triggering from the full moon is largely responsible for these major earthquakes

as noted in previous issues of this summary:

"The full moon will arrive at 03:47 UT on October 7, 2025. This is the largest super-moon of the year as it is closest to earth at this time. This in turn, considerably enhances tidal stresses (at the inverse third power of distance) and can lead to larger global earthquakes within a couple of days of the full moon. Longitudes at local solar noon are near 124 East and those at local solar midnight are near 56 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 full moon before October 8, 2025" (revised to October 11, 2025).

This includes the aftershock area of the earthquake of M 6.9 in the Philiippines of September 30 (at 124E longitude) and is likely to enhance regional seismicity in that area at this time." (October 2-10, 2025)

Today's M 7.7 in the Drake Passage follows a M 7.5 near the same epicenter

on August 22, 2025. At the time this summary noted:

"A major earthquake occurred today south of the Drake Passage near the South Shetland Islands

south of South America. NEIC reported it was lightly felt in Tierra del Fuego, Argentina.

CSN reported this event at M 7.6 was felt in Chile at Magallanes and Antarctica with V in Base Frei and IV in Base Fildes and Base Prat. This event appears to be a regional aftershock of

an M 7.4 in the Drake Passage which occurred about 1000 km northwest of today's

epicenter on May 2, 2025. Today's epicenter is in the general antipodal

region of the M 8.8 in Kamchatka of July 29, 2025 and may have been promoted

be energy from that source. It occurred near local solar midnight and was

probably promoted by strong tidal stresses with the new moon of August 23

as noted in previous issues of this summary:

...

No major tsunami is expected with today's earthquake but minor waves may

be generated in the generally unpopulated area of southern Chile and the

Antarctic.

The last earthquake within about 400 km of today's epicenter with M>=7 occurred

more than 35 years ago. The last significant earthquake in this area was an

M 6.9 on January 23, 2021. At the time this summary noted:

"The strongest earthquake in the world today was an M 6.9-7.1 in the South Shetland Islands south of Chile. NEIC reported it was felt with light intensity as far as Punta Arenas, Magellanes, Chile.

GUC reported this earthquake of 7.1 was felt with intensity III in Magallanes and Antartida, Chilena at Antartida.

In addition to being the largest earthquake in the world since an M 7.6 in the

Alaska Peninsula October 19, 2020, this M 7.1 is the first in the South

Sheland Islands within about 400 km of this epicenter of M>=7.0 since an M 7.0 on July 11, 1983

and a similar M 7.0 on November 18, 1941 and the strongest recorded in this area, tied with an M 7.0-7.1 on February 8, 1971." (January 23, 2021)

Observant readers may recognize the date in 1971 was the same as the San

Fernando Earthquake in Southern California of M 6.7. The distance between

these two epicenters is 103 degrees and triggering may occurred in that

case. Similar triggering in the Los Angeles/Southern California is possible

following today's M 7.5 in the next several days.

Today's earthquake in the Drake Passage is near 100 degrees from the current

location of the eye of Hurricane Erin and may have been promoted by energy associated

with that storm." (August 22, 2025)

The statement regarding possible seismic enhancement in the area of Central

or southern California at the current time needs to be emphasized under

the current conditions. In addition to being at 103-104 degrees from the

Drake Passage event of October 10, 2025, the area of Central and Southern

California is also at this distance from the M 7.4 in Mindanao, Philippines of October 10, 2025

that occurred earlier in the day. A moderate to large area is most likely

in this area of Southern or central California could occur shortly after an expected major nor'easter hits

the U.S. East coast early next week (October 11-14).

Seismicity in coastal California often shows spikes with strong nor'easter systems.

Several events in eastern Los Angeles area today of M 2.4 and M 2.5 may be precursory. The 103-107 degree

line from the Drake Passage passes through several seismic active areas

which can also be promoted after a major geomagnetic storm as listed below.

Today's epicenter in the Drake Passage occurred at 144-145 degrees from the

current eyes of Tropical Storm Nakri and Typhoon Halong and at 104 degrees

from Tropical Storm Karen in the north Atlantic and at the fourth node (90 degrees)

from Hurricane Jerry and Tropical Storm Raymond and may have been

promoted by energy from those storms. Vibrations caused by waves and winds

can pass through the earth from such storms reflecting and refracting off

the core boundaries and returning to the surface as strong arrivals at this

distances from their sources (143-146 degrees). Enhanced seismicity often follows at this distance

from major earthquakes.

At the time of the August 22 event this summary published a listing of far-field

areas where enhanced seismic triggering from the Drake Passage was expected as:

"Preliminary expectations for far field triggering from the Drake Passage earthquake of M 7.5 of August 22, 2025:

Antipodal (~180 degrees)

Drake Passage to Mongolia, Siberia

Outer shadow zone edge (141-148 degrees)

Drake Passage to Afghanistan, northern India, Taiwan, Rat/Andreanof Is, northern Alaska

Node 3 (120 degrees)

Drake Passage to Sumatra, Greece, western Turkey, Italy, Reykjanes Ridge, SE Alaska, Vancouver B.C.

P- and S- shadow zone edge and node 7 (101-110 degrees)

Drake Passage to Central, southern California, Nevada/Utah, Azores/Northern Mid-Atlantic Ridge, Gibraltar, Spain, New Guinea, New Britain, Hawaii, Ethiopia,

Node 4 (90 degrees)

Drake Passage to Baja, Gulf of California, Northern Mid-Atlantic, Kenya, South Indian Ocean, Vanuatu, Western Australia, Vanuatu, Loyalty Is. Central Tonga

Node 5 (72 degrees)

Drake Passage to Costa Rica, Central Mid-Atlantic, North Island, NZ, Fiji,

Node 6 (60 degrees)

Drake Passage to Southern New Zealand, Peru/Ecuador, Macquarie, South Africa,

Node 7 (52 degrees)

Drake Passage to Central, Northern Peru, Southern mid-Atlantic Balleny Islands

" (August 22, 2025)

As noted above a curious arrangement of tropical storms today may have helped

trigger today's Drake Passage event. This epicenter is at 144-145 degrees from Tropical Storm Nakri and Halong south of

Honshu, Japan; at 104 degrees from Tropical Storm Karen in the North Atlantic and at the fourth node from Tropical Storm Raymond off Western Mexico.

Today's earthquake in the Drake Passage may also have been promoted by

SFE associated with the second strongest solar flare of the day - a C1.7 (#7720).

The earthquake occurred near the end of that flare. Data from SWPC for

this flare follow:

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

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

7720 1956 2016 2026 C1.7 (October 10, 2025) 2.3E-03

Drake Passage M 7.7 20:29 UT

Central Peru M 4.1 20:11 UT

O: 10OCT2025 10:20:29 60.2S 61.9W mb=7.6 NEIC DRAKE PASSAGE

O: 10OCT2025 10:20:29 60.3S 62.0W MW=7.8 CSN DRAKE PASSAGE

An aftershock of M 6.7 also occurred today in Mindanao, Philippines. This follows the M 7.4 in that area which occurred earlier on UT October 10, 2025.

NEIC reported today's aftershock was felt with damage and intensity VI in Southern Mindanao at Baganga, Babag, Mabantao; V in Lasang, Buayan, Davao, Ula, and IV in San Jose, Hagonoy and Nabunturan.

EMSC reported moderate to strong shaking in Mindanao at Santo Nino, Limao, Babak, Davao, Ula, Bansalan, Maramag, Tandag, General Santos, San Martin, Cagayan de Oro, Balingasag, Cotabato, General Luna, San Francisco, Surigao, La Paz, Gabi, Calero, San Goque, Consolacion, Danao, Tabuelan, northern Cebu.

PHIVOLCS reported intensity VI in Manay, Davao Oriental; V in Baganga, Boston, Caraga, Cateel and Tarragona, Davao Oriental and IV in Mawab, Monkayo, Nabunturan and Pantukan, Davao de Oro; City of Davao, City of Mati, Davao Orienta; City of Bislig, Surigao. It was also reported with intensity II-III in Leyte, Davao del Sur, Cotabo, Sultan Kudarat, Dinagat Islands, Eastern Samar, Northern Samat, Cagayan de Oro, Cotabato.

This epicenter is at 144 degrees from Tropical Storm Jerry in the North Atlantic and

at 51.4 degrees (node 7) from the recent major seismicity in Kamchatka.

It is likely it was promoted by energy from those sources.

It also lies on the geomagnetic equator at the fifth node from the South

Geomagnetic Pole and may have been set up by energy associated with the recent major geomagnetic storm.

More details on the M 7.4 mainshock were published in the previous issue of

this summary. Readers are encouraged to review that for additional information.

Latest news on the tolls from that earthquake and today's M 6.7 indicate that at least 7 were

killed in that event - mostly by heart attacks and falling debris. In Manay, houses,

churches, roads an bridges were damaged. Damage was described as "quite big" by

local officials. Children were forced from school and power was off in many

areas of Mindanao, Philippines.

O: 10OCT2025 11:12:07 7.2N 126.7E mb=6.7 NEIC MINDANAO, PHILIPPINES

O: 10OCT2025 11:12:07 7.2N 126.7E mb=6.8 PHIV MINDANAO, PHILIPPINES

An earthquake of M 5.5 in the Banda Sea, Indonesia today was reported by NEIC to

have likely been felt in the Banda Sea with intensity up to IV.

BMG reported intensity III in Tanimbar at Selaru and in Maluku at Damer, Pulau and Dawelor Da.

Like the earthquakes in the Philippines this epicenter is located at 144 degrees

from Tropical Storm Karen and may have been promoted by energy from that

unusual source.

O: 10OCT2025 10:02:51 6.9S 129.5E mb=5.5 NEIC BANDA SEA, INDONESIA

O: 10OCT2025 10:02:50 7.1S 129.7E mb=5.7 BMG TANIMBAR, INDONESIA

EMSC also reported that an M 5.7 aftershock in Kamchatka was felt with moderate intensity in Kamchatka at Petropavlovsk-Kamchatsky, Yelizovo, Vilyuchinsk.

This epicenter is located at the seventh node (52 degrees) from the M 7.4 in

the Philippines of October 10. It is likely it was promoted by energy related

to that source.

O: 11OCT2025 03:08:43 53.2N 159.8E mb=5.7 EMSC KAMCHATKA, RUSSIA

NEIC reported an earthquake of M 2.4 in Kentucky was felt with intensity up to II-III in the area(s) of Kentucky in Crestwood and Morehead.

SEISMIC EFFECTS OF TROPICAL CYCLONES

TROPICAL STORM NAKRI (29W)

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

TS NAKRI 2025-10-11 00:00 UT 29.3N 131.8E 70 kts Ryukyu Islands, Japan

Tropical Storm Nakri continued south of the Ryukyu Islands today with winds up to 70 kts. It also made landfall October 8-9 the northern Ryukyu Islands and may promote seismicity in that area and in Kyushu, Japan at this time. The antipode is at 29S 48W in an area of the South Atlantic and are not seismic.

TROPICAL STORM RAYMOND (17E)

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

TS RAYMOND 2025-10-11 00:00 UT 21.1N 109.0W 45 kts South of Guerrero, Mexico

TS Raymond continued today in area west of Mexico with winds up to 45 kts. It is expected to track to the north and west. Regional seismicity in the area of Baja California and the Gulf of California could be enhanced at that time. The antipode is at 21S 71E is in the South Indian Ocean and could see moderately enhanced seismicity while this storm is active.

TYPHOON HALONG (DEPRESSION 28W)

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

TYPH HALONG 2025-10-11 00:00 UT 34.1N 149.9E 85 kts East of Honshu, Japan

Typhoon Halong (28W) continued today in the area east of Honshu, Japan with winds up to 85 kts. This system is moving to the northeast and could help promote seismicity east of Honshu in the next day. It will turn to the east around October 8 but is unlikely at this point to trigger a significant earthquake. The current antipode is at 34S 30W in the South Atlantic and is not expected to see enhanced seismicity at this time.

TROPICAL STORM KAREN

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

TS KAREN 2025-10-11 00:00 UT 43.3N 36.1W 45 kts North Atlantic

Tropical Storm Karen continued today in the area of the north Atlantic. It is expected to dissipate in the next two days and is unlikely to generate enhanced seismicity at this time.

TROPICAL STORM JERRY

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

TS JERRY 2025-10-11 00:00 UT 27.2N 63.0W 45 kts Atlantic Ocean north of Virgin Islands

Tropical Storm Jerry continued today in the area north of Puerto Rico and the Virgin Islands with winds up to 45 kts. It is expected track to the north and east and is not likely to enhance further regional seismicity at this time. The antipode is at 27S 117E is in western Australia near an active seismic zone which could see enhanced seismicity at this time (30S 117E).

Following is the listing of C- M- or X-class flares from SWPC for the date

of October 10, 2025. These listings are published daily in this summary and at SWPC.

The main line gives details of flares. Subsequent lines identify some earthquakes

which are at or after the time of the flare and could have been affected by

immediate Solar Flare Effects (SFE). Some earthquakes occur at longitudes

which were at local solar noon or local solar midnight and may also have

been affected by SFE. These are not identified here.

SOLAR FLARES

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

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

7690 0613 0629 0643 C2.3 (October 10, 2025) 2.8E-03

El Salvador M 4.6 06:27 UT

Mindanao M 4.9 06:32 UT

7710 1926 1933 1942 C1.0 (October 10, 2025) 9.7E-04

Mindanao M 4.2 19:37 UT

7720 1956 2016 2026 C1.7 (October 10, 2025) 2.3E-03

Drake Passage M 7.7 20:29 UT

Central Peru M 4.1 20:11 UT

7760 2156 2202 2205 C1.8 (October 10, 2025) 7.3E-04

Drake Passage M 4.8 22:09 UT

Hokkaido M 4.3 22:06 UT

*indicates modified reading from NOAA GOES Graph

GEOMAGNETIC FIELD: unsettled October 11-13. Solar M-flare chance: 40% X-class: 10% proton storm: 10%

AP Indicies (global, high, mid-latitude, time of max AP, Max AP, Sunspot Number, Radio Flux) 9 12 9 12:00 5 81 121

October 10, 2025

Notable earthquakes and events:

A major M 7.4 earthquake has occurred in Mindanao, Philippines. A tsunami alert

is currently in effect. PTWC issued a tsunami warning but only small waves

were reported and it was later withdrawn. NEIC reported the mainshock of M 7.4

was widely felt with intensity up to VIII (with damage) in Central and northern Mindanao

north to Cebu. Intensity reports published by NEIC indicated it was felt with

intensity VI in Caraga Philippines at Bayugan; V in Butuan; IV in Masarawag, Bicol, Bancasi, and III in Caraga at San Francisco, Legazpi City, Albay, Brasilisa, and II-II in Pulau at Meyungs, and Ngetkip and in Sulawesi, Indonesia.

PHIVOLCS (the local Philippines earthquake network) reported intensity V in Copostela, Maco, Mawab, Monkayo, Montevista, Nabunturan and Pantukan, Davao De Oro; Asuncion, Braulio E. Dujali, Carmen, New Corella,City of Panabo, Island Garden City of Samat, Santo Tomas and City of Tagum, Davao del Norte,

City of Davao, Jose Abad Santos, Davao Occidental; Cateel and City of Mati, Davao Oriental; City of Kidapawan, Cotabato; Alabel, Glan and Malungon, Sarangani, City of Koronadal, Tampakan and Tup, South Cotabate, City of General Santos; City of Butuan, Claver, Gigaquit and Mainit, Surigao Del Norte, In addition intensity IV was felt in the areas of the city of Tacloban, Budkidnon, Davao Del Sur, Davao Occidental, Cotabato, Sarangani, South Cotabato, Surigao del Norte and III in City of Iloilo, Eastern Samar, Leyte, Ormoc City, southern Leyte, Budidnon, City of Iligan, City of Cagayan de Oro, Davao Occidental, Cotabato, Sarangani, Sorsogon as well as throughout most of Mindanao, Leyte and Samar, Philippines.

The largest aftershocks at the time of this writing were of M 5.8-5.9. The first

of these occurred 8 minutes after the mainshock and could have been triggered

by a reflected PcP seismic wave. The second occurred within a couple

of minutes of local solar noon - as did many other significant earthquakes

around the world today and was probably promoted by strong tidal stresses

with the full moon of October 7. PHIVOLCS reported it was felt with strong intensity.

The last earthquake at shallow depth within about 200 km of this epicenter

in Mindanao, Philippines was an M 7.6 on December 2, 2023. At the time this

summary noted (in part):

The strongest earthquake in the world today was an M 7.6 in Mindanao, Philippines. NEIC reported it was felt with damage and intensity up to IX in Mindanao, Philippines.

PHIVOLCS reported it was felt with maximum intensity VII in the City of Tandag, Surigao del Sur; VI in Maco and Monkayo, Davao de Oro; Bayabas, City of Bislig and Hinatuan, Surgao del sur and V in the City of Borongan, Eastern Samar; Palo, Leyte, City of Cagayan de Oro; Nabunturan, Davao de Oro; City of Tagum, Davao del Norte; City of Davao; City of Cadadbaran, Agusan del Norte, Esperanza and Talacogon, Agusan del Sur and with lesser shaling in Bohol, City of Nandaue, Tacloban, Leyte, Budidon, Iligan, Sarangani, South Cotabato, Zamboanga, Davao, Bukidnon among others. Moderate to strong aftershocks were reported by NEIC with intensity up to V.

At least one person was confirmed killed in the earthquake with four others injured

and nine missing at initial count. More than 500 families were displaced. A tsunami warning was initially

made but was later withdrawn when no major tsunami waves were observed. Many people fled to higher ground because of the

fear of tsunami. Tsunami waves were observed in Japan with height up to 0.4 meters (1.3 feet).

Other tsunami waves were measured in the Philippines in Davao (0.3 ft); Legaspi (0.1 ft) and in Malakal Koror (Palau) east of the Philippines with 0.01 m height. A smaller event of M 6.9 hit Mindanao to the south of this two weeks ago. That event killed at least

9 and caused considerable damage to built structures, including a shopping mall ceiling

which collapsed. In today's activity there were no reports of major damage but some

roads in Surigao Del Sur were cracked by the movement associated with the

earthquakes. The mainshock occurred near local solar midnight at a location on the geomagnetic

equator as the strong geomagnetic storm was prevalent and was probably

triggered by effects associated with that storm.

Today's event of M 7.6 was the strongest in the world since an M 7.7 on May 19, 2023 in the

Loyalty Islands. Other events of M>=7.6 in the year 2023 occurred with M 7.6 in the Banda Sea on Januayr 9; in Turkey with M 7.8 on February 6 and in Tonga with M 7.6 on May 10, 2023.

The M 7.6 in Mindanao today is the strongest in the Philippines in the region

of Mindanao within about 300 km of today's epicenter since an M 7.6 on August 31, 2012, the only such event

in this area in at least 35 years. Other events of M >=7.5 hit somewhat further

to the south of today's epicenter on July 23, 2010, March 5, 2002 and January 1, 2001 (all with M 7.5).

.. " (December 2, 2023)

The M 7.4 on January 1, 2001 is the only other shallow focus epicenter within

about 200 km of this epicenter in at least 35 years.

This summary had expected this area of the central Philippines to see strong

seismic enhancement at this time. The major factor in this assessment was

that the maximum tidal stresses associated with the full (Super) harvest moon

of October 7 was at a longitude directly over this epicenter as noted in

previous issues of this summary:

This was reinforced by a series of earthquakes in China, Kamchatka, Japan, Taiwan,

Indonesia of moderately strong to strong magnitude along this longitude

of maximum tidal stress in the previous issue of this summary as:

"Recall that an earlier event in Sichuan today of M 5.6 occurred within a couple

of minutes from local solar noon at that epicenter. The earthquake in China

is located at 24 degrees longitude west of the longitude of maximum

tidal stress with the super and full moon of October 7 while the earthquake

in Kamchatka today is symmetrically at 34 degrees east of that longitude." (October 9, 2025)

This epicenter is located on the geomagnetic equator at the fifth node (72 degrees)

from the South Geomagnetic Pole. It is likely it was promoted by geomagnetic

energy associated with the major geomagnetic storm of early October, 2025.

It is also at 144 degrees from the strong Hurricane Jerry currently north

of the Caribbean; at 120 degrees from Hurricane Octave and may have been promoted by energy from those storms.

Far-Field triggering is likely with today's earthquake in Mindanao. Some

of this includes:

DISTANCE RELATIONS BETWEEN EARTHQUAKES

Statistical evidence indicates that some triggering or promotion forward in time can occur in regions which are under high stress due to additional stress events of small size. Among these are surface and body waves passing through a region. Triggering may be dynamic with the promoted earthquake occurring at the same time as the stress event or delayed with an earthquake occurring later in time but still related to the stress event through water lubrication or other various geophysical effects on the faults. We have argued in this report for the past 35 years that this effect is most observable where the seismic waves are largest. In general this occurs at distances from the rupture ends of the earthquake producing those waves (mainshock) which we have termed nodal distances. These are defined by the formula D=360*m/n where D is the distance in degrees and m<=m where n an m are small integers. These are also the locations of the maximum corrections to magnitude in the standard Jeffreys-Bullen tables. In addition there is focusing of seismic energy from reflections and refractions of f the core-mantle and the inner-outer core boundary of the earth. This focuses energy at the surface in the distance between 101 and 108 degrees (core-mantle) and 141-148 degrees (inner-outer core boundary). In this report we monitor seismicity at these distances following major earthquakes as experience has shown that strong and/or unusual earthquake are much more likely to occur at these distance from the mainshock.

Antipodal (~180 degrees)

Mindanao to Central Brazil

Outer shadow zone edge (141-148 degrees)

Mindanao to Bio-Bio, Chile, Panama, Costa Rica, Puerto Rico, Dominican Republic, Nicaragua, Maule, Chile, Canary Islands,

Node 3 (120 degrees)

Mindanao to East Pacific Rise, Morocco, Ontario, Arkansas, Illinois, Quebec, Oklahoma, Southeast Pacific, Western Texas, South Sandwich Is,

P- and S- shadow zone edge and node 7 (101-110 degrees)

Mindanao to California, NevadaGreenland, Iceland, , Italy, Idaho, Southern, Geysers, Central California, Yellowstone, South of Africa, Scotland, Iceland, southern Idaho, San Francisco, Mammoth Lakes, CA, Los Angeles, California, Montana, Oregon, Tyrrhenian Sea, France, Central, northern California,

Node 4 (90 degrees)

Mindanao to South Indian Ocean, Tanzania, Norwegian Sea, Greenland Sea, Romania, Istanbul, Turkey, Yukon Terr, Canada, SE Alaska, Crete,

Node 5 (72 degrees)

Mindanao to Caspian Sea, Unimak, Fox Islands, East of South Island, N.Z,

Node 6 (60 degrees)

Mindanao to Carlsberg Ridge, So. Indian Ridge, Rat Is. Near Islands, Fiji, Pakistan, Afghanistan,

Node 7 (52 degrees)

Mindanao to Kamchatka, Northern India, Xingiang, China, Pakistan, Loyalty Islands,

O: 10OCT2025 01:43:55 7.2N 127.0E MW=7.4 PHIV MINDANAO, PHILIPPINES

O: 10OCT2025 01:43:59 7.3N 126.8E MW=7.4 EMSC MINDANAO, PHILIPPINES

O: 10OCT2025 01:51:15 7.3N 126.7E MW=5.9 EMSC MINDANAO, PHILIPPINES

O: 10OCT2025 03:32:15 7.1N 125.8E MW=5.8 PHIV MINDANAO, PHILIPPINES

Twenty-four minutes after the M 7.4 in Mindanao an M 6.3 occurred in the

Bismarck Sea north of New Guinea. NEIC reported it was felt with intensity

II in Papua New Guinea at Lorengau Manus. This earthquake also occurred

within a couple of minutes of local solar noon today and was probably

promoted by energy associated with the full moon of October 7.

This earthquake occurred about 16 minutes after the M 5.9 aftershock

in Mindanao at 23 degrees distance. This is the time it takes from a refected

ScS seismic phase to travel this distance and it may have helped trigger

this earthquake. The surface wave from Mindanao arrived about six minutes before

this earthquake in the Bismarck Sea.

This epicenter is at 102 degrees from Hurricane Octave and at the sixth node (60 degrees)

from the South Geomagnetic Pole and the fourth node (90 degrees) from the North

Geomagnetic Pole and may have been promoted by energy associated with those

sources.

O: 10OCT2025 02:08:10 3.0S 148.0E MW=6.3 NEIC BISMARCK SEA

A moderately sized solar flare (M2.0) appears to have led to a strong M 6.0

aftershock in Kamchatka which occurred towards the end of that flare.

Other moderate earthquake associated with the flare occurred in the Kermadec

Islands near the International Date Line (IDL) and south of Africa near the

Greenwich Meridian. These were at local solar midnight and noon respective

when the flare was near maximum. The earthquake in Kamchatka occurred within

a couple of minutes of exactly local solar midnight and was likely triggered

by SFE associated with this flare. None of these events were reported felt.

Recall that an earlier event in Sichuan today of M 5.6 occurred within a couple

of minutes from local solar noon at that epicenter. The earthquake in China

is located at 24 degrees longitude west of the longitude of maximum

tidal stress with the super and full moon of October 7 while the earthquake

in Kamchatka today is symmetrically at 34 degrees east of that longitude.

An M 6.1 on October 3 about 150 km to the east of today's epicenter in Kamchatka

is the only aftershock of M>=6 in this region of Kamchatka since late July 2025.

EMSC reported it was felt with light to moderate intensity in Kamchatka at

Vilyuchinsk, Paratunka, Petropavlovsk-Kamchatsky, and Yelizovo.

Data on the accompanying flare from SWPC follow:

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

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

XXXX 1211 1231 1252 M2.0 (October 10, 2025) 2.8E-02

Kamchatka M 6.0 13:29 UT

Kermadec Is. M 5.2 13:22 UT

Southwest of Africa M 5.2 14:45 UT

XXXX 0509 0517 0522 C1.7 (October 9, 2025) 9.8E-04

China M 5.6 05:17 UT

O: 09OCT2025 13:28:46 51.7N 158.2E MW=6.0 EMSC NEAR EAST COAST OF KAMCHATKA

O: 09OCT2025 13:22:51 34.0S 178.6W MW=5.2 EMSC SOUTH OF KERMADEC ISLANDS

O: 09OCT2025 14:45:05 52.0S 14.6E MW=5.2 EMSC SOUTHWEST OF AFRICA

O: 09OCT2025 15:03:00 52.2S 14.3E MW=5.4 NEIC SOUTHWEST OF AFRICA

O: 09OCT2025 05:17:42 30.9N 99.9E MW=5.5 EMSC WESTERN SICHUAN, CHINA

The strongest earthquake in the U.S. or Canada today was an M 4.5 near Sand Point, Alaska on the Alaska Peninsula.

NEIC reported it was felt with intensity up to III at Sand Point.

NEIC reported an earthquake of M 2.8 in Central California was felt with intensity up to II-III in the area(s) of Central California in Bakersfield with IV.

NEIC reported an earthquake of M 2.9 in Central Alaska was felt with intensity up to II-III in the area(s) of Central Alaska in Salcha (V) and III in Fairbanks and North Pole and II in Eielson AFB.

NEIC reported an earthquake of M 2.5 in San Francisco, California was felt with intensity up to II-III in the area(s) of San Francisco, California with III in San Francisco and II in El Cerrito, Lafayette, Moraga.

NEIC reported an earthquake of M 3.7 in Southern Alaska was felt with intensity up to II-III in the area(s) of Southern Alaska iat Anchorage, Elmendorf AFB.

BMG reported an earthquake of M 5.1 in Bengkulu, Indonesia was felt with intensity up to IV in the area(s) of Bengkulu, Indonesia in Enggaino.

TROPICAL STORM NAKRI (29W)

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

TS NAKRI 2025-10-10 00:00 UT 27.2N 131.6E 45 kts Ryukyu Islands, Japan

Tropical Storm Nakri continued south of the Ryukyu Islands today with winds up to 45 kts. It also made landfall October 8-9 the northern Ryukyu Islands and may promote seismicity in that area at this time. The antipode is at 27S 49W in an area of the South Atlantic and are not seismic.

TROPICAL STORM RAYMOND (17E)

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

TS RAYMOND 2025-10-10 00:00 UT 16.3N 101.9W 55 kts South of Guerrero, Mexico

TS Raymond continued today in area southwest of Guerrero, Mexico with winds up to 55 kts. It is expected to track to the north and west. Regional seismicity in the area of Baja California and the Gulf of California could be enhanced at that time. The antipode is at 16S 78E is in the South Indian Ocean and could see moderately enhanced seismicity while this storm is active.

HURRICANE PRISCILLA

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

HURR PRISCILLA 2025-10-10 00:00 UT 24.7N 114.9W 55 kts Revilla Gigedo Islands, Mexico

Hurricane Priscilla continued today in area southwest of Baja California, Mexico with winds up to 55 kts. It is expected to track to the north. Regional seismicity in the area of Baja California and the Gulf of California could be enhanced at this time. The antipode is at 25S 65E is in the South Indian Ocean and could see moderately enhanced seismicity while this storm is active.

HURRICANE OCTAVE (DEPRESSION 15E)

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

HURR OCTAVE 2025-10-10 00:00 UT 15.9N 114.0W 50 kts South of Baja, Mexico

Hurricane Octave (depression 15E) continued today in the Pacific south of Baja California, Mexico with winds up to 50 kts. It is expected to track to the north and east and not to approach landfall at this time. Regional seismicity is not likely to be enhanced by this storm at this time. The antipode is at 16S 66E is in the South Indian Ocean. This is a minor seismic zone and it could see minor earthquake enhancement in the next several days.

TYPHOON HALONG (DEPRESSION 28W)

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

TYPH HALONG 2025-10-10 00:00 UT 34.1N 149.9E 85 kts East of Honshu, Japan

TROPICAL STORM KAREN

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

TS KAREN 2025-10-10 00:00 UT 45.3N 32.1W 45 kts North Atlantic

Tropical Storm Karen continued today in the area of the north Atlantic. It is expected to dissipate in the next two days and is unlikely to generate enhanced seismicity at this time.

TROPICAL STORM JERRY

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

TS JERRY 2025-10-10 00:00 UT 19.2N 62.5W 50 kts East of Virgin Islands

Tropical Storm Jerry continued today in the area east of Puerto Rico and the Virgin Islands with winds up to 50 kts. It is expected track to the north and east and could enhancement seismicity in the currently active areas of Puerto Rico and the Virgin Islands in the next couple of days. The antipode is at 16S 123E north of Australia and south of Indonesia, an area where seismic enhancement is possible at this time.

A tropical Cyclone may be forming south of Guatemala and Chiapas, Mexico. This system is currently at 15N 93W and tracking to the north and west. It may enhance seismicity in the area of El Salvador, Guatemala and eastern Mexico in the next several days. The antipode is at 15S 87E and is not expected to see seismic enhancement at this time.

Following is the listing of C- M- or X-class flares from SWPC for the date

of October 9, 2025. These listings are published daily in this summary and at SWPC.

The main line gives details of flares. Subsequent lines identify some earthquakes

which are at or after the time of the flare and could have been affected by

immediate Solar Flare Effects (SFE). Some earthquakes occur at longitudes

which were at local solar noon or local solar midnight and may also have

been affected by SFE. These are not identified here.

SOLAR FLARES

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

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

7590 0509 0517 0522 C1.7 (October 9, 2025) 9.8E-04

Sichuan, China M 5.5 05:17 UT

7620 1211 1231 1252 M2.0 (October 9, 2025) 2.8E-02

Kamchatka M 6.0 13:29 UT

Kermadec Is. M 5.2 13:22 UT

Southwest of Africa M 5.2 14:45 UT

Sumatra M 4.3 12:21 UT

7660 1833 1848 1902 C1.3 (October 9, 2025) 2.3E-03

7670 1936 1945 1948 C1.8 (October 9, 2025) 1.1E-03

*indicates modified reading from NOAA GOES Graph

GEOMAGNETIC FIELD: unsettled October 10-12. Solar M-flare chance: 40% X-class: 10% proton storm: 10%

AP Indicies (global, high, mid-latitude, time of max AP, Max AP, Sunspot Number, Radio Flux) 5 3 5 17:00 2 87 122

A strong Gamma Ray Burst was recorded by SWIFT on October 7, 2025 at 19:43:06 UT (#251007B). A preliminary UVOT Magnitude was not assigned to this GRB.

An M 2.1 earthquake in southern Texas occurred at 19:45 UT

A strong Gamma Ray Burst was recorded by SWIFT on October 7, 2025 at 19:36:58 UT (#251007A). A preliminary UVOT Magnitude was not assigned to this GRB.

An M 3.6 earthquake in Veracruz Mexico occurred at 19:38 UT

October 9, 2025

Notable earthquakes and events:

A moderate sized solar flare (C1.7) appears to have led to a moderately

strong earthquake in Sichuan China at noon local solar time on October 9, 2025.

While only a moderate sized solar flare, the C1.7 today is the largest in the past 24 hours with

only one C-class (C1.0) in this time frame. Areas at local solar noon at the

peak output of this flare would be most likely to be affected by Solar Flare

effects (SFE) related to it. In this case the peak of the flare occurred

(according to SWPC) at 05:17 UT so the longitude at local solar noon

is 100 degrees East.

Data on this flare from SWPC follow:

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

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

XXXX 0509 0517 0522 C1.7 (October 9, 2025) 9.8E-04 *

An M 5.6 is now being listed by EMSC as occurring at 05:17 UT in western Sichuan, China within

a couple of minutes of local solar noon. This is the strongest earthquake in the world

in the past 24 hours. Based on its timing and location it is very likely

triggered by the SFE from the solar flare described above.

This is an unusual earthquake. It is the largest event within about 200 km

of this epicenter in at least 35 years. Earthquakes of larger or equal

magnitude hit the region about 300 km to the east on June 9, 2022 (M 5.6 and M 5.9)

and in November 2014 about 300 km south east also with M 5.6 and M 5.9.

An M 5.6 also occurred about 300 km southeast of today's epicenter on

February 23, 2001. No earthquakes of M>=6 have occurred in this extended

radius of 300 km from today's epicenter in the past 35 years.

This earthquake may also have been promoted by tidal stresses with the

full moon of October 7 as it lies near the longitude of maximum tidal

stress with that alignment as described in previous issues of this summary:

Initial reports from NEIC are that this earthquake was damaging in the epicentral area near Daocheng, China.

NEIC reported intensity up to VIII in the epicentral area with four people responding with felt reports.

Typhoon Matmo was dissipating directly south of this event in China when

it occurred. Energy from that storm may have helped promote the earthquakes

at this time.

O: 09OCT2025 05:17:40 30.9N 99.9E MW-5.6 EMSC WESTERN SICHUAN, CHINA

An aftershock of M 4.9 occurred today in the region of western Turkey. NEIC reported intensity III in Balikesir, Izmit, Cinarcik, Istanbul, Turkey and in Sipka Bulgaria with II in Turkey at Mudanya, Bursa, Yakuply, Istanbul.

EMSC reported it was felt with moderate shaking in Turkey at Tavsanli, Usak, Gordes, Bolme, Bigadic, Kutahya, Inegol, Yildirim, Mstafakemalapasa, Bursa, Balikesir among others.

O: 08OCT2025 23:54:05 39.2N 29.1E MW-4.9 NEIC WESTERN TURKEY

The strongest earthquake in the U.S. or Canada today was an M 4.5 in the western Andreanof Islands, Aleutians, Alaska. NEIC reported it was probably felt with intensity up to II in the epicentral area.

NEIC reported an earthquake of M 2.5 in Central California was felt with intensity up to II-III in the area(s) of Central California at the Pinnacles.

This event occurred within a couple of minutes of local solar noon and was likely

promoted by tidal stresses with the full moon of October 7 and/or geomagnetic

stresses which maximize near this hour.

This appears to be an aftershock of an M 3.2 that occurred earlier in the

day near local solar midnight at the same epicenter. It occurred directly

on the San Andreas Fault and may indicate enhanced seismicity in that

area in the near future. This event of M 3.2 was reported

by NEIC to have been felt with intensity III in California at Soledad and II in Salinas, Brisbane, San Bruno and Monterey.

The last earthquake of M>=3.2 within about 50 km of today's event

was listed by NEIC as occurring with M 3.7 on September 1, 2025. At the time

this summary noted:

"A light earthquake of M 3.7 today was widely felt in Central California south of San Francisco. NEIC reported maximum intensity III in Salinas, Carmel Valley, Hollister, San Juan Bautista, and Santa Cruz with II in Irvine, Salinas, Gonzales, Marina, Monterey, Scotts Valley, Watsonville, San Jose, Merced, Modesto, San Ramon, Morgan Hill.

EMSC reported light shaking in Central California at Ridgemark, Hollister, San Juan Bautista, Prunedale, Marina, Santa Cruz, and Oildale.

This earthquake occurred within minutes of local solar noon and may have been

promoted by tidal and/or geomagnetic effects which maximize near this hour.

This event in Central California occurred simultaneously with the start of a major

geomagnetic storm. The GOES magnetometer shows this storm began about 20:30 UT and peaked

at about 21:30 doubling the strength of the geomagnetic field at GOES altitudes

by about double and was responsible for a geomagnetic storm with AP of 6.

The coincidence of this storm at local solar noon with the earthquakes

Central California strongly suggest the earthquake was triggered by this storm.

The last earthquake in Central California within about 100 km of this epicenter

with M>=3.7 occurred on February 22, 2025 with M 3.9 and prior to that on September 29, 2024 (M 4.2).

At the time of the February, 2025 event this summary noted:

"The series in the Salinas area of central California continued today. The largest of these was an M 3.9 which NEIC reported was felt with intensity IV in California at Paicines and III in Salinas, Gonzales, Marina, Seaside, Sunnyvale, Hayward, Aptos, Hollister, San Juan Bautista, Santa Crus with III in Fresno, Carmel, Montery, Soledad, Felton, Scotts Valley and Watsonville.

"NEIC reported earthquakes up to M 3.3 in Central California were felt with intensity up to II-III in the area(s) of Central California with intensity II-III in Salinas, Gonzales, Marina, Monterey and II in Fresno and Carmel, California.

Larger earthquakes in this slipping section of the San Andreas often come in series of events with

M3-4 but seldom much larger. This can be expected with today's activity." (February 22, 2025)

and in September, 2024 as:

A moderate earthquake of M 4.2 shook the region south of San Francisco, California today. NEIC reported it was felt with intensity IV in Salinas and King City and III in Carmel, Carmel Valley, Kerman and Fresno, California.

This follows a pair of moderate earthquakes off the coast of northern California

yesterday of M 5.1 and 4.6

...

This epicenter in Central California is at the longitude of maximum tidal stress

with the coming new moon of October 2, 2024 and could indicate a busy week

in regional seismicity with the new moon" (September 29, 2024, September 1, 2025)

These epicenters area at 102-103 degrees from the M 7.0 in Leyte, Philippines

and may have been promted by energy from that source.

O: 08OCT2025 19:59:18 36.5N 121.2W MW-2.5 NEIC CENTRAL CALIFORNIA

O: 08OCT2025 09:46:19 36.6N 121.2W MW-3.2 NEIC CENTRAL CALIFORNIA

An M 3.4 was widely felt in northern Hawaii today. NEIC reported intensity up to IV in Hawaii at Kapaau with III in Hawi, Honokaa, Waikoloa and Kamuela.

O: 08OCT2025 17:23:53 20.0N 155.8W MW-3.4 NEIC HAWAII REGION

NEIC reported an earthquake of M 2.8 in Washington State was felt with intensity up to II-III in the area(s) of Washington State in Seattle, Kingston and Port Angeles.

NEIC reported an earthquake of M 2.6 in Southern California was felt with intensity up to II-III in the area(s) of Southern California with III in Desert Hot Springs, Joshua Tree and Yucca Valley and II in Pasadena, Morongo Valley.

NEIC reported earthquakes of M 2.7 and M 2.5 in California-Nevada border were felt with intensity up to II-III in the area(s) of California-Nevada border at Minden Nevada and San Francisco, California.

NEIC reported an earthquake of M 2.8 in Utah was felt with intensity up to II-III in the area(s) of Utah with III in Heber City, Orem, Provo and II in Springville.

NEIC reported an earthquake of M 4.0 in Southern Alaska was felt with intensity up to II-III in the area(s) of Southern Alaska wit III in Girdwood, homer and II in Anchorage and Anchor Point.

EMSC reported an earthquake of M 4.7 in Luzon, Philippines was felt with intensity up to IV in the area(s) of Luzon, Philippines in Baguio, Binalonan, San Fernando.

TROPICAL STORM NAKRI (29W)

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

TS NAKRI 2025-10-09 00:00 UT 24.1N 134.8E 45 kts Ryukyu Islands, Japan

Tropical Storm Nakri continued south of the Ryukyu Islands today with winds up to 45 kts. It also made landfall October 8-9 the northern Ryukyu Islands and may promote seismicity in that area at this time. The antipode is at 27S 48W in an area of the South Atlantic and are not seismic.

HURRICANE PRISCILLA

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

HURR PRISCILLA 2025-10-09 00:00 UT 22.3N 113.3W 70 kts Revilla Gigedo Islands, Mexico

Hurricane Priscilla continued today in area southwest of Baja California, Mexico with winds up to 70 kts. It is expected to track to the north. Regional seismicity in the area of Baja California and the Gulf of California could be enhanced at this time. The antipode is at 22S 67E is in the South Indian Ocean and could see moderately enhanced seismicity while this storm is active.

HURRICANE OCTAVE (DEPRESSION 15E)

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

HURR OCTAVE 2025-10-09 00:00 UT 15.9N 114.0W 50 kts South of Baja, Mexico

TYPHOON HALONG (DEPRESSION 28W)

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

TYPH HALONG 2025-10-09 00:00 UT 33.6N 143.6E 115 kts Izu Islands, Japan

Typhoon Halong (28W) continued today in the area east of the Izu Islands, Japan with winds up to 115 kts. This system is moving to the northeast and could help promote seismicity in the Izu Islands north to Honshu in the next day. It will turn to the east around October 8 and could promote a moderate to large earthquake in that area east of Japan at the time. The current antipode is at 34S 37W in the South Atlantic and is not expected to see enhanced seismicity at this time.

TROPICAL STORM JERRY

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

TS JERRY 2025-10-09 00:00 UT 15.7N 57.7W 65 kts East of western Caribbean

Tropical Storm Jerry continued today in the area west of Guadeloupe and the Leeward Islands with winds up to 65 kts. It is expected track to the north and west and could enhancement seismicity in the currently active areas of Puerto Rico and the Virgin Islands in the next couple of days. The antipode is at 16S 123E north of Australia and south of Indonesia, an area where seismic enhancement is possible at this time.

Following is the listing of C- M- or X-class flares from SWPC for the date

of October 8, 2025. These listings are published daily in this summary and at SWPC.

The main line gives details of flares. Subsequent lines identify some earthquakes

which are at or after the time of the flare and could have been affected by

immediate Solar Flare Effects (SFE). Some earthquakes occur at longitudes

which were at local solar noon or local solar midnight and may also have

been affected by SFE. These are not identified here.

SOLAR FLARES

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

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

XXXX 0509 0517 0522 C1.7 (October 9, 2025) 9.8E-04

China M 5.6 05:17 UT

7520 0431 0437 0441 C1.9 (October 8, 2025) 8.8E-04

Los Lagos M 3.7 04:33 UT

7530 0504 0515 0529 C1.0 (October 8, 2025) 1.4E-03

Virgin Islands M 3.7 05:12 UT

Halmahera M 4.7 05:20 UT

7560 1236 1248 1302 C1.2 (October 8, 2025) 1.7E-03

Kuril Is. M 4.4 12:41 UT

Leyte M 3.5 12:42 UT

*indicates modified reading from NOAA GOES Graph

GEOMAGNETIC FIELD: unsettled October 9-11. Solar M-flare chance: 40% X-class: 10% proton storm: 10%

AP Indicies (global, high, mid-latitude, time of max AP, Max AP, Sunspot Number, Radio Flux) 11 18 9 17:00 5 109 131

A strong Gamma Ray Burst was recorded by SWIFT on October 7, 2025 at 19:43:06 UT (#251007B). A preliminary UVOT Magnitude was not assigned to this GRB.

An M 2.1 earthquake in southern Texas occurred at 19:45 UT

A strong Gamma Ray Burst was recorded by SWIFT on October 7, 2025 at 19:36:58 UT (#251007A). A preliminary UVOT Magnitude was not assigned to this GRB.

An M 3.6 earthquake in Veracruz Mexico occurred at 19:38 UT

October 8, 2025

Notable earthquakes and events:

Seismicity today was marked by enhanced earthquakes near 120 East longitude,

a latitude where the maximum tidal stresses with the full moon of October 7

had been expected. The longitudes from about 95E to 145E are the most likely

affected by these tidal stresses as noted in previous issues of this summary:

Moderate earthquakes today were recorded as an M 4.4 and M 5.3 in Taiwan (121E); an M 4.9 in the northern Ryukyu Islands, Japan (129E)

These follow a strong M 6.7 in Papua New Guinea (146E) and a series off northeastern

Honshu, Japan of M 5.0-5.5 (144E) which were discussed in the previous

issue of this summary. Readers are referred to that as reference.

In the previous issues of this summary a small experiment was performed.

Within minutes of a C9.1 solar flare this summary issued a "prediction" for

a minor earthquake in the area of Central California, and expecially in the

area near San Francisco as follows:

"A moderately large solar flare of C9.1 class has just occurred (at 20:00 UT).

The area of California is near local solar noon at this time. In recent days

moderate flares such as this have been followed by light to moderate felt earthquakes

in California. These have often occurred about an hour later in the San Francisco Bay region with M 2.0-3.0.

If such an earthquake occurs in the next two hours, it should come as no

surprise to readers of this summary.

Data on this flare from SWPC follow:

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

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

7510 1955 2007 2021 C9.1 (October 7, 2025) 8.3E-03*

Molucca Sea M 4.3 20:20 UT

" (October 7, 2025)

Within an hour after this prediction was first issued publicly in this summary

an earthquake of M 2.1 did occur in the general area of San Francisco, California,

consistent with the expected earthquake as follows:

O: 07OCT2025 21:36:04 37.5N 121.7W MB=2.1 NEIC SAN FRANCISCO, CALIFORNIA

This is the first "prediction" for an event within a limited area and time

of this type made in this summary. But it was based on data. In the past month

the largest earthquakes in this area have generally occurred within about

an hour of local solar noon, occasionally in conjunction with a C- or higher class

solar flare. These included the following:

9 10 20 27 45 2025 36.532 -121.158 7.4 2.8 10

9 15 22 0 8 2025 37.941 -121.850 7.5 3.3 10

9 17 22 39 39 2025 38.114 -121.805 4.9 2.2 10

9 24 19 4 9 2025 38.128 -122.159 3.0 2.1 10

9 28 21 12 37 2025 37.843 -121.997 9.1 2.1 10

9 29 23 32 23 2025 37.422 -121.896 2.1 2.2 10

9 30 18 26 16 2025 37.589 -122.467 9.5 2.4 10

9 30 18 27 51 2025 36.559 -121.117 8.7 2.0 10

10 2 19 40 37 2025 38.124 -122.159 2.9 2.1 10

10 4 21 20 55 2025 37.592 -122.465 9.1 2.2 10

10 7 21 36 4 2025 37.451 -121.718 16.5 2.1 10

10 8 18 50 9 2025 36.893 -121.616 1.0 2.0 10

10 8 19 59 18 2025 36.572 -121.202 5.4 2.5 10

Of the 35 events in the past month of M>=2.1 fourteen occurred within about

1.5 hours of local solar noon. For this time frame of three hours in a random

sample only 4-5 would be expected, so this is well above the expected

number suggesting a periodic trigger may be involved - perhaps tidal stresses.

The strongest earthquake in the world today was an M 5.7 in Central Vanuatu. It was not reported felt in this area.

This earthquake occurred near local solar noon and may have been promoted

by today's full moon tidal stresses.

This epicenter is at 102 degrees from the North Geomagnetic pole and 52 degrees from

the South Geomagnetic pole and may have been promoted by energy associated with the recent strong geomagnetic storm. It is also at the

seventh node (51 degrees) from the M 7.0 in Leyte Philippines and may have

been promoted by energy associated with that source.

O: 07OCT2025 22:36:21 15.6S 168.2E MB=5.7 NEIC VANUATU

The second strongest earthquake in the world today was an M 5.4 in the South Sandwich Islands region. It was not reported felt in this remote epicentral area.

This continues a series of moderately strong earthquakes in this region nearly

antipodal to Kamchatka which have been occurring since the major earthquakes

in Kamchatka began in July, 2025. The last of the moderately large earthquakes

in this region of the South Sandwich Islands occurred on September 19, 2025 with

M 5.4. At the time this summary noted:

"The current swarm of earthquakes in and near the South Sandwich Islands south of South America continued today. An M 5.0 at a new epicenter was recorded but not reported felt east of the South Sandwich Islands but about 100 km north of a swarm recorded earlier on September 19.

This joins a series of earthquakes earlier in the day southeast of this as reported

in the previous issue of this summary:

"The Scotia Sea is not the only seismic active area nearly antipodal to the

area of Kamchatka, Russia. The most active area in this region is the South

Sandwich Islands. Early on September 19 a series of moderate to moderately

large earthquake hit this region, but because of its remoteness were not

reported felt. These events began with an M 5.4 and were followed by events of M 4.8 and M 4.9.

The South Sandwich Islands often show enhanced seismicity with major

events in Kamchatka but today's events occurred further to the west

than typical moderate earthquakes in the area and are closer to antipodal

to Kamchatka than usual. An event of M<=5.4 hit this far to the east in the

South Sandwich Islands last on February 14, 2024 with M 5.4 and M 5.7. But this

is the exception not the rule for moderately large seismicity in the

South Sandwich Islands. At the time this summary noted:

"A moderately large earthquake also occurred today in the South Sandwich Islands

with M 5.7. It was followed by an aftershock of M 5.2 twelve minutes later

which was probably triggered by PcS reflections from the mainshock. These

are seismic pulses which reflect off the core back to the original epicenter.

Larger aftershocks often occur at this time after the mainshock in most areas

of the world (also see ScS and PcP times near 8 and 15 minutes after the mainshock).

The last earthquake with M>=5.7 within about 200 km of today's epicenter occurred asan

M 5.8 on November 30, 2023. At the time this summary noted:

"The strongest earthquake in the world today was an M 5.8 in the South Sandwich Islands. This event was not reported felt in this remote area.

A major earthquake of M 7.5 hit about 200 km southeast of today's epicenter on August 12, 2021 but hte last

earthquake within this range of today's event with equal of larger magnitude

was recorded on August 18 and December 7, 2021 with M 5.8-5.9.

Today's event was probably promoted by geomagnetic effects which maximize

near the geomagnetic equator and at high latitudes." (December 1, 2023)

This is similar environmental conditions as current and is probably related

to the timing of earthquakes in this area." (February 14, 2024, September 18-19, 2025)

Today's events in the South Sandwich Islands area in the antipodal area of

the major events in Kamchatka and may have been promoted by energy from that source." (September 19, 2025)

O: 08OCT2025 03:50:46 57.8S 24.2W MB=5.4 NEIC SOUTH SANDWICH ISLANDS REGION

An M 5.1 also occurred today in Taiwan near the longitude of maximum tidal stress with

the full moon of October 7. NEIC reported it was felt with intensity V in Hualien, Taiwan. But CWB.

the local Taiwanese seismic network recorded two separate events of M 5.0 each.

The later of these was reported by CWB with intensity III in Hualien and Taitung Counties with I in Nantou, Yilan, Taichung, Chiayi, Changhua, Hsinchu and Tainan Counties.

The first was reported with IV in Hualien County and III in Nantou; II in Taichung, Yilan and Yunlin and I in Taitung, Taoyuan, Chiayi, Hsinchu, Changhua, Miaoli, Taipei, Tainan, Kaohsiung and Pingtung Counties, Taiwan.

The last earthquake NEIC listed in Taiwan with M>5.1 occurred as an M

5.3 on August 27, 2025. At the time this summary noted:

"A moderately strong earthquake of M 5.3 (EMSC) to M 6.0 (CWB) occurred today in northern Taiwan. NEIC reported it was felt with intensity IV in Taiwan at Ilan, Taipei; III in Hsinchu, and II in Changhwa and Taichung.

CWB reported intensity IV in Yilan, Taipei, III in Taoyuan, Hualien, Hsinchu, Miaoli, Nantou and II in Keelung City, Changhua, Yunlin, Chiayi, Taitung, Tainan and Kaohsiung areas.

Taiwan has been hit by several typhoons in the past week included Lingling

and Kajiki and may have been set up for this seismicity by energy from those events.

This epicenter is at 144 degrees from the M 7.5 in the Drake Passage of

August 22 and was probably promoted by energy from that source.

The last earthquake of M>=6 in Taiwan occurred as an M 6.0 on January 20, 2025.

At the time this summary noted:

"The strongest earthquake in the world today was an M 6.0 (CWB gives this M 6.4) in Taiwan. NEIC reported this earthquake was felt with damage and intensity up to VIII in Taiwan at Tainan with VI in Chiayi, Nantou, Taichung, Yunlin; V in Changhua, Chiayi, Hsinchu, JKaohsiung, Nantou, Pngtung, IV in Taipei, Taoyuan, and III in mainland China in Fujian, Hong Kong, Hangzhou and Hefei among others.

EMSC reported significant shaking in Zhongpu Township, Beigang, Wuri District, Nantun District, Zhudong, Zhongzheng, Da'an, Beitou, Tamsui, and Yuanshan Townships and in Fuzhou Citym China,

TAI reported intensity VI in Chiayi, V in Tainan, Kaohsiung; IV in Chiayi, Yunlin, Taitung, Nantou, Pingtung, Hualien, Changhua, Taichung, Penghu, III in Miaoli, Yilan, Hsinchu; II in Taoyuan, Taipei, and Lienchiang Counties, Taiwan.

A number of aftershocks were recorded - up to 50 at this writing. A fire broke out in a printing facility in Chiayi City but there were no reports

of injuries with this fire.

News reports are that some TSMC, a computer chip maker, closed its plant down due to the

earthquake. Shaking can cause errors in computer chips and adjustment

following earthquakes is often necessary. Initial reports indicate up to 27 injuries in mountainous areas and damage to

items falling. Six were rescued from a collapsed house in Nanxi District in Tainan City. The Zhuwei Bridge was also damaged. The earthquake occurred near local solar midnight and was probably

promoted by strong tidal and/or geomagnetic effects which maximize near this hour.

The last earthquake in Taiwan of M>=6.4 within about 250 km of today's

epicenter occurred on April 4, 2024 as an M 7.4 with an aftershock of M 6.4 on

April 3, 2024. At the time this summary noted:

"A major M 7.4 earthquake damaged much of the Island of Taiwan today. International Press reports indicated that this event and several

strong aftershocks killed at least 7 while injuring more than 700. The quake

occurred about 20 km south of Hualien and damaged and toppled buildings while

causing many damaging landslides. It is the strongest earthquake to hit

Taiwan in at least 25 years - since September 20, 1999 (M 7.7) - the strongest

event in Taiwan in the past 35 years. Major earthquakes have most recently

hit with M>=7.5 in Taiwan on November 14, 1986 (M 7.8); July 24, 1978 (M 8.0); April 24, 1972 (M 7.7) and January 25, 1972 (M 7.7)." (April 3, 2024, January 20, 2025, August 29, 2025)

This epicenter may have been promoted by energy from the last geomagnetic

storm as it lies at the fourth node (909 degrees) from the South Geomagnetic Pole and

at the sixth node (60 degrees) from the North Geomagnetic pole.

O: 07OCT2025 23:52:12 23.9N 121.6E ML=5.1 NEIC HUALIEN, TAIWAN

O: 07OCT2025 23:52:12 24.0N 121.5E ML=5.0 CWB HUALIEN, TAIWAN

O: 08OCT2025 03:33:54 23.5N 122.0E ML=5.0 CWB HUALIEN, TAIWAN

A moderate earthquake of M 4.6 occurred in southern Peru today. NEIC reported it was probably felt with light intensity in the area of San Juan, Peru.

This event is at the antipode of the dissipation of Typhoon Matmo.

"TYPH MATMO 2025-10-06 00:00 UT 19.0N 108.4E 80 kts Vietnam" (October 6, 2025)

Typhoon Matmo continued today making landfall in Vietnam with winds up to 80 kts. It is made landfall October 3 in Luzon and northern Philippines as a typhoon. Regional seismicity and aftershocks from the Leyte M 7.0 event occurred in northern Luzon as this storm passed through. The antipode is at 19S 72W in an area of northern Chile and southern Peru where seismicity could be enhanced at this time." (October 6, 2025)

Typhoon Berloi also dissipated over the antipode to this epicenter in Peru

early in October and may have contributed energy helping promote today's event in Peru as described at the time:

"Typhoon Burloi (26W) continued today after making landfall in Vietnam with winds up to 100 kts where it did considerable damage. It is expected to track to the west in the next several days dissipating in the next two days. . The Antipode at 18S 74W ... will pass over southern Peru and Tarapaca and Arica, Chile and elevated seismicity is likely in that area in the next several days." (September 29-October 1, 2025)"

O: 07OCT2025 23:00:06 16.0S 75.4W ML=4.6 NEIC SOUTHERN PERU

Another of the moderate to moderately strong earthquakes near 124 East longitude,

occurred today as an M 5.3 in the northern Ryukyu Islands of Japan. It was not

reported felt in this epicentral area. The last earthquake within about 200

km of this epicenter with M>=5.3 occurred at the end of a swarm of moderately

strong earthquakes in late June to early July, 2025 as an M 5.5 on July 6, 2025.

"A moderately strong earthquake of M 5.6 occurred in the currently active swarm in the northern Ryukyu Islands, Japan. NEIC reported it was felt with intensity II in Kagoshima, Japan.

This event is the largest in a series of events of M>=5 in the region today. Some of these may

have been felt in Kagoshima and the northern Ryukyu Islands. The swarm has been

active for at least a week and could see a strong tsunamigenic earthquake

in the next week. This may be related to an eruption of Shinmoedake volcano in Takaharu in Miyazaki Prefecture

which has been ongoing during this period." (July 6, 2025)

O: 07OCT2025 21:38:37 29.2N 129.4E ML=5.3 NEIC RYUKYU ISLANDS, JAPAN

NEIC reported an earthquake of M 3.4 in Northern Nevada was felt with intensity up to II-III in the area(s) of Northern Nevada with III in Winnemucca.

TROPICAL STORM NAKRI (29W)

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

TS NAKRI 2025-10-08 00:00 UT 27.1N 131.8E 45 kts Ryukyu Islands, Japan

Tropical Storm Nakri continued south of the Ryukyu Islands today with winds up to 45 kts. It also made landfall October 8-9 the northern Ryukyu Islands and may promote seismicity in that area at this time. The antipode is at 27S 48W in an area of the South Atlantic and are not seismic.

HURRICANE PRISCILLA

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

HURR PRISCILLA 2025-10-08 00:00 UT 20.0N 110.0W 100 kts Revilla Gigedo Islands, Mexico

Hurricane Priscilla continued today in area over the Revilla Gidedo Islands south of Baja California, Mexico with winds up to 100 kts. It is expected to track to the north and west. Regional seismicity in the area of Baja California and the Gulf of California could be enhanced at this time. The antipode is at 19S 71E is in the South Indian Ocean and could see moderately enhanced seismicity while this storm is active.

HURRICANE OCTAVE (DEPRESSION 15E)

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

HURR OCTAVE 2025-10-08 00:00 UT 16.9N 120.0W 55 kts South of Baja, Mexico

Hurricane Octave (depression 15E) continued today in the Pacific south of Baja California, Mexico with winds up to 55 kts. It is expected to track to the north and east and not to approach landfall at this time. Regional seismicity is not likely to be enhanced by this storm at this time. The antipode is at 16S 60E is in the South Indian Ocean. This is a minor seismic zone and it could see minor earthquake enhancement in the next several days.

TYPHOON HALONG (DEPRESSION 28W)

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

TYPH HALONG 2025-10-08 00:00 UT 28.1N 137.3E 140 kts West of Bonin Islands, Japan

Typhoon Halong (28W) continued today in the area west of the Bonin Islands, Japan with winds up to 140 kts. This system is moving to the northeast and could help promote seismicity in the Bonin Islands north to Honshu in the next day. It will turn to the east around October 8 and with the full moon could promote a moderate to large earthquake in that area of Japan at the time. The current antipode is at 28S 43W in the South Atlantic and is not expected to see enhanced seismicity at this time.

TROPICAL STORM JERRY

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

TS JERRY 2025-10-08 00:00 UT 14.0N 52.5W 60 kts Northern Mid-Atlantic Ridge

Tropical Storm Jerry continued today in the area of the North mid-Atlantic Ridge with winds up to 55 kts. This system is moving to the northwest and could help promote seismicity in the northeastern Caribbean at this time. It will track to the west reaching the Virgin Islands as a hurricane around October 10 and could promote a moderate earthquake in that area of of the north-eastern Caribbean at the time. The current antipode is at 16S 123E in the region north of Australia where light earthquakes could occur at this time.

Following is the listing of C- M- or X-class flares from SWPC for the date

of October 6, 2025. These listings are published daily in this summary and at SWPC.

The main line gives details of flares. Subsequent lines identify some earthquakes

which are at or after the time of the flare and could have been affected by

immediate Solar Flare Effects (SFE). Some earthquakes occur at longitudes

which were at local solar noon or local solar midnight and may also have

been affected by SFE. These are not identified here.

SOLAR FLARES

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

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

7460 1100 1129 1134 C5.6 (October 7, 2025) 2.5E-03*

Papua New Guinea M 6.6 11:05 UT

New Zealand M 3.5 1:12 UT

Hindu Kush M 5.1 11:35 UT

Central California M 2.3 11:19 UT

7510 1955 2007 2021 C9.1 (October 7, 2025) 8.3E-03*

Molucca Sea M 4.3 20:20 UT

*indicates modified reading from NOAA GOES Graph

GEOMAGNETIC FIELD: minor storms October 8 unsettled October 9-10. Solar M-flare chance: 40% X-class: 10% proton storm: 10%

AP Indicies (global, high, mid-latitude, time of max AP, Max AP, Sunspot Number, Radio Flux) 15 33 14 15:00 6 67 120

A strong Gamma Ray Burst was recorded by SWIFT on October 7, 2025 at 19:43:06 UT (#251007B). A preliminary UVOT Magnitude was not assigned to this GRB.

An M 2.1 earthquake in southern Texas occurred at 19:45 UT

A strong Gamma Ray Burst was recorded by SWIFT on October 7, 2025 at 19:36:58 UT (#251007A). A preliminary UVOT Magnitude was not assigned to this GRB.

An M 3.6 earthquake in Veracruz Mexico occurred at 19:38 UT

A strong Gamma Ray Burst was recorded by SWIFT on October 5, 2025 at 16:06:53 UT (#251005C). A preliminary UVOT Magnitude of V>19.4 was assigned to this GRB.

An immediate M 3.8 in the Guatemala coincided with this GRB. An M 5.1 earthquake

Kamchatka occurred five minutes earlier.

October 7, 2025

Notable earthquakes and events:

The full moon (Supermoon) arrived today (October 7, 2025) at 03:47 UT. This

summary had previously anticipated this alignment's effect on global seismicity

as:

Seismicity in the world today reflected this expectation. The largest earthquake

in the world was an M 6.6-6.7 in New Guinea at 146 East longitude near the maximum

expected tidal stress longitude. This was preceded by a strong swarm in the

eastern Caribbean with moderate quakes in Puerto Rico and the Virgin Islands (at 64-67 West longitude).

A swarm of events with magnitude up to M 5.1 also occurred off the coast of

Honshu, Japan (at 144 East longitude) following an M 4.9 in the Leyte, Philippines

aftershock zone (at 124 East longitude) and an M 4.1 in the Bonin Islands,

Japan (at 144 East longitude). These and other events today probably

were promoted by tidal stresses associated with today's super (full) moon.

The strongest earthquake in the world today was an M 6.6-6.7 in Papua New Guinea

east of Indonesia. NEIC reported it was felt in Papua New Guinea with maximum intensity VI in the Eastern Highlands at Kainantu and IV in Goroka, and Mount Hagen and V in the Morobe area at Lae, Wau and in the national Capital at Port Moresby with IV. Also felt with III in the north Solomons at Panguna and II in Balimo, Fly River and Kundiawa, Simbu, Papua New Guinea.

EMSC reported strong shaking in Papua New Guinea at Lae, Popondetta, Port Moresby.

This is the strongest earthquake within about 200 km of this epicenter since

a pair of events of M 6.7 and M 6.9 on October 7, 2023, exactly two years ago today. At the time this

summary noted:

"The strongest earthquake in the world today was an M 6.9 in Papua New Guinea.

It was followed by an M 6.7 and several moderate events of M>=5.

An M 5.1 aftershock was felt in Madang and Port Moresby, Papua New Guinea.

Other events in the series were not initially given intensities by NEIC however some felt data

comes from Madang, PNG. No tsunami was reported as this epicenter is inland near

the coast.

...

The earthquakes in New Guinea coincided with a moderate solar flare (#5480)

and may have been promoted by SFE associated with that flare.

...

An M 7.0 occurred about 350 km north of today's epicenter on April 2, 2023.

At the time this summary noted:

"The last earthquake of M>=6 in this area of Papua was an M 6.0 on January 18, 2020.

but no earthquake larger size than this have been recorded in this area since

an M 6.7 on January 10, 2002. ... This epicenter is at 103 degrees from the mainshocks in

Turkey and was probably promoted by energy from those sources." (February 9, 2023, April 2, 2023, October 7, 2023)

Today's event occurred shortly after the full moon arrived with maximum stress

in this area and near the geomagnetic equator.

A foreshock of M 4.9 south of this epiceter occurred earlier in the day. NEIC reported it

was felt iwth intensity III in Port Moresby, Papaa New Guinea.

This earthquake may have also been promoted by SFE from a moderately strong

solar flare as it occurred at the beginning of that C5.6 flare. Preliminary

data from SWPC for this flare follow:

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

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

XXXX 1100 1129 1134 C5.6 (October 7, 2025) 2.5E-03*

Papua New Guinea M 6.6 11:05 UT

Hindu Kush M 5.1 11:35 UT

Central California M 2.3 11:19 UT

This epicenter was at the antipode to Tropical Storm Jerry two days ago as noted

in this summary:

"TS JERRY 2025-10-07 00:00 UT 12.0N 44.5W 45 kts Northern Mid-Atlantic Ridge

Tropical Storm Jerry continued today in the area of the North mid-Atlantic Ridge with winds up to 45 kts. This system is moving to the northwest and could help promote seismicity in the northern mid-Atlantic at this time. It will track to the west reaching the Virgin Islands as a hurricane around October 10 and could promote a moderate earthquake in that area of of the north-eastern Caribbean at the time. The current antipode is at 12S 135E in the region of New Guinea. This storm passed over 8N 35W two days ago. This is antipodal to the epicenter of the M 6.6 in New Guinea today and may have helped promote that event. Further antipodal activity is possible as this storm tracks to the west." (October 6-7, 2025)

and

"A moderate M 5.0 earthquake occurred in the northern Mid-Atlantic today. It

was not reported felt in this remote area. It occurred as a new tropical

cyclone was passing over the epicenter as reported in this summary:

"A tropical cyclone may be forming in the northern Mid-Atlantic region. This system is currently located by NHC at 13N 44W and moving to the west with winds up to 30 kts. NHC gives this 70% chance of developing into a tropical storm in the next several days." (October 6, 2025)

O: 06OCT2025 05:10:03 13.2N 44.6W MB=5.0 NEIC NORTHERN MID-ATLANTIC" (October 6, 2025)

Today's epicenter in New Guinea is at the sixth node (60 degrees) from

major earthquakes in Kamchatka and like many other recent earthquakes at this

distance from Kamchatka was likely promoted by energy from that source.

It was also likely promoted by the recent major geomagnetic storm as it

lies at the sixth node from the South Geomagnetic Pole and at the fourth node

(90 degrees) from the North Geomagnetic Pole.

O: 07OCT2025 11:05:17 6.8S 146.8E Mw=6.6 NEIC PAPUA NEW GUINEA

O: 07OCT2025 11:05:17 6.8S 146.8E Mw=6.7 EMSC PAPUA NEW GUINEA

O: 06OCT2025 17:11:08 8.1S 148.5E Mw=4.9 NEIC PAPUA NEW GUINEA

A light earthquake series occurred today in the Tonopah, Nevada area. The maximum magnitude in this series was an M 3.7. NEIC reported it was probably felt in the Tonopah, Nevada area with intensity up to III.

This epicenter is at 104 degrees from the M 7.0 in Leyte, Philippines and

was probably promoted by energy from that source.

O: 07OCT2025 09:14:40 38.4N 116.5W Mw=3.7 NEIC NEVADA

Two series of earthquakes also occurred today in the areas of the eastern Caribbean near the

Virgin Islands and near southern Puerto Rico and were probably promoted by the

full moon tides. The events in Puerto were reported by NEIC to have been

felt with intensity up to II in Sabana Grande, Puerto Rico Arroyo and Cauguas

and III in Ensenada.

O: 06OCT2025 16:50:51 19.1N 64.7W Mw=3.6 NEIC VIRGIN ISLANDS

O: 07OCT2025 05:46:14 19.3N 64.8W Mw=3.8 NEIC VIRGIN ISLANDS

O: 07OCT2025 05:19:11 17.8N 66.9W Mw=3.6 NEIC PUERTO RICO

O: 07OCT2025 02:01:20 17.8N 66.9W Mw=3.7 NEIC PUERTO RICO

On the other side of the world near local solar noon with the full moon, an M 4.9

occurred near Santa Monica, Philippines. This followed an M 4.8 in Mindanao,

Philippines minutes earlier. NEIC did not reported felt information for

either of these earthquakes but PHIVOLCS reported intensity IV in the City of Bogo, Cebu, Philippines. An earthquake of M 4.9 in the Panay/Cebu region of the Philippines,

however, was reported to have been felt with intensity II in Bayawan, Central Visayas, Philippines.

PHIVOLCS reported the M 5.1 in Panay with intensity III in City of Sipalay and Cauayan, ?Negros Occidental; II in the city of Iloilo, and I in Candoni, Negros Occidental.

O: 07OCT2025 04:55:50 10.1N 126.5E Mw=4.9 NEIC PHILIPPINE ISLANDS

O: 07OCT2025 04:14:03 5.5N 126.4E Mw=4.8 NEIC MINDANAO, PHILIPPINE ISLANDS

O: 07OCT2025 00:03:59 10.0N 122.1E Mw=4.9 NEIC PANAY, PHILIPPINE ISLANDS

O: 07OCT2025 00:03:59 9.9N 122.0E Mw=5.1 PHIV NEGROS OCCIDENTAL, PHILIPPINE ISLANDS

A strong series of moderate earthquakes also occurred off the eastern Coast of

Honshu, Japan today. These had been expected at this time in this summary (see above)

with the full moon. The largest of these was an M 5.1 which occurred far east

of Honshu and was accompanied by a series of moderate foreshocks and aftershocks.

Some of these including an M 5.1 nearer the coast of Japan were widely felt as

reported by NEIC with III in Fukushima, Ibaraki, Miyagi, Tochigi Prefectures

and II in Kanagawa, and Tokyo and specifically in Tokyo, Komae, Tomiya, Kawasaki, Narashino, Itsunomiya, Sendai, Mito and Koriyama.

Some of these including an M 4.9 and M 4.8 ocurred near local midnight

and may have been promoted by tidal and/or geomagnetic stresses which maximize

near this hour. The last earthquake of M>=5 in this area off eastern Honshu

this far to the east was an M 5.5 on August 7, 2018. and before that an M 5.8 on

November 12, 2017. At the time this summary noted:

"A moderately large earthquake of M 5.6 occurred off the east coast of Honshu, Japan today. This

epicenter is near that of the great quake of March 11, 2011 (M>9). NEIC reported

today's earthquake was felt with intensity II-III in Natori and Sendai, Miyagi; in Ibaraki in Hitachi, Tokai, Naka, Toride and in Tokyo, Japan.

Today's activity had been expected in the previous issue of this summary and prior

to that as a promoted quake from Typhoon Shanshan which passed over today's

epicenter today as:

"As TS Shanshan moves north it may encounter the Kuril Islands around August 9-10 but this is unlikely since

it is expected veer to the east after reaching Tokyo. A moderate to strong induced earthquake

in the region of Tokyo is possible as Shanshan passes by the area." (August 5-6, 2018)

The last earthquake of M>=5.6 within about 200 km of this epicenter was an M 5.8 on November 12, 2017 and prior to that events of M 6.0 and 6.1 on October 6, 2017 and September 20, 2017." (August 7, 2025)

This activity in Japan could also be related to a strong typhoon with winds up to

140 kts currently south of Honshu (Typhoon Halong). This summary in this

and previous issues had identified the risk to Honshu from this storm as:

"TYPH HALONG 2025-10-07 00:00 UT 28.1N 137.3E 140 kts West of Bonin Islands, Japan

These earthquake are located at 102 degrees from the South Geomagnetic Pole

and were probably promoted by energy from the recent major geomagnetic storm.

O: 07OCT2025 01:42:51 37.7N 144.1E Mw=4.6 NEIC OFF EAST COAST OF HONSHU, JAPAN

O: 06OCT2025 18:25:05 37.9N 144.1E Mw=4.7 NEIC OFF EAST COAST OF HONSHU, JAPAN

O: 06OCT2025 14:57:59 37.8N 144.2E Mw=4.9 NEIC OFF EAST COAST OF HONSHU, JAPAN

O: 06OCT2025 14:20:28 37.8N 144.0E Mw=4.8 NEIC OFF EAST COAST OF HONSHU, JAPAN

O: 06OCT2025 20:02:43 27.3N 140.2E Mw=4.1 EMSC BONIN ISLANDS, JAPAN

A moderately strong earthquake of M 5.6 also occurred today in the Fiji Islands

at a deep focus. NEIC did not report any felt effects for this remote earthquake.

This earthquake occurred within a few minutes of local solar midnight and was probably

promoted by strong tidal stresses associated with today's full moon which

maximize near this hour.

This epicenter is located at the sixth node (60 degrees) from the Leyte, Philippines

M 7.0 and was probably promoted by energy from that source. It is also at

the seventh node from the South Geomagnetic Pole (51 degrees) and was

likely promoted by energy from the last major geomagnetic storm.

O: 06OCT2025 12:08:42 21.1S 175.6E Mw=5.6 NEIC SOUTH OF THE FIJI ISLANDS

The strongest earthquake felt in the U.S. or Canada today occurred as an M 3.9

in Baja California, Mexico. NEIC reported it was felt in California with intensity III in El Cajon, La Jolla and II in Chula Vista, Lakeside, San Diego, and Spring Valley.

EMSC reported moderate shaking in Tijuana, Mexico.

O: 06OCT2025 16:53:27 31.3N 116.2W Mw=3.9 NEIC BAJA CALIFORNIA, MEXICO

O: 06OCT2025 16:53:27 31.3N 116.2W Mw=4.0 EMSC BAJA CALIFORNIA, MEXICO

An earthquake of M 4.0 also occurred today in the Revilla Gigedo Islands of

western Mexico. It was not reported felt in this remote area. This event

may have been promoted by strong energy associated with Hurricane Priscilla

which was over this epicenter at the time of this earthquake as noted in this

and previous issues of this summary:

"HURR PRISCILLA 2025-10-07 00:00 UT 19.0N 109.0W 100 kts Revilla Gigedo Islands, Mexico

and

"HURR PRISCILLA 2025-10-07 00:00 UT 17.0N 107.2W 90 kts South of Gulf of California

Hurricane Priscilla continued today in area southeast of Baja California, Mexico and west of Jalisco Mexico with winds up to 90 kts. It is expected to track to the north and west. Regional seismicity in the area of Baja California and the Gulf of California could be enhanced at this time. The antipode is at 17S 73E is in the South Indian Ocean and could see moderately enhanced seismicity while this storm is active." (October 6-7, 2025)

O: 06OCT2025 16:28:12 19.4N 109.0W Mw=4.0 NEIC REVILLA GIGEGO ISLANDS REGION

BMG reported an M 5.5 earthquake near southern Sumatra today.

BMG reported moderate intensity in Tidak ada Wilayah Terdampak, Indonesia

O: 06OCT2025 10:11:54 00.8N 92.5E Mw=5.5 BMG WEST OF NORTHERN SUMATRA, INDONESIA

O: 06OCT2025 10:11:57 00.9N 92.8E Mw=4.9 EMSC WEST OF NORTHERN SUMATRA, INDONESIA

TYPHOON MATMO (27W)

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

TYPH MATMO 2025-10-07 00:00 UT 21.9N 108.5E 80 kts Vietnam

Typhoon Matmo made landfall in Vietnam with winds up to 80 kts. It also made landfall October 3 in Luzon and northern Philippines as a typhoon. Regional seismicity and aftershocks from the Leyte M 7.0 event occurred in northern Luzon as this storm passed through. The antipode is at 21S 71W in an area of northern Chile near Tarapaca and Antofagasta where seismicity could be enhanced at this time.

HURRICANE PRISCILLA

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

HURR PRISCILLA 2025-10-07 00:00 UT 19.0N 109.0W 100 kts Revilla Gigedo Islands, Mexico

HURRICANE OCTAVE (DEPRESSION 15E)

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

HURR OCTAVE 2025-10-07 00:00 UT 15.9N 119.8W 55 kts South of Baja, Mexico

TYPHOON HALONG (DEPRESSION 28W)

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

TYPH HALONG 2025-10-07 00:00 UT 28.1N 137.3E 140 kts West of Bonin Islands, Japan

TROPICAL STORM JERRY

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

TS JERRY 2025-10-07 00:00 UT 12.0N 44.5W 45 kts Northern Mid-Atlantic Ridge

A tropical cyclone may be forming in the northern Mid-Atlantic region. This system is currently located by NHC at 13N 44W and moving to the west with winds up to 30 kts. NHC gives this 70% chance of developing into a tropical storm in the next several days.

A tropical cyclone may be forming near Guam. This system is currednly located at 14N 144E north of Guam with winds up to 23 kts and moving to the northwest. Some enhanced seismicity in the area of Guam and the Mariana Islands is possible with this storm. The antipode at 15S 36W is not a seismic area.

Following is the listing of C- M- or X-class flares from SWPC for the date

of October 6, 2025. These listings are published daily in this summary and at SWPC.

The main line gives details of flares. Subsequent lines identify some earthquakes

which are at or after the time of the flare and could have been affected by

immediate Solar Flare Effects (SFE). Some earthquakes occur at longitudes

which were at local solar noon or local solar midnight and may also have

been affected by SFE. These are not identified here.

SOLAR FLARES

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

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

XXXX 1100 1129 1134 C5.6 (October 7, 2025) 2.5E-03 *

Papua New Guinea M 6.6 11:05 UT

Hindu Kush M 5.1 11:35 UT

Central California M 2.3 11:19 UT

7340 0838 0849 0924 C1.9 (October 6, 2025) 4.6E-03

7350 1225 1231 1237 C1.7 (October 6, 2025) 1.2E-03

7380 1513 1521 1527 C1.5 (October 6, 2025) 1.2E-03

7400 1955 2007 2022 C1.2 (October 6, 2025) 1.9E-03

Kamchatla M 4.9 19:59 UT

Bonin Is. M 4.1 20:02 UT

Central California M 2.5 20:17 UT

Southeern Texas M 2.5 20:23 UT

7410 2022 2037 2044 C5.1 (October 6, 2025) 4.4E-03

Southern Texas M 2.5 20:23 UT

*indicates modified reading from NOAA GOES Graph

GEOMAGNETIC FIELD: unsettled October 9 minor storms October 7-8. Solar M-flare chance: 40% X-class: 10% proton storm: 10%

AP Indicies (global, high, mid-latitude, time of max AP, Max AP, Sunspot Number, Radio Flux) 6 5 5 13:00 3 136 133

A strong Gamma Ray Burst was recorded by SWIFT on October 5, 2025 at 16:06:53 UT (#251005C). A preliminary UVOT Magnitude of V>19.4 was assigned to this GRB.

An immediate M 3.8 in the Guatemala coincided with this GRB. An M 5.1 earthquake

Kamchatka occurred five minutes earlier.

A strong Gamma Ray Burst was recorded by SWIFT on October 3, 2025 at 01:58:30 UT (#251003A). A preliminary UVOT Magnitude of V>20.01 was assigned to this GRB.

An earthquake of M 4.7 in Kamchatka coincided with this GRB at 01:59 UT

and may have been triggered by it.

October 6, 2025

Notable earthquakes and events:

The strong geomagnetic storm of the past week finally dissipated today with

planetary A index down to a quiet 9. This should allow seismicity to become

stronger in the next several days as telluric currents can again be generated

by induction from newly formed ionospheric ring currents. The most widely

felt earthquake today was an M 4.9 in Central Italy. As this earthquake

occurred within minutes of local solar noon (one respondent to EMSC noted it was 12:15), it is likely it was promoted

by tidal and/or geomagnetic effects which maximize near this hour.

EMSC reported this earthquake was felt with strong shaking in Italy at Senigallia, Fano, Bellocchi, Falconara Marittima, Ancona, Le Grazie di Ancona, Posatora, Pietra la Croce, Rio Salso-Case Bernardi, Arcevia, and in Rab, Pag, Zadar, Buzdohanj, Knin, Split, Croatia and as far as Slovenia and Bosnia and Herzegovina.

This is the strongest earthquake in Central or northern Italy within about 200

km of this epicenter since an M 4.7 on November 20, 2022 - an aftershock of an M t.6 of

November 9, 2022. At that time this summary noted in this regard:

"The earthquake of M 5.6-5.7 in Italy and the Adriatic Sea today was reported

by NEIC to have been felt with damage in Marken Italy at Mondolfo and VII in Fano. Intensity VI was also felt

in Montarado, Pesaro and IV in Senigallia, Morro d'Alba, Ancona and Orciano with lesser

shaking in Monsano. An earthquake of M 4.5 occurred earlier in the day in Northern Italy near Portofino

and was lightly felt in the epicentral area according to EMSC. BBC reported this

earthquake was lightly felt in the area with some moderate damage in Central Italy.

No major damage was reported. Cracks appeared in some buildings. The quake was

felt in Italy, Slovenia, Croatia and San Marino and Bosnia and Herzegovina. A number

of light aftershocks followed the mainshock. The last earthquake within about

200 km of this epicenter with M>=5.6 was an M 5.7 on January 18, 2017, an aftershock of

an M 6.6 about 150 km south of today's epicenter on October 30, 2016. At the time

...

The M 5.6-5.7 in Italy today occurred with the full moon and at the longitude of maximum

tidal stresses with this alignment" (November 9, 2022)

Note that today's earthquake in Italy also occurred with the full moon (of October 7, 2025).

O: 06OCT2025 10:13:59 43.9N 13.3E ML=4.9 EMSC CENTRAL ITALY

An unusual M 4.8 earthquake occurred today in Central Vietnam. NEIC reported this event near Kon Tum, Vietnam was felt with maximum intensity IV in Nguyen, Vietnam at Play Cu Thai; III in Duyen Hai Mien Trung at Hoi An and Tam Ky and II in Danang. It was also lightly felt in Thailand.

EMSC reported moderate shaking in Vietnam in Ngu Hanh, Tra, Da Nang, Buon Ma Thuot, Nha Trang, and in Thailand at Ubon Ratchathani.

This follows a similar earthquake in Laos reported in this summary on October

3, 2025 as:

"An M 4.3 occurred today in Laos. It was not reported felt. The only earthquake

in the region of Laos with M>=4.3 in the past 35 years was an M 4.4 on January 27, 2017.

Today's earthquake in Laos is significant because it occurred in the area where Typhoon Burloi dissipated at the

end of September and early October and was probably promoted by energy

associated with that storm as noted at the time in this summary:

"TYPH BURLOI 2025-09-29 00:00 UT 18.2N 106.2 100 kts Vietnam

Typhoon Burloi (26W) continued today after making landfall in Vietnam with winds up to 100 kts where it did considerable damage. It is expected to track to the west in the next several days dissipating in the next two days. . The Antipode at 18S 74W is will pass over southern Peru and Tarapaca and Arica, Chile and elevated seismicity is likely in that area in the next several days." (September 29-October 1, 2025)

O: 03OCT2025 10:00:17 17.4N 105.7E ML=4.3 EMSC LAOS" (October 4, 2025)

Today's earthquake in Vietnam is the strongest within about 200 km of this epicenter

since an M 5.1 on July 27, 2024. The only other earthquakes of M>=4.8 in this area

in the past 35 years occurred with M 4.8 on August 23, 2022 and April 18, 2022.

"An unusual earthquake of M 5.1 occurred today in the region of Vietnam. NEIC reported

it was felt with intensity IV in Kon Tum, Vietman.

EMSC reported moderate shaking was felt in Vietnam at Hoi An, Da Nang, Tua Hoa, and Nha Trang.

This event was likely triggered by stresses induced by landfall of Typhoon

Gaemi today north of this epicenter. This was expected in previous issues

of this report as:

"Typhoon Gaemi made landfall today in the area of the coast of southeastern China with winds up to 65 kts. This system is expected to dissipate over China today. Some enhanced seismicity is expected in the area of transform faults in Southeastern Asia in the next several days." (July 27, 2024)

Today's event in Vietnam appears to have been triggered by landfall of Typhoon

Matmo north of this epicenter in Vietnam near the time of the earthquake as

reported in the previous issues of this summary:

"TYPH MATMO 2025-10-06 00:00 UT 19.0N 108.4E 80 kts Vietnam" (October 6, 2025)

O: 05OCT2025 18:28:45 14.8N 108.1E MB=4.8 NEIC VIETNAM

The strongest earthquake of the day was an M 5.4 in Kyrgyzstan. NEIC reported it was felt with maximum intensity VI in Namangan, Uzbekistan and III in Quva Farg'ona, Jomboy, Samarkand, Salor, Tashkent, Uzbekistan; in Kazakhstan at Taraz with IV and III in Kokerek and Shymkent, Ontustik and II in Os, Kyrgyzstan.

EMSC reported moderate to strong shaking in Kazakhstan at Zhabagly, Taraz, Turar Ryskulov, Tyul'kubas, Kokterk, Lenger, Sayram, Shymkent, and in Uzbekistan at Haqqulobod, Kysyldzhar, Namangan, among others.

This is the strongest earthquake within about 200 km of this epicenter since

an M 5.5 on May 22, 2003 - the only such event in the past 25 years in this region.

A strong M 6.2 hit the area on May 15, 1992. The event in 2003 was accompanied

by a moderate earthquake of M 4.6 in southeastern Alaska and an M 5.9 in Central

Philippines, not unlike the current seismic climate.

This earthquake occurred near local solar midnight and may have been promoted by tidal stresses associated with the coming full moon of October 7

as previously noted in this summary:

O: 05OCT2025 20:28:59 42.2N 71.3E MB=5.4 NEIC KYRGYZSTAN

A series of moderate earthquakes occurred today in the areas of Svalbard and Jan Mayen Islands, Arctic Ocean. These events of M 4.6-4.8 were note

reported felt in this remote area. They occurred near local solar noon with

the second largest of M 4.8 within several minutes of local noon. At high latitude near the

full moon and at the end of a major geomagnetic storm they may have been

promoted by energy from those sources.

These earthquakes are located at the fourth node (90 degrees) from the M 7.0 in

Leyte, Philippines and may have been promoted by energy from that source.

O: 05OCT2025 14:30:36 71.1N 7.8W MB=4.6 NEIC SVALBARD AND JAN MAYEN IS.

O: 05OCT2025 12:01:22 71.3N 7.9W MB=4.9 NEIC SVALBARD AND JAN MAYEN IS.

O: 05OCT2025 09:08:15 71.2N 7.9W MB=5.2 NEIC SVALBARD AND JAN MAYEN IS.

An earthquake of M 4.9 was felt in the area of Pakistan near the Afghanistan border today.

NEIC it was felt in Punjab Pakistan at Kot Abdul Malik with intensity II.

EMSC reported moderate shaking in Quetta, Balochistan, Kot Malik, Barkhurdar, Pakistan.

This follows a similar magnitude earthquake in southern Pakistan

of October 3, 2025 as reported in this summary at the time:

"An unusual earthquake of M 4.9 occurred in Pakistan north of Karachi today.

The last earthquake in the area of today's epicenter of M>=4.9 occurred on March 29, 2024

with M 5.5 and 5.4. At the time this summary noted:

"NEIC reported this earthquake of M 5.5 in Pakistan was felt with intensity up to VII in the area(s) of Pakistan in Nushki.

EMSC reported moderate shaking in Pakistan at Quetta, and in Kandahar, Afghanistan." (March 19, 2024)

This event may have been promoted by a tropical cyclone currently south of

Karachi in the Arabian Sea. This summary had anticipated this possibility

in the previous issue as:

"TC SHAKHTI 2025-10-03 00:00 UT 22.0N 66.7E 70 kts Pakistan

Tropical cyclone formed south of Pakistan today with winds up to 70 kts. This system is currently south of Karachi, Pakistan and moving to the northeast. It could promote moderate seismicity in the epicentral area of southwestern Pakistan near 24N 65E in the next couple of days as it moves through the region. The antipodal area at 22S 116W near the East Pacific Rise could also see enhanced seismicity at this time." (October 3, 2025)

This event also occurred near local solar midnight and may have been promoted

by tidal stresses associated with the coming full moon and/or geomagnetic

effects from the current strong geomagnetic storm which maximize near this hour.

This epicenter is at the fifth node (72 degrees) from Kamchatka and the sixth node (60 degrees)

from the M 7 in Leyte, Philippine. It may also have been related to the current

geomagnetic storm as it lies at the sixth node from the North Geomagnetic

pole and at 105 degrees from the South Geomagnetic Pole. Energy from these

sources may have helped promote this earthquake in Pakistan.

O: 03OCT2025 20:29:32 28.3N 64.2E ML=4.9 NEIC WESTERN PAKISTAN" (October 4, 2025)

The position of TC Shakhti when today's event in Pakistan occurred was approximately:

"TC SHAKHTI 2025-10-06 00:00 UT 20.3N 60.4E 75 kts South of Pakistan

Tropical cyclone Shakhti continued south of Pakistan today with winds up to 75 kts. This system is currently south of Karachi, Pakistan and moving to the northeast. It could promote moderate additional seismicity in the epicentral area of southwestern Pakistan in the next couple of days as it moves through the region. The antipodal area at 20S 120W near the East Pacific Rise could also see enhanced seismicity at this time." (October 5, 2025)

This epicenter is at the sixth node (60 degrees) frrom the north geomagnetic Pole and

energy from that source related to the current geomagnetic storm may have helped promote today's earthquake.

O: 05OCT2025 13:29:27 30.3N 66.3E MB=4.9 NEIC PAKISTAN-AFGHANISTAN BORDER

The strongest earthquake in the U.S. or Canada today was an M 4.4 in southeastern

Alaska bordering on the Yukon Territory, Canada. NEIC reported it was felt with

intensity II-III in Alaska at Anchorage and Copper Center and II in Edmonton, Alberta, Canada.

This is the strongest earthquake in southeastern Alaska within about 150 km

of this epicenter since an M 4.8 on August 6, 2023. At the time this summary

noted:

"The strongest earthquake in the U.S. or Canada today was an M 4.8-5.0 in the Southern Yukon Territory, Canada. NEIC reported it was felt with intensity III in Haines Junction, Yukon, Canada and II in Whitehorse, Yukon with intensity II in Glennallen, Alaska.

This earthquake occurred within about an hour of local solar noon and may

have been promoted by strong tidal stresses which maximize near this hour.

The last earthquake within about 150 km of this epicenter in the Yukon or

in Southeastern Alaska with magnitude greater than 4.7 was an M 5.2 on January 8, 2022

and prior to that an M 6.0 on July 17, 2014." (August 6, 2023)

Today's event occurred near local solar midnight and may have been promoted

by tidal and/or geomagnetic stresses which maximize near this hour.

O: 05OCT2025 11:20:04 61.4N 140.5W MB=4.4 NEIC SOUTHEASTERN ALASKA

An M 3.5 earthquake was widely felt today in southern California east of Los Angeles. NEIC reported it was felt

with intensity III in Big Bear City, California and possibly in Yumna, Arizona and Pasadena, California with II in California at Rancho Cucamonga, Palm Springs, Apple Valley and Barstow.

NEIC reported aftershocks of M 2.6 and M 2.4 in Southern California were felt with intensity up to II-III in the area(s) of Southern California in Big Bear City.

The last earthquake within about 75 km of this epicenter with M>=3.5 was an M 4.9 and aftershock

of M 3.5 on July 29, 2024. At the time this summary noted:

"A moderate earthquake shook southern California today with M 4.9. NEIC and the press

reported it was felt with intensity up to VI in Barstow and Los Angeles areas.

EMSC reported moderate shaking with a rolling motion with earthquake noises in California at Fort Irwin,

Helendale, Victorville, Apple Valley, Hesperia, Big Bear City, Adelanto, Cedar Glen, Yucca Valley, Pinon Hills, Edwards, Trona, Pinon Hills, Morongo Valley, San Bernardino, Searles Valley, Redlands, Yucaipa, Ridgecrest, California City, Loma Linda, Twentynine Palms, Beaumont, Fontana and as far as Bakersfield and Simi Valley more than 200 km from the epicenter.

It occurred within minutes of local solar noon and was probably promoted

by strong geomagnetic and tidal stresses which maximize near this hour.

A number of smaller aftershocks were felt with light intensity in the Barstow

area. This is a remote area of southern California and no major damage

was reported with this earthquake. Today's earthquake of M 4.9 is the strongest

recorded in Southern California within about 100 km of today's epicenter since an M 5.1

on December 6, 2008. At the time this summary noted:

"A moderate earthquake of M 5.1 hit the area of Southern California today in

the region of Ludlow which an event of M 7.0 in 1999 may have stressed to

near rupture. Today's earthquake was felt throughout Southern California and

into Arizona, Utah and Nevada. Maximum intensity IV was reported at Pahrump,

NV and in California at Pearblossom, Little Rock, Thousand Palms, Twentynine

Palms, Fort Irwin, Fontana, Loma Linda, Newberry Springs, San Diego, La Puente,

San Fernando, Encino, Beverly Hills, Culver City, Whittier, Los Angeles,

and in general within about 200 km of the epicenter. Likewise intensity II-III

was felt within about 250 km of the earthquake and intensity I was felt throughout

the remainder of the region according to data on the NEIC website.

AP reported no immediate damage or casualties from the earthquake.

We have been undergoing the strongest geomagnetic storm in the past month

over the past three days. Sudden changes in geomagnetic field can change

the fault parameters such that an earthquake may occur simultaneously with

such change. This often, but not always occurs. Southern California often

shows such triggering. In the case today, a strong and sudden geomagnetic change in

Hp, Hn and in the total field occurred. SEC shows data indicating the

Hn field increased from 0.9e+1 to 1.6e+1 nT from 03:40 to 04:23 UT and was

accompanied by equivalent changes in the total field and the Hp field both

maximizing between 04:10 and 04:20 UT. The M 5.1 in Southern California

occurred at then end of this field change at 04:18 UT. This is not the first

time such observations have been made but is found more often than not

especially in this region of California. This suggest direct triggering of the earthquake by

the geomagnetic change." (December 6, 2008, July 29, 2024)

Readers may note the coincidence of these previous regional earthquakes

with the end of strong geomagnetic storms. This is consistent with the

conditions of the current earthquake in southern California.

O: 05OCT2025 10:41:24 34.3N 116.9W MB=3.5 NEIC SOUTHERN CALIFORNIA

O: 05OCT2025 09:51:36 34.3N 116.9W MB=3.3 NEIC SOUTHERN CALIFORNIA

O: 05OCT2025 06:15:39 34.3N 116.9W MB=3.3 NEIC SOUTHERN CALIFORNIA

A moderate M 5.0 earthquake occurred in the northern Mid-Atlantic today. It

was not reported felt in this remote area. It occurred as a new tropical

cyclone was passing over the epicenter as reported in this summary:

O: 06OCT2025 05:10:03 13.2N 44.6W MB=5.0 NEIC NORTHERN MID-ATLANTIC

NEIC reported an earthquake of M 4.2 in Santiago, Chile was felt with intensity up to II-III in the area(s) of Santiago, Chile.

EMSC reported moderate shaking and loud deep noise in Chile at Providencia, Santiago, Lo Prado, Penaflor, and Colina.

NEIC reported an earthquake of M 2.8 in Northern Kansas was felt with intensity up to II-III in the area(s) of Northern Kansas in Stockton and Wichita.

NEIC reported an earthquake of M 4.9 in Southern Mindanao, Philippines was felt with intensity up to II-III in the area(s) of Southern Mindanao, Philippines in Cablalan.

NEIC reported an earthquake of M 4.4 in Guam was felt with intensity up to II-III in the area(s) of Guam with IV in Asan and III in Santa Rita.

NEIC reported an earthquake of M 3.1 in Southern Idaho was felt with intensity up to II-III in the area(s) of Southern Idaho and western Montana in Kuna, Idaho.

EMSC reported an earthquake of M 2.0 in Los Angeles, California was felt with intensity up to IV in the area(s) of Los Angeles, California in Fontana.

TYPHOON MATMO (27W)

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

TYPH MATMO 2025-10-06 00:00 UT 21.9N 108.5E 80 kts Vietnam

HURRICANE PRISCILLA

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

HURR PRISCILLA 2025-10-06 00:00 UT 17.0N 107.2W 90 kts South of Gulf of California

HURRICANE OCTAVE (DEPRESSION 15E)

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

HURR OCTAVE 2025-10-06 00:00 UT 16.3N 122.5W 80 kts South of Baja, Mexico

Hurricane Octave (depression 15E) continued today in the Pacific south of Baja California, Mexico with winds up to 80 kts. It is expected to track to the north and east and not to approach landfall at this time. Regional seismicity is not likely to be enhanced at this time. The antipode is at 16S 57E is in the South Indian Ocean. This is a minor seismic zone and it could see minor earthquake enhancement in the next several days.

TYPHOON HALONG (DEPRESSION 28W)

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

TYPH HALONG 2025-10-06 00:00 UT 25.7N 140.9E 80 kts Bonin Islands, Japan

Typhoon Halong (28W) continued today in the area of the Bonin Islands, Japan with winds up to 80 kts. This system is moving to the northeast and could help promote seismicity in the Bonin Islands north to Honshu in the next day. It will turn to the east around October 7 and with the full moon could promote a moderate to large earthquake in that area of Japan at the time. The current antipode is at 26S 39W in the South Atlantic and is not expected to see enhanced seismicity at this time.

TROPICAL CYCLONE SHAKHTI (02A)

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

TC SHAKHTI 2025-10-06 00:00 UT 19.8N 60.4E 50 kts South of Pakistan

Tropical cyclone Shakhti continued south of Pakistan today with winds up to 50 kts. This system is currently south of Karachi, Pakistan and moving to the northeast. It could promote moderate additional seismicity in the epicentral area of southwestern Pakistan in the next couple of days as it moves through the region. The antipodal area at 20S 120W near the East Pacific Rise could also see enhanced seismicity at this time.

Following is the listing of C- M- or X-class flares from SWPC for the date

of October 5, 2025. These listings are published daily in this summary and at SWPC.

The main line gives details of flares. Subsequent lines identify some earthquakes

which are at or after the time of the flare and could have been affected by

immediate Solar Flare Effects (SFE). Some earthquakes occur at longitudes

which were at local solar noon or local solar midnight and may also have

been affected by SFE. These are not identified here.

SOLAR FLARES

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

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

7290 2337 2342 2345 C3.4 (October 5, 2025) 1.8E-03

*indicates modified reading from NOAA GOES Graph

GEOMAGNETIC FIELD: active October 6 minor storms October 7-8. Solar M-flare chance: 45% X-class: 10% proton storm: 10%

AP Indicies (global, high, mid-latitude, time of max AP, Max AP, Sunspot Number, Radio Flux) 9 14 6 07:00 4 127 148

A strong Gamma Ray Burst was recorded by SWIFT on October 3, 2025 at 01:58:30 UT (#251003A). A preliminary UVOT Magnitude of V>20.01 was assigned to this GRB.

An earthquake of M 4.7 in Kamchatka coincided with this GRB at 01:59 UT

and may have been triggered by it.

October 5, 2025

Notable earthquakes and events:

The strongest earthquake in the world today was an M 6.0 off the coast of Honshu, Japan. NEIC reported it was felt with maximum intensityV in Fukushima and IV in Shirakawa, Fukushima, Japan. Intensity III was also felt in Chiba Prefecture at Chiba, Narashino, Tomisato; in Koriyama, Fukushima, Oizumi, Gunma, and II in Chiba at Urayasu, Nagaryama, Matsudo.

EMSC reported it was felt with strong shaking in Kamagaya, Tokyo, Japan. JMA reported

maximum shaking of V (Japanese scale) at Ken Hamadori, Fukushima near local solar midnight with intensity II-III throughout most of eastern Honshu, Japan. No tsunami was expected nor observed.

This is the first earthquake of M>=6 off the east coast of Honshu, Japan since

an M 6.1 on April 4, 2024 and an M 6.1 on May 26, 2023. But the last event

within about 250 km of today's epicenter of significantly larger magnitude than

M 6.0 occurred 3.5 years ago as an M 7.3 on March 16, 2022. At the time of the

event on April 4, 2024 this summary noted:

"The strongest earthquake in the world today was an M 6.1 in the region of eastern Honshu, Japan. NEIC reported it was felt with maximum intensity IV in Minami-Soma, Honshu, Japan.

EMSC reported moderate to strong shaking in Japan at Minuma, Nakahara, Tokyo.

No major damage was reported with this earthquake. The last earthquake of M>=6.1

off the east coast of Honshu, Japan within about 150 km of this epicenter occurred

on March 16, 2022 with M 7.3 - an event which, like today's occurred at the end

of a strong geomagnetic storm. Today's event caused some concern of a repeat

of the March 11, 2011 earthquake and tsunami of M>9. That event however

was probably triggered by several strong X-class flares and the current

solar conditions are quiet, so a repeat appears unlikely at this time.

At the time of March 16, 2022 event this summary noted:

"A major earthquake of M 7.3 off the east coast of Honshu, Japan followed an M 6.4 minutes earlier.

Today's mainshock killed four in Fukushima, Japan and did minor damage

throughout the area. More than 97 were injured in this earthquake but millions

lost power. Some trains came off their tracks but no injuries

were reported with these incidents. High Speed trains were temporarily

shut down. A tsunami warning was issued and waves of up to 20 cm were

reported. No damage was reported at nuclear facilities with these earthquakes. Some

residents of Fukushima were evacuated for fear of tsunamis. This is the strongest earthquake in this area since a similar M 7.3 on February 13, 2021.

An M 9.3+ earthquake shook this area and triggered a major Pacific-wide tsunami

NEIC reported maximum intensity IX with the M 7.3 with damage was felt in Namie, Fukushima with VIII in Haramachi, Soma, Watan, Natori, Shiogama, Miyagi and lesser shaking throughout most of eastern Honshu, Japan.

The M 6.5 foreshock was reported with maximum intensity VII in Miyagi and V in Fukushima

with lesser shaking in Chiba, Saitama, and Tokyo Prefectures, Japan.

These earthquakes occurred within a couple of minutes of local solar midnight and were probably

promoted by strong tidal and geomagnetic stresses which maximize near this

hour. Today's earthquake followed a major geomagnetic storm of the past

three days. A series of M-class solar flares have been occurring over

the past day and a moderate geomagnetic sudden commencement storm began about

14:00 UT today, coincident with the earthquakes in Japan and may have

helped trigger this activity." (March 16, 2022, April 4, 2024)

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

tidal stresses with the upcominig full and super moon of October 7 as noted

in previous issues of this summary:

The earthquake of M 6.0 in Japan also coincided with a major peak in the

intensity of the current geomagnetic storm. This occurred around 12:00 - 17:00 UT

with K-index at high latitudes reaching 7 (Gs storm) at 12:00 and 15:00 UT.

In the previous summary this possibility had been emphasized as:

"The strong geomagnetic storm continued today with Planetary AP 30; high latitude

45 and middle latitude 20. This storm has delayed stronger seismicity but

this is probably about to end. The full moon will arrive early on October 7

with maximum stress in the ring of fire in the western Pacific which includes

highly seismic areas of Japan, Indonesia and the Philippines. On the

basis of previous observations and discussions in this summary these regions

are susceptible to geomagnetic seismic triggering, especially in Japan which

has been relatively quiet during this storm and prior to it. It is likely

that a strong earthquake will accompany the end of the storm or a sudden

flareup of the storm in the next two days (October 4-6, 2025)." (October 4, 2025)

An M 4.5 earthquake about 250 km north of today's M 6.0 preceded it as a regional

foreshock about an hour earlier but was not reported felt.

This activity in Japan occurred as Tropical Storm Halong was making land fall in

the Volcano and Bonin Islands of southeastern Japan and may have been

promoted by energy associated with that landfall.

"TS HALONG 2025-10-05 00:00 UT 25.5N 141.9E 70 kts Bonin Islands, Japan

Tropical Storm Halong (28W) continued today in the area of the Bonin Islands, Japan with winds up to 70 kts. This system is moving to the northwest and could help promote seismicity in the Bonin Islands north to Honshu in the next day. It will turn to the east around October 8 and with the full moon could promote a moderate to large earthquake in that area of Japan at the time. The current antipode is at 25S 39W in the South Atlantic and is not expected to see enhanced seismicity at this time." (October 5, 2025)

Today's events in Japan are located at 101-103 degrees from the south Geomagnetic

pole and are likely being promoted by energy that accumulated there with the

current geomagnetic storm. The M 6.0 is also at the 12th node (30 degrees) from

the M 6.9 in Leyte, Philippines and may have been promoted by energy associated

with that source.

O: 04OCT2025 15:21:09 37.4N 141.7E MB=6.0 NEIC OFF THE COAST OF HONSHU JAPAN

O: 04OCT2025 14:15:19 39.7N 142.2E MB=4.5 NEIC OFF THE COAST OF HONSHU JAPAN

Moderate aftershocks also continued in the area of Leyte, Philippines today.

An M 5.0 was reported by NEIC to have been felt with intensity II in Talisay, Cebu in the Central Visayas, Philippines

among others. EMSC reported slight trembling in Baugo, Philippines for this and an M 4.6

aftershock nine minutes later. This area could see a sizable aftershock near the time of the

super full moon on October 7 as it lies at the longitude of maximum stress

with that alignment.

O: 04OCT2025 09:41:18 10.9N 124.0E MB=5.0 NEIC LEYTE, PHILIPPINES

O: 04OCT2025 09:50:17 10.8N 123.8E MB=4.6 EMSC NEGROS-CEBU REGION, PHILIPPINES

O: 04OCT2025 09:30:15 10.9N 123.9E MB=4.4 EMSC NEGROS-CEBU REGION, PHILIPPINES

A moderately strong M 5.5 earthquake occurred today south of Michoacan, Mexico on

the northern East Pacific Rise. NEIC reported it may have been lightly felt

in this remote epicentral area.

This epicenter is located near the position of Hurricane Octave which passed near

this epicenter several days ago. Hurricane Narda also passed nearby this

epicenter in late September, 2025 and may have helped set the area up for

a moderate earthquake at this time. This M 5.5 occurred as a new Tropical

Storm (Priscilla) was passing near this epicenter. It may have been promoted

by energy associated with that storm as noted in this summary:

"TS PRISCILLA 2025-10-05 00:00 UT 11.0N 103.0W 45 kts Northern East Pacific Rise

TS Priscilla continued today in area of the East Pacific Rise south of Baja California, Mexico with winds up to 45 kts. It is expected to track to the north and west. Regional seismicity in the northern East Pacific Rise could be enhanced at this time. The antipode is at 11S 77E is in the South Indian Ocean and is not a seismic area." (October 5, 2025)

O: 04OCT2025 09:02:03 8.4N 103.9E MB=5.5 NEIC NORTHERN EAST PACIFIC RISE

NEIC reported an earthquake of M 2.5 in Washington State was felt with intensity up to II-III in the area(s) of Washington State in Victoria British Columbia, Canada.

NEIC reported an earthquake of M 4.3 in the Andreanof Islands, Alaska was felt with intensity up to II-III in the area(s) of the Andreanof Islands, Alaska.

NEIC reported an earthquake of M 4.7 in Costa Rica was felt with intensity up to II-III in the area(s) of Costa Rica with V in Tilaran, Guanacaste and IV in El Roble, Panama.

NEIC reported an earthquake of M 3.0 in Southern Alaska was felt with intensity up to II-III in the area(s) of Southern Alaska in Eagle River.

NEIC reported an earthquake of M 2.8 in Oklahoma was felt with intensity up to II-III in the area(s) of Oklahoma in Covington.

EMSC reported an earthquake of M 3.2 in Southern California was felt with intensity up to IV in the area(s) of Southern California at Big Bear Lake with a rumbling sound.

EMSC reported an earthquake of M 4.4 in Southern Xinjiang, China was felt with intensity up to IV in the area(s) of Southern Xinjiang, China in Almaty, Kazakhstan.

EMSC reported an earthquake of M 5.2 in Kamchatka, Russia was felt with intensity up to IV in the area(s) of Kamchatka, Russia in Vilyuchinsk.

EMSC reported an earthquake of M 3.6 in Portugal was felt with intensity up to IV in the area(s) of Portugal in Sines.

Hurricane Gabrielle is currently in this area dissipating and may have helped

promoted this earthquake. An earthquake of M 4.3 also occurred near this epicenter

as Hurricane Gabrielle was dissipating over this epicenter today.

O: 05OCT2025 06:38:36 36.0N 10.2W MB=4.3 NEIC AZORES-CAPE St. VINCENT RIDGE, PORTUGAL

TYPHOON MATMO (27W)

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

TYPH MATMO 2025-10-05 00:00 UT 19.0N 108.4E 80 kts Vietnam

TROPICAL STORM PRISCILLA

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

TS PRISCILLA 2025-10-05 00:00 UT 11.0N 103.0W 45 kts Northern East Pacific Rise

HURRICANE OCTAVE (DEPRESSION 15E)

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

HURR OCTAVE 2025-10-05 00:00 UT 15.6N 123.9W 85 kts South of Baja, Mexico

Hurricane Octave (depression 15E) continued today in the Pacific south of Baja California, Mexico with winds up to 85 kts. It is expected to track to the north and east and not to approach landfall at this time. Regional seismicity is not likely to be enhanced at this time. The antipode is at 16S 57E is in the South Indian Ocean. This is a minor seismic zone and it could see minor earthquake enhancement in the next several days.

TROPICAL STORM HALONG (DEPRESSION 28W)

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

TS HALONG 2025-10-05 00:00 UT 25.5N 141.9E 70 kts Bonin Islands, Japan

TROPICAL CYCLONE SHAKHTI (02A)

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

TC SHAKHTI 2025-10-05 00:00 UT 20.3N 60.4E 75 kts South of Pakistan

Following is the listing of C- M- or X-class flares from SWPC for the date

of October 3, 2025. These listings are published daily in this summary and at SWPC.

The main line gives details of flares. Subsequent lines identify some earthquakes

which are at or after the time of the flare and could have been affected by

immediate Solar Flare Effects (SFE). Some earthquakes occur at longitudes

which were at local solar noon or local solar midnight and may also have

been affected by SFE. These are not identified here.

SOLAR FLARES

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

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

6530 0025 0035 0041 C3.4 (October 4, 2025) 2.8E-03

6540 0049 0054 0058 C2.7 (October 4, 2025) 1.6E-03

6560 0136 0142 0147 C5.5 (October 4, 2025) 3.1E-03

6590 0310 0322 0331 C4.7 (October 4, 2025) 5.1E-03

6600 0407 0414 0416 C3.2 (October 4, 2025) 1.8E-03

6630 0455 0502 0509 C3.5 (October 4, 2025) 2.6E-03

Kamchatka M 4.4 05:03 UT

6850 1745 1752 1756 C3.5 (October 4, 2025) 2.1E-03

Kamchatka M 4.8 17:44 UT

6860 1837 1845 1850 C2.7 (October 4, 2025) 2.5E-03

Fiji M 4.9 18:50 UT

6880 1850 1905 1911 C3.0 (October 4, 2025) 3.9E-03

Banda Sea M 4.2 19:02 UT

6950 2202 2205 2211 C2.0 (October 4, 2025) 1.2E-03

6970 2317 2323 2326 C2.1 (October 4, 2025) 1.1E-03

Kuril Is. M 4.1 23:31 UT

*indicates modified reading from NOAA GOES Graph

GEOMAGNETIC FIELD: active October 5-7. Solar M-flare chance: 60% X-class: 15% proton storm: 5%

AP Indicies (global, high, mid-latitude, time of max AP, Max AP, Sunspot Number, Radio Flux) 30 25 20 07:00 6 137 158

A strong Gamma Ray Burst was recorded by SWIFT on October 3, 2025 at 01:58:30 UT (#251003A). A preliminary UVOT Magnitude of V>20.01 was assigned to this GRB.

An earthquake of M 4.7 in Kamchatka coincided with this GRB at 01:59 UT

and may have been triggered by it.

October 4, 2025

Notable earthquakes and events:

The strong geomagnetic storm continued today with Planetary AP 30; high latitude