MODERATE EARTHQUAKES SHAKE NORTHERN CALIFORNIA
EARTHQUAKE SUMMARY FOR SEPTEMBER 30, 2023
The strongest earthquakes in the U.S. or Canada today occurred off the coast of northern California. NEIC reported the largest of these - of M 4.7 was felt with maximum intensity V in California at Loleta and IV in Ferndale, Fortuna, Rio Dell, Hydesville, Eureka, Petrolia and Samoa. An aftershock of M 4.2 was felt with intensity IV in Ferndale, Loleta and III in Rio Dell, Fortuna, Petrolia, Hydesville and Scotia among others. An M 3.7 aftershock was also felt with intensity II-III in northern California in Hydesville, Eureka and Whitethorn.
The last earthquake off the coast of Northern California with M>=4.7 was an M 5.6 on May 21, 2023. A strong M 6.4 hit the area on December 20, 2022. At the time this summary noted:
"Today's M 6.4 is the strongest within about 200 km of this epicenter in Northern California since an M 6.8 on March 10, 2014 and an M 6.5 on January 10, 2010 and an M 7.1 on June 15, 2005, the only such earthquakes in this area in at least 25 years." (December 20, 2022)
Forecast 156791 had expected today's event off Northern California was likely within about 25 km of today's epicenter around September 26. Today's activity was timed near local solar noon and may have been promoted by tidal stresses with the full moon of September 29.
O: 30SEP2023 17:25:19 40.5N 124.5W md=2.1 ANSS OFF COAST OF NORTHERN CALIFORNIA
O: 30SEP2023 15:26:26 40.6N 124.3W mw=4.7 ANSS OFF COAST OF NORTHERN CALIFORNIA
O: 30SEP2023 17:25:19 40.5N 124.5W md=2.1 ANSS OFF COAST OF NORTHERN CALIFORNIA
O: 30SEP2023 17:16:47 40.5N 124.4W mw=4.2 ANSS OFF COAST OF NORTHERN CALIFORNIA
O: 30SEP2023 17:16:47 40.5N 124.4W mw=4.2 ANSS OFF COAST OF NORTHERN CALIFORNIA
O: 30SEP2023 19:58:21 40.5N 124.5W md=2.0 ANSS OFF COAST OF NORTHERN CALIFORNIA
O: 30SEP2023 19:58:21 40.5N 124.5W md=2.0 ANSS OFF COAST OF NORTHERN CALIFORNIA
P: 26SEP2023 156791 40.4N 124.2W 2.5-4.6 AAAAA Off Coast of No. Calif
OTHER GLOBAL EARTHQUAKE ACTIVITY
For most events there are two listings. The first line is the observed event starting with "O:" for Observed. There follows the date, month and year, the time in UT hours:minutes:seconds, the latitude and longitude, the given magnitude and the reporting agency followed by the geographic location. The second line starts with "P:" This is the forecast event as forecast in our summaries normally more than a month in advance. Magnitudes may vary in response to updated seismic watches and daily variations due to tidal and other influences. This line has the forecast date, month and year, the forecast number, latitude, longitude and forecast magnitude range. This is followed by a comparison between the forecast and the event. The comparison includes letters A-D. The first is number of days difference from predicted (A:up to 2, B3-5; C:6-10; D:more than 10), Difference in latitude (A:up to 1 degree; B:1-2 degrees; C:2-4 degrees; D:more than 4 degrees); longitude (same comparison as with latitude); magnitude (A: within forecast range; B: higher than forecast range; C: lower than forecast range; D: no comparison possible). The last letter is a stand in for a future comparison which needs to be done statistically after a large number of forecasts have been made. In previous data, an excellent match is generally AAAAA; a good match as one or two B's; a fair match has several B's and C's and a poor match is one which contains a number of C's or D's.
ASIA
O: 30SEP2023 07:17:36 51.3N 158.3E ML=4.1 KRS KAMCHATKA
P: 22SEP2023 156816 52.0N 159.0E 4.0-5.9 CAAAA Kamchatka
P: 26SEP2023 156813 52.0N 160.0E 4.0-5.5 BABAA E. of Kamchatka
O: 30SEP2023 08:57:46 54.7N 163.3E ML=4.2 KRS KOMANDORSKY ISLANDS
P: 28SEP2023 156817 56.0N 166.0E 4.0-6.1 ABBAA Komandorsky Isl
O: 30SEP2023 08:30:17 36.8N 71.2E mb=4.2 ANSS HINDU KUSH, AFGHANISTAN
P: 29SEP2023 156716 36.0N 70.0E 3.8-5.2 AAAAA Hindu Kush/Pakistan
O: 30SEP2023 21:30:09 42.1N 77.1E mb=4.1 ANSS KYRGYZSTAN
O: 30SEP2023 21:30:05 42.0N 77.1E ML=4.7 KRN KYRGYZSTAN
P: 30SEP2023 156776 40.0N 75.0E 4.0-5.6 ABBAA Kirgizstan/Xinjiang
NEIC reported this earthquake of M 4.1 in Kyrgyzstan was felt with intensity II-III in the area(s) of Kyrgyzstan in Kyzyl-Tuu.
O: 30SEP2023 11:19:40 39.7N 74.8E ML=4.2 KRN KYRGYZSTAN
P: 30SEP2023 156776 40.0N 75.0E 4.0-5.6 AAAAA Kirgizstan/Xinjiang
INDONESIA AND PHILIPPINES
O: 30SEP2023 16:16:45 2.9S 129.6E mb=4.4 ANSS SERAM INDONESIA
P: 29SEP2023 156644 3.0S 129.0E 4.0-5.4 AAAAA Ceram area
O: 30SEP2023 23:30:35 4.4S 152.6E mb=4.8 ANSS PAPUA NEW GUINEA
P: 22SEP2023 156649 5.0S 153.0E 4.0-5.4 CAAAA New Britain
O: 30SEP2023 06:33:43 9.1S 105.4E mb=4.9 ANSS SOUTH OF SUMATRA, INDONESIA
P: 28SEP2023 156655 9.0S 106.0E 4.0-5.4 AAAAA So. of Java
NEIC reported an earthquake of M 5.3 in Java, Indonesia was felt with intensity II-III in the area(s) of Java, Indonesia in Sukabumi, Ciawi, Pamulang, Bekasi, Jakarta, Tangerang, Bandung, Cikeruh.
CENTRAL AND SOUTH AMERICA
O: 30SEP2023 17:53:24 32.2S 72.0W mw=4.2 ANSS CENTRAL CHILE
P: 27SEP2023 156874 32.0S 71.0W 4.0-5.4 BAAAA Central Chile
O: 30SEP2023 17:44:06 33.7S 72.6W mw=4.3 ANSS CENTRAL CHILE
P: 29SEP2023 156874 33.0S 70.0W 4.0-5.6 AABAA Central Chile
O: 30SEP2023 05:02:40 15.4N 94.7W ML=4.1 UNAM CRUZ, OAX, MEXICO
O: 30SEP2023 11:47:13 15.9N 95.6W ML=4.0 UNAM CRUZ, OAX, MEXICO
O: 30SEP2023 16:52:18 16.0N 95.2W ML=4.0 UNAM CRUZ, OAX, MEXICO
O: 30SEP2023 20:36:00 16.9N 94.1W ML=4.2 UNAM CINTALAPA, CHIS, MEXICO
P: 25SEP2023 156667 17.0N 94.0W 3.5-5.3 BAAAA Chiapas, Mexico
O: 01OCT2023 03:21:00 15.9N 98.0W ML=4.0 UNAM NACIONAL, OAX, MEXICO
P: 23SEP2023 156682 16.0N 98.0W 3.5-5.4 CAAAA Oaxaca, Mexico
P: 27SEP2023 156683 16.0N 100.0W 3.5-5.3 BABAA Oaxaca, Mexico
O: 30SEP2023 10:12:24 28.0N 112.2W ML=3.6 UNAM ROSALIA, BCS, MEXICO
P: 25SEP2023 156692 28.0N 112.0W 3.5-5.2 BAAAA Gulf of California
O: 01OCT2023 05:20:19 17.9N 66.3W md=3.2 ANSS PUERTO RICO REGION
O: 01OCT2023 05:43:09 17.9N 66.3W md=3.3 ANSS PUERTO RICO REGION
O: 01OCT2023 02:22:42 17.9N 66.9W md=3.2 ANSS PUERTO RICO REGION
O: 30SEP2023 18:40:51 18.1N 66.4W md=3.4 ANSS PUERTO RICO REGION
O: 30SEP2023 18:40:51 18.1N 66.4W md=3.4 ANSS PUERTO RICO
P: 26SEP2023 156685 19.0N 68.0W 3.4-5.1 BAAAA Puerto Rico
O: 30SEP2023 21:28:39 20.6S 67.9W mb=4.4 ANSS BOLIVIA
P: 29SEP2023 156864 21.0S 69.0W 4.0-5.7 AAAAA Coast No. Chile
AFRICA AND EUROPE
O: 30SEP2023 06:05:57 37.2N 9.1W ML=3.7 MDD SPAIN
P: 22SEP2023 156722 37.0N 10.0W 3.5-5.1 CAAAA Morocco/Spain
P: 25SEP2023 156722 39.0N 8.0W 3.5-5.1 BBAAA Morocco/Spain
O: 30SEP2023 09:38:55 36.9N 27.0E ML=4.3 GFZ AEGEAN SEA, GREECE
P: 27SEP2023 156703 38.0N 26.0E 3.0-4.7 BBAAA Aegean Sea
NEIC reported this earthquake of M 4.1 in the Dodecanese Islands, Greece was felt with intensity II-III in the area(s) of the Dodecanese Islands, Greece in Kalimnos, Khorion, Pilion, Kardamaina, Kos and in Bodrum, Mugla, Turkey.
O: 30SEP2023 08:04:22 31.1N 8.3W ML=3.9 MDD MOROCCO
O: 30SEP2023 08:04:21 31.0N 8.4W mb=4.0 ANSS MOROCCO
O: 30SEP2023 23:30:22 31.5N 8.1W ML=3.5 MDD MOROCCO
P: 22SEP2023 156722 30.0N 8.0W 3.5-5.4 CAAAA Morocco/Spain
NEIC reported this earthquake of M 4.0 in Morocco was felt with intensity II-III in the area(s) of Morocco in Marrakech and Oulad Teima, Massa-Draa.
O: 30SEP2023 09:38:52 36.9N 27.0E mb=4.1 ANSS AEGEAN SEA, GREECE
P: 27SEP2023 156703 38.0N 26.0E 3.0-4.7 BBAAA Aegean Sea
O: 30SEP2023 12:46:37 42.8N 6.2W mb=4.0 ANSS SPAIN
P: 22SEP2023 156796 43.0N 9.0W 3.0-4.9 CABAA Portugal
No significant (M>=5) or unusual earthquakes were reported in Europe today.
SOUTHWEST PACIFIC
O: 30SEP2023 19:14:04 16.2S 174.0W mb=4.6 ANSS TONGA
P: 29SEP2023 156849 15.0S 173.0W 4.0-5.8 ABAAA Samoa Islands
O: 30SEP2023 10:08:02 23.5S 174.8W mb=4.8 ANSS TONGA
P: 27SEP2023 156872 25.0S 176.0W 4.0-5.4 BBAAA Tonga Islands
P: 23SEP2023 156871 24.0S 175.0W 4.0-5.6 CAAAA Tonga Islands
OCEAN RIDGES
No significant (M>=5) or unusual earthquakes were reported on Ocean Ridges today.
ZEALANDIA AND AUSTRALIA REGION
No earthquakes of M>=4 were recorded in the regions of Zealandia or Australia
today. GeoNet did not report any felt events in the area.
JAPAN AND KURIL ISLANDS
O: 30SEP2023 17:41:58 30.8N 141.8E mb=4.5 ANSS IZU ISLANDS, JAPAN
O: 30SEP2023 17:41:58 30.9N 142.0E ML=4.7 MOS BONIN ISLANDS, JAPAN
P: 24SEP2023 156732 32.0N 142.0E 4.0-5.4 CBAAA Off East Coast Honshu
O: 30SEP2023 18:09:00 39.5N 143.6E mb=4.4 ANSS OFF EAST COAST HONSHU, JAPAN
O: 30SEP2023 18:09:02 39.5N 143.5E ML=4.6 MOS NORTHERN HONSHU, JAPAN
P: 28SEP2023 156735 39.0N 142.0E 4.0-5.4 AAAAA Off East Coast Honshu
U.S./CANADA*
WESTERN U.S./CANADA
CALIFORNIA
O: 30SEP2023 05:46:05 30.8N 115.2W ML=3.3 UNAM FELIPE, BC, MEXICO
O: 30SEP2023 8:26:39 30.4N 116.1W ML=3.3 UNAM CARDENAS, BC, MEXICO
P: 30SEP2023 156741 31.0N 116.3W 2.5-4.7 AAAAA So. California
O: 30SEP2023 09:35:51 38.1N 118.0W ml=2.1 ANSS CALIFORNIA-NEVADA BORDER
P: 29SEP2023 156705 38.2N 117.9W 2.5-4.5 AAAAA California/Nevada area
O: 30SEP2023 14:45:11 38.3N 119.4W md=2.7 ANSS CALIFORNIA-NEVADA BORDER
P: 25SEP2023 156708 38.6N 119.6W 2.5-4.4 BAAAA California/Nevada area
NEIC reported this earthquake of M 2.6 in Central California was felt with intensity II-III in the area(s) of Central California in Modesto and Fresno.
An earlier event of M 2.7 was felt with intensity II in Reno, Nevada.
O: 30SEP2023 10:25:10 38.7N 122.5W md=2.3 ANSS NORTHERN CALIFORNIA
P: 29SEP2023 156711 38.7N 122.7W 2.5-4.8 AAAAA Central California
O: 30SEP2023 16:36:43 40.4N 125.7W mw=3.7 ANSS OFF COAST OF NORTHERN CALIFORNIA
P: 25SEP2023 156792 40.9N 126.3W 2.5-4.8 BAAAA Off Coast of No. Calif
O: 30SEP2023 17:25:19 40.5N 124.5W md=2.1 ANSS OFF COAST OF NORTHERN CALIFORNIA
O: 30SEP2023 15:26:26 40.6N 124.3W mw=4.7 ANSS OFF COAST OF NORTHERN CALIFORNIA
O: 30SEP2023 17:25:19 40.5N 124.5W md=2.1 ANSS OFF COAST OF NORTHERN CALIFORNIA
O: 30SEP2023 17:16:47 40.5N 124.4W mw=4.2 ANSS OFF COAST OF NORTHERN CALIFORNIA
O: 30SEP2023 17:16:47 40.5N 124.4W mw=4.2 ANSS OFF COAST OF NORTHERN CALIFORNIA
O: 30SEP2023 19:58:21 40.5N 124.5W md=2.0 ANSS OFF COAST OF NORTHERN CALIFORNIA
O: 30SEP2023 19:58:21 40.5N 124.5W md=2.0 ANSS OFF COAST OF NORTHERN CALIFORNIA
P: 26SEP2023 156791 40.4N 124.2W 2.5-4.6 AAAAA Off Coast of No. Calif
ALASKA
No events of M>=3 were located in Alaska today.
PACIFIC NORTHWESTERN U.S./WESTERN CANADA
No events of M>=2 were located in the northwestern U.S. or western Canada today.
ROCKY MOUNTAINS REGION
No earthquakes of M>=2 were located in the Rocky Mountain region today.
EASTERN U.S./CANADA
O: 30SEP2023 09:47:28 34.5N 97.7W ml=2.0 ANSS OKLAHOMA
P: 28SEP2023 156757 35.0N 97.0W 2.0-4.1 AAAAA Southern Plains
O: 30SEP2023 11:21:51 35.3N 97.9W ml=1.7 ANSS OKLAHOMA
P: 28SEP2023 156757 35.0N 97.0W 2.0-4.1 AAAAA Southern Plains
P: 29SEP2023 156756 36.0N 97.0W 2.0-4.1 AAAAA Southern Plains
HAWAII
No earthquakes of M>=3 were located in Hawaii.
STRONG EARTHQUAKE IN MACQUARIE ISLANDS
EARTHQUAKE SUMMARY FOR SEPTEMBER 29, 2023
The strongest earthquakes in the world today occurred in the world's oceans
with an M 5.8 in the Macquarie Islands south of Australia, an M 5.2 in the Azores and an M 5.2 in the South Sandwich Islands. These occurred near local solar noon and midnight and may have been promoted by tidal stresses with the current full moon as noted in this and previous issues of this summary:
"The full moon arrived on September 29 at 09:57 UT. This is the last supermoon of the year. Supermoons occur when the moon is closest to the earth on its elliptical orbit. The considerably increases tidal stress and possibility of strong earthquakes. Longitudes which are at local solar noon at this time are located near 30 East longitude while those at local solar midnight are near 150 West longitude. In the east these include These include Hawaii and areas of eastern Alaska and western Canada and to a lesser extent areas off the coast of Oregon and California while in the east they include Eastern Turkey where an M 7.7 hit on February 6, 2023 as well as Ethiopia and areas off southern Africa and eastern Europe. These and surrounding areas are the most likely to see tidally enhanced seismicity at this time. A large to major earthquake is considered likely in the next week at this time." (September 28-30, 2023)
The last similar earthquake in the Macquarie Islands within about 300 km of today's epicenter was an M 5.7-5.8 on November 20, 2020. At the time this summary noted:
"The strongest earthquake in the world, and the only event of M>=5 today was an M 5.7 in the Macquarie Island area south of Australia. This continues a series of moderate to moderately strong earthquakes in this area which began several days ago and included event of M 4.6 on November 9; an M 5.7 on November 13 and an M 4.4 on November 14. These events occurred about 1000 km to the east of today's activity. The last activity within about 300 km of today's event with M>4 occurred on August 27, 2020 with M 4.8. The last earthquake of M>=5.7 within about 500 km of today's epicenter was an M 6.0 on August 21, 2019 and an M 6.5 April 18, 2019 and M 5.9 February 27, 2016." November 20, 2020)
O: 30SEP2023 00:32:00 52.8S 140.2E ML=5.8 AUS MACQUARIE IS
O: 30SEP2023 00:31:59 52.9S 140.2E mw=5.8 ANSS MACQUARIE ISLANDS
The event of M 5.2 in the South Sandwich Islands of larger magnitude than M 5.2 2as an M 5.7 on August 20, 2023. A regional foreshock of M 5.0 hit the South Sandwich Islands on September 25 following a series of such events in mid-September. Forecast 156892 had expected today's earthquake within about 25 km was likely in the South Sandwich Islands around September 27.
O: 29SEP2023 22:36:09 58.0S 25.5W mb=5.2 ANSS SOUTH SANDWICH ISLANDS
P: 27SEP2023 156892 58.0S 25.0W 4.0-5.8 AAAAA So. Sandwich Islands
The M 5.2 in the Azores follows a series in the Azores on September 23-25, 2023.
At the time this summary noted:
A swarm of earthquakes has been occurring in the Azores Islands region of Portugal over the past several days. The largest of these events occurred today with M 4.6 and M 4.1. This activity may be related to the passage of Hurricane Nigel through the region over the past several days as noted in previous issues of this summary. For example it was stated on September 22:
"Hurricane Nigel (15) continued today in the area of the central Atlantic north of the Azores and over the mid-Atlantic Ridge with winds up to 70 kts. It is expected to track to the northeast. Some seismic enhancement is possible in the Atlantic Ridge system as this storm passes through." (September 22, 2023)
The last earthquake with M>=4.6 within about 200 km of today's epicenters in the Azores occurred as an M 4.8 on January 27, 2020." (September 25, 2023)
Today's event was not part of that swarm having occurred about 200 km to the west of the events of September 25. Forecast 156730 expected today's event was likely in late September within about 150 km of this epicenter.
O: 29SEP2023 19:05:44 38.4N 30.2W mw=5.2 ANSS AZORES
P: 22SEP2023 156730 38.0N 32.0W 4.0-5.6 CABAA No. Mid-Atlantic Ridge
The strongest earthquake in the U.S. or Canada today was an M 4.7-4.9 in the eastern Andreanof Islands, Aleutians, Alaska. It was not reported felt in this remote area. Forecast 156814 had expected today's event was likely within about 100 km was likely to occur around September 26.
O: 29SEP2023 15:23:51 51.0N 170.2W ML=4.7 MOS ANDREANOF ISLANDS
O: 29SEP2023 15:24:21 56.7N 173.5W ML=4.9 GFZ ANDREANOF ISLANDS
O: 29SEP2023 15:23:51 51.1N 170.2W mb=4.2 ANSS ANDREANOF ISLANDS
P: 26SEP2023 156814 51.9N 169.2W 3.5-5.0 BAAAA Fox Islands, Aleutians
OTHER GLOBAL EARTHQUAKE ACTIVITY
For most events there are two listings. The first line is the observed event starting with "O:" for Observed. There follows the date, month and year, the time in UT hours:minutes:seconds, the latitude and longitude, the given magnitude and the reporting agency followed by the geographic location. The second line starts with "P:" This is the forecast event as forecast in our summaries normally more than a month in advance. Magnitudes may vary in response to updated seismic watches and daily variations due to tidal and other influences. This line has the forecast date, month and year, the forecast number, latitude, longitude and forecast magnitude range. This is followed by a comparison between the forecast and the event. The comparison includes letters A-D. The first is number of days difference from predicted (A:up to 2, B3-5; C:6-10; D:more than 10), Difference in latitude (A:up to 1 degree; B:1-2 degrees; C:2-4 degrees; D:more than 4 degrees); longitude (same comparison as with latitude); magnitude (A: within forecast range; B: higher than forecast range; C: lower than forecast range; D: no comparison possible). The last letter is a stand in for a future comparison which needs to be done statistically after a large number of forecasts have been made. In previous data, an excellent match is generally AAAAA; a good match as one or two B's; a fair match has several B's and C's and a poor match is one which contains a number of C's or D's.
ASIA
O: 29SEP2023 12:25:52 37.5N 56.8E mb=4.4 ANSS NORTHERN IRAN
O: 29SEP2023 12:25:53 37.3N 56.9E ML=4.6 GFZ NORTHERN IRAN
P: 24SEP2023 156729 37.0N 55.0E 3.8-5.3 BABAA No. Iran
O: 29SEP2023 16:29:43 50.2N 153.5E ML=4.0 KRS KAMCHATKA
P: 25SEP2023 156784 49.0N 155.0E 3.5-5.5 BBAAA NE Pacific
O: 30SEP2023 01:09:51 45.3N 137.1E ML=4.1 MOS SAKHALIN, RUSSIA
P: 22SEP2023 156799 41.0N 136.0E 3.5-5.5 CCAAA Sea of Japan
INDONESIA AND PHILIPPINES
O: 30SEP2023 02:07:43 0.5N 126.3E mb=4.4 ANSS CERAM, INDONESIA
P: 27SEP2023 156633 1.0N 127.0E 4.0-5.4 BAAAA Halmahera
O: 30SEP2023 06:33:43 9.1S 105.4E mb=4.9 ANSS SOUTH OF SUMATRA, INDONESIA
P: 28SEP2023 156655 9.0S 106.0E 4.0-5.4 AAAAA So. of Java
O: 29SEP2023 11:41:14 4.1S 138.4E ML=4.4 GFZ PAPUA NEW GUINEA
O: 29SEP2023 11:41:12 4.3S 138.5E mb=4.1 ANSS PAPUA NEW GUINEA
P: 27SEP2023 156662 5.0S 138.0E 4.0-5.4 AAAAA West Irian, PNG
No significant (M>=5) or unusual earthquakes were reported in Indonesia or the Philippines today.
CENTRAL AND SOUTH AMERICA
O: 29SEP2023 07:58:11 15.6S 70.6W ML=4.3 GFZ CENTRAL PERU
O: 29SEP2023 07:58:12 15.7S 70.5W mb=4.3 ANSS CENTRAL PERU
P: 28SEP2023 156852 17.0S 70.0W 4.0-5.7 ABAAA So. Peru/Bolivia
O: 29SEP2023 15:32:31 16.7N 95.7W mb=4.5 ANSS OAXACA, MEXICO
O: 29SEP2023 14:32:37 16.5N 95.8W ML=4.5 UNAM TEHUANTEPEC, OAX, MEXICO
P: 27SEP2023 156667 15.0N 95.0W 3.5-5.5 ABAAA Chiapas, Mexico
NEIC reported this earthquake of M 4.5 in Oaxaca, Mexico was felt with intensity II-III in the area(s) of Mexico in Tlalnepantla.
O: 29SEP2023 15:17:08 17.9N 66.3W md=3.0 ANSS PUERTO RICO
O: 29SEP2023 15:17:08 17.9N 66.3W md=3.0 ANSS PUERTO RICO
O: 30SEP2023 03:56:45 17.9N 66.3W md=3.2 ANSS PUERTO RICO
O: 29SEP2023 19:38:55 18.8N 67.4W md=3.0 ANSS PUERTO RICO
O: 29SEP2023 20:20:34 18.8N 67.4W md=3.2 ANSS PUERTO RICO
P: 28SEP2023 156684 18.0N 69.0W 3.4-4.9 AACAA Puerto Rico
O: 30SEP2023 00:21:36 19.5N 67.9W md=3.7 ANSS DOMINICAN REPUBLIC
P: 26SEP2023 156685 19.0N 68.0W 3.4-5.1 BAAAA Puerto Rico
P: 29SEP2023 156689 20.0N 69.0W 3.0-4.6 AAAAA Bahamas/No. Caribbean
O: 30SEP2023 05:14:07 24.1S 67.1W mb=4.5 ANSS ARGENTINA
O: 30SEP2023 01:21:01 24.0S 67.0W mb=4.4 ANSS ARGENTINA
P: 29SEP2023 156864 24.0S 69.0W 4.0-5.7 AABAA Coast No. Chile
P: 30SEP2023 156860 22.0S 68.0W 4.0-5.9 ABAAA Argentina
O: 29SEP2023 11:55:38 27.7S 71.5W mw=4.1 ANSS VALLENAR, CHILE
O: 29SEP2023 11:55:41 27.7S 71.4W ML=4.7 GFZ ATACAMA, CHILE
P: 24SEP2023 156863 28.0S 71.0W 4.0-5.6 AAAAA Coast Central Chile
O: 29SEP2023 7:21:47 14.7N 93.9W ML=4.0 UNAM PIJIJIAPAN, CHIS, MEXICO
O: 29SEP2023 17:39:25 14.3N 93.9W ML=4.1 UNAM MAPASTEPEC, CHIS, MEXICO
O: 30SEP2023 02:21:00 15.7N 93.5W ML=3.9 UNAM PIJIJIAPAN, CHIS, MEXICO
O: 29SEP2023 17:12:30 15.2N 94.6W ML=4.1 UNAM CRUZ, OAX, MEXICO
P: 27SEP2023 156667 15.0N 95.0W 3.5-5.5 AAAAA Chiapas, Mexico
AFRICA AND EUROPE
O: 30SEP2023 06:05:57 37.2N 9.1W ML=3.7 MDD SPAIN
P: 22SEP2023 156722 37.0N 10.0W 3.5-5.1 CAAAA Morocco/Spain
P: 25SEP2023 156722 39.0N 8.0W 3.5-5.1 BBAAA Morocco/Spain
No significant (M>=5) or unusual earthquakes were reported in Europe today.
SOUTHWEST PACIFIC
O: 29SEP2023 15:45:13 17.7S 175.0W mb=4.4 ANSS TONGA
P: 26SEP2023 156855 16.0S 173.0W 4.0-5.8 BBBAA Tonga Islands
O: 29SEP2023 08:58:02 14.8S 177.7W mb=4.6 ANSS SAMOA
O: 29SEP2023 08:58:03 14.8S 177.9W ML=4.6 GFZ TONGA
P: 29SEP2023 156849 15.0S 173.0W 4.0-5.8 AACAA Samoa Islands
O: 30SEP2023 06:10:41 22.5S 171.6E mb=4.9 ANSS LOYALTY ISLANDS
P: 26SEP2023 156873 23.0S 173.0E 4.0-5.6 BABAA Tonga/Fiji
No significant (M>=5) or unusual earthquakes were reported in the Southwest Pacific region today.
OCEAN RIDGES
O: 29SEP2023 19:05:44 38.4N 30.2W mw=5.2 ANSS AZORES
P: 22SEP2023 156730 38.0N 32.0W 4.0-5.6 CABAA No. Mid-Atlantic Ridge
O: 30SEP2023 00:32:00 52.8S 140.2E ML=5.8 AUS MACQUARIE IS
O: 30SEP2023 00:31:59 52.9S 140.2E mw=5.8 ANSS MACQUARIE ISLANDS
O: 29SEP2023 22:36:09 58.0S 25.5W mb=5.2 ANSS SOUTH SANDWICH ISLANDS
P: 27SEP2023 156892 58.0S 25.0W 4.0-5.8 AAAAA So. Sandwich Islands
ZEALANDIA AND AUSTRALIA REGION
No earthquakes of M>=4 were recorded in the regions of Zealandia or Australia
today. GeoNet did not report any felt events in the area.
JAPAN AND KURIL ISLANDS
O: 29SEP2023 07:57:52 37.0N 140.2E ML=4.9 GFZ OFF COAST OF EASTERN HONSHU
O: 29SEP2023 07:57:51 36.8N 140.3E mb=4.5 ANSS OFF COAST OF EASTERN HONSHU, J
P: 24SEP2023 156733 36.0N 141.0E 4.0-5.4 BAAAA Off East Coast Honshu
P: 27SEP2023 156733 35.0N 141.0E 4.0-5.4 ABAAA Off East Coast Honshu
P: 26SEP2023 156734 38.0N 140.0E 4.0-5.6 BAAAA Off East Coast Honshu
NEIC reported this earthquake of M 4.5 in eastern Honshu, Japan was felt with intensity II-III in the area(s) of eastern Honshu, Japan in Tokyo.
O: 29SEP2023 15:44:58 40.2N 144.1E ML=4.9 MOS HOKKAIDO, JAPAN
O: 29SEP2023 15:44:57 40.1N 144.2E mb=4.6 ANSS HOKKAIDO, JAPAN
P: 25SEP2023 156774 40.0N 143.0E 3.5-5.6 BAAAA Hokkaido, Japan
O: 30SEP2023 03:07:24 43.4N 143.9E mb=4.4 ANSS KURIL ISLANDS
O: 30SEP2023 03:07:24 43.4N 143.9E ML=4.5 MOS KURIL ISLANDS
P: 25SEP2023 156774 40.0N 143.0E 3.5-5.6 BCAAA Hokkaido, Japan
U.S./CANADA*
WESTERN U.S./CANADA
CALIFORNIA
O: 29SEP2023 13:14:25 31.1N 115.6W ML=2.9 UNAM GUERRERO, BC, MEXICO
O: 29SEP2023 13:14:43 31.1N 115.5W ML=3.1 UNAM GUERRERO, BC, MEXICO
O: 29SEP2023 16:40:41 31.3N 115.3W ML=3.0 UNAM FELIPE, BC, MEXICO
O: 29SEP2023 19:47:14 31.3N 115.3W ML=3.0 UNAM FELIPE, BC, MEXICO
O: 30SEP2023 04:03:00 31.4N 115.6W ML=3.4 UNAM GUERRERO, BC, MEXICO
O: 29SEP2023 11:45:49 30.8N 116.1W ML=3.5 UNAM GUERRERO, BC, MEXICO
O: 29SEP2023 17:00:26 31.4N 115.4W ml=2.9 ANSS SOUTHERN CALIFORNIA : 29SEP20
P: 30SEP2023 156741 31.0N 116.3W 2.5-4.7 AAAAA So. California
O: 29SEP2023 19:13:26 32.7N 115.6W ml=2.9 ANSS SOUTHERN CALIFORNIA
O: 30SEP2023 00:30:02 33.1N 115.6W ml=2.4 ANSS SOUTHERN CALIFORNIA
O: 29SEP2023 19:03:59 32.7N 115.6W ml=2.1 ANSS SOUTHERN CALIFORNIA
P: 28SEP2023 156744 32.4N 115.8W 2.5-4.7 AAAAA So. California
NEIC reported this earthquake of M 2.9 in Southern California was felt with intensity II-III in the area(s) of Southern California in Heber and Mexicali (IV) and III in Calexico, El Centro and Palmdale.
O: 29SEP2023 10:30:23 33.3N 116.8W ml=2.0 ANSS SOUTHERN CALIFORNIA
O: 29SEP2023 13:14:26 34.1N 116.4W ml=2.2 ANSS SOUTHERN CALIFORNIA
P: 28SEP2023 156747 34.7N 116.4W 2.5-4.9 AAAAA So. California
P: 29SEP2023 156745 33.9N 116.9W 2.5-4.8 AAAAA So. California
O: 29SEP2023 16:46:23 35.3N 118.6W ml=2.1 ANSS CENTRAL CALIFORNIA
P: 27SEP2023 156749 35.3N 118.6W 2.5-4.6 AAAAA So. California
O: 29SEP2023 14:03:32 38.8N 122.8W md=2.6 ANSS NORTHERN CALIFORNIA
O: 30SEP2023 00:25:56 39.0N 122.2W md=2.3 ANSS NORTHERN CALIFORNIA
O: 29SEP2023 14:46:30 38.8N 122.8W md=2.1 ANSS NORTHERN CALIFORNIA
P: 29SEP2023 156711 38.7N 122.7W 2.5-4.8 AAAAA Central California
O: 29SEP2023 15:47:44 39.7N 120.3W md=2.4 ANSS NORTHERN CALIFORNIA
P: 30SEP2023 156790 40.3N 121.2W 2.5-4.5 AAAAA Northern California
ALASKA
O: 29SEP2023 15:23:51 51.0N 170.2W ML=4.7 MOS ANDREANOF ISLANDS
O: 29SEP2023 15:24:21 56.7N 173.5W ML=4.9 GFZ ANDREANOF ISLANDS
O: 29SEP2023 15:23:51 51.1N 170.2W mb=4.2 ANSS ANDREANOF ISLANDS
P: 26SEP2023 156814 51.9N 169.2W 3.5-5.0 BAAAA Fox Islands, Aleutians
O: 29SEP2023 07:40:56 51.5N 178.0W mb=3.7 ANSS ANDREANOF ISLANDS
P: 26SEP2023 156809 51.9N 179.8W 3.5-5.3 BAAAA Andreanoff Isls, Aleutians
O: 30SEP2023 00:46:33 54.7N 156.7W ml=3.2 ANSS SE of Perryville Alaska
P: 27SEP2023 156807 54.7N 156.9W 3.5-4.9 BAAAA Alaska Peninsula
PACIFIC NORTHWESTERN U.S./WESTERN CANADA
No events of M>=2 were located in the northwestern U.S. or western Canada today.
ROCKY MOUNTAINS REGION
O: 29SEP2023 09:11:01 31.8N 104.2W ml=2.0 ANSS WESTERN TEXAS
O: 29SEP2023 20:14:40 31.5N 104.0W ml=2.5 ANSS WESTERN TEXAS
P: 27SEP2023 156738 31.6N 103.6W 2.0-4.1 AAAAA SW U.S.A
O: 30SEP2023 06:08:07 32.7N 100.7W ml=3.1 ANSS WESTERN TEXAS
O: 30SEP2023 01:11:31 32.7N 100.7W ml=3.0 ANSS WESTERN TEXAS
P: 23SEP2023 156738 31.6N 101.6W 2.0-4.1 CAAAA SW U.S.A
NEIC reported this earthquake of M 3.0 in Western Texas was felt with intensity II-III in the area(s) of Western Texas in Hermleigh.
O: 29SEP2023 19:15:44 44.5N 115.2W ml=2.4 ANSS SOUTHERN IDAHO
P: 24SEP2023 156780 44.4N 115.1W 2.0-4.1 BAAAA Montana/Idaho
O: 29SEP2023 12:26:31 44.8N 114.4W ml=2.2 ANSS SOUTHERN IDAHO
P: 27SEP2023 156780 44.4N 114.1W 2.0-4.1 AAAAA Montana/Idaho
EASTERN U.S./CANADA
O: 29SEP2023 20:17:32 60.6N 63.8W mb=4.2 ANSS GREENLAND
O: 29SEP2023 20:17:37 60.5N 64.0W MB=4.1 ECAN of Kangiqsualujjuaq, QC
O: 28SEP2023 23:15:43 61.3N 59.5W MB=4.3 ECAN of Nuuk, GL
P: 23SEP2023 156827 61.0N 58.0W 2.5-4.0 BAAAA Baffin/Davis Strait Canada
O: 29SEP2023 09:20:27 41.8N 81.0W MB=2.4 ECAN of Cleveland, OH
P: 26SEP2023 156794 41.8N 81.4W 2.0-3.9 BAAAA Ohio/Lake Erie
HAWAII
O: 30SEP2023 02:42:39 19.1N 155.4W ml=3.2 ANSS HAWAII
P: 22SEP2023 156671 19.2N 155.2W 3.0-4.5 CAAAA Hawaii
NEIC reported this earthquake of M 3.2 in Hawaii was felt with intensity II-III in the area(s) of Hawaii in Naalehu.
STRONG INCREASE IN SEISMICITY WITH FULL SUPER-MOON TIDAL STRESSES
EARTHQUAKE SUMMARY FOR SEPTEMBER 28, 2023
Seismicity was considerably higher in the world today than in the past week. Included in this activity was an M 6.1 in Vanuatu and an M 6.3 in New Ireland. These are near the equator and as noted in previous issues of this summary may have been promoted by strong tidal stresses associated with the overhead noon time sun at this time of year as In the previous summary this had been addressed as:
"A series of earthquakes occurred along the equator over the past several days.
These included moderate events in Gabon, the Central Atlantic, Ecuador, Indonesia and Rwanda among others. This summary has noted in previous issues that seismic enhancement often occurs at sub-solar latitudes due to the vertical tidal stresses. At the fall and spring equinox the sun is directly over the equator and can help promote seismicity along the equator as is currently being seen with the fall equinox." (September 28, 2023)
Among today's equatorial earthquakes were a series in Papua New Guinea and New Ireland which included events of MM 5.6, M 5.4-5.5 and M 5.0. The last earthquake of M>=5.4 in New Ireland was an M 6.0 on March 7, 2023 about 250 km north of today's events. A series of smaller events occurred in the past week as a regional activation of seismicity. This included an M 4.5 on September 27, an M 4.7 on September 24 and an M 5.0 on September 22, 2023. Forecast 156649 had expected today's activity within about 25 km was likely at the end of September.
This activity is at 148 degrees from the M 6.8 in Morocco of September 8 and at 103 degrees from the Prince Edward Islands M 6.8 of May 21, 2023 and at the fifth node (72 degrees) from the Alaska Peninsula and may have been promoted by energy from those sources.
O: 29SEP2023 01:53:17 5.2S 152.8E mb=5.0 ANSS NEW IRELAND
O: 29SEP2023 01:19:37 4.6S 153.2E mw=5.5 ANSS PAPUA NEW GUINEA
O: 29SEP2023 01:19:36 4.6S 153.1E ML=5.4 GFZ NEW IRELAND
O: 29SEP2023 00:14:36 5.3S 152.7E mb=4.7 ANSS PAPUA NEW GUINEA
O: 28SEP2023 19:39:04 5.3S 152.9E mb=4.5 ANSS PAPUA NEW GUINEA
O: 29SEP2023 01:19:36 4.6S 153.1E ML=5.4 GFZ NEW IRELAND
O: 28SEP2023 19:21:14 5.2S 152.7E ML=5.6 GFZ NEW BRITAIN
P: 26SEP2023 156649 7.0S 154.0E 4.0-5.6 ABBAA New Britain
P: 22SEP2023 156649 5.0S 153.0E 4.0-5.4 CAAAA New Britain
A strong earthquake also occurred today in the region of the Kuril Islands, Hokkaido, Japan with M 6.2. The last earthquake within the Kuril Islands and within about 200 km of today's epicenter was an M 7.0 on February 13, 2020 and an M 6.3 on July 7, 2015. On February 13, 2020 this summary noted in regard to the seismic history of this region:
"Today's event of M 7.0 in the Kuril Islands is the strongest quake recorded in the Southern Kuril Islands in near seven years - since an M 7.2 on April 19, 2013 and prior to that an M 7.3 on November 17, 2002. After the M 7.7 in Cuba region of January 28, it is the strongest earthquake in the world during 2020." (February 13, 2020)
Forecast 156774 had expected today's event was likely around September 27 within about 50 km. This epicenter is located at 102 degrees from the M 6.8 in Morocco of September 8, 2023 and may have been promoted by energy from that source.
O: 28SEP2023 17:40:04 44.3N 148.6E mw=5.8 ANSS KURIL ISLANDS
O: 28SEP2023 17:40:07 44.3N 148.5E ML=6.2 GFZ KURIL ISLANDS
P: 27SEP2023 156774 44.0N 149.0E 3.5-5.4 AAAAA Hokkaido, Japan
Another strong earthquake in the world today was an M 6.1 in Central Vanuatu. NEIC reported it was felt with intensity IV in Luganville, Sanma. The last earthquakes in Vanuatu of equal of greater magnitude than M 6.0 were an M 6.1 on September 21, 2023 about 200 km north of today's epicenter and a similarly placed M 6.5 on August 16, 2023. At the time of the August event this summary noted:
"The strongest earthquake in the world today was an M 6.5 in northern Vanuatu. The mainshock was reported by NEIC to have been felt with intensity VII in Vanuatu at Sola Torba and IV in Sanma at Port Olry and Luganville and possibly in the Solomon Islands and New South Wales, Australia. The mainshock was preceded by an M 5.2 regional foreshock several hours earlier. That event was
felt with intensity III in Luganville, Sanma, Vanuatu. An aftershock of M 4.3 was felt with intensity IV in Port Olry, Sanma, Vanuatu. The mainshock within minutes of local solar midnight and most likely was promoted by tidal stresses with the new moon which was completed within hours of the occurrence of this earthquake. This is the first earthquake of M>=6.5 in the world since an M 6.5 in El Salvador on July 19, 2023 with the last new moon. Other strong earthquakes with that new moon were an M 6.6 in Chile and an M 7.2 in the Alaska Peninsula.
…
Today's event of M 6.5 is the largest in northern Vanuatu since an M 7.0 about 150 km south of this epicenter on January 8, 2023. The last within 100 km at this magnitude level was an M 6.6 on January 15, 2019. Today's event occurred within several minutes of local solar midnight and was probably promoted by tidal stresses with today's new moon which maximize near this hour." (August 16, 2023)
Today's event also occurred near local solar midnight and may have been promoted by strong tidal stresses with the full moon as noted in this and previous issues of this summary:
"The full moon will arrive on September 29 at 09:57 UT. This is the last supermoon of the year. Supermoons occur when the moon is closest to the earth on its elliptical orbit. The considerably increases tidal stress and possibility of strong earthquakes. Longitudes which are at local solar noon at this time are located near 30 East longitude while those at local solar midnight are near 150 West longitude. In the east these include These include Hawaii and areas of eastern Alaska and western Canada and to a lesser extent areas off the coast of Oregon and California while in the east they include Eastern Turkey where an M 7.7 hit on February 6, 2023 as well as Ethiopia and areas off southern Africa and eastern Europe. These and surrounding areas are the most likely to see tidally enhanced seismicity at this time. A large to major earthquake is considered likely in the next week at this time." (September 28, 2023)
Forecast 156859 had expected this earthquake in Vanuatu was likely about 150 km south of today's epicenter around September 28.
O: 28SEP2023 14:40:27 15.5S 167.6E ML=6.0 GFZ VANUATU
O: 28SEP2023 14:40:26 15.6S 167.7E mw=6.1 ANSS VANUATU
P: 28SEP2023 156859 17.0S 168.0E 4.0-5.9 ABAAA Vanuatu Islands
The largest earthquake in the U.S. or Canada or vicinity today was an M 4.3 near Nuuk, Greenland. A similar M 4.3 hit this area on August 1, 2023. Other event of M>=4.3 in this area have occurred as an M 5.2 on July 12, 2022 and prior to that in 2005 and 2006 with M 4.4, 4.3 and 4.6. The M 5.2 in July, 2022 is the largest reported in this area in the past 35 years and was noted in this summary at the time as:
"A series of unusual earthquake today in many area of the western hemisphere appear to be related to strong tidal stresses associated with the super-moon which will be complete on July 13. ...
The M 5.1-5.2 in the Davis Strait near Greenland was the strongest event in the U.S. or Canada today. It may have been lightly felt in this remote epicentral area. This earthquake occurred within about an hour of local solar noon and was probably promoted by high tides associated with the full moon of July 13 and/or geomagnetic effects from today's geomagnetic storm as reported in this summary:
This is the strongest earthquake within about 300 km of this epicenter in at least 30 years. The only event in the region with M>4.6 since 1990 was an M 4.9 about 200 km to the east on July 29, 1999." (July 12, 2022)
Forecast 156827 had expected today's event within about 50 km was likely around September 23.
O: 28SEP2023 23:15:43 61.3N 59.5W MB=4.3 ECAN of Nuuk, GL
P: 23SEP2023 156827 61.0N 58.0W 2.5-4.0 BAAAA Baffin/Davis Strait Canada
An M 3.0 was also recorded in northern Greenland today. It was not felt in this remote epicentral area. This event occurred within minutes of local solar noon and may have been promoted by strong tidal stresses with the supermoon.
O: 28SEP2023 12:45:48 80.0N 1.2W ML=3.0 BER GREENLAND
An earthquake of M 3.5 was also felt in southeastern Alaska today. The last earthquake of larger magnitude within about 200 km of this epicenter was an M 4.0 on September 14, 2023. The last event of M>4 in the area was an M 4.4 on August 6, 2023. Forecast 156824 had expected today's event in this region was likely around September 30, 2023.
O: 29SEP2023 02:35:52 58.4N 133.5W ML=3.5 PGC SOUTHEAST ALASKA
O: 29SEP2023 02:35:52 58.4N 133.5W MB=3.5 ECAN of Juneau, Alaska, USA
P: 30SEP2023 156824 58.0N 136.0W 3.0-4.4 AABAA Southeast Alaska
OTHER GLOBAL EARTHQUAKE ACTIVITY
For most events there are two listings. The first line is the observed event starting with "O:" for Observed. There follows the date, month and year, the time in UT hours:minutes:seconds, the latitude and longitude, the given magnitude and the reporting agency followed by the geographic location. The second line starts with "P:" This is the forecast event as forecast in our summaries normally more than a month in advance. Magnitudes may vary in response to updated seismic watches and daily variations due to tidal and other influences. This line has the forecast date, month and year, the forecast number, latitude, longitude and forecast magnitude range. This is followed by a comparison between the forecast and the event. The comparison includes letters A-D. The first is number of days difference from predicted (A:up to 2, B3-5; C:6-10; D:more than 10), Difference in latitude (A:up to 1 degree; B:1-2 degrees; C:2-4 degrees; D:more than 4 degrees); longitude (same comparison as with latitude); magnitude (A: within forecast range; B: higher than forecast range; C: lower than forecast range; D: no comparison possible). The last letter is a stand in for a future comparison which needs to be done statistically after a large number of forecasts have been made. In previous data, an excellent match is generally AAAAA; a good match as one or two B's; a fair match has several B's and C's and a poor match is one which contains a number of C's or D's.
ASIA
O: 28SEP2023 14:10:00 40.0N 75.8E ML=4.1 KRN NORTHERN INDIA
P: 30SEP2023 156776 40.0N 75.0E 4.0-5.6 AAAAA Kirgizstan/Xinjiang
INDONESIA AND PHILIPPINES
O: 28SEP2023 09:05:40 2.9S 126.5E mb=4.9 ANSS SERAM, INDONESIA
O: 28SEP2023 09:05:40 2.7S 126.6E ML=4.9 GFZ CERAM, INDONESIA
P: 24SEP2023 156644 4.0S 127.0E 4.0-5.4 BBAAA Ceram area
P: 27SEP2023 156633 1.0N 127.0E 4.0-5.4 AAAAA Halmahera
O: 28SEP2023 19:21:17 5.3S 152.8E mw=5.7 ANSS PAPUA NEW GUINEA
P: 22SEP2023 156649 5.0S 153.0E 4.0-5.4 CAAAA New Britain
P: 26SEP2023 156649 7.0S 154.0E 4.0-5.6 ABAAA New Britain
O: 28SEP2023 19:43:36 5.9S 149.2E mb=5.2 ANSS PAPUA NEW GUINEA
P: 25SEP2023 156650 6.0S 151.0E 4.0-5.4 BABAA New Ireland
O: 28SEP2023 11:16:44 6.6S 129.6E mb=4.6 ANSS BANDA SEA
O: 28SEP2023 11:16:45 6.6S 129.7E ML=4.9 GFZ BANDA SEA
O: 28SEP2023 14:00:46 6.3S 130.1E ML=4.9 GFZ BANDA SEA
O: 28SEP2023 14:00:45 6.3S 130.1E mb=4.9 ANSS BANDA SEA
P: 29SEP2023 156644 3.0S 129.0E 4.0-5.4 ACAAA Ceram area
P: 29SEP2023 156644 3.0S 129.0E 4.0-5.4 ACAAA Ceram area
O: 28SEP2023 17:06:26 9.1N 126.5E mb=4.9 ANSS MINDANAO, PHILIPPINES
O: 28SEP2023 17:06:23 9.0N 126.6E ML=5.3 GFZ MINDANAO, PHILIPPINES
P: 26SEP2023 156629 9.0N 126.0E 4.0-5.4 AAAAA Central Philippines
O: 28SEP2023 17:26:43 12.5N 126.0E mb=4.7 ANSS PHILIPPINES
O: 28SEP2023 17:26:53 12.6N 126.0E ML=4.8 GFZ CENTRAL PHILIPPINES
P: 25SEP2023 156674 12.0N 124.0E 3.5-4.9 BABAA Luzon, Philippines
O: 29SEP2023 01:53:17 5.2S 152.8E mb=5.0 ANSS NEW IRELAND
O: 29SEP2023 01:19:37 4.6S 153.2E mw=5.5 ANSS PAPUA NEW GUINEA
O: 29SEP2023 01:19:36 4.6S 153.1E ML=5.4 GFZ NEW IRELAND
O: 29SEP2023 00:14:36 5.3S 152.7E mb=4.7 ANSS PAPUA NEW GUINEA
O: 28SEP2023 19:39:04 5.3S 152.9E mb=4.5 ANSS PAPUA NEW GUINEA
O: 28SEP2023 19:21:14 5.2S 152.7E ML=5.6 GFZ NEW BRITAIN
P: 26SEP2023 156649 7.0S 154.0E 4.0-5.6 ABBAA New Britain
O: 28SEP2023 19:43:36 6.0S 149.0E ML=5.2 GFZ PAPUA NEW GUINEA
P: 25SEP2023 156650 6.0S 151.0E 4.0-5.4 BABAA New Ireland
CENTRAL AND SOUTH AMERICA
O: 28SEP2023 19:46:18 13.3N 90.2W mb=4.6 ANSS GUATEMALA
O: 28SEP2023 19:46:20 13.4N 90.0W ML=4.8 GFZ GUATEMALA
P: 24SEP2023 156669 13.0N 90.0W 3.5-5.4 BAAAA Guatemala
NEIC reported this earthquake of M 4.6 in Guatemala was felt with intensity II-III in the area(s) of Guatemala in Escuintla at San Jose, Siquinala and in Chiapas, Mexico.
O: 28SEP2023 12:05:00 18.8N 69.8W mb=4.2 ANSS DOMINICAN REPUBLIC
P: 28SEP2023 156684 18.0N 69.0W 3.4-4.9 AAAAA Puerto Rico
NEIC reported this earthquake of M 4.2 in the Dominican Republic was felt with intensity II-III in the area(s) of the Dominican Republic in Santo Domingo.
O: 28SEP2023 11:26:13 18.8N 64.3W md=3.6 ANSS VIRGIN ISLANDS
O: 29SEP2023 00:12:18 19.0N 64.4W md=3.7 ANSS VIRGIN ISLANDS
P: 27SEP2023 156673 18.0N 64.0W 3.0-5.0 AAAAA Leeward Islands
O: 29SEP2023 01:54:18 21.0S 68.8W mw=4.2 ANSS BOLIVIA
P: 29SEP2023 156864 21.0S 69.0W 4.0-5.7 AAAAA Coast No. Chile
P: 30SEP2023 156860 22.0S 68.0W 4.0-5.9 AAAAA Argentina
O: 29SEP2023 05:39:44 21.3S 68.6W mb=4.4 ANSS CHILE
P: 29SEP2023 156864 21.0S 69.0W 4.0-5.7 AAAAA Coast No. Chile
NEIC reported this earthquake of M 4.2 in Tarapaca, Chile was felt with intensity II-III in the area(s) of Tarapaca, Chile in Iquique.
O: 28SEP2023 06:57:12 23.8S 70.2W mb=4.2 ANSS ANTOFAGASTA, CHILE
P: 29SEP2023 156864 24.0S 69.0W 4.0-5.7 AAAAA Coast No. Chile
O: 29SEP2023 03:00:00 13.3N 92.6W ML=4.1 UNAM HIDALGO, CHIS, MEXICO
O: 29SEP2023 04:32:00 14.0N 93.4W ML=4.1 UNAM HIDALGO, CHIS, MEXICO
P: 30SEP2023 156666 14.0N 93.0W 3.5-5.6 AAAAA Chiapas, Mexico
O: 28SEP2023 15:14:45 17.7N 92.8W ML=4.0 UNAM MACUSPANA, TAB, MEXICO
P: 25SEP2023 156667 17.0N 94.0W 3.5-5.3 BAAAA Chiapas, Mexico
O: 28SEP2023 22:58:41 16.0N 95.2W ML=4.0 UNAM CRUZ, OAX, MEXICO
O: 28SEP2023 13:49:48 15.3N 94.5W ML=3.9 UNAM TONALA, CHIS, MEXICO
P: 27SEP2023 156667 15.0N 95.0W 3.5-5.5 AAAAA Chiapas, Mexico
O: 28SEP2023 19:47:11 19.5N 107.3W ML=4.2 UNAM VALLARTA, JAL, MEXICO
P: 28SEP2023 156668 19.0N 109.0W 3.5-5.3 AAAAA Coast of Jalisco, Mexico
O: 28SEP2023 23:03:34 30.8N 114.4W ML=3.9 UNAM FELIPE, BC, MEXICO
P: 30SEP2023 156741 31.0N 116.3W 2.5-4.7 AABAA So. California
O: 28SEP2023 23:28:58 31.2N 115.3W ML=3.1 UNAM FELIPE, BC, MEXICO
P: 29SEP2023 156741 31.9N 116.3W 2.5-4.6 AAAAA So. California
AFRICA AND EUROPE
No significant (M>=5) or unusual earthquakes were reported in Europe today.
SOUTHWEST PACIFIC
O: 28SEP2023 14:40:27 15.5S 167.6E ML=6.0 GFZ VANUATU
O: 28SEP2023 14:40:26 15.6S 167.7E mw=6.1 ANSS VANUATU
P: 28SEP2023 156859 17.0S 168.0E 4.0-5.9 ABAAA Vanuatu Islands
O: 29SEP2023 01:39:44 17.9S 178.1W mb=4.3 ANSS FIJI REGION
P: 25SEP2023 156856 17.0S 179.0W 4.0-5.4 BAAAA Tonga Islands
O: 28SEP2023 23:27:48 19.3S 177.9W mb=4.9 ANSS FIJI REGION
O: 28SEP2023 18:19:12 19.2S 177.6W mb=4.4 ANSS FIJI REGION
O: 28SEP2023 18:19:14 19.3S 177.6W ML=4.8 GFZ FIJI REGION
O: 28SEP2023 23:27:49 19.3S 177.7W ML=4.8 GFZ FIJI REGION
P: 27SEP2023 156856 18.0S 179.0W 4.0-5.6 ABAAA Tonga Islands
OCEAN RIDGES
No significant (M>=5) or unusual earthquakes were reported on Ocean Ridges today.
ZEALANDIA AND AUSTRALIA REGION
No earthquakes of M>=4 were recorded in the regions of Zealandia or Australia
today. GeoNet did not report any felt events in the area.
JAPAN AND KURIL ISLANDS
O: 28SEP2023 14:29:48 37.4N 137.0E ML=4.8 GFZ HONSHU, JAPAN
O: 28SEP2023 14:29:48 37.4N 137.2E mb=4.5 ANSS HONSHU, JAPAN
P: 30SEP2023 156713 34.0N 137.0E 3.5-4.9 ACAAA Central/So. Honshu Japan
O: 28SEP2023 17:40:04 44.3N 148.6E mw=5.8 ANSS KURIL ISLANDS
O: 28SEP2023 17:40:07 44.3N 148.5E ML=6.2 GFZ KURIL ISLANDS
P: 27SEP2023 156774 44.0N 149.0E 3.5-5.4 AAAAA Hokkaido, Japan
U.S./CANADA*
WESTERN U.S./CANADA
CALIFORNIA
O: 28SEP2023 23:44:53 31.8N 116.2W ml=2.5 ANSS BAJA CALIFORNIA MEXICO
P: 29SEP2023 156741 31.9N 116.3W 2.5-4.6 AAAAA So. California
O: 29SEP2023 05:50:26 35.5N 118.4W ml=2.4 ANSS CENTRAL CALIFORNIA
P: 27SEP2023 156749 35.3N 118.6W 2.5-4.6 AAAAA So. California
O: 28SEP2023 07:04:51 38.2N 117.8W ml=2.2 ANSS NEVADA
P: 29SEP2023 156705 38.2N 117.9W 2.5-4.5 AAAAA California/Nevada area
O: 28SEP2023 17:56:18 38.3N 119.4W md=2.7 ANSS CENTRAL CALIFORNIA
P: 25SEP2023 156708 38.6N 119.6W 2.5-4.4 BAAAA California/Nevada area
NEIC reported this earthquake of M 2.7 in Central California was felt with intensity II-III in the area(s) of Central California in Glenbrook, Nevada and North Fork, California.
O: 28SEP2023 10:46:21 39.8N 122.8W md=2.5 ANSS NORTHERN CALIFORNIA
P: 26SEP2023 156712 39.6N 123.4W 2.5-4.6 AAAAA Central California
ALASKA
O: 28SEP2023 23:13:06 60.5N 151.1W ml=3.0 ANSS SOUTHERN ALASKA
P: 27SEP2023 156828 60.8N 151.7W 3.2-5.1 AAAAA Central Alaska
NEIC reported this earthquake of M 3.0 in Southern Alaska was felt with intensity II-III in the area(s) of Southern Alaska in Soldotna.
O: 28SEP2023 23:56:54 61.5N 147.0W ml=3.1 ANSS SOUTHERN ALASKA
P: 26SEP2023 156829 60.2N 147.1W 3.2-5.1 ABAAA Central Alaska
O: 28SEP2023 21:08:30 69.1N 144.6W ml=3.3 ANSS NORTHERN ALASKA
O: 29SEP2023 02:35:52 58.4N 133.5W ML=3.5 PGC SOUTHEAST ALASKA
P: 30SEP2023 156824 58.0N 136.0W 3.0-4.4 AABAA Southeast Alaska
PACIFIC NORTHWESTERN U.S./WESTERN CANADA
O: 28SEP2023 20:33:26 44.4N 122.7W ml=2.0 ANSS OFF COAST OF OREGON
P: 25SEP2023 156795 45.3N 121.7W 2.0-3.9 BAAAA Oregon state, U.S.
O: 29SEP2023 03:56:18 54.8N 118.7W ML=2.9 PGC ALBERTA
P: 22SEP2023 156808 52.0N 115.0W 2.0-4.7 CCCAA Alberta
ROCKY MOUNTAINS REGION
O: 29SEP2023 04:56:21 31.7N 104.4W ml=2.0 ANSS WESTERN TEXAS
O: 28SEP2023 22:09:14 31.7N 104.5W ml=2.3 ANSS WESTERN TEXAS
O: 28SEP2023 15:55:43 31.6N 104.6W ml=2.7 ANSS WESTERN TEXAS
O: 28SEP2023 15:21:28 31.6N 104.5W ml=2.2 ANSS WESTERN TEXAS
O: 28SEP2023 11:13:23 31.6N 104.5W ml=2.6 ANSS WESTERN TEXAS
O: 28SEP2023 11:10:49 32.1N 101.1W ml=2.4 ANSS WESTERN TEXAS
O: 28SEP2023 11:02:51 31.6N 104.4W ml=2.2 ANSS WESTERN TEXAS
O: 28SEP2023 10:35:52 31.6N 104.6W ml=2.0 ANSS WESTERN TEXAS
O: 28SEP2023 10:17:24 31.8N 104.2W ml=2.3 ANSS WESTERN TEXAS
O: 28SEP2023 09:26:54 31.8N 104.2W ml=3.2 ANSS WESTERN TEXAS
O: 28SEP2023 09:24:49 31.6N 104.5W ml=2.4 ANSS WESTERN TEXAS
O: 28SEP2023 08:34:04 31.6N 104.5W ml=2.4 ANSS WESTERN TEXAS
O: 28SEP2023 22:09:14 31.7N 104.5W ml=2.3 ANSS WESTERN TEXAS
P: 27SEP2023 156738 31.6N 103.6W 2.0-4.1 AAAAA SW U.S.A
O: 28SEP2023 10:50:20 32.2N 110.5W ml=3.1 ANSS ARIZONA
P: 30SEP2023 156739 34.7N 111.0W 2.0-4.4 ACAAA SW U.S.A
NEIC reported this earthquake of M 3.1 in Arizona was felt with intensity II-III in the area(s) of Arizona in Tucson, Vail, and Chandler.
EASTERN U.S./CANADA
O: 28SEP2023 11:57:03 28.8N 98.1W ml=2.8 ANSS SOUTHERN TEXAS
O: 28SEP2023 10:46:09 28.8N 98.5W ml=2.1 ANSS SOUTHERN TEXAS
P: 23SEP2023 156738 31.6N 101.6W 2.0-4.1 BCCAA SW U.S.A
O: 28SEP2023 08:30:04 34.5N 97.8W ml=2.1 ANSS OKLAHOMA
P: 28SEP2023 156757 35.0N 97.0W 2.0-4.1 AAAAA Southern Plains
O: 28SEP2023 09:55:15 35.0N 97.6W ml=1.4 ANSS OKLAHOMA
P: 28SEP2023 156757 35.0N 97.0W 2.0-4.1 AAAAA Southern Plains
O: 29SEP2023 03:57:48 36.5N 99.0W ml=1.6 ANSS OKLAHOMA
P: 29SEP2023 156756 36.0N 97.0W 2.0-4.1 AABAA Southern Plains
O: 29SEP2023 05:35:26 36.2N 89.4W md=1.8 ANSS MISSOURI
P: 27SEP2023 156724 36.7N 89.7W 2.0-4.1 AAAAA New Madrid area
O: 28SEP2023 12:45:48 80.0N 1.2W ML=3.0 BER GREENLAND
O: 28SEP2023 23:15:43 61.3N 59.5W MB=4.3 ECAN of Nuuk, GL
P: 23SEP2023 156827 61.0N 58.0W 2.5-4.0 BAAAA Baffin/Davis Strait Canada
O: 28SEP2023 21:08:57 47.8N 69.8W MB=1.0 ECAN of Saint-Siméon, QC
O: 28SEP2023 11:34:11 47.6N 70.2W MB=0.6 ECAN of La Malbaie, QC
P: 27SEP2023 156778 47.0N 70.0W 2.0-4.1 AAAAA Maine
O: 28SEP2023 02:27:36 41.8N 81.0W MB=2.4 ECAN of Cleveland, OH
P: 22SEP2023 156786 43.0N 78.0W 2.0-4.1 AAAAA New York State
P: 26SEP2023 156794 41.8N 81.4W 2.0-3.9 AAAAA Ohio/Lake Erie
HAWAII
No earthquakes of M>=3 were located in Hawaii.
EARTHQUAKES IN DJIBOUTI LINKED TO SOLAR FLARES
EARTHQUAKE SUMMARY FOR SEPTEMBER 27, 2023
A pair of moderate earthquakes occurred in Djibouti, Africa today. NEIC reported these earthquakes of M 4.6 and M 4.7 in Djibouti were felt with intensity IV in the area(s) of Djibouti at Jibuti, Tajurah and Dorra.
The earlier event of M 4.7 in Djibouti was felt with intensity V in Jibuti, VI in Ta'izz, Yemen and III Tajurah and in Asmara, Eritrea. These occurred at the peak of C-class solar flares and were probably promoted by SFE associated with this flare. Readers can visit the "SOLAR FLARE" portion of this summary for details of these events.
When a similar set of events in Djibouti occurred in January, 2023, this summary noted:
"A moderate M 5.1 also occurred near 45 East longitude in the area of Djibouti today. A smaller foreshock preceded this event. This continues activation of this region in recent days much of which was promoted by strong solar and geomagnetic storms. Most of this including an M 5.5 on December 26, 2022 and an M 4.9 on January 9, 2023 occurred about 400 km west of today's event. The last event in Djibouti listed by EMSC was an M 3.8 on January 4, 2023. At the time this summary noted:
" ... an M 3.5 occurred in Djibouti, Ethiopia today. This possibility had been discussed on December 12 as being a possible triggering point from strong solar flares at this time as:
"The area of Africa was unusually seismic today. Moderate earthquakes were recorded in Djibouti (M 3.5), South Africa (M 4.4) and Morocco (M 4.5). The earthquake in Djibouti may be the beginning of stronger activity in that region and in Ethiopia. This usually peaks during high solar flare periods as it is located on the geomagnetic equator in areas of high heat flow." (December 12, 2022, December 26, 2022)
The only earthquake in Djibouti with equal or larger magnitude in the past
5 years was an M 4.4 on August 31, 2020. The last of significantly larger magnitude were of M 4.7 on April 14, 2017. The only event of M>=5 in the area was an M 5.6 on June 17, 2012, part of a strong regional activation with the last solar active period." (January 18, 2023)
Forecast 156669 had expected today's earthquake in the area was likely around
September 28.
O: 28SEP2023 01:22:05 11.7N 43.1E mb=4.7 EMSC GOLFE DE TADJOURA, DJIBOUTI
O: 28SEP2023 05:53:12 11.6N 43.3E mb=4.6 EMSC NEAR THE COAST OF DJIBOUTI
P: 28SEP2023 156669 12.0N 40.0E 3.5-5.4 AACAA Ethiopia
The strongest earthquake in the U.S. or Canada today was an M 4.8 in the Pribilof Islands of Alaska. The only event in the Pribilof Islands in the past three years of equal or larger magnitude occurred as an M 5.3 on July 4, 2022. At the time this summary noted:
"The M 5.3 in the Pribilof Islands is the strongest in that region since an M 5.3 on February 1, 2015 and a similar event on January 31, 2015. The only event in the region of larger magnitude in the past 35 years was an M 6.0 on August 14, 1991. At the time of the 2015 activity this summary noted in this regard:
"The swarm of moderate earthquakes in the Pribilof Islands north of the Fox Islands in the Bering Sea continued today and expanded. Two earthquakes of M 5.3 and one of M 5.0 today were the strongest events located within 200 km of this epicenter since an M 5.5 west of this epicenter on October 22, 1965." (February 1, 2015, July 4, 2022)
Today's activity follows a series of moderate quakes of M>=5 in the Fox and Unimak and Alaska Peninsula area and occurred near local solar midnight. It may have been promoted by today's strong geomagnetic storm as it occurred at the peak of this storm as noted in previous issues of this summary:
"The geomagnetic field saw stormy conditions today. The AP level was 32. High latitudes saw major storm conditions with AP 68. Middle latitudes were at stormy conditions with AP 26. This may enhance global seismicity at the end of September or in early October." (September 27-28,, 2023)
Forecast 156825 had expected enhanced seismicity in this area was likely around
September 24.
O: 27SEP2023 09:51:05 56.4N 168.2W mb=4.8 EMSC PRIBILOF ISLANDS, ALASKA REGIO
P: 24SEP2023 156825 54.1N 164.4W 3.5-4.9 BCBAA Unimak Islands, Aleutians
A series of earthquakes occurred along the equator over the past several days.
These included moderate events in Gabon, the Central Atlantic, Ecuador, Indonesia and Rwanda among others. This summary has noted in previous issues that seismic enhancement often occurs at sub-solar latitudes due to the vertical tidal stresses. At the fall and spring equinox the sun is directly over the equator and can help promote seismicity along the equator as is currently being seen with the fall equinox.
The strongest earthquake in the world today was an M 5.4 off the west coast of Northern Sumatra, Indonesia. The earthquake on the equator occurred at local solar midnight and may have been promoted by strong tidal stresses with the full moon as noted in this and previous summaries:
"The full moon will arrive on September 29 at 09:57 UT. This is the last supermoon of the year. Supermoons occur when the moon is closest to the earth on its elliptical orbit. The considerably increases tidal stress and possibility of strong earthquakes. Longitudes which are at local solar noon at this time are located near 30 East longitude while those at local solar midnight are near 150 West longitude. In the east these include These include Hawaii and areas of eastern Alaska and western Canada and to a lesser extent areas off the coast of Oregon and California while in the east they include Eastern Turkey where an M 7.7 hit on February 6, 2023 as well as Ethiopia and areas off southern Africa and eastern Europe. These and surrounding areas are the most likely to see tidally enhanced seismicity at this time. A large to major earthquake is considered likely in the next week at this time." (September 26-27, 2023)
The last earthquake of M>=5.4 within about 200 km of today's event in Sumatra occurred on 5.7 occurred on May 14, 2013. An M 8.2 was recorded near today's epicenter on April 11, 2012. Forecast 156638 expected today's event was likely within this area around September 26. This epicenter is at 103 degrees from the M 6.8 in Morocco of September 8, 2023 and was probably promoted by energy from that source.
O: 27SEP2023 17:47:22 0.9N 93.2E Mw=5.4 EMSC OFF W COAST OF NORTHERN SUMATR
P: 26SEP2023 156638 3.0N 94.0E 4.0-6.0 ACAAA Nicobar Islands
O: 28SEP2023 00:14:01 0.8N 26.0W mb=4.9 EMSC CENTRAL MID-ATLANTIC RIDGE
P: 23SEP2023 156627 1.0N 28.0W 4.0-5.6 BAAAA Central Mid-Atlantic Ridg
O: 28SEP2023 00:08:02 2.6N 66.4E mb=4.5 EMSC CARLSBERG RIDGE
P: 30SEP2023 156647 1.0S 67.0E 4.0-5.6 ACAAA Indian Ocean
OTHER GLOBAL EARTHQUAKE ACTIVITY
For most events there are two listings. The first line is the observed event starting with "O:" for Observed. There follows the date, month and year, the time in UT hours:minutes:seconds, the latitude and longitude, the given magnitude and the reporting agency followed by the geographic location. The second line starts with "P:" This is the forecast event as forecast in our summaries normally more than a month in advance. Magnitudes may vary in response to updated seismic watches and daily variations due to tidal and other influences. This line has the forecast date, month and year, the forecast number, latitude, longitude and forecast magnitude range. This is followed by a comparison between the forecast and the event. The comparison includes letters A-D. The first is number of days difference from predicted (A:up to 2, B3-5; C:6-10; D:more than 10), Difference in latitude (A:up to 1 degree; B:1-2 degrees; C:2-4 degrees; D:more than 4 degrees); longitude (same comparison as with latitude); magnitude (A: within forecast range; B: higher than forecast range; C: lower than forecast range; D: no comparison possible). The last letter is a stand in for a future comparison which needs to be done statistically after a large number of forecasts have been made. In previous data, an excellent match is generally AAAAA; a good match as one or two B's; a fair match has several B's and C's and a poor match is one which contains a number of C's or D's.
ASIA
O: 27SEP2023 09:25:30 47.5N 102.6E mb=4.5 EMSC CENTRAL MONGOLIA
P: 21SEP2023 156779 45.0N 102.0E 4.0-5.4 CCAAA Mongolia
No significant (M>=5) or unusual earthquakes were reported in Asia today.
INDONESIA AND PHILIPPINES
O: 27SEP2023 17:47:22 0.9N 93.2E Mw=5.4 EMSC OFF W COAST OF NORTHERN SUMATR
P: 26SEP2023 156638 3.0N 94.0E 4.0-6.0 ACAAA Nicobar Islands
O: 28SEP2023 03:56:00 2.1N 97.4E ML=4.2 EMSC NORTHERN SUMATRA, INDONESIA
P: 23SEP2023 156638 1.0N 97.0E 4.0-5.5 BBAAA Nicobar Islands
O: 27SEP2023 22:32:57 2.8S 128.8E mb=4.6 EMSC CERAM SEA, INDONESIA
O: 27SEP2023 16:15:22 3.3S 128.8E mb=5.0 EMSC SERAM, INDONESIA
P: 29SEP2023 156644 3.0S 129.0E 4.0-5.4 AAAAA Ceram area
O: 27SEP2023 20:59:39 6.1S 127.7E ML=4.2 EMSC BANDA SEA
P: 16SEP2023 156379 7.0S 126.0E 4.0-5.6 CAAAA Banda Sea
O: 27SEP2023 09:07:21 7.0S 126.2E mb=4.2 EMSC BANDA SEA
O: 27SEP2023 18:59:21 8.4S 129.1E mb=4.2 EMSC KEPULAUAN BABAR, INDONESIA
P: 28SEP2023 156641 7.0S 125.0E 4.0-5.7 AAAAA Banda Sea
CENTRAL AND SOUTH AMERICA
O: 27SEP2023 08:31:55 10.0S 79.0W ML=4.0 EMSC NEAR COAST OF CENTRAL PERU
P: 26SEP2023 156653 9.0S 81.0W 4.0-6.0 AABAA No. Peru
O: 27SEP2023 09:09:00 13.9N 93.1W ML=4.1 EMSC OFF COAST OF CHIAPAS, MEXICO
P: 30SEP2023 156666 14.0N 93.0W 3.5-5.6 BAAAA Chiapas, Mexico
O: 28SEP2023 06:28:04 1.2N 78.8W mb=4.1 EMSC COLOMBIA-ECUADOR BORDER REGION
P: 28SEP2023 156645 2.0S 78.0W 4.0-5.7 ACAAA Ecuador
O: 27SEP2023 16:04:04 15.2N 93.9W mb=4.6 EMSC OFFSHORE CHIAPAS, MEXICO
P: 30SEP2023 156666 14.0N 93.0W 3.5-5.6 BBAAA Chiapas, Mexico
O: 28SEP2023 01:23:45 16.0S 74.7W mb=4.4 EMSC NEAR COAST OF SOUTHERN PERU
P: 23SEP2023 156845 15.0S 73.0W 4.0-5.9 BABAA Central Peru
O: 27SEP2023 10:54:43 16.8N 100.5W ML=4.1 EMSC OFFSHORE GUERRERO, MEXICO
P: 27SEP2023 156683 16.0N 100.0W 3.5-5.3 AAAAA Oaxaca, Mexico
O: 27SEP2023 13:19:20 17.6N 95.0W ML=4.1 EMSC VERACRUZ, MEXICO
P: 25SEP2023 156667 17.0N 94.0W 3.5-5.3 AAAAA Chiapas, Mexico
O: 27SEP2023 07:01:59 18.8N 69.7W ML=3.2 EMSC DOMINICAN REPUBLIC
P: 28SEP2023 156684 18.0N 69.0W 3.4-4.9 AAAAA Puerto Rico
O: 27SEP2023 22:10:37 18.9N 65.3W MD=3.2 EMSC PUERTO RICO REGION
P: 27SEP2023 156673 18.0N 64.0W 3.0-5.0 AAAAA Leeward Islands
O: 27SEP2023 11:38:01 18.0N 68.2W MD=3.3 EMSC DOMINICAN REPUBLIC REGION
O: 27SEP2023 09:11:45 19.1N 67.3W MD=3.2 EMSC PUERTO RICO REGION
P: 26SEP2023 156685 19.0N 68.0W 3.4-5.1 AAAAA Puerto Rico
O: 27SEP2023 12:30:32 19.6N 70.7W ML=3.3 EMSC DOMINICAN REPUBLIC
O: 27SEP2023 22:43:18 20.0N 70.3W ML=3.0 EMSC DOMINICAN REPUBLIC REGION
O: 27SEP2023 11:10:59 20.1N 70.3W ML=3.4 EMSC DOMINICAN REPUBLIC REGION
O: 27SEP2023 07:56:10 19.4N 70.3W ML=3.1 EMSC DOMINICAN REPUBLIC
P: 25SEP2023 156684 19.0N 71.0W 3.4-5.1 AAAAA Puerto Rico
O: 28SEP2023 06:57:13 23.9S 70.1W ML=4.3 EMSC ANTOFAGASTA, CHILE
P: 29SEP2023 156864 24.0S 69.0W 4.0-5.7 AAAAA Coast No. Chile
O: 27SEP2023 22:20:37 27.3N 111.2W ML=3.4 EMSC GULF OF CALIFORNIA
O: 27SEP2023 08:35:55 27.5N 112.6W ML=3.5 EMSC BAJA CALIFORNIA SUR, MEXICO
P: 25SEP2023 156692 28.0N 112.0W 3.5-5.2 AAAAA Gulf of California
AFRICA AND EUROPE
O: 28SEP2023 01:22:05 11.7N 43.1E mb=4.7 EMSC GOLFE DE TADJOURA, DJIBOUTI
O: 28SEP2023 05:53:12 11.6N 43.3E mb=4.6 EMSC NEAR THE COAST OF DJIBOUTI
P: 28SEP2023 156669 12.0N 40.0E 3.5-5.4 AACAA Ethiopia
O: 27SEP2023 09:13:20 31.1N 8.5W ML=3.6 EMSC MOROCCO
P: 22SEP2023 156722 30.0N 8.0W 3.5-5.4 BAAAA Morocco/Spain
O: 27SEP2023 15:09:33 63.9N 22.6W ML=3.5 EMSC ICELAND REGION
P: 29SEP2023 156834 63.0N 23.0W 3.0-4.5 AAAAA Iceland area
SOUTHWEST PACIFIC
O: 28SEP2023 01:43:34 14.9S 173.4W mb=5.0 EMSC SAMOA ISLANDS REGION
P: 29SEP2023 156849 15.0S 173.0W 4.0-5.8 AAAAA Samoa Islands
NEIC reported this earthquake of M 5.0 in Samoa was felt with intensity II-III in the area(s) of Samoa
O: 27SEP2023 08:38:43 18.8S 169.3E mb=4.6 EMSC VANUATU
P: 26SEP2023 156859 19.0S 168.0E 4.0-5.6 AAAAA Vanuatu Islands
O: 27SEP2023 18:00:40 18.8S 178.0W mb=4.8 EMSC FIJI REGION
P: 27SEP2023 156856 18.0S 179.0W 4.0-5.6 AAAAA Tonga Islands
O: 27SEP2023 23:43:10 22.2S 179.5W mb=4.5 EMSC SOUTH OF FIJI ISLANDS
P: 27SEP2023 156872 24.0S 178.0W 4.0-5.4 ABBAA Tonga Islands
OCEAN RIDGES
O: 28SEP2023 00:14:01 0.8N 26.0W mb=4.9 EMSC CENTRAL MID-ATLANTIC RIDGE
P: 23SEP2023 156627 1.0N 28.0W 4.0-5.6 BAAAA Central Mid-Atlantic Ridg
O: 28SEP2023 00:08:02 2.6N 66.4E mb=4.5 EMSC CARLSBERG RIDGE
P: 30SEP2023 156647 1.0S 67.0E 4.0-5.6 ACAAA Indian Ocean
O: 27SEP2023 17:37:36 53.5S 134.8W mb=4.5 EMSC PACIFIC-ANTARCTIC RIDGE
No significant (M>=5) or unusual earthquakes were reported on Ocean Ridges today.
ZEALANDIA AND AUSTRALIA REGION
O: 27SEP2023 10:56:41 40.7S 172.7E mb=4.2 EMSC OFF W. COAST OF S. ISLAND, N.Z
O: 27AUG2023 10:56:41 40.8S 172.7E MS=4.7 GEONET South Island, New Zealand
P: 27SEP2023 156886 42.0S 172.0E 3.0-5.3 ABAAA So. Island, N.Z.
GEONET reported this earthquake was felt with moderate to strong intensity in the area southeast of Wellington, New Zealand and in southern North Island and northern South Island. 1013 reports of felt events were made of which 378 reported weak and 389 light intensity with 137 report of moderate shaking and 16 with strong and 2 severe and 1 with extreme intensity came from the area.
NEIC reported this earthquake of M 4.2 in South Island, New Zealand was felt with intensity II-III in the area(s) of South Island, New Zealand in Tasman at Takaka and Richmond.
JAPAN AND KURIL ISLANDS
O: 27SEP2023 15:34:33 30.8N 142.0E mb=4.5 EMSC IZU ISLANDS, JAPAN REGION
P: 24SEP2023 156732 32.0N 142.0E 4.0-5.4 BBAAA Off East Coast Honshu
U.S./CANADA*
WESTERN U.S./CANADA
CALIFORNIA
O: 27SEP2023 22:08:51 30.3N 115.9W ML=3.5 EMSC OFFSHORE BAJA CALIFORNIA, MEXI
O: 27SEP2023 21:49:59 30.7N 114.1W ML=3.6 EMSC GULF OF CALIFORNIA
P: 30SEP2023 156741 31.0N 116.3W 2.5-4.7 BAAAA So. California
O: 27SEP2023 08:06:48 32.1N 116.5W ML=2.2 EMSC BAJA CALIFORNIA, MEXICO
P: 29SEP2023 156741 31.9N 116.3W 2.5-4.6 AAAAA So. California
O: 28SEP2023 01:09:20 32.3N 115.4W ML=2.0 EMSC BAJA CALIFORNIA, MEXICO
P: 28SEP2023 156744 32.4N 115.8W 2.5-4.7 AAAAA So. California
O: 27SEP2023 23:01:57 35.9N 120.4W MD=2.3 EMSC CENTRAL CALIFORNIA
P: 27SEP2023 156709 36.2N 120.8W 2.5-4.4 AAAAA Central California
O: 27SEP2023 20:00:21 38.6N 119.5W ML=3.4 EMSC CENTRAL CALIFORNIA
O: 28SEP2023 00:42:39 38.6N 119.5W MD=2.2 EMSC CENTRAL CALIFORNIA
P: 25SEP2023 156708 38.6N 119.6W 2.5-4.4 AAAAA California/Nevada area
NEIC reported this earthquake of M 3.6 in Central California was felt with intensity II-III in Topaz, Coleville, California and Glenbrook Nevada. An M 2.6 aftershock in Central California was felt with intensity II-III in the area(s) of Glenbrook, Nevada.
O: 27SEP2023 21:49:54 38.8N 122.8W MD=2.5 EMSC NORTHERN CALIFORNIA
P: 29SEP2023 156711 38.7N 122.7W 2.5-4.8 AAAAA Central California
ALASKA
No events of M>=3 were located in Alaska today.
PACIFIC NORTHWESTERN U.S./WESTERN CANADA
O: 27SEP2023 21:14:02 49.3N 120.5W ML=2.1 EMSC BRITISH COLUMBIA, CANADA
P: 19SEP2023 156539 48.9N 122.1W 2.0-3.9 CAAAA Washington state, U.S.
ROCKY MOUNTAINS REGION
O: 27SEP2023 19:34:27 31.6N 104.5W ML=2.2 EMSC WESTERN TEXAS
P: 27SEP2023 156738 31.6N 103.6W 2.0-4.1 AAAAA SW U.S.A
O: 27SEP2023 07:20:20 38.5N 112.8W ML=2.1 EMSC UTAH
P: 25SEP2023 156763 38.3N 112.2W 2.0-4.3 AAAAA Utah area
EASTERN U.S./CANADA
O: 27SEP2023 05:16:44 45.9N 67.1W MB=1.5 ECAN of Dumfries, NB
P: 27SEP2023 156772 46.0N 66.0W 2.0-4.4 AAAAA E. of Maine
O: 27SEP2023 04:53:07 45.6N 76.1W MB=1.3 ECAN of Constance Bay, ON
P: 16SEP2023 156522 46.0N 75.0W 2.0-4.0 CAAAA New York State
O: 26SEP2023 07:25:48 47.5N 70.1W MB=1.7 ECAN of La Malbaie, QC
P: 27SEP2023 156778 47.0N 70.0W 2.0-4.1 AAAAA Maine
O: 27SEP2023 16:05:30 35.0N 97.6W ML=2.1 EMSC OKLAHOMA
P: 28SEP2023 156757 35.0N 97.0W 2.0-4.1 AAAAA Southern Plains
HAWAII
No earthquakes of M>=3 were located in Hawaii.
MODERATE, UNUSUAL QUAKE NEAR NAPLES, ITALY RAISES CONCERNS
EARTHQUAKE SUMMARY FOR SEPTEMBER 26, 2023
An earthquake of M 4.2 near Naples, Italy occurred today and was accompanied by a swarm of minor quakes. This is the strongest earthquake in the region in about 40 years. The quake occurred in the Phlegraean Fields (Campi Flegrei) which is a vast volcano near Naples. Recent smaller events in the region have raised concern that this may be a precursory swarm to increased seismicity and volcanism in the are - a concern echoed by the National Institute of Geophysics and Volcanology (INGV). The area is populated by nearly half a million residents. The major eruption in the area was an eruption of lava and ash in 1538. Some believe that the extinction of the Neanderthal species was - in part - caused by major eruptions in this area.
Forecasts 156775 and 156721 had expected enhanced seismicity in this area was likely around September 28-29.
O: 27SEP2023 01:35:35 40.8N 14.2E ML=4.2 EMSC SOUTHERN ITALY
P: 28SEP2023 156775 43.0N 16.0E 3.0-5.4 ACAAA Italy
P: 29SEP2023 156721 38.0N 14.0E 3.0-4.9 ACAAA Mediterranean/Sicily
The strongest earthquake in the U.S. or Canada today was an M 5.1 in the Alaska Peninsula. NEIC reported it was felt with intensity II-III in Alaska at Sand Point and King Cove. This appears to be an aftershock of the M 5.4 in the Alaska Peninsula of September 21. At the time of that event this summary noted:
"The strongest earthquake in the U.S. or Canada today was an M 5.4 in the Alaska Peninsula Alaska. NEIC reported it was felt with intensity V in Sand Point and King Cove and III in False Pass, Alaska. This is the strongest earthquake in the region of the Alaska Peninsula since an M 5.6 on August 3, 2023. At the time this summary noted:
"The strongest earthquake in the world, the U.S. or Canada today was an M 5.6 in the Unimak Island area of Alaska. NEIC reported it was felt with intensity IV in Sand Point, King Cove and II-III in False Pass, Chignik Lagoon, Alaska. This is the strongest aftershock to date of the M 7.2-7.4 of July 16, 2023 in the Alaska Peninsula about 50 km east of today's epicenter. It is the second largest earthquake in this area since an M 6.1 on July 28 and July 29, 2020. In the past 15 years many of the strongest earthquakes in this region have occurred in mid- to late-July and early August, perhaps indicating a seasonal triggering component. All events in the region with M>=6 since 2008 have occurred in late July including an M 6.1 on July 16, 2011; an M 6.0 on July 19, 2018; an M 6.1 on July 28, 2020 and an M 7.2 on July 16, 2023." (August 3, 2023, September 21, 2023)
Forecast 156825 had expected today's earthquake within about 100 km was likely at the end of September.
O: 27SEP2023 02:14:27 55.0N 160.4W mb=5.1 EMSC ALASKA PENINSULA
P: 30SEP2023 156825 54.5N 161.8W 3.5-5.0 BAAAA Unimak Islands, Aleutians
An M 4.1 also occurred today off the coast of Washington State. NEIC reported this earthquake of M 4.1 off the coast of Washington may have been felt with intensity II-III in the area(s) of Washington in Everett and Bellevue and in British Columbia, Canada at Victoria and Walnut Grove. This is the strongest earthquake within about 150 km of this epicenter off the coast of Washington since an M 4.5 on February 22, 2021 and an M 4.1 on September 22, 2020.
Forecast 156803 had expected today's event in this region to the north was likely around September 26.
O: 25SEP2023 19:46:02 48.8N 128.2W MB=3.4 ECAN of Tofino, BC
O: 25SEP2023 13:31:47 47.4N 128.9W MB=4.1 ECAN of Tofino, BC
O: 26SEP2023 02:09:09 47.5N 129.2W MB=4.1 ECAN of Tofino, BC
P: 26SEP2023 156803 49.5N 127.2W 2.8-5.3 ABAAA Vancouver Island area
P: 30SEP2023 156803 49.3N 129.0W 2.8-5.4 BBAAA Vancouver Island area
OTHER GLOBAL EARTHQUAKE ACTIVITY
For most events there are two listings. The first line is the observed event starting with "O:" for Observed. There follows the date, month and year, the time in UT hours:minutes:seconds, the latitude and longitude, the given magnitude and the reporting agency followed by the geographic location. The second line starts with "P:" This is the forecast event as forecast in our summaries normally more than a month in advance. Magnitudes may vary in response to updated seismic watches and daily variations due to tidal and other influences. This line has the forecast date, month and year, the forecast number, latitude, longitude and forecast magnitude range. This is followed by a comparison between the forecast and the event. The comparison includes letters A-D. The first is number of days difference from predicted (A:up to 2, B3-5; C:6-10; D:more than 10), Difference in latitude (A:up to 1 degree; B:1-2 degrees; C:2-4 degrees; D:more than 4 degrees); longitude (same comparison as with latitude); magnitude (A: within forecast range; B: higher than forecast range; C: lower than forecast range; D: no comparison possible). The last letter is a stand in for a future comparison which needs to be done statistically after a large number of forecasts have been made. In previous data, an excellent match is generally AAAAA; a good match as one or two B's; a fair match has several B's and C's and a poor match is one which contains a number of C's or D's.
ASIA
No significant (M>=5) or unusual earthquakes were reported in Asia today.
INDONESIA AND PHILIPPINES
O: 26SEP2023 17:25:06 2.1S 99.8E mb=4.4 EMSC KEP. MENTAWAI REGION, INDONESI
P: 27SEP2023 156656 2.0S 99.0E 4.0-5.4 AAAAA So. of Sumatera
O: 27SEP2023 04:06:53 2.4N 123.2E ML=4.2 EMSC CELEBES SEA
P: 29SEP2023 156626 1.0N 122.0E 4.0-5.8 ABBAA Celebes Sea
O: 27SEP2023 05:40:03 4.4S 153.1E mb=4.5 EMSC NEW IRELAND REGION, P.N.G.
P: 22SEP2023 156649 5.0S 153.0E 4.0-5.4 BAAAA New Britain
O: 26SEP2023 07:36:48 9.8N 126.1E mb=4.5 EMSC MINDANAO, PHILIPPINES
P: 26SEP2023 156629 9.0N 126.0E 4.0-5.4 AAAAA Central Philippines
O: 26SEP2023 08:04:08 13.2N 145.0E mb=4.8 EMSC GUAM REGION
P: 23SEP2023 156686 13.0N 143.0E 4.0-5.4 BABAA So. Marianas/Guam
NEIC reported this earthquake of M 4.8 in Guam was felt with intensity II-III in the area(s) of Guam in Merizo and Barrigada (IV), Mangilao, Tamuning, Snajana, Hagatna, Agat, Yigo, and Dededo.
O: 26SEP2023 20:05:12 18.3N 146.8E mb=4.6 EMSC PAGAN REG., N. MARIANA ISLANDS
P: 24SEP2023 156680 19.0N 145.0E 4.0-5.4 AAAAA No. Marianas
CENTRAL AND SOUTH AMERICA
O: 26SEP2023 12:22:02 14.8N 94.1W ML=4.0 EMSC OFF COAST OF CHIAPAS, MEXICO
O: 26SEP2023 11:15:45 15.4N 94.7W ML=4.1 EMSC OFFSHORE OAXACA, MEXICO
O: 26SEP2023 07:48:06 15.6N 95.2W ML=4.1 EMSC OFFSHORE OAXACA, MEXICO
O: 26SEP2023 14:06:08 16.1N 95.3W ML=4.0 EMSC OFFSHORE OAXACA, MEXICO
O: 27SEP2023 06:23:24 14.6N 93.3W ML=4.2 EMSC OFFSHORE CHIAPAS, MEXICO
P: 27SEP2023 156667 15.0N 95.0W 3.5-5.5 AABAA Chiapas, Mexico
P: 30SEP2023 156666 14.0N 93.0W 3.5-5.6 BAAAA Chiapas, Mexico
O: 26SEP2023 17:40:52 17.4N 94.6W mb=4.8 EMSC VERACRUZ, MEXICO
P: 25SEP2023 156667 17.0N 94.0W 3.5-5.3 AAAAA Chiapas, Mexico
NEIC reported this earthquake of M 4.8 in Guerrero, Mexico was felt with intensity II-III in the area(s) of Oaxaca and Tlalnepantla, Mexico.
O: 27SEP2023 02:13:22 17.9N 66.9W MD=3.3 EMSC PUERTO RICO
P: 26SEP2023 156685 19.0N 68.0W 3.4-5.1 ABAAA Puerto Rico
O: 26SEP2023 19:25:01 1.2N 79.1W mb=4.5 EMSC NEAR COAST OF ECUADOR
P: 28SEP2023 156645 2.0S 78.0W 4.0-5.7 ACAAA Ecuador
O: 27SEP2023 03:01:22 5.6S 76.7W ML=4.2 EMSC NORTHERN PERU
P: 29SEP2023 156653 6.0S 76.0W 4.0-5.9 AAAAA No. Peru
O: 27SEP2023 00:28:57 19.1N 65.7W MD=3.1 EMSC PUERTO RICO REGION
P: 27SEP2023 156673 18.0N 64.0W 3.0-5.0 ABBAA Leeward Islands
O: 26SEP2023 08:59:20 19.7N 71.8W ML=3.0 EMSC DOMINICAN REPUBLIC REGION
O: 27SEP2023 02:55:06 19.6N 70.7W ML=3.0 EMSC DOMINICAN REPUBLIC
P: 25SEP2023 156684 19.0N 71.0W 3.4-5.1 AAAAA Puerto Rico
O: 26SEP2023 09:11:15 20.2S 69.2W ML=4.8 EMSC TARAPACA, CHILE
P: 24SEP2023 156870 20.0S 69.0W 4.0-5.6 AAAAA So. Peru/Bolivia
NEIC reported this earthquake of M 4.7 in Tarapaca, Chile was felt with intensity II-III in the area(s) of Tarapaca, Chile in Iquique.
O: 26SEP2023 10:32:40 24.8N 109.3W ML=4.0 EMSC GULF OF CALIFORNIA
P: 21SEP2023 156692 24.0N 109.0W 3.5-5.1 BAAAA Gulf of California
O: 26SEP2023 19:56:12 27.6S 71.2W mb=4.7 EMSC OFFSHORE ATACAMA, CHILE
P: 24SEP2023 156863 28.0S 71.0W 4.0-5.6 AAAAA Coast Central Chile
O: 26SEP2023 08:18:00 28.8S 71.5W Mw=4.1 EMSC OFFSHORE ATACAMA, CHILE
P: 27SEP2023 156863 29.0S 72.0W 4.0-5.8 AAAAA Coast Central Chile
AFRICA AND EUROPE
O: 27SEP2023 01:35:35 40.8N 14.2E ML=4.2 EMSC SOUTHERN ITALY
P: 28SEP2023 156775 43.0N 16.0E 3.0-5.4 ACAAA Italy
P: 29SEP2023 156721 38.0N 14.0E 3.0-4.9 ACAAA Mediterranean/Sicily
O: 26SEP2023 13:15:19 41.7N 1.8W ML=4.1 EMSC SPAIN
P: 26SEP2023 156773 42.0N 2.0E 3.0-5.4 AABAA France
P: 29SEP2023 156802 44.0N 1.0W 3.0-5.3 BCAAA Spain
O: 26SEP2023 15:54:13 51.5N 16.1E mb=4.5 EMSC POLAND
P: 22SEP2023 156820 51.0N 16.0E 3.0-4.8 BAAAA Poland
O: 26SEP2023 18:42:39 63.9N 22.0W ML=3.1 EMSC ICELAND REGION
O: 26SEP2023 21:32:25 63.9N 22.6W ML=3.1 EMSC ICELAND REGION
P: 29SEP2023 156834 63.0N 23.0W 3.0-4.5 BAAAA Iceland area
SOUTHWEST PACIFIC
O: 26SEP2023 23:54:09 23.0S 177.8W mb=4.5 EMSC SOUTH OF FIJI ISLANDS
P: 27SEP2023 156872 24.0S 178.0W 4.0-5.4 AAAAA Tonga Islands
O: 26SEP2023 14:05:31 23.4S 179.8E Mw=5.2 EMSC SOUTH OF FIJI ISLANDS
P: 25SEP2023 156873 24.0S 179.0E 4.0-5.4 AAAAA Tonga/Fiji
OCEAN RIDGES
No significant (M>=5) or unusual earthquakes were reported on Ocean Ridges today.
ZEALANDIA AND AUSTRALIA REGION
O: 26SEP2023 11:48:23 35.7S 178.4E ML=4.0 EMSC OFF E. COAST OF N. ISLAND, N.Z
P: 25SEP2023 156878 37.0S 177.0E 3.0-4.4 ABBAA North Island, N.Z.
O: 26SEP2023 17:28:34 45.0S 167.5E ML=3.6 EMSC SOUTH ISLAND OF NEW ZEALAND
O: 26SEP2023 17:28:35 45.0S 167.5E MS=4.0 GEONET Not reported Felt
P: 29SEP2023 156887 45.0S 167.0E 3.0-4.9 BAAAA So. Island, N.Z.
JAPAN AND KURIL ISLANDS
O: 27SEP2023 00:33:18 23.2N 142.2E mb=4.5 EMSC VOLCANO ISLANDS, JAPAN REGION
P: 23SEP2023 156702 24.0N 143.0E 4.0-5.5 BAAAA Volcano Islands
O: 27SEP2023 02:54:44 31.4N 141.8E mb=5.0 EMSC IZU ISLANDS, JAPAN REGION
P: 24SEP2023 156732 32.0N 142.0E 4.0-5.4 BAAAA Off East Coast Honshu
O: 26SEP2023 22:21:41 37.5N 141.5E Mw=4.5 EMSC NEAR EAST COAST OF HONSHU, JAP
P: 26SEP2023 156734 38.0N 140.0E 4.0-5.6 AAAAA Off East Coast Honshu
NEIC reported this earthquake of M 4.5 east of Honshu, Japan was felt with intensity II-III in the area(s) of Honshu, Japan in Miyagi Prefecture.
U.S./CANADA*
WESTERN U.S./CANADA
CALIFORNIA
O: 26SEP2023 18:16:02 31.2N 116.8W ML=3.7 EMSC OFFSHORE BAJA CALIFORNIA, MEXI
P: 29SEP2023 156741 31.9N 116.3W 2.5-4.6 BAAAA So. California
O: 26SEP2023 07:22:31 31.5N 115.7W ML=3.0 EMSC BAJA CALIFORNIA, MEXICO
O: 26SEP2023 22:55:07 32.0N 116.2W ML=2.0 EMSC BAJA CALIFORNIA, MEXICO
P: 26SEP2023 156743 32.1N 116.4W 2.5-4.6 AAAAA So. California
O: 26SEP2023 12:28:16 35.7N 117.5W ML=2.0 EMSC SOUTHERN CALIFORNIA
O: 26SEP2023 11:44:47 35.8N 117.6W ML=2.5 EMSC SOUTHERN CALIFORNIA
O: 27SEP2023 01:29:07 35.9N 117.7W ML=3.0 EMSC CENTRAL CALIFORNIA
O: 26SEP2023 22:46:22 36.1N 117.9W ML=2.4 EMSC CENTRAL CALIFORNIA
P: 27SEP2023 156750 35.9N 117.7W 2.5-4.4 AAAAA So. California
O: 27SEP2023 02:24:34 36.1N 121.7W MD=2.2 EMSC OFFSHORE CENTRAL CALIFORNIA
P: 27SEP2023 156736 35.6N 121.3W 2.5-4.6 AAAAA Off So. California
O: 26SEP2023 19:10:51 37.4N 117.7W ML=2.0 EMSC NEVADA
P: 24SEP2023 156705 37.4N 117.2W 2.5-4.7 AAAAA California/Nevada area
O: 26SEP2023 23:25:51 37.0N 121.6W MD=2.4 EMSC NORTHERN CALIFORNIA
O: 26SEP2023 21:52:25 37.5N 121.8W MD=2.3 EMSC SAN FRANCISCO BAY AREA, CALIF.
O: 26SEP2023 11:56:40 37.8N 121.8W MD=2.0 EMSC SAN FRANCISCO BAY AREA, CALIF.
P: 24SEP2023 156710 38.0N 122.3W 2.5-4.4 AAAAA Central California
O: 27SEP2023 01:07:46 39.8N 123.6W MD=2.4 EMSC NORTHERN CALIFORNIA
O: 26SEP2023 18:40:02 40.7N 123.6W ML=3.2 EMSC NORTHERN CALIFORNIA
P: 27SEP2023 156789 40.0N 123.0W 2.5-4.7 AAAAA Northern California
NEIC reported this earthquake of M 3.4 in Northern California was felt with intensity II-III in the area(s) of Northern California in Willow Creek, Arcata, Hayfork, Fortuna and Trinidad.
ALASKA
No events of M>=3 were located in Alaska today.
PACIFIC NORTHWESTERN U.S./WESTERN CANADA
O: 25SEP2023 19:46:02 48.8N 128.2W MB=3.4 ECAN of Tofino, BC
O: 25SEP2023 13:31:47 47.4N 128.9W MB=4.1 ECAN of Tofino, BC
O: 26SEP2023 02:09:09 47.5N 129.2W MB=4.1 ECAN of Tofino, BC
P: 26SEP2023 156803 49.5N 127.2W 2.8-5.3 ABAAA Vancouver Island area
P: 30SEP2023 156803 49.3N 129.0W 2.8-5.4 BBAAA Vancouver Island area
O: 26SEP2023 22:44:39 43.2N 127.0W ML=3.4 EMSC OFF COAST OF OREGON
P: 24SEP2023 156792 41.8N 126.9W 2.5-4.4 ABAAA Off Coast of No. Calif
ROCKY MOUNTAINS REGION
O: 26SEP2023 19:10:51 31.7N 104.2W ML=2.6 EMSC WESTERN TEXAS
O: 26SEP2023 23:24:29 31.7N 104.4W ML=2.1 EMSC WESTERN TEXAS
O: 26SEP2023 17:12:25 31.7N 104.5W ML=2.0 EMSC WESTERN TEXAS
P: 27SEP2023 156738 31.6N 103.6W 2.0-4.1 AAAAA SW U.S.A
O: 27SEP2023 05:20:44 32.8N 100.6W ML=2.4 EMSC WESTERN TEXAS
O: 27SEP2023 04:21:52 32.7N 100.6W ML=2.2 EMSC WESTERN TEXAS
P: 23SEP2023 156738 31.6N 101.6W 2.0-4.1 BBAAA SW U.S.A
O: 26SEP2023 21:15:00 44.3N 114.1W ML=2.1 EMSC SOUTHERN IDAHO
P: 27SEP2023 156780 44.4N 114.1W 2.0-4.1 AAAAA Montana/Idaho
O: 26SEP2023 23:29:26 47.8N 113.7W ML=2.1 EMSC WESTERN MONTANA
P: 22SEP2023 156782 47.5N 115.8W 2.0-3.9 BABAA Montana/Idaho
EASTERN U.S./CANADA
O: 27SEP2023 04:53:07 45.6N 76.1W MB=1.3 ECAN of Constance Bay, ON
P: 25SEP2023 156786 44.0N 74.0W 2.0-4.1 ABBAA New York State
O: 26SEP2023 07:25:48 47.5N 70.1W MB=1.7 ECAN of La Malbaie, QC
P: 27SEP2023 156778 47.0N 70.0W 2.0-4.1 AAAAA Maine
O: 25SEP2023 12:42:21 46.8N 65.8W MB=2.0 ECAN of Renous-Quarryville part A, NB
O: 25SEP2023 12:47:12 46.8N 65.9W MB=1.7 ECAN of Blackville, NB
P: 27SEP2023 156772 46.0N 66.0W 2.0-4.4 AAAAA E. of Maine
O: 26SEP2023 19:56:43 34.1N 97.4W ML=2.1 EMSC OKLAHOMA
P: 28SEP2023 156757 35.0N 97.0W 2.0-4.1 AAAAA Southern Plains
HAWAII
No earthquakes of M>=3 were located in Hawaii.
STRONG QUAKE IN TALAUD ISLANDS
EARTHQUAKE SUMMARY FOR SEPTEMBER 25, 2023
The strongest earthquake today in the world was an M 5.9 in the Talaud Islands, Philippines. NEIC reported it was felt with intensity II-III in Southern Mindanao at Davao and Buayan. PHIVOLCS reported this earthquake was felt with intensity IV in Glan, Sarangani; II in Malapatan and Malungon, Sarangani; Don Marcelino and Malita, Davao Occidental and I in the City of General Santos and Polomolok, South Catabato; City of Davao, Philippines. Similar earthquakes of M 6.0-6.1 hit the Talaud Islands about 100 km south of today's epicenter on February 11, 2023 and January 22, 2022. Forecast 156634 had expected today's activity within about 100 km was likely around September 27.
O: 26SEP2023 01:39:45 4.7N 127.5E Mw=5.9 EMSC KEPULAUAN TALAUD, INDONESIA
P: 27SEP2023 156634 4.0N 128.0E 4.0-5.4 AAAAA Halmahera
A swarm of earthquakes has been occurring in the Azores Islands region of Portugal over the past several days. The largest of these events occurred today with M 4.6 and M 4.1. This activity may be related to the passage of Hurricane Nigel through the region over the past several days as noted in previous issues of this summary. For example it was stated on September 22:
"Hurricane Nigel (15) continued today in the area of the central Atlantic north of the Azores and over the mid-Atlantic Ridge with winds up to 70 kts. It is expected to track to the northeast. Some seismic enhancement is possible in the Atlantic Ridge system as this storm passes through." (September 22, 2023)
The last earthquake with M>=4.6 within about 200 km of today's epicenters in the Azores occurred as an M 4.8 on January 27, 2020. Forecast 156523 and 156787
had expected this activity in the Azores region in mid- to late September.
O: 25SEP2023 16:47:26 38.7N 27.3W ML=4.1 EMSC AZORES ISLANDS, PORTUGAL
O: 25SEP2023 16:44:24 38.7N 27.3W mb=4.6 EMSC AZORES ISLANDS, PORTUGAL
P: 15SEP2023 156523 40.0N 30.0W 4.0-5.7 CBBAA No. Mid-Atlantic Ridge
P: 28SEP2023 156787 41.0N 30.0W 4.0-5.9 BCBAA No. Mid-Atlantic Ridge
An earthquake of M 5.4 also occurred today off the southern coast of Michoacan, Mexico. It was not reported felt in this area. This event occurred near local solar midnight and may have been promoted by strong tidal stresses at this hour or by geomagnetic/solar flares which maximize their seismic influence near this time. At M 5.4 this is the first event of this magnitude within about 150 km of this epicenter since an M 5.5 on March 29, 2022. Events of M 5.4 also hit the area on July 23, 2016 and January 22, 2011. The only earthquake in this area of significantly larger size in the past 35 years was an M 5.9 on October 28, 1994. At the time of the M 5.4 on March 29, 2022, this summary noted:
"NEIC reported this earthquake south of Michoacan Mexico was felt in Coahuayana, Michoacan, Mexico with intensity III. The last earthquake of M>=5.5 within about 200 km of this epicenter south of Michoacan, Mexico occurred on January 22, 2011, eleven years ago with M 5.5. The only other such event in the area in the past 30 years was an M 5.9 on October 28, 1994." (March 29, 2022)
Forecast 156411 had expected today's event was likely in mid- to late September.
O: 26SEP2023 06:21:40 15.1N 104.4W Mw=5.4 EMSC OFF COAST OF MICHOACAN, MEXICO
P: 16SEP2023 156411 15.0N 104.0W 3.5-5.2 CAAAA Michoacan, Mexico
The largest earthquake in the U.S. or Canada today was an M 4.1 off the coast of Washington. NEIC reported this earthquake of M 4.1 off the coast of Washington may have been felt with intensity II-III in the area(s) of Washington in Everett and Bellevue and in British Columbia, Canada at Victoria and Walnut Grove. This is the strongest earthquake within about 150 km of this epicenter off the coast of Washington since an M 4.5 on February 22, 2021 and an M 4.1 on September 22, 2020.
Forecast 156803 had expected today's event in this region to the north was likely around September 26.
O: 25SEP2023 13:31:50 47.7N 128.5W mb=4.1 EMSC OFF COAST OF WASHINGTON
P: 26SEP2023 156803 49.5N 127.2W 2.8-5.3 ABAAA Vancouver Island area
OTHER GLOBAL EARTHQUAKE ACTIVITY
For most events there are two listings. The first line is the observed event starting with "O:" for Observed. There follows the date, month and year, the time in UT hours:minutes:seconds, the latitude and longitude, the given magnitude and the reporting agency followed by the geographic location. The second line starts with "P:" This is the forecast event as forecast in our summaries normally more than a month in advance. Magnitudes may vary in response to updated seismic watches and daily variations due to tidal and other influences. This line has the forecast date, month and year, the forecast number, latitude, longitude and forecast magnitude range. This is followed by a comparison between the forecast and the event. The comparison includes letters A-D. The first is number of days difference from predicted (A:up to 2, B3-5; C:6-10; D:more than 10), Difference in latitude (A:up to 1 degree; B:1-2 degrees; C:2-4 degrees; D:more than 4 degrees); longitude (same comparison as with latitude); magnitude (A: within forecast range; B: higher than forecast range; C: lower than forecast range; D: no comparison possible). The last letter is a stand in for a future comparison which needs to be done statistically after a large number of forecasts have been made. In previous data, an excellent match is generally AAAAA; a good match as one or two B's; a fair match has several B's and C's and a poor match is one which contains a number of C's or D's.
ASIA
O: 26SEP2023 06:53:26 34.9N 73.9E mb=4.5 EMSC PAKISTAN
P: 22SEP2023 156731 35.0N 75.0E 3.8-5.3 BAAAA Northern India
O: 25SEP2023 23:04:32 24.5N 122.8E mb=4.3 EMSC TAIWAN REGION
O: 25SEP2023 23:04:32 24.5N 122.7E mb=4.7 CWB TAIWAN REGION
P: 27SEP2023 156701 24.0N 123.0E 4.0-5.6 AAAAA Taiwan
CWB reported this earthquake was felt with intensity II in Hualien and Yilan and I in Nantou, Taichung, Taipei, Taoyuan, Hsinchu Counties, Taiwan.
No significant (M>=5) or unusual earthquakes were reported in Asia today.
INDONESIA AND PHILIPPINES
O: 26SEP2023 01:39:45 4.7N 127.5E Mw=5.9 EMSC KEPULAUAN TALAUD, INDONESIA
P: 27SEP2023 156634 4.0N 128.0E 4.0-5.4 AAAAA Halmahera
O: 25SEP2023 10:32:18 6.4S 102.4E ML=4.0 EMSC SOUTHWEST OF SUMATRA, INDONESI
P: 24SEP2023 156657 5.0S 103.0E 4.0-5.7 ABAAA So. of Sumatera
O: 25SEP2023 12:11:57 6.7S 129.7E mb=4.5 EMSC BANDA SEA
O: 25SEP2023 15:48:52 6.9S 130.0E mb=4.7 EMSC BANDA SEA
O: 25SEP2023 21:01:27 7.2S 129.6E ML=4.3 EMSC KEPULAUAN BABAR, INDONESIA
P: 29SEP2023 156644 3.0S 129.0E 4.0-5.4 BCAAA Ceram area
CENTRAL AND SOUTH AMERICA
O: 25SEP2023 21:49:19 13.8N 93.3W ML=4.0 EMSC OFF COAST OF CHIAPAS, MEXICO
P: 30SEP2023 156666 14.0N 93.0W 3.5-5.6 BAAAA Chiapas, Mexico
O: 26SEP2023 06:21:40 15.1N 104.4W Mw=5.4 EMSC OFF COAST OF MICHOACAN, MEXICO
P: 16SEP2023 156411 15.0N 104.0W 3.5-5.2 CAAAA Michoacan, Mexico
O: 25SEP2023 19:41:36 16.3S 74.5W ML=4.2 EMSC NEAR COAST OF SOUTHERN PERU
O: 26SEP2023 01:30:43 15.2S 75.1W ML=4.0 EMSC NEAR COAST OF CENTRAL PERU
P: 26SEP2023 156845 14.0S 76.0W 4.0-5.8 ABAAA Central Peru
O: 26SEP2023 03:50:09 17.9N 66.3W MD=3.6 EMSC PUERTO RICO REGION
O: 26SEP2023 06:32:19 18.5N 66.1W MD=3.2 EMSC PUERTO RICO REGION
P: 26SEP2023 156685 19.0N 68.0W 3.4-5.1 AABAA Puerto Rico
NEIC reported this earthquake of M 3.6 in Puerto Rico was felt with intensity II-III in the area(s) of Puerto Rico in Santa Isabel (V), Arroyo, Guaynabo, San Juan.
O: 25SEP2023 07:12:50 18.5N 73.5W ML=3.5 EMSC HAITI REGION
P: 27SEP2023 156689 20.0N 73.0W 3.0-4.8 ABAAA Bahamas/No. Caribbean
O: 26SEP2023 00:46:36 19.8N 64.3W MD=4.0 EMSC NORTH OF THE VIRGIN ISLANDS
P: 27SEP2023 156673 18.0N 64.0W 3.0-5.0 ABAAA Leeward Islands
P: 28SEP2023 156688 20.0N 63.0W 3.0-4.4 AAAAA Bahamas/No. Caribbean
O: 26SEP2023 05:09:04 26.9N 108.4W ML=4.0 EMSC SINALOA, MEXICO
P: 21SEP2023 156692 24.0N 109.0W 3.5-5.1 BCAAA Gulf of California
AFRICA AND EUROPE
No significant (M>=5) or unusual earthquakes were reported in Europe today.
SOUTHWEST PACIFIC
O: 26SEP2023 06:50:30 10.2S 161.6E mb=4.7 EMSC SOLOMON ISLANDS
P: 28SEP2023 156857 11.0S 162.0E 4.0-5.5 AAAAA Vanuatu Islands
O: 26SEP2023 05:03:33 24.4S 179.8W mb=4.3 EMSC SOUTH OF FIJI ISLANDS
P: 27SEP2023 156872 24.0S 178.0W 4.0-5.4 AABAA Tonga Islands
No significant (M>=5) or unusual earthquakes were reported in the Southwest Pacific region today.
OCEAN RIDGES
O: 25SEP2023 16:47:26 38.7N 27.3W ML=4.1 EMSC AZORES ISLANDS, PORTUGAL
O: 25SEP2023 16:44:24 38.7N 27.3W mb=4.6 EMSC AZORES ISLANDS, PORTUGAL
P: 15SEP2023 156523 40.0N 30.0W 4.0-5.7 CBBAA No. Mid-Atlantic Ridge
P: 28SEP2023 156787 41.0N 30.0W 4.0-5.9 BCBAA No. Mid-Atlantic Ridge
O: 26SEP2023 01:38:16 78.7N 8.9E ML=3.3 EMSC SVALBARD REGION
P: 28SEP2023 156840 79.0N 7.0E 4.0-5.6 AAAAA Arctic Ocean Region
ZEALANDIA AND AUSTRALIA REGION
No earthquakes of M>=4 were recorded in the regions of Zealandia or Australia
today. GeoNet did not report any felt events in the area.
JAPAN AND KURIL ISLANDS
O: 25SEP2023 23:39:22 38.3N 141.2E Mw=4.5 EMSC NEAR EAST COAST OF HONSHU,
P: 23SEP2023 156735 38.0N 141.0E 4.0-5.7 AAAAA Off East Coast Honshu
U.S./CANADA*
WESTERN U.S./CANADA
CALIFORNIA
O: 25SEP2023 08:20:56 30.3N 115.8W ML=3.7 EMSC BAJA CALIFORNIA, MEXICO
O: 25SEP2023 18:02:40 30.9N 115.0W ML=3.2 EMSC BAJA CALIFORNIA, MEXICO
P: 30SEP2023 156741 31.0N 116.3W 2.5-4.7 BAAAA So. California
O: 25SEP2023 09:10:06 36.7N 121.4W MD=2.6 EMSC CENTRAL CALIFORNIA
P: 27SEP2023 156709 36.2N 120.8W 2.5-4.4 AAAAA Central California
NEIC reported this earthquake of M 2.6 in Central California was felt with intensity II-III in the area(s) of Central California in Los Banos, Moss Beach.
O: 26SEP2023 04:30:50 37.6N 122.2W MD=2.2 EMSC SAN FRANCISCO BAY, CALIFORNIA
P: 24SEP2023 156710 38.0N 122.3W 2.5-4.4 AAAAA Central California
O: 26SEP2023 00:26:41 39.7N 120.6W MD=2.7 EMSC NORTHERN CALIFORNIA
P: 20SEP2023 156446 39.4N 120.5W 2.5-4.4 CAAAA Central California
P: 24SEP2023 156790 40.3N 121.2W 2.5-4.5 AAAAA Northern California
NEIC reported this earthquake of M 2.8 in Northern California was felt with intensity II-III in the area(s) of Northern California in Clio, Portola, Downieville and Janesville.
ALASKA
O: 26SEP2023 00:05:43 59.3N 151.7W ML=3.1 EMSC KENAI PENINSULA, ALASKA
P: 27SEP2023 156828 60.8N 151.7W 3.2-5.1 ABAAA Central Alaska
NEIC reported this earthquake of M 3.1 in Southern Alaska was felt with intensity II-III in the area(s) of Southern Alaska in Homer and Willow.
PACIFIC NORTHWESTERN U.S./WESTERN CANADA
O: 25SEP2023 13:31:50 47.7N 128.5W mb=4.1 EMSC OFF COAST OF WASHINGTON
P: 26SEP2023 156803 49.5N 127.2W 2.8-5.3 ABAAA Vancouver Island area
O: 25SEP2023 09:03:53 50.9N 130.4W ML=3.5 EMSC VANCOUVER ISLAND, CANADA REGIO
O: 25SEP2023 09:03:53 50.9N 130.4W MB=3.5 ECAN of Port Hardy, BC
P: 22SEP2023 156812 50.7N 130.5W 3.0-4.9 BAAAA British Colombia
ROCKY MOUNTAINS REGION
O: 25SEP2023 07:20:54 31.7N 104.4W ML=2.1 EMSC WESTERN TEXAS
P: 27SEP2023 156738 31.6N 103.6W 2.0-4.1 AAAAA SW U.S.A
O: 25SEP2023 21:48:06 44.5N 115.2W ML=2.6 EMSC SOUTHERN IDAHO
P: 24SEP2023 156780 44.4N 115.1W 2.0-4.1 AAAAA Montana/Idaho
EASTERN U.S./CANADA
O: 25SEP2023 09:02:20 28.9N 98.0W ML=3.2 EMSC SOUTHERN TEXAS
O: 25SEP2023 17:17:19 28.8N 98.4W ML=2.4 EMSC SOUTHERN TEXAS
P: 23SEP2023 156738 31.6N 101.6W 2.0-4.1 ACCAA SW U.S.A
NEIC reported this earthquake of M 3.1 in Southern Texas was felt with intensity II-III in the area(s) of Southern Texas in Hobson and Falls City (IV) and in Karnes City and San Antonio.
O: 25SEP2023 13:25:49 34.1N 97.4W ML=2.3 EMSC OKLAHOMA
O: 25SEP2023 18:10:11 34.1N 97.4W ML=2.7 EMSC OKLAHOMA
O: 25SEP2023 12:31:57 34.1N 97.4W ML=2.0 EMSC OKLAHOMA
P: 22SEP2023 156755 34.0N 97.0W 2.0-4.1 BAAAA Southeast U.S.
O: 26SEP2023 02:20:30 36.4N 98.2W ML=2.4 EMSC OKLAHOMA
P: 29SEP2023 156756 36.0N 97.0W 2.0-4.1 BAAAA Southern Plains
HAWAII
O: 25SEP2023 16:00:12 19.3N 155.1W ML=3.0 EMSC ISLAND OF HAWAII, HAWAII
P: 22SEP2023 156671 19.2N 155.2W 3.0-4.5 BAAAA Hawaii
MODERATE QUAKES NEAR EQUATOR IN GABON AND RWANDA, AFRICA
EARTHQUAKE SUMMARY FOR SEPTEMBER 24, 2023
A pair of moderate earthquakes shook the equatorial zone of Africa today. These events occurred in Gabon (M 4.7) and Rwanda (M 4.5). An M 5.4 occurred on March 9, 2021 and on M 5.5 on December 4, 2022 was followed by an M 4.6 on January 10, 2023. At the time of the December, 2022 event this summary noted:
"The moderately strong earthquake of M 5.5 occurred in Gabon, West Africa today. NEIC reported it was felt with maximum intensity VIII in Gabon at Lambarene, Moyen-Ogooue; IV in Booue, Ogooue-Ivindo and III in Libreville Estuaire.
A series of islands apparently cause by the African Plate passing over a hot spot in the mantle aligns from southwest to northeast off the coast of western Africa and passes near this event in Gabon, which may be related to activity associated with this hot spot. The only similar event near Gabon within about 400 km of this epicenter in the past 35 years occurred as an M 5.5 on December 19, 2019 about 300 km northwest of today's epicenter." (December 4, 2022)
O: 25SEP2023 01:28:55 1.0S 10.3E mb=4.7 EMSC GABON
A series of events near M 4.5 occurred last in Rwanda in late May, 2021 and may have been related to volcanism. The last earthquake of significantly larger magnitude in the area of Rwanda within about 200 km of today's epicenter was an M i5.3 on October 20, 2019. Forecast 156386 had expected today's activity in Rwanda was likely in mid-September.
NEIC reported this earthquake of M 4.5 in Rwanda was felt with intensity II-III in the area(s) of Rwanda in Kibungo (IV), Cyangugu, Kigali and Byumba.
O: 24SEP2023 14:21:56 2.3S 29.5E mb=4.5 EMSC RWANDA
P: 16SEP2023 156386 2.0S 29.0E 3.0-4.8 CAAAA Lake Victoria area
The largest earthquake in the U.S. or Canada today was an M 5.0 in the eastern Andreanof Islands. NEIC reported it was felt with light intensity in Atka, Alaska. The last earthquake of M>=5 in the Fox Islands was an M 5.2 on August 20, 2023 with an epicenter about 250 km to the east of today's event. The last event in the Fox Islands within about 200 km of today's earthquake was an M 5.4 on May 13, 2023. At the time this summary noted in this regard:
"The strongest earthquake in the world today was an M 5.4 in the Fox Islands, Aleutians, Alaska. It was not reported felt in this remote area. The last earthquake in the Fox Islands with greater magnitude was an M 5.5 on November 21, 2022 but the last of significantly larger magnitude in this region was an M 6.8 on January 11, 2022 and aftershocks of M 6.1 on January 22, 2022. At the time this summary noted in this regard:
"Strong earthquakes of M 6.8 and M 6.4 shook the region of the Fox Islands, Aleutians, Alaska today. NEIC reported the M 6.8 was felt with intensity VI in Nikolski; IV in Dutch Harbor, Unalaska, False Pass and II-III in Akutan, Atka, Cold Bay, and Adak, Alaska. The M 6.4 aftershock was reported with intensity IV in Nikolski, Alaska and III in Unalaska. An aftershock of M 5.8 was also reported felt with intensity IV in Nikolski and Dutch Harbor, Alaska. The last earthquake within about 250 km of this epicenter in the Fox Islands with M>=6.8 was an M 6.9 on July 27, 2015 about 150 km west of today's epicenter." (January 11, 2022, May 13, 2023)
Forecast 156811 had expected enhanced seismicity within about 50 km of today's epicenter was likely around September 25.
O: 24SEP2023 15:01:37 52.6N 171.8W mb=5.0 EMSC FOX ISLANDS, ALEUTIAN ISLANDS
P: 25SEP2023 156811 52.4N 170.7W 3.5-5.2 AAAAA Andreanoff Isls, Aleutians
A series of aftershocks of M 3-4 continued in the Vancouver Island area of British Columbia today. These are apparently aftershocks of the M 5.6 on September 17. Most of this series occurred near local solar noon and may have been promoted by tidal stresses which maximize near this hour. Forecast 156812 had expected this activity was likely within about 25 km around September 22.
O: 23SEP2023 19:44:02 50.7N 130.4W MB=3.3 ECAN of Port Hardy, BC
O: 23SEP2023 19:32:36 50.6N 130.5W MB=3.2 ECAN of Port Hardy, BC
P: 22SEP2023 156812 50.7N 130.5W 3.0-4.9 AAAAA British Colombia
An earthquake of M 3.9 was also felt in southern Oklahoma today. NEIC reported this earthquake of M 3.7-3.9 in Oklahoma was felt with intensity II-III in the area(s) of Oklahoma with IV in Marlow, Comanche, Altus and lesser shaking in Duncan, Loco, Hennepin, Ryan, Altus, and in Texas at Lewisville and the Colony. This is generally south of the current moderate seismicity in the area. The last earthquake in Oklahoma within about 100 km of the M 3.9 today was an M 4.4 on October 13, 2010. The only event in the past 35 years closer than 100 km to today's epicenter with M>=3.9 occurred on January 18, 1995. Forecast 156755 had expected today's event was likely within 100 km around September 22.
O: 24SEP2023 19:15:00 35.0N 97.5W ML=2.2 EMSC OKLAHOMA
O: 25SEP2023 00:40:32 34.5N 97.8W mb=3.9 EMSC OKLAHOMA
P: 22SEP2023 156755 34.0N 97.0W 2.0-4.1 BAAAA Southeast U.S.
OTHER GLOBAL EARTHQUAKE ACTIVITY
For most events there are two listings. The first line is the observed event starting with "O:" for Observed. There follows the date, month and year, the time in UT hours:minutes:seconds, the latitude and longitude, the given magnitude and the reporting agency followed by the geographic location. The second line starts with "P:" This is the forecast event as forecast in our summaries normally more than a month in advance. Magnitudes may vary in response to updated seismic watches and daily variations due to tidal and other influences. This line has the forecast date, month and year, the forecast number, latitude, longitude and forecast magnitude range. This is followed by a comparison between the forecast and the event. The comparison includes letters A-D. The first is number of days difference from predicted (A:up to 2, B3-5; C:6-10; D:more than 10), Difference in latitude (A:up to 1 degree; B:1-2 degrees; C:2-4 degrees; D:more than 4 degrees); longitude (same comparison as with latitude); magnitude (A: within forecast range; B: higher than forecast range; C: lower than forecast range; D: no comparison possible). The last letter is a stand in for a future comparison which needs to be done statistically after a large number of forecasts have been made. In previous data, an excellent match is generally AAAAA; a good match as one or two B's; a fair match has several B's and C's and a poor match is one which contains a number of C's or D's.
ASIA
O: 24SEP2023 19:32:25 29.8N 91.3E ML=4.3 EMSC EASTERN XIZANG
P: 25SEP2023 156766 30.0N 90.0E 3.8-5.3 AAAAA Xizang
O: 24SEP2023 17:39:03 36.1N 70.9E mb=4.3 EMSC HINDU KUSH REGION, AFGHANISTAN
P: 22SEP2023 156717 37.0N 71.0E 3.8-5.2 AAAAA Hindu Kush/Pakistan
O: 25SEP2023 05:56:34 42.0N 81.5E mb=4.5 EMSC SOUTHERN XINJIANG, CHINA
P: 15SEP2023 156512 42.0N 83.0E 4.0-5.4 CAAAA Kirgizstan/Xinjiang
O: 24SEP2023 17:22:04 51.2N 92.5E mb=4.0 EMSC SOUTHWESTERN SIBERIA, RUSSIA
P: 29SEP2023 156779 46.0N 96.0E 4.0-5.6 BCCAA Mongolia
O: 25SEP2023 02:44:18 53.3N 159.6E mb=4.3 EMSC NEAR EAST COAST OF KAMCHATKA
P: 26SEP2023 156813 52.0N 160.0E 4.0-5.5 ABAAA E. of Kamchatka
O: 25SEP2023 05:27:16 67.4N 170.3W ML=3.9 EMSC NEAR N COAST OF CHUKOTKA, RUSS
No significant (M>=5) or unusual earthquakes were reported in Asia today.
INDONESIA AND PHILIPPINES
O: 24SEP2023 21:44:20 2.3S 121.0E ML=4.2 EMSC SULAWESI, INDONESIA
P: 21SEP2023 156659 1.0S 120.0E 4.0-5.5 BBAAA Sulawesi area
O: 24SEP2023 23:23:41 2.6S 139.2E ML=4.0 EMSC NEAR N COAST OF PAPUA, INDONES
P: 21SEP2023 156654 3.0S 140.0E 4.0-5.6 BAAAA Papua New Guinea
O: 24SEP2023 09:36:07 4.4S 153.5E mb=4.7 EMSC NEW IRELAND REGION, P.N.G.
P: 22SEP2023 156649 5.0S 153.0E 4.0-5.4 AAAAA New Britain
O: 24SEP2023 15:08:51 6.1S 130.4E ML=4.0 EMSC BANDA SEA
P: 29SEP2023 156644 3.0S 129.0E 4.0-5.4 BCBAA Ceram area
O: 24SEP2023 16:34:31 6.9N 94.6E mb=4.8 EMSC NICOBAR ISLANDS, INDIA REGION
O: 24SEP2023 21:01:44 6.9N 94.9E ML=4.5 EMSC NICOBAR ISLANDS, INDIA REGION
O: 24SEP2023 21:32:00 6.7N 95.2E ML=4.0 EMSC NICOBAR ISLANDS, INDIA REGION
P: 21SEP2023 156638 5.0N 95.0E 4.0-5.9 BBAAA Nicobar Islands
O: 25SEP2023 05:11:20 7.1S 129.1E mb=4.8 EMSC KEPULAUAN BABAR, INDONESIA
P: 29SEP2023 156644 3.0S 129.0E 4.0-5.4 BCAAA Ceram area
O: 24SEP2023 23:20:14 8.0S 107.1E ML=4.1 EMSC JAVA, INDONESIA
P: 29SEP2023 156655 7.0S 107.0E 4.0-5.6 BAAAA So. of Java
O: 25SEP2023 04:01:39 10.3N 126.2E ML=4.1 EMSC PHILIPPINE ISLANDS REGION
P: 21SEP2023 156674 10.0N 125.0E 3.5-5.1 BAAAA Luzon, Philippines
CENTRAL AND SOUTH AMERICA
O: 25SEP2023 00:56:42 12.7N 84.7W ML=4.3 EMSC NICARAGUA
P: 28SEP2023 156679 10.0N 86.0W 3.5-5.2 BCBAA Nicaragua
O: 24SEP2023 14:47:39 13.1S 74.2W ML=4.2 EMSC CENTRAL PERU
P: 26SEP2023 156845 14.0S 76.0W 4.0-5.8 AABAA Central Peru
O: 25SEP2023 06:57:45 13.9N 92.0W mb=4.7 EMSC OFFSHORE GUATEMALA
P: 17SEP2023 156406 14.0N 92.0W 3.5-5.2 CAAAA Guatemala
P: 20SEP2023 156406 13.0N 91.0W 3.5-5.1 BAAAA Guatemala
O: 24SEP2023 21:31:02 14.1N 94.1W ML=4.2 EMSC OFF COAST OF CHIAPAS, MEXICO
O: 24SEP2023 12:04:26 15.6N 93.8W ML=4.2 EMSC OFFSHORE CHIAPAS, MEXICO
O: 24SEP2023 13:18:04 15.1N 94.5W ML=4.0 EMSC OFF COAST OF CHIAPAS, MEXICO
P: 21SEP2023 156666 15.0N 94.0W 3.5-5.6 BAAAA Chiapas, Mexico
O: 24SEP2023 18:00:46 15.9N 98.9W ML=4.0 EMSC OFFSHORE GUERRERO, MEXICO
P: 23SEP2023 156682 16.0N 98.0W 3.5-5.4 AAAAA Oaxaca, Mexico
O: 25SEP2023 04:11:55 18.7N 67.1W MD=3.2 EMSC PUERTO RICO REGION
O: 25SEP2023 01:23:00 17.9N 66.9W MD=3.0 EMSC PUERTO RICO
O: 24SEP2023 21:19:57 18.1N 68.4W MD=3.5 EMSC MONA PASSAGE, DOMINICAN REPUBL
P: 26SEP2023 156685 19.0N 68.0W 3.4-5.1 AAAAA Puerto Rico
O: 25SEP2023 02:25:39 19.1N 64.6W MD=3.6 EMSC VIRGIN ISLANDS REGION
P: 27SEP2023 156673 18.0N 64.0W 3.0-5.0 ABAAA Leeward Islands
AFRICA AND EUROPE
O: 25SEP2023 01:28:55 1.0S 10.3E mb=4.7 EMSC GABON
O: 24SEP2023 14:21:56 2.3S 29.5E mb=4.5 EMSC RWANDA
P: 16SEP2023 156386 2.0S 29.0E 3.0-4.8 CAAAA Lake Victoria area
O: 25SEP2023 01:48:11 38.2N 22.7E mb=4.1 EMSC GREECE
P: 23SEP2023 156727 39.0N 22.0E 3.0-4.4 AAAAA No. Greece
O: 24SEP2023 20:18:20 39.3N 40.2E ML=4.0 EMSC EASTERN TURKEY
P: 24SEP2023 156761 38.0N 39.0E 3.5-5.0 ABAAA Turkey
O: 24SEP2023 23:35:03 63.9N 21.5W ML=3.0 EMSC ICELAND REGION
O: 24SEP2023 20:49:57 63.9N 21.5W ML=2.9 EMSC ICELAND REGION
P: 29SEP2023 156834 63.0N 23.0W 3.0-4.5 BAAAA Iceland area
SOUTHWEST PACIFIC
O: 24SEP2023 23:50:40 14.5S 173.6E mb=4.5 EMSC FIJI REGION
P: 25SEP2023 156846 14.0S 172.0E 4.0-5.4 AABAA Fiji Islands
O: 24SEP2023 08:13:46 17.6S 178.8W mb=4.5 EMSC FIJI REGION
O: 24SEP2023 11:01:53 18.0S 178.4W mb=4.4 EMSC FIJI REGION
P: 25SEP2023 156856 17.0S 179.0W 4.0-5.4 AAAAA Tonga Islands
P: 27SEP2023 156856 18.0S 179.0W 4.0-5.6 BAAAA Tonga Islands
O: 24SEP2023 21:24:58 20.4S 174.3W mb=4.7 EMSC TONGA
P: 22SEP2023 156871 20.0S 174.0W 4.0-5.6 AAAAA Tonga Islands
O: 25SEP2023 05:21:56 24.4S 177.0W mb=4.7 EMSC SOUTH OF FIJI ISLANDS
P: 27SEP2023 156872 24.0S 178.0W 4.0-5.4 AAAAA Tonga Islands
OCEAN RIDGES
O: 25SEP2023 04:12:19 55.9S 28.3W mb=5.0 EMSC SOUTH SANDWICH ISLANDS REGION
P: 27SEP2023 156891 56.0S 29.0W 4.0-6.0 AAAAA So. Sandwich Islands
ZEALANDIA AND AUSTRALIA REGION
O: 24SEP2023 10:25:52 36.1S 179.3E ML=4.0 EMSC OFF E. COAST OF N. ISLAND, N.Z
P: 25SEP2023 156878 37.0S 177.0E 3.0-4.4 AABAA North Island, N.Z.
JAPAN AND KURIL ISLANDS
O: 25SEP2023 03:38:00 33.8N 137.0E mb=4.3 EMSC NEAR S. COAST OF WESTERN HONSHU JAPAN
P: 26SEP2023 156728 35.0N 136.0E 3.5-4.9 ABAAA No. Honshu, Japan
O: 24SEP2023 14:30:36 35.4N 141.3E ML=4.0 EMSC NEAR EAST COAST OF HONSHU, JAP
P: 24SEP2023 156733 36.0N 141.0E 4.0-5.4 AAAAA Off East Coast Honshu
O: 25SEP2023 04:35:50 41.7N 142.0E mb=4.8 EMSC HOKKAIDO, JAPAN REGION
P: 23SEP2023 156774 41.0N 141.0E 3.5-5.6 AAAAA Hokkaido, Japan
U.S./CANADA*
WESTERN U.S./CANADA
CALIFORNIA
O: 25SEP2023 06:42:33 35.1N 119.6W ML=3.2 EMSC CENTRAL CALIFORNIA
P: 24SEP2023 156748 34.7N 119.0W 2.5-4.6 AAAAA So. California
NEIC reported this earthquake of M 3.1 in Central California was felt with intensity II-III in the area(s) of Central California in New Cuyama, Taft, Ventura, Bakersfield, Oxnard, Moorpark, Camarillo.
O: 24SEP2023 16:55:47 35.5N 118.4W ML=2.5 EMSC CENTRAL CALIFORNIA
P: 23SEP2023 156749 35.4N 118.5W 2.5-4.6 AAAAA So. California
O: 24SEP2023 19:28:54 38.2N 122.7W MD=2.2 EMSC NORTHERN CALIFORNIA
P: 24SEP2023 156710 38.0N 122.3W 2.5-4.4 AAAAA Central California
ALASKA
O: 24SEP2023 18:20:15 51.6N 179.4E ML=4.1 EMSC RAT ISLANDS, ALEUTIAN ISLANDS
P: 28SEP2023 156822 51.0N 178.0E 4.0-5.8 BAAAA Rat Islands
O: 25SEP2023 05:24:33 51.9N 178.5W ML=3.1 EMSC ANDREANOF ISLANDS, ALEUTIAN IS
P: 24SEP2023 156809 50.8N 179.5W 3.5-5.3 AAAAA Andreanoff Isls, Aleutians
O: 24SEP2023 15:01:37 52.6N 171.8W mb=5.0 EMSC FOX ISLANDS, ALEUTIAN ISLANDS
P: 25SEP2023 156811 52.4N 170.7W 3.5-5.2 AAAAA Andreanoff Isls, Aleutians
O: 23SEP2023 21:52:39 55.4N 135.3W MB=3.5 ECAN of Sitka, AK
P: 14SEP2023 156547 55.0N 135.0W 3.0-4.9 CAAAA British Colombia
PACIFIC NORTHWESTERN U.S./WESTERN CANADA
O: 23SEP2023 19:44:02 50.7N 130.4W MB=3.3 ECAN of Port Hardy, BC
O: 23SEP2023 19:32:36 50.6N 130.5W MB=3.2 ECAN of Port Hardy, BC
P: 22SEP2023 156812 50.7N 130.5W 3.0-4.9 AAAAA British Colombia
O: 23SEP2023 21:52:39 55.4N 135.3W MB=3.5 ECAN of Sitka, AK
P: 14SEP2023 156547 55.0N 135.0W 3.0-4.9 CAAAA British Colombia
ROCKY MOUNTAINS REGION
O: 24SEP2023 07:13:14 31.6N 104.6W ML=3.2 EMSC WESTERN TEXAS
O: 24SEP2023 07:13:14 31.6N 104.6W ML=3.3 ANSS WESTERN TEXAS
O: 24SEP2023 07:11:41 31.7N 104.6W ML=2.8 EMSC WESTERN TEXAS
P: 22SEP2023 156738 32.5N 104.6W 2.0-4.1 AAAAA SW U.S.A
NEIC reported this earthquake of M 3.3 in Western Texas was felt with intensity II-III in the area(s) of Western Texas in Tarzan.
O: 25SEP2023 03:18:10 32.4N 102.0W ML=3.1 EMSC WESTERN TEXAS
O: 24SEP2023 08:50:18 32.7N 100.7W ML=2.8 EMSC WESTERN TEXAS
P: 23SEP2023 156738 31.6N 101.6W 2.0-4.1 AAAAA SW U.S.A
O: 24SEP2023 12:55:33 44.7N 114.4W ML=2.4 EMSC SOUTHERN IDAHO
P: 24SEP2023 156780 44.4N 115.1W 2.0-4.1 AAAAA Montana/Idaho
P: 27SEP2023 156780 44.4N 114.1W 2.0-4.1 BAAAA Montana/Idaho
EASTERN U.S./CANADA
O: 24SEP2023 23:59:29 45.7N 73.5W MB=3.3 ECAN of Repentigny, QC, felt
P: 26SEP2023 156785 46.2N 72.7W 2.0-4.1 AAAAA New England
NEIC reported this earthquake of M 2.7 in Quebec, Canada was felt with intensity II-III in the area(s) of Quebec, Canada in Vercheres, Montreal, Oka-Kanesatake and in Rouses Point, New York.
O: 24SEP2023 16:08:42 49.4N 66.5W MB=1.8 ECAN of Sainte-Anne-des-Monts, QC
P: 28SEP2023 156772 49.0N 66.0W 2.0-4.3 BAAAA E. of Maine
O: 24SEP2023 10:16:41 45.1N 66.7W MB=1.5 ECAN of Beaver Harbour, NB
P: 27SEP2023 156772 46.0N 66.0W 2.0-4.4 BAAAA E. of Maine
O: 23SEP2023 13:07:13 47.9N 70.0W MB=1.6 ECAN of Saint-Siméon, QC
O: 23SEP2023 12:11:30 47.6N 70.2W MB=1.3 ECAN of La Malbaie, QC
P: 22SEP2023 156778 47.0N 70.0W 2.0-4.1 AAAAA Maine
O: 24SEP2023 19:15:00 35.0N 97.5W ML=2.2 EMSC OKLAHOMA
O: 25SEP2023 00:40:32 34.5N 97.8W mb=3.9 EMSC OKLAHOMA
P: 22SEP2023 156755 34.0N 97.0W 2.0-4.1 BAAAA Southeast U.S.
HAWAII
No earthquakes of M>=3 were located in Hawaii.
QUIET DAY WITH DISTURBED IONOSPHERE
EARTHQUAKE SUMMARY FOR SEPTEMBER 23, 2023
It was a quiet day in global seismicity. The largest quakes was an M 5.1 in the Loyalty Islands of the southwest Pacific and in Nias Indonesia. These events were not reported felt. This seismic lull occurred as a new geomagnetic storm was brewing with AP 21 on September 24. It is likely there is a relation between the seismic lull and this geomagnetic storm.
"The geomagnetic field saw disturbed conditions today. The AP level was 10. High latitudes saw active conditions with AP 24. Middle latitudes were at quiet conditions with AP 9. The geomagnetic field is expected to see major storm conditions September 25 with minor storms September 24 and active September 26. Solar activity is expected to be at disturbed levels September 24-26 with a moderate chance (60%) of an M-class flare and 10% chance of an X-class flare. A proton storm is expected with 20% probability in this time period." (September 23-24, 2023)
The M 5.1 in the Loyalty Islands has been relatively quiet in recent months with the only events of larger magnitude an M 5.3 on July 3 and an M 5.2 on September 13, 2023. Forecast 156865 had expected this event was likely within about 100 km around September 24.
O: 23SEP2023 15:51:21 22.2S 170.5E Mw=5.1 EMSC SOUTHEAST OF LOYALTY ISLANDS
P: 24SEP2023 156865 23.0S 170.0E 4.0-5.4 AAAAA Loyalty Islands
An earthquake of M 5.1 also occurred in Sumatra today in the Nias Region of Indonesia. A major M 7.3 hit the Nias area on April 24, 2023. This may be a regional aftershock of that event. Forecast 156638 expected today's event within about 100 km was likely around September 23.
O: 24SEP2023 01:27:34 2.0N 97.0E mb=5.1 EMSC NIAS REGION, INDONESIA
P: 23SEP2023 156638 1.0N 97.0E 4.0-5.5 AAAAA Nicobar Islands
NEIC reported this earthquake of M 4.0 in Georgia was felt with intensity II-III in the area(s) of Georgia in Samgori, Tbilisi, Zahesi, Mtskheta, Tskneti, Tianeti and in Balakhonovskoye, Russia. The last activity in Georgia of M>=4 occurred February 11-12, 2023 with maximum intensity M 4.4. At the time this summary noted:
"The earthquake of M 4.4 in the Caucasus was the strongest in that area since M 5.3 on September 27, 2022. At the time this summary noted in this regard:
"An M 5.3 was also felt in eastern Turkey near the Georgia border today. NEIC reported these earthquake of M 5.3 and 4.4 in Eastern Turkey was felt with intensity CI in Susuz, Kars, Turkey and II-III in the area(s) of in Tbilisi and Batumi, Ajaria, Georgia. A similar M 5.3 hit within about 200 km on February 13, 2022 but the only earthquake of larger magnitude in this area of eastern Turkey in the past thirty-two years was an M 5.5 on December 16, 1990." (September 28, 2022, February 11, 2023)
Forecast 156770 had expected today's event within about 200 km was likely around September 24.
O: 24SEP2023 04:00:07 41.8N 45.0E mb=4.0 EMSC GEORGIA (SAK'ART'VELO)
P: 24SEP2023 156770 40.0N 44.0E 3.5-5.2 ABAAA Caucasus/Caspian Sea
NEIC reported an earthquake of M 2.9 in Northern California was felt with intensity II-III in the area(s) of Northern California in Paradise, Lodi.
An earlier M 3.3 was felt with intensity II-III in Patterson, Newman, Tracy, Gustine, Manteca, San Jose, Sunnyvale, Aptos, Palo Alto. NEIC reported this earthquake of M 2.7 in San Francisco, California was felt with intensity II-III in the area(s) of San Francisco, California in Milpitas, San Jose, Sunol among others. These appear to be largest long-term aftershocks of the M 4.5 of September 19, 2023. This area appears to be promoted by geomagnetic storms and by solar flares as noted with the M 4.5 in this summary as:
"The strongest earthquake in the U.S. or Canada today was an M 4.5 in Northern California east of the San Francisco, California Bay. This event was widely felt throughout much of central and northern California. … The mainshock was preceded by an M 4.0 foreshock, among others of smaller magnitude and by a number of felt aftershocks of M>=3. ... This largest event in the series may have been triggered by an M1.1 class solar flare which coincided with it.
...
This is the first M-class solar flare in the past three days.
The earthquakes in California also occurred at the height of the strongest geomagnetic storm since September 2 and may have been promoted by changes in the geomagnetic field associated with that storm. This summary noted in this regard:
"The geomagnetic field saw minor storm conditions today. The AP level was 30. High latitudes saw major storm conditions with AP 49. Middle latitudes were at active conditions with AP 21. This is the strongest disturbance in the geomagnetic field since AP reached 38 on September 2 with high latitude AP 59 on that date. This storm is expected to intensity on September 19, 2023. Some initial seismic enhancement is likely with a stronger intense period around September 21-22." (September 19, 2023)
Today's event in Northern California is the first of M>=4.5 within about 100 km of today's epicenter since an M 5.1 about 50 km southwest of this on October 25, 2022 and may be a regional aftershock of that event." (September 19, 2023)
Forecast 156710 had expected this aftershock was likely within about 50 km around September 23.
O: 23SEP2023 22:02:35 37.4N 121.8W MD=2.7 EMSC SAN FRANCISCO BAY AREA, CALIF.
P: 23SEP2023 156710 37.4N 121.3W 2.5-4.4 AAAAA Central California
OTHER GLOBAL EARTHQUAKE ACTIVITY
For most events there are two listings. The first line is the observed event starting with "O:" for Observed. There follows the date, month and year, the time in UT hours:minutes:seconds, the latitude and longitude, the given magnitude and the reporting agency followed by the geographic location. The second line starts with "P:" This is the forecast event as forecast in our summaries normally more than a month in advance. Magnitudes may vary in response to updated seismic watches and daily variations due to tidal and other influences. This line has the forecast date, month and year, the forecast number, latitude, longitude and forecast magnitude range. This is followed by a comparison between the forecast and the event. The comparison includes letters A-D. The first is number of days difference from predicted (A:up to 2, B3-5; C:6-10; D:more than 10), Difference in latitude (A:up to 1 degree; B:1-2 degrees; C:2-4 degrees; D:more than 4 degrees); longitude (same comparison as with latitude); magnitude (A: within forecast range; B: higher than forecast range; C: lower than forecast range; D: no comparison possible). The last letter is a stand in for a future comparison which needs to be done statistically after a large number of forecasts have been made. In previous data, an excellent match is generally AAAAA; a good match as one or two B's; a fair match has several B's and C's and a poor match is one which contains a number of C's or D's.
ASIA
O: 24SEP2023 04:43:04 29.5N 83.6E ML=4.1 EMSC XIZANG-NEPAL BORDER REGION
P: 27SEP2023 156765 30.0N 82.0E 3.8-5.4 BABAA Xizang
O: 23SEP2023 14:24:35 17.2N 96.2E mb=4.8 EMSC MYANMAR
P: 20SEP2023 156429 20.0N 96.0E 4.0-5.4 BCAAA Myanmar
NEIC reported this earthquake of M 4.8 in Myanmar was felt with intensity II-III in the area(s) of Myanmar in Bago (V); IV in Rangoon and Kyaiklat and II-III in Syriam, Maubin, and Mandalay.
No significant (M>=5) or unusual earthquakes were reported in Asia today.
INDONESIA AND PHILIPPINES
O: 23SEP2023 07:03:43 0.7S 135.9E ML=4.0 EMSC BIAK REGION, INDONESIA
P: 26SEP2023 156661 2.0S 135.0E 4.0-5.4 BAAAA West Irian, PNG
O: 24SEP2023 01:27:34 2.0N 97.0E mb=5.1 EMSC NIAS REGION, INDONESIA
P: 23SEP2023 156638 1.0N 97.0E 4.0-5.5 AAAAA Nicobar Islands
O: 23SEP2023 19:43:15 7.4S 122.0E ML=4.3 EMSC FLORES SEA
P: 25SEP2023 156646 8.0S 121.0E 4.0-5.4 AAAAA Flores Island area
O: 24SEP2023 00:10:18 8.7S 116.2E ML=4.3 EMSC LOMBOK REGION, INDONESIA
P: 22SEP2023 156660 8.0S 117.0E 4.0-5.6 AAAAA Sumbawa Island area
O: 23SEP2023 22:21:31 12.5N 123.7E ML=4.1 EMSC MASBATE REGION, PHILIPPINES
P: 25SEP2023 156674 12.0N 124.0E 3.5-4.9 AAAAA Luzon, Philippines
CENTRAL AND SOUTH AMERICA
O: 23SEP2023 09:27:08 15.8N 95.1W ML=4.0 EMSC OFFSHORE OAXACA, MEXICO
P: 23SEP2023 156682 16.0N 96.0W 3.5-5.1 AAAAA Oaxaca, Mexico
P: 27SEP2023 156667 15.0N 95.0W 3.5-5.5 BAAAA Chiapas, Mexico
O: 24SEP2023 04:42:09 16.1N 61.2W ML=4.1 EMSC GUADELOUPE REGION, LEEWARD ISL
P: 25SEP2023 156672 16.0N 60.0W 3.0-5.0 AAAAA Leeward Islands
O: 24SEP2023 02:58:09 16.1N 97.1W ML=4.0 EMSC OAXACA, MEXICO
P: 23SEP2023 156682 16.0N 98.0W 3.5-5.4 AAAAA Oaxaca, Mexico
O: 24SEP2023 05:41:40 16.5S 72.5W ML=4.0 EMSC NEAR COAST OF SOUTHERN PERU
P: 24SEP2023 156852 16.0S 72.0W 4.0-5.8 AAAAA So. Peru/Bolivia
O: 23SEP2023 08:53:15 16.6N 94.9W ML=4.2 EMSC OAXACA, MEXICO
P: 25SEP2023 156667 17.0N 94.0W 3.5-5.3 AAAAA Chiapas, Mexico
O: 23SEP2023 12:54:28 18.7S 70.1W ML=4.2 EMSC TARAPACA, CHILE
P: 24SEP2023 156853 19.0S 69.0W 4.0-5.7 AAAAA So. Peru/Bolivia
O: 23SEP2023 18:00:56 20.1N 70.9W ML=3.4 EMSC DOMINICAN REPUBLIC REGION
O: 24SEP2023 03:39:10 19.3N 67.4W MD=3.6 EMSC PUERTO RICO REGION
O: 24SEP2023 01:24:27 18.8N 67.2W MD=3.2 EMSC PUERTO RICO REGION
P: 26SEP2023 156685 19.0N 68.0W 3.4-5.1 AAAAA Puerto Rico
O: 23SEP2023 18:16:13 19.5N 65.5W MD=3.4 EMSC PUERTO RICO REGION
P: 17SEP2023 156408 19.0N 65.0W 3.0-4.9 CAAAA Leeward Islands
O: 23SEP2023 20:16:33 21.2S 68.7W mb=4.5 EMSC ANTOFAGASTA, CHILE
P: 23SEP2023 156860 21.0S 68.0W 4.0-6.2 AAAAA Argentina
AFRICA AND EUROPE
O: 23SEP2023 16:52:15 5.9S 30.7E mb=4.6 EMSC LAKE TANGANYIKA REGION, TANZAN
P: 14SEP2023 156386 6.0S 30.0E 3.0-4.4 CAAAA Lake Victoria area
O: 23SEP2023 10:54:53 31.4N 7.7W mb=3.5 EMSC MOROCCO
O: 23SEP2023 15:15:28 31.4N 8.1W mb=3.0 EMSC MOROCCO
P: 22SEP2023 156722 30.0N 8.0W 3.5-5.4 ABAAA Morocco/Spain
O: 24SEP2023 02:12:30 34.1N 26.1E mb=4.4 EMSC CRETE, GREECE
P: 23SEP2023 156715 34.0N 25.0E 3.0-4.8 AAAAA Crete
P: 24SEP2023 156703 35.0N 26.0E 3.0-4.8 AAAAA Aegean Sea
O: 23SEP2023 08:22:23 37.9N 36.4E mb=4.5 EMSC CENTRAL TURKEY
P: 22SEP2023 156761 38.0N 36.0E 3.5-5.2 AAAAA Turkey
NEIC reported this earthquake of M 4.5 in Eastern Turkey was felt with intensity II-III in the area(s) of Eastern Turkey in Gaziantep (V), Polateli, Kilis (IV and Kayseri.
O: 24SEP2023 04:00:07 41.8N 45.0E mb=4.0 EMSC GEORGIA (SAK'ART'VELO)
P: 24SEP2023 156770 40.0N 44.0E 3.5-5.2 ABAAA Caucasus/Caspian Sea
O: 23SEP2023 17:01:35 42.9N 17.6E mb=4.0 EMSC ADRIATIC SEA
P: 23SEP2023 156767 44.0N 18.0E 3.0-5.7 ABAAA Adriatic Sea
NEIC reported this earthquake of M 4.0 in Croatia was felt with intensity II-III in the area(s) of Croatia in Blato, Dubrovnik, Opuzen, Lumbarda, Orebic, Curzola, Zaton, Dubronik.
O: 23SEP2023 18:51:08 45.7N 26.6E ML=3.6 EMSC ROMANIA
P: 23SEP2023 156798 46.0N 26.0E 3.0-5.3 AAAAA Romania/NW Turkey
O: 23SEP2023 22:03:17 38.6N 26.7W ML=3.4 EMSC AZORES ISLANDS, PORTUGAL
P: 15SEP2023 156523 40.0N 30.0W 4.0-5.7 CBCAA No. Mid-Atlantic Ridge
SOUTHWEST PACIFIC
O: 23SEP2023 09:10:04 10.6S 165.8E mb=4.5 EMSC SANTA CRUZ ISLANDS
P: 29SEP2023 156857 11.0S 166.0E 4.0-5.4 CAAAA Vanuatu Islands
O: 24SEP2023 05:55:44 25.7S 179.8E mb=4.4 EMSC SOUTH OF FIJI ISLANDS
P: 25SEP2023 156873 24.0S 179.0E 4.0-5.4 ABAAA Tonga/Fiji
O: 23SEP2023 15:51:21 22.2S 170.5E Mw=5.1 EMSC SOUTHEAST OF LOYALTY ISLANDS
P: 24SEP2023 156865 23.0S 170.0E 4.0-5.4 AAAAA Loyalty Islands
OCEAN RIDGES
No significant (M>=5) or unusual earthquakes were reported on Ocean Ridges today.
ZEALANDIA AND AUSTRALIA REGION
O: 24SEP2023 02:28:31 35.1S 179.8E ML=4.3 EMSC OFF E. COAST OF N. ISLAND, N.Z
P: 25SEP2023 156878 37.0S 177.0E 3.0-4.4 ABBAA North Island, N.Z.
JAPAN AND KURIL ISLANDS
O: 24SEP2023 02:28:51 31.1N 141.9E mb=4.5 EMSC IZU ISLANDS, JAPAN REGION
O: 24SEP2023 02:07:25 31.0N 141.9E mb=4.5 EMSC IZU ISLANDS, JAPAN REGION
P: 24SEP2023 156732 32.0N 142.0E 4.0-5.4 AAAAA Off East Coast Honshu
O: 23SEP2023 15:01:13 35.7N 140.8E mb=4.4 EMSC NEAR EAST COAST OF HONSHU, JAP
P: 24SEP2023 156733 36.0N 141.0E 4.0-5.4 AAAAA Off East Coast Honshu
NEIC reported this earthquake of M 4.4 near Tokyo, Japan was felt with intensity II-III in the area(s) of near Tokyo, Japan in Ibaraki Prefecture.
U.S./CANADA*
WESTERN U.S./CANADA
CALIFORNIA
O: 23SEP2023 20:03:17 30.9N 115.0W ML=3.4 EMSC BAJA CALIFORNIA, MEXICO
O: 23SEP2023 07:19:01 30.4N 114.9W ML=3.2 EMSC BAJA CALIFORNIA, MEXICO
P: 14SEP2023 156426 30.0N 114.0W 3.5-5.1 CAAAA Gulf of California
O: 23SEP2023 10:53:36 31.3N 115.6W ML=3.0 EMSC BAJA CALIFORNIA, MEXICO
P: 29SEP2023 156741 31.9N 116.3W 2.5-4.6 CAAAA So. California
O: 24SEP2023 06:02:58 34.3N 119.9W ML=1.9 EMSC SANTA BARBARA CHANNEL, CALIF.
P: 25SEP2023 156746 33.8N 119.7W 2.5-4.6 AAAAA So. California
O: 23SEP2023 11:59:56 37.3N 114.7W ML=2.3 EMSC NEVADA
P: 26SEP2023 156707 37.3N 114.9W 2.5-4.6 BAAAA Nevada area
O: 23SEP2023 22:02:35 37.4N 121.8W MD=2.7 EMSC SAN FRANCISCO BAY AREA, CALIF.
P: 23SEP2023 156710 37.4N 121.3W 2.5-4.4 AAAAA Central California
O: 23SEP2023 07:26:09 37.5N 118.8W MD=2.8 EMSC CENTRAL CALIFORNIA
P: 23SEP2023 156706 37.5N 118.6W 2.5-4.4 AAAAA California/Nevada area
O: 23SEP2023 15:57:46 37.5N 121.2W ML=3.2 EMSC NORTHERN CALIFORNIA
P: 23SEP2023 156710 37.4N 121.3W 2.5-4.4 AAAAA Central California
O: 23SEP2023 23:31:14 39.5N 122.0W MD=2.9 EMSC NORTHERN CALIFORNIA
P: 30SEP2023 156790 40.3N 121.2W 2.5-4.5 CAAAA Northern California
O: 23SEP2023 15:14:22 39.7N 123.6W MD=2.3 EMSC NORTHERN CALIFORNIA
P: 26SEP2023 156712 39.6N 123.4W 2.5-4.6 BAAAA Central California
O: 24SEP2023 04:52:28 40.7N 124.2W MD=2.1 EMSC NORTHERN CALIFORNIA
P: 26SEP2023 156791 40.4N 124.2W 2.5-4.6 AAAAA Off Coast of No. Calif
ALASKA
O: 23SEP2023 20:38:13 54.9N 160.4W ML=3.6 EMSC ALASKA PENINSULA
P: 22SEP2023 156807 55.0N 160.9W 3.5-4.9 AAAAA Alaska Peninsula
O: 23SEP2023 21:52:38 55.4N 135.5W ML=3.4 EMSC OFF COAST OF SOUTHEASTERN ALAS
P: 14SEP2023 156547 55.0N 135.0W 3.0-4.9 CAAAA British Colombia
P: 24SEP2023 156824 57.0N 138.0W 3.0-4.6 ABBAA Southeast Alaska
O: 23SEP2023 08:16:44 57.5N 152.6W ML=3.0 EMSC KODIAK ISLAND REGION, ALASKA
P: 25SEP2023 156828 60.0N 153.5W 3.2-5.1 ACAAA Central Alaska
O: 23SEP2023 11:12:51 64.5N 147.0W ML=3.9 EMSC CENTRAL ALASKA
P: 19SEP2023 156569 63.3N 147.5W 3.2-5.0 BBAAA Central Alaska
NEIC reported this earthquake of M 3.9 in Central Alaska was felt with intensity II-III in the area(s) of Central Alaska with IV in Eielson AFB and in Fairbanks, North Pole, Fort Wainwright, Delta Junction.
PACIFIC NORTHWESTERN U.S./WESTERN CANADA
O: 24SEP2023 01:07:15 47.8N 122.9W ML=2.0 EMSC PUGET SOUND REGION, WASHINGTON
P: 26SEP2023 156804 48.4N 123.2W 2.0-4.1 AAAAA Washington state, U.S.
ROCKY MOUNTAINS REGION
O: 23SEP2023 16:36:41 31.5N 103.6W ML=2.7 EMSC WESTERN TEXAS
P: 22SEP2023 156738 32.5N 104.6W 2.0-4.1 AAAAA SW U.S.A
O: 23SEP2023 21:50:19 32.7N 100.7W ML=2.6 EMSC WESTERN TEXAS
P: 23SEP2023 156738 31.6N 101.6W 2.0-4.1 ABAAA SW U.S.A
O: 24SEP2023 00:48:32 37.4N 113.1W ML=2.6 EMSC UTAH
P: 26SEP2023 156707 37.3N 114.9W 2.5-4.6 AABAA Nevada area
O: 23SEP2023 20:24:18 38.4N 112.8W ML=2.1 EMSC UTAH
P: 25SEP2023 156763 38.3N 112.2W 2.0-4.3 AAAAA Utah area
O: 23SEP2023 10:07:00 37.5N 104.7W ML=2.2 EMSC COLORADO
P: 22SEP2023 156714 37.0N 105.9W 2.0-4.1 AAAAA Colorado area
EASTERN U.S./CANADA
O: 23SEP2023 12:47:42 34.5N 97.8W ML=2.0 EMSC OKLAHOMA
P: 22SEP2023 156755 34.0N 97.0W 2.0-4.1 AAAAA Southeast U.S.
O: 23SEP2023 07:46:59 35.5N 96.8W ML=2.0 EMSC OKLAHOMA
P: 22SEP2023 156757 35.0N 96.0W 2.0-4.3 AAAAA Southern Plains
O: 23SEP2023 20:56:55 36.7N 97.7W ML=2.0 EMSC OKLAHOMA
P: 14SEP2023 156493 36.0N 97.0W 2.0-4.4 CAAAA Southern Plains
HAWAII
No earthquakes of M>=3 were located in Hawaii.
MODERATELY LARGE QUAKE IN BANDA SEA FELT IN NORTHERN AUSTRALIA
EARTHQUAKE SUMMARY FOR SEPTEMBER 22, 2023
The strongest earthquake in the world today was an M 5.8 in the Banda Sea, Indonesia at a deep focus. NEIC reported it was felt in East Timor at Dili in Dili and Dare and in northern Territory, Australia with IV in Howard Springs, Katherine and II-III in Coonawarra, Darwin, Humpty Doo-MacMinns Lagoon. This is the largest earthquake within about 200 km of this epicenter since an M 5.9 on August 29, 2023, and an M 6.2 on May 24, 2023. A major M 7.6 hit near today's epicenter on January 9, 2023. This may be an aftershock of that mainshock. Forecast 156644 had expected enhanced seismicity in this region was likely to the north at the end of September, 2023.
O: 22SEP2023 14:59:17 7.1S 129.7E Mw=5.8 EMSC KEPULAUAN BABAR, INDONESIA
P: 29SEP2023 156644 3.0S 129.0E 4.0-5.4 CCAAA Ceram area
The largest earthquake in the U.S. or Canada today was an M 5.0 in the Alaska Peninsula, continuing the enhanced seismicity in that region at this time. NEIC reported it was felt with intensity V in King Cove, Alaska. This appears to be an aftershock of the M 5.4 which hit the region yesterday and was noted in this summary ini the previous issue as:
"The strongest earthquake in the U.S. or Canada today was an M 5.4 in the Alaska Peninsula Alaska. NEIC reported it was felt with intensity V in Sand Point and King Cove and III in False Pass, Alaska. This is the strongest earthquake in the region of the Alaska Peninsula since an M 5.6 on August 3, 2023. At the time this summary noted:
"The strongest earthquake in the world, the U.S. or Canada today was an M 5.6 in the Unimak Island area of Alaska. NEIC reported it was felt with intensity IV in Sand Point, King Cove and II-III in False Pass, Chignik Lagoon, Alaska. This is the strongest aftershock to date of the M 7.2-7.4 of July 16, 2023 in the Alaska Peninsula about 50 km east of today's epicenter. It is the second largest earthquake in this area since an M 6.1 on July 28 and July 29, 2020. In the past 15 years many of the strongest earthquakes in this region have occurred in mid- to late-July and early August, perhaps indicating a seasonal triggering component. All events in the region with M>=6 since 2008 have occurred in late July including an M 6.1 on July 16, 2011; an M 6.0 on July 19, 2018; an M 6.1 on July 28, 2020 and an M 7.2 on July 16, 2023." (August 3, 2023, September 21, 2023)
This event occurred near local solar noon and may have been promoted by strong tidal stresses which maximize near this hour. Forecast 156562 and 156807 had expected enhanced seismicity in this region in mid-September.
O: 22SEP2023 11:59:07 54.9N 160.4W ML=3.5 EMSC ALASKA PENINSULA
O: 22SEP2023 09:04:41 55.0N 160.4W Mw=4.9 EMSC ALASKA PENINSULA
O: 22SEP2023 09:04:41 55.0N 160.4W Mw=5.0 ANSS ALASKA PENINSULA
P: 22SEP2023 156807 55.0N 160.9W 3.5-4.9 AAAAA Alaska Peninsula
An unusual earthquake of M 3.9 occurred today in central Texas. NEIC reported it was felt with maximum intensity IV in Hermleight, Snyder, Loraine and II-III in Roby, Colorado City, Roscoe and Midland among others. This is the strongest earthquake within about 150 km of this epicenter since an M 4.7 on February 16, 2023. At the time this summary noted:
"The strongest earthquake in the U.S. or Canada today was an M 4.7 in Western Texas. NEIC reported it was felt with maximum intensity V in Texas at Roby and IV in Hermleigh, Rotan, Hamlin and II-III in Snyder, Colorado City, Roscoe, Sweetwater, Sylvester, Aspermont and as far as Austin and Dallas, Texas. This is not an area of western Texas where moderate earthquakes have been occurring (those about 200-300 km to the west of this). The last earthquake within about 200 km of today's epicenter in Western Texas with M>=4.7 was an M 5.4 on December 16, 2022 about 200 km to the west of today's epicenter, but today's earthquake is the largest within about 150 km in at least 35 years." (February 16, 2023)
Today's event occurred near local solar noon and may have been promoted by tidal stresses. Forecast 156738 had expected today's event was likely in this area around September 23.
O: 22SEP2023 20:15:58 32.7N 100.7W ML=3.9 ANSS WESTERN TEXAS
O: 22SEP2023 20:15:58 32.7N 100.7W ML=3.8 EMSC WESTERN TEXAS
P: 23SEP2023 156738 31.6N 101.6W 2.0-4.1 ABAAA SW U.S.A
OTHER GLOBAL EARTHQUAKE ACTIVITY
For most events there are two listings. The first line is the observed event starting with "O:" for Observed. There follows the date, month and year, the time in UT hours:minutes:seconds, the latitude and longitude, the given magnitude and the reporting agency followed by the geographic location. The second line starts with "P:" This is the forecast event as forecast in our summaries normally more than a month in advance. Magnitudes may vary in response to updated seismic watches and daily variations due to tidal and other influences. This line has the forecast date, month and year, the forecast number, latitude, longitude and forecast magnitude range. This is followed by a comparison between the forecast and the event. The comparison includes letters A-D. The first is number of days difference from predicted (A:up to 2, B3-5; C:6-10; D:more than 10), Difference in latitude (A:up to 1 degree; B:1-2 degrees; C:2-4 degrees; D:more than 4 degrees); longitude (same comparison as with latitude); magnitude (A: within forecast range; B: higher than forecast range; C: lower than forecast range; D: no comparison possible). The last letter is a stand in for a future comparison which needs to be done statistically after a large number of forecasts have been made. In previous data, an excellent match is generally AAAAA; a good match as one or two B's; a fair match has several B's and C's and a poor match is one which contains a number of C's or D's.
ASIA
O: 22SEP2023 13:53:51 36.7N 71.0E mb=4.2 EMSC HINDU KUSH REGION, AFGHANISTAN
P: 22SEP2023 156717 37.0N 71.0E 3.8-5.2 AAAAA Hindu Kush/Pakistan
O: 22SEP2023 23:39:31 37.5N 73.2E mb=4.3 EMSC TAJIKISTAN
P: 20SEP2023 156452 39.0N 72.0E 3.8-5.2 ABAAA Hindu Kush/Pakistan
O: 22SEP2023 19:31:28 51.4N 100.4E mb=4.3 EMSC RUSSIA-MONGOLIA BORDER REGION
P: 14SEP2023 156514 46.0N 96.0E 4.0-5.7 CCCAA Mongolia
No significant (M>=5) or unusual earthquakes were reported in Asia today.
INDONESIA AND PHILIPPINES
O: 23SEP2023 02:20:16 5.4S 131.3E ML=4.3 EMSC BANDA SEA
P: 26SEP2023 156661 4.0S 134.0E 4.0-5.4 BBCAA West Irian, PNG
O: 22SEP2023 15:12:51 6.5S 121.3E ML=4.0 EMSC FLORES SEA
P: 25SEP2023 156646 8.0S 121.0E 4.0-5.4 BBAAA Flores Island area
O: 22SEP2023 14:59:17 7.1S 129.7E Mw=5.8 EMSC KEPULAUAN BABAR, INDONESIA
P: 29SEP2023 156644 3.0S 129.0E 4.0-5.4 CCAAA Ceram area
O: 22SEP2023 11:01:58 11.4S 117.5E ML=4.1 EMSC SOUTH OF SUMBAWA, INDONESIA
P: 22SEP2023 156660 8.0S 117.0E 4.0-5.6 ACAAA Sumbawa Island area
CENTRAL AND SOUTH AMERICA
O: 23SEP2023 05:06:17 14.5N 94.1W ML=4.1 EMSC OFF COAST OF CHIAPAS, MEXICO
P: 21SEP2023 156666 15.0N 94.0W 3.5-5.6 AAAAA Chiapas, Mexico
O: 22SEP2023 21:17:51 14.6S 75.5W ML=4.2 EMSC NEAR COAST OF CENTRAL PERU
P: 26SEP2023 156845 14.0S 76.0W 4.0-5.8 BAAAA Central Peru
O: 22SEP2023 10:14:55 10.1S 72.9W mb=4.6 EMSC CENTRAL PERU
P: 24SEP2023 156844 10.0S 75.0W 3.5-5.1 AABAA Brazil
O: 22SEP2023 10:50:17 15.0N 94.2W ML=4.0 EMSC OFF COAST OF CHIAPAS, MEXICO
P: 21SEP2023 156666 15.0N 94.0W 3.5-5.6 AAAAA Chiapas, Mexico
O: 22SEP2023 12:35:59 17.0N 100.9W ML=4.3 EMSC OFFSHORE GUERRERO, MEXICO
P: 25SEP2023 156677 18.0N 101.0W 3.5-5.2 BAAAA Michoacan, Mexico
O: 23SEP2023 03:05:33 18.2N 76.6W ML=3.0 EMSC JAMAICA REGION
P: 23SEP2023 156665 19.0N 81.0W 3.5-5.1 AACAA Caribbean Sea
NEIC reported this earthquake of M 3.0 in Jamaica was felt with intensity II-III in the area(s) of Jamaica in Hope Bay, Portland, Staony Hill, Constant Spring, Half Way Tree, Kingston, Saint Andrew.
O: 23SEP2023 04:57:12 18.8N 107.2W ML=4.3 EMSC OFF COAST OF JALISCO, MEXICO
P: 22SEP2023 156668 19.0N 107.0W 3.5-5.4 AAAAA Coast of Jalisco, Mexico
O: 22SEP2023 09:05:40 19.3N 121.0E ML=4.2 EMSC BABUYAN ISL REGION, PHILIPPINE
P: 22SEP2023 156699 20.0N 122.0E 4.0-5.4 AAAAA Taiwan
O: 22SEP2023 20:19:48 22.2S 68.7W ML=4.2 EMSC ANTOFAGASTA, CHILE
P: 23SEP2023 156860 21.0S 68.0W 4.0-6.2 ABAAA Argentina
NEIC reported this earthquake of M 4.4 in Tarapaca, Chile was felt with intensity II-III in the area(s) of Tarapaca, Chile in Iquique.
O: 22SEP2023 14:47:18 28.2S 70.4W ML=4.0 EMSC ATACAMA, CHILE
P: 21SEP2023 156863 29.0S 70.0W 4.0-5.6 AAAAA Coast Central Chile
AFRICA AND EUROPE
O: 22SEP2023 13:17:40 72.3N 15.3E mb=3.0 EMSC NORWEGIAN SEA
P: 14SEP2023 156579 74.0N 14.0E 3.0-4.6 CBAAA Norway
SOUTHWEST PACIFIC
O: 22SEP2023 16:19:32 14.9S 166.8E Mw=5.4 EMSC VANUATU
P: 22SEP2023 156858 14.0S 167.0E 4.0-5.4 AAAAA Vanuatu Islands
O: 22SEP2023 22:13:50 18.9S 174.3W mb=4.9 EMSC TONGA
P: 23SEP2023 156855 19.0S 173.0W 4.0-5.8 AAAAA Tonga Islands
NEIC reported this earthquake of M 4.9 in Tonga was felt with intensity II-III in the area(s) of Tonga in Neiafu, Vava'u.
O: 22SEP2023 12:22:00 24.6S 179.9E mb=4.3 EMSC SOUTH OF FIJI ISLANDS
O: 22SEP2023 08:20:58 25.3S 179.8W mb=4.8 EMSC SOUTH OF FIJI ISLANDS
P: 25SEP2023 156873 24.0S 179.0E 4.0-5.4 BAAAA Tonga/Fiji
P: 27SEP2023 156872 24.0S 178.0W 4.0-5.4 BBBAA Tonga Islands
No significant (M>=5) or unusual earthquakes were reported in the Southwest Pacific region today.
OCEAN RIDGES
No significant (M>=5) or unusual earthquakes were reported on Ocean Ridges today.
ZEALANDIA AND AUSTRALIA REGION
No earthquakes of M>=4 were recorded in the regions of Zealandia or Australia
today. GeoNet did not report any felt events in the area.
JAPAN AND KURIL ISLANDS
O: 22SEP2023 16:33:14 30.9N 142.1E mb=5.0 EMSC IZU ISLANDS, JAPAN REGION
P: 24SEP2023 156732 32.0N 142.0E 4.0-5.4 ABAAA Off East Coast Honshu
O: 22SEP2023 19:13:40 43.3N 139.0E mb=4.1 EMSC EASTERN SEA OF JAPAN
P: 18SEP2023 156508 43.0N 142.0E 3.5-5.5 BABAA Hokkaido, Japan
O: 22SEP2023 23:31:24 44.9N 144.3E mb=4.0 EMSC HOKKAIDO, JAPAN REGION
P: 20SEP2023 156535 45.0N 146.0E 3.5-5.4 AAAAA So. Kurils
P: 21SEP2023 156800 45.0N 146.0E 3.5-5.4 AAAAA So. Kurils
O: 23SEP2023 01:49:14 50.5N 156.7E mb=4.5 EMSC KURIL ISLANDS
P: 24SEP2023 156816 50.0N 156.0E 4.0-6.1 AAAAA Kamchatka
U.S./CANADA*
WESTERN U.S./CANADA
CALIFORNIA
O: 22SEP2023 10:22:49 31.0N 116.5W ML=3.6 EMSC OFFSHORE BAJA CALIFORNIA, MEXI
P: 26SEP2023 156743 32.1N 116.4W 2.5-4.6 BBAAA So. California
O: 22SEP2023 15:08:32 32.3N 115.3W ML=2.0 EMSC BAJA CALIFORNIA, MEXICO
P: 24SEP2023 156744 32.9N 115.6W 2.5-4.7 AAAAA So. California
O: 22SEP2023 20:38:41 32.3N 116.3W ML=2.3 EMSC BAJA CALIFORNIA, MEXICO
P: 22SEP2023 156743 32.6N 116.1W 2.5-4.6 AAAAA So. California
O: 22SEP2023 13:42:38 35.8N 117.6W ML=2.2 EMSC SOUTHERN CALIFORNIA
O: 22SEP2023 23:14:03 35.6N 117.4W ML=2.1 EMSC SOUTHERN CALIFORNIA
P: 23SEP2023 156750 35.8N 117.6W 2.5-4.4 AAAAA So. California
O: 23SEP2023 06:59:24 37.3N 122.1W MD=2.1 EMSC SAN FRANCISCO BAY AREA, CALIF.
O: 22SEP2023 18:03:14 37.3N 122.1W MD=2.7 EMSC SAN FRANCISCO BAY AREA, CALIF.
P: 23SEP2023 156710 37.4N 121.3W 2.5-4.4 AAAAA Central California
P: 24SEP2023 156710 38.0N 122.3W 2.5-4.4 AAAAA Central California
NEIC reported this earthquake of M 2.8 in San Francisco, California was felt with intensity II-III in the area(s) of San Francisco, California in Cupertino, Los Altos, Sunnyvale, Saratoga, San Jose, Mountain View among others.
O: 22SEP2023 09:50:13 40.4N 124.6W MD=2.4 EMSC OFFSHORE NORTHERN CALIFORNIA
O: 22SEP2023 08:11:07 40.4N 124.4W MD=2.1 EMSC OFFSHORE NORTHERN CALIFORNIA
P: 26SEP2023 156791 40.4N 124.2W 2.5-4.6 BAAAA Off Coast of No. Calif
ALASKA
O: 22SEP2023 20:06:30 51.5N 179.2W ML=3.8 EMSC ANDREANOF ISLANDS, ALEUTIAN IS
P: 24SEP2023 156809 50.8N 179.5W 3.5-5.3 AAAAA Andreanoff Isls, Aleutians
O: 22SEP2023 11:59:07 54.9N 160.4W ML=3.5 EMSC ALASKA PENINSULA
O: 22SEP2023 09:04:41 55.0N 160.4W Mw=4.9 EMSC ALASKA PENINSULA
P: 22SEP2023 156807 55.0N 160.9W 3.5-4.9 AAAAA Alaska Peninsula
O: 22SEP2023 21:54:59 57.1N 154.5W ML=3.4 EMSC KODIAK ISLAND REGION, ALASKA
P: 27SEP2023 156807 54.7N 156.9W 3.5-4.9 BCBAA Alaska Peninsula
PACIFIC NORTHWESTERN U.S./WESTERN CANADA
O: 22SEP2023 05:46:43 50.6N 130.4W MB=3.1 ECAN of Port Hardy, BC
P: 22SEP2023 156812 50.7N 130.5W 3.0-4.9 AAAAA British Colombia
ROCKY MOUNTAINS REGION
O: 23SEP2023 00:48:19 31.6N 104.4W ML=2.6 EMSC WESTERN TEXAS
O: 22SEP2023 12:18:31 32.3N 103.3W ML=3.5 EMSC NEW MEXICO
P: 22SEP2023 156738 32.5N 104.6W 2.0-4.1 AAAAA SW U.S.A
O: 22SEP2023 20:15:58 32.7N 100.7W ML=3.8 EMSC WESTERN TEXAS
P: 23SEP2023 156738 31.6N 101.6W 2.0-4.1 ABAAA SW U.S.A
EASTERN U.S./CANADA
O: 21SEP2023 23:00:06 49.1N 66.8W MB=1.8 ECAN of Cap-Chat, QC
P: 28SEP2023 156772 49.0N 66.0W 2.0-4.3 CAAAA E. of Maine
O: 22SEP2023 20:58:44 41.7N 81.0W ML=2.1 EMSC OHIO
O: 21SEP2023 21:28:55 41.8N 81.0W MB=2.7 ECAN of Cleveland, OH
P: 26SEP2023 156794 41.8N 81.4W 2.0-3.9 BAAAA Ohio/Lake Erie
O: 22SEP2023 09:42:08 29.1N 97.9W ML=2.2 EMSC SOUTHERN TEXAS
P: 13SEP2023 156430 28.0N 98.0W 3.0-4.6 CBAAA Northern Mexico
O: 22SEP2023 20:12:24 34.1N 97.4W ML=2.5 EMSC OKLAHOMA
O: 22SEP2023 10:46:38 35.5N 96.8W ML=3.2 EMSC OKLAHOMA
O: 22SEP2023 19:24:43 34.1N 97.4W ML=2.4 EMSC OKLAHOMA
P: 22SEP2023 156755 34.0N 97.0W 2.0-4.1 AAAAA Southeast U.S.
NEIC reported this earthquake of M 3.0 in Oklahoma was felt with intensity II-III in the area(s) of Oklahoma in Prague.
An M 3.2 was also felt in Oklahoma today with maximum intensity IV in Prague and II-III in Sparks, Shawnee, Meeker, Chandler, Stroud and Oklahoma City.
The M 2.8 was reported felt with intensity II in Morrison, Oklahoma.
O: 22SEP2023 18:51:55 35.5N 96.8W ML=2.8 EMSC OKLAHOMA
P: 22SEP2023 156757 35.0N 96.0W 2.0-4.3 AAAAA Southern Plains
O: 22SEP2023 08:19:17 36.4N 96.9W ML=2.7 EMSC OKLAHOMA
O: 22SEP2023 08:56:47 36.4N 96.9W ML=2.8 EMSC OKLAHOMA
P: 29SEP2023 156756 36.0N 97.0W 2.0-4.1 CAAAA Southern Plains
HAWAII
No earthquakes of M>=3 were located in Hawaii.
STRONG EARTHQUAKE IN NORTHERN VANUATU
EARTHQUAKE SUMMARY FOR SEPTEMBER 21, 2023
The strongest earthquake of the day in the world was an M 6.1 in northern Vanuatu. NEIC reported it was felt with intensity IV in Luganville, Sanma, Vanuatu. This may be an aftershock of an M 6.5 which occurred on August 16, 2023. At the time this summary noted in this regard:
"The strongest earthquake in the world today was an M 6.5 in northern Vanuatu. The mainshock was reported by NEIC to have been felt with intensity VII in Vanuatu at Sola Torba and IV in Sanma at Port Olry and Luganville and possibly in the Solomon Islands and New South Wales, Australia. The mainshock was preceded by an M 5.2 regional foreshock several hours earlier. That event was
felt with intensity III in Luganville, Sanma, Vanuatu. An aftershock of M 4.3 was felt with intensity IV in Port Olry, Sanma, Vanuatu. The mainshock within minutes of local solar midnight and most likely was promoted by tidal stresses with the new moon which was completed within hours of the occurrence of this earthquake.
...
Today's event of M 6.5 is the largest in northern Vanuatu since an M 7.0 about 150 km south of this epicenter on January 8, 2023. The last within 100 km at this magnitude level was an M 6.6 on January 15, 2019. (August 16, 2022)
Forecast 156858 had expected today's event within about 25 km was likely around September 22.
O: 21SEP2023 21:11:52 14.0S 167.2E Mw=6.1 EMSC VANUATU
P: 22SEP2023 156858 14.0S 167.0E 4.0-5.4 AAAAA Vanuatu Islands
Moderately large events of M 5.7 also occurred today in the Kermadec Islands and in the Izu Islands of Japan. These occurred in areas where moderately strong activity has been occurring in recent days.
The earthquake of M 5.7 in the Izu Islands, Japan was followed by an M 4.7 three hours later. follows a series of such events in the area including an M 5.8 on September 19. At the time this summary noted:
"An M 5.8 also occurred in the Izu Islands south of southeastern Honshu, Japan today. A similar M 5.8 occurred on February 5, 2023 and an M 6.3 in the Izu Islands was recorded on January 16, 2023. At the time of that event this summary noted:
"The strongest earthquake in the world today was an M 6.3 in the Izu Islands, Japan. NEIC reported it was felt with intensity II-III in Japan at Shizuoka, Kanagawa, Tokyo, Chiba, Fukushima and Okinawa Prefectures. This follows an M 5.2 in the area yesterday. In the previous summary it had been noted in this regard:
"The strongest earthquake in the world today was an M 5.2 in the Izu Islands of Southeastern Japan. Today's event was reported by JMA to have been lightly felt in southeastern Honshu, Japan. The last earthquake in the Izu Islands of significantly larger magnitude in this area of Izu Islands occurred on August 4, 2022 with M 5.7 after similar activity on July 31, 2022." (January 16, 2023, September 19, 2023)
Forecast 156732 had expected today's event within about 100 km was likely around September 24.
O: 22SEP2023 00:46:51 31.0N 142.0E mb=4.7 EMSC IZU ISLANDS, JAPAN REGION
O: 21SEP2023 21:22:13 31.0N 141.8E Mw=5.7 EMSC IZU ISLANDS, JAPAN REGION
P: 24SEP2023 156732 32.0N 142.0E 4.0-5.4 BAAAA Off East Coast Honshu
The M 5.7 in the Kermadec Islands is likely a regional aftershock of the M 6.6
south of this on September 8, 2023. It was not felt in this remote area. At the time of the September 8 event this summary noted:
"The M 6.6 in the Kermadec Islands, New Zealand today was widely felt in North Island, New Zealand - unlike most strong earthquakes in the Kermadec Islands. NEIC reported maximum intensity for the M 6.6 at IV in Gisborne at Te Karaka and II-III in the Bay of Plenty at Opotiki, Whakatane, in North Shore, Auckland, Napier, Hawke's Bay, in Manawatu-Wanganui at Palmerston North and Shannon, and more than 1000 km away in Wellington at Porirua, Lower Hutt and Wellington.
This is the strongest earthquake in the Kermadec Islands within about 200 km of this epicenter since an M 6.6 on August 14, 2022 and an M 7.4 on June 18, 2020." (September 9, 2023)
Forecast 156877 had expected today's event was likely within about 100 km around
September 22.
O: 21SEP2023 15:20:30 30.7S 178.0W Mw=5.7 EMSC KERMADEC ISLANDS, NEW ZEALAND
P: 22SEP2023 156877 30.0S 179.0W 4.0-5.6 AAAAA No. Kermadec Islands
The strongest earthquake in the U.S. or Canada today was an M 4.7 in eastern Greenland. It was not reported felt in this remote area. This is the strongest earthquake in eastern Greenland within about 300 km of this epicenter since an M 5.2 north of this epicenter on November 23, 2021. Similar events in the region occurred on January 16, 2018 with M 4.7 and August 15, 2008 with M 4.8.
Forecast 156842 had expected enhanced seismicity in this region was likely around September 22.
O: 21SEP2023 22:41:40 79.6N 18.4W mb=4.7 EMSC EASTERN GREENLAND
O: 21SEP2023 22:41:40 79.6N 18.6W mb=4.7 ANSS eastern Greenland"
P: 22SEP2023 156842 71.0N 8.0W 3.5-5.2 ACAAA Jan Mayen Isl. area
OTHER GLOBAL EARTHQUAKE ACTIVITY
For most events there are two listings. The first line is the observed event starting with "O:" for Observed. There follows the date, month and year, the time in UT hours:minutes:seconds, the latitude and longitude, the given magnitude and the reporting agency followed by the geographic location. The second line starts with "P:" This is the forecast event as forecast in our summaries normally more than a month in advance. Magnitudes may vary in response to updated seismic watches and daily variations due to tidal and other influences. This line has the forecast date, month and year, the forecast number, latitude, longitude and forecast magnitude range. This is followed by a comparison between the forecast and the event. The comparison includes letters A-D. The first is number of days difference from predicted (A:up to 2, B3-5; C:6-10; D:more than 10), Difference in latitude (A:up to 1 degree; B:1-2 degrees; C:2-4 degrees; D:more than 4 degrees); longitude (same comparison as with latitude); magnitude (A: within forecast range; B: higher than forecast range; C: lower than forecast range; D: no comparison possible). The last letter is a stand in for a future comparison which needs to be done statistically after a large number of forecasts have been made. In previous data, an excellent match is generally AAAAA; a good match as one or two B's; a fair match has several B's and C's and a poor match is one which contains a number of C's or D's.
ASIA
O: 22SEP2023 02:21:45 36.6N 71.0E mb=4.4 EMSC HINDU KUSH REGION, AFGHANISTAN
P: 22SEP2023 156717 37.0N 71.0E 3.8-5.2 AAAAA Hindu Kush/Pakistan
O: 21SEP2023 14:43:08 38.5N 45.4E mb=4.4 EMSC NORTHWESTERN IRAN
P: 17SEP2023 156496 38.0N 44.0E 3.5-5.0 BABAA Turkey
O: 21SEP2023 10:56:01 40.4N 77.4E mb=4.4 EMSC SOUTHERN XINJIANG, CHINA
P: 17SEP2023 156512 40.0N 77.0E 4.0-5.4 BAAAA Kirgizstan/Xinjiang
No significant (M>=5) or unusual earthquakes were reported in Asia today.
INDONESIA AND PHILIPPINES
O: 21SEP2023 15:41:36 0.4N 120.2E ML=4.0 EMSC MINAHASA, SULAWESI, INDONESIA
P: 21SEP2023 156659 1.0S 120.0E 4.0-5.5 ABAAA Sulawesi area
O: 21SEP2023 22:55:23 2.2S 119.2E ML=4.2 EMSC SULAWESI, INDONESIA
P: 21SEP2023 156659 1.0S 120.0E 4.0-5.5 ABAAA Sulawesi area
O: 21SEP2023 13:55:27 2.4N 128.5E ML=4.0 EMSC HALMAHERA, INDONESIA
P: 21SEP2023 156634 4.0N 129.0E 4.0-5.4 ABAAA Halmahera
O: 21SEP2023 15:37:56 2.8S 130.0E ML=4.2 EMSC SERAM, INDONESIA
P: 23SEP2023 156661 1.0S 133.0E 4.0-5.5 ABCAA West Irian, PNG
O: 22SEP2023 01:11:44 3.8S 151.9E mb=5.0 EMSC NEW IRELAND REGION, P.N.G.
P: 16SEP2023 156389 4.0S 151.0E 4.0-5.4 CAAAA New Ireland
O: 21SEP2023 18:23:23 6.2S 122.6E mb=4.7 EMSC FLORES SEA
P: 14SEP2023 156384 8.0S 123.0E 4.0-5.4 CBAAA Flores Island area
O: 21SEP2023 18:13:37 6.3S 103.7E mb=4.5 EMSC SOUTHWEST OF SUMATRA, INDONESI
P: 21SEP2023 156657 7.0S 104.0E 4.0-5.4 AAAAA So. of Sumatera
O: 22SEP2023 02:18:14 8.3S 119.7E mb=4.4 EMSC FLORES REGION, INDONESIA
O: 21SEP2023 16:43:07 8.6S 118.4E mb=4.5 EMSC SUMBAWA REGION, INDONESIA
P: 21SEP2023 156660 8.0S 119.0E 4.0-5.4 AAAAA Sumbawa Island area
O: 21SEP2023 08:22:38 10.3N 126.2E ML=4.2 EMSC PHILIPPINE ISLANDS REGION
O: 21SEP2023 09:29:51 10.9N 126.6E ML=4.0 EMSC PHILIPPINE ISLANDS REGION
P: 20SEP2023 156366 9.0N 126.0E 4.0-5.4 ABAAA Central Philippines
P: 21SEP2023 156674 10.0N 125.0E 3.5-5.1 AABAA Luzon, Philippines
O: 21SEP2023 09:48:24 13.8N 144.7E mb=4.5 EMSC GUAM REGION
O: 21SEP2023 09:48:24 13.8N 144.7E mb=5.0 ANSS GUAM REGION
P: 19SEP2023 156420 14.0N 146.0E 4.0-5.4 AAAAA So. Marianas/Guam
P: 23SEP2023 156686 13.0N 143.0E 4.0-5.4 AAAAA So. Marianas/Guam
NEIC reported this earthquake of M 5.0 in Guam was felt with intensity III-IV in the area(s) of Guam in Tamuning, Barrigada, Hagatna, Asan, Sinajana, Yigo, Yona, Santa Rita, and Mangilao with lesser shaking in Dededo, Guam.
O: 22SEP2023 00:45:49 14.9N 108.2E mb=4.6 EMSC VIETNAM
O: 22SEP2023 03:18:12 6.2N 123.8E mb=4.4 EMSC MORO GULF, MINDANAO, PHILIPPINES
CENTRAL AND SOUTH AMERICA
O: 21SEP2023 20:55:59 5.7S 76.7W ML=4.0 EMSC NORTHERN PERU
P: 29SEP2023 156653 6.0S 76.0W 4.0-5.9 CAAAA No. Peru
O: 22SEP2023 05:07:15 11.8N 87.2W mb=4.9 EMSC NEAR COAST OF NICARAGUA
P: 15SEP2023 156414 12.0N 87.0W 3.5-5.1 CAAAA Nicaragua
O: 22SEP2023 01:03:09 12.7S 76.1W ML=4.3 EMSC NEAR COAST OF CENTRAL PERU
P: 17SEP2023 156581 14.0S 76.0W 4.0-5.9 BBAAA Central Peru
P: 26SEP2023 156845 14.0S 76.0W 4.0-5.8 BBAAA Central Peru
O: 22SEP2023 00:15:28 8.1S 74.5W ML=4.4 EMSC CENTRAL PERU
O: 22SEP2023 02:11:56 8.8S 74.4W mb=4.9 EMSC CENTRAL PERU
P: 23SEP2023 156642 8.0S 74.0W 3.5-5.1 AAAAA Brazil
O: 21SEP2023 20:33:52 16.5N 96.0W ML=4.0 EMSC OAXACA, MEXICO
O: 21SEP2023 23:13:50 16.6N 94.9W ML=4.0 EMSC OAXACA, MEXICO
O: 21SEP2023 19:29:12 17.0N 94.7W ML=4.0 EMSC OAXACA, MEXICO
O: 21SEP2023 18:41:57 17.7N 95.6W ML=4.4 EMSC VERACRUZ, MEXICO
O: 21SEP2023 16:33:31 15.9N 95.1W ML=4.0 EMSC OFFSHORE OAXACA, MEXICO
P: 20SEP2023 156417 16.0N 96.0W 3.5-5.2 AAAAA Oaxaca, Mexico
O: 21SEP2023 13:50:27 16.9N 98.5W ML=4.1 EMSC GUERRERO, MEXICO
P: 23SEP2023 156682 16.0N 98.0W 3.5-5.4 AAAAA Oaxaca, Mexico
O: 21SEP2023 23:27:53 18.1N 68.9W ML=3.2 EMSC DOMINICAN REPUBLIC REGION
P: 26SEP2023 156685 19.0N 68.0W 3.4-5.1 BAAAA Puerto Rico
O: 22SEP2023 00:31:12 18.1N 76.6W mb=4.3 EMSC JAMAICA REGION
P: 15SEP2023 156422 19.0N 73.0W 3.0-4.6 CACAA Bahamas/No. Caribbean
P: 23SEP2023 156665 19.0N 81.0W 3.5-5.1 AACAA Caribbean Sea
NEIC reported this earthquake of M 4.3 in Jamaica was felt with intensity IV-V in the area(s) of Jamaica in Constant Spring, Mona, Kingston, Half Way Tree, Above Rocks, Trinity Ville, Port Antonio, Portland, Portmore, Spanish Town, Saint Catherine Gayle, Saint Mary among others.
O: 21SEP2023 07:29:42 18.6N 70.7W ML=3.1 EMSC DOMINICAN REPUBLIC
P: 20SEP2023 156422 20.0N 71.0W 3.0-4.6 ABAAA Bahamas/No. Caribbean
O: 21SEP2023 11:19:00 18.9N 67.3W MD=3.0 EMSC PUERTO RICO REGION
P: 22SEP2023 156684 18.0N 68.0W 3.4-5.1 AAAAA Puerto Rico
O: 21SEP2023 22:49:20 21.8S 67.2W Mw=4.3 EMSC POTOSI, BOLIVIA
P: 20SEP2023 156591 21.0S 68.0W 4.0-6.2 AAAAA Argentina
O: 21SEP2023 10:09:26 23.2S 66.8W mb=4.5 EMSC JUJUY, ARGENTINA
P: 22SEP2023 156861 23.0S 67.0W 4.0-5.6 AAAAA Argentina
AFRICA AND EUROPE
O: 22SEP2023 01:08:06 31.0N 8.5W ML=3.6 EMSC MOROCCO
P: 22SEP2023 156722 30.0N 8.0W 3.5-5.4 AAAAA Morocco/Spain
O: 22SEP2023 05:27:34 70.0N 12.0E ML=2.6 EMSC NORWEGIAN SEA
P: 14SEP2023 156579 74.0N 14.0E 3.0-4.6 AAAAA Norway
No significant (M>=5) or unusual earthquakes were reported in Europe today.
SOUTHWEST PACIFIC
O: 21SEP2023 21:11:52 14.0S 167.2E Mw=6.1 EMSC VANUATU
P: 22SEP2023 156858 14.0S 167.0E 4.0-5.4 AAAAA Vanuatu Islands
OCEAN RIDGES
No significant (M>=5) or unusual earthquakes were reported on Ocean Ridges today.
ZEALANDIA AND AUSTRALIA REGION
O: 21SEP2023 15:20:30 30.7S 178.0W Mw=5.7 EMSC KERMADEC ISLANDS, NEW ZEALAND
P: 22SEP2023 156877 30.0S 179.0W 4.0-5.6 AAAAA No. Kermadec Islands
JAPAN AND KURIL ISLANDS
O: 22SEP2023 00:46:51 31.0N 142.0E mb=4.7 EMSC IZU ISLANDS, JAPAN REGION
O: 21SEP2023 21:22:13 31.0N 141.8E Mw=5.7 EMSC IZU ISLANDS, JAPAN REGION
P: 24SEP2023 156732 32.0N 142.0E 4.0-5.4 BAAAA Off East Coast Honshu
O: 21SEP2023 12:54:57 49.4N 155.6E mb=4.5 EMSC KURIL ISLANDS
P: 24SEP2023 156816 50.0N 156.0E 4.0-6.1 BAAAA Kamchatka
P: 25SEP2023 156784 49.0N 155.0E 3.5-5.5 BAAAA NE Pacific
U.S./CANADA*
WESTERN U.S./CANADA
CALIFORNIA
O: 22SEP2023 05:33:43 32.1N 115.1W ML=2.0 EMSC BAJA CALIFORNIA, MEXICO
P: 24SEP2023 156744 32.9N 115.6W 2.5-4.7 AAAAA So. California
O: 21SEP2023 21:26:10 34.0N 116.9W ML=2.3 EMSC SOUTHERN CALIFORNIA
P: 23SEP2023 156745 33.4N 116.7W 2.5-4.6 AAAAA So. California
O: 21SEP2023 07:05:36 35.4N 118.6W ML=2.0 EMSC CENTRAL CALIFORNIA
P: 23SEP2023 156749 35.4N 118.5W 2.5-4.6 AAAAA So. California
O: 21SEP2023 07:14:07 37.3N 122.1W MD=2.8 EMSC SAN FRANCISCO BAY AREA, CALIF.
P: 23SEP2023 156710 37.4N 121.3W 2.5-4.4 AAAAA Central California
NEIC reported this earthquake of M 2.9 in San Francisco Bay, California was felt with intensity II-III in the area(s) of San Francisco Bay, Californian Cupertino, Los Altos, Sunnyvale, San Jose, Saratoga, Mountain View, Santa Clara among others.
O: 22SEP2023 03:06:57 37.6N 118.5W MD=2.2 EMSC CENTRAL CALIFORNIA
O: 21SEP2023 15:05:14 37.6N 118.9W MD=2.2 EMSC LONG VALLEY AREA, CALIFORNIA
P: 23SEP2023 156706 37.5N 118.6W 2.5-4.4 AAAAA California/Nevada area
O: 21SEP2023 19:57:42 39.7N 120.6W MD=2.4 EMSC NORTHERN CALIFORNIA
P: 20SEP2023 156446 39.4N 120.5W 2.5-4.4 AAAAA Central California
O: 22SEP2023 00:54:46 40.7N 123.9W MD=2.4 EMSC NORTHERN CALIFORNIA
P: 27SEP2023 156789 40.0N 123.0W 2.5-4.7 BAAAA Northern California
ALASKA
O: 22SEP2023 06:34:21 55.0N 156.3W ML=3.6 EMSC SOUTH OF ALASKA
P: 27SEP2023 156807 54.7N 156.9W 3.5-4.9 BAAAA Alaska Peninsula
PACIFIC NORTHWESTERN U.S./WESTERN CANADA
O: 21SEP2023 23:42:02 47.2N 122.9W ML=2.0 EMSC PUGET SOUND REGION, WASHINGTON
P: 22SEP2023 156804 47.5N 121.8W 2.0-4.1 AAAAA Washington state, U.S.
P: 24SEP2023 156804 46.9N 122.0W 2.0-3.9 BAAAA Washington state, U.S.
O: 21SEP2023 07:26:13 54.5N 118.5W MB=3.1 ECAN of Grande Prairie, AB
O: 21SEP2023 07:26:13 54.5N 118.5W ML=3.1 EMSC ALBERTA, CANADA
P: 16SEP2023 156542 56.0N 117.0W 2.0-4.1 BBAAA Alberta
ROCKY MOUNTAINS REGION
O: 21SEP2023 16:53:31 32.0N 103.8W ML=2.3 EMSC WESTERN TEXAS
O: 21SEP2023 19:35:48 32.0N 103.8W ML=2.6 EMSC WESTERN TEXAS
P: 22SEP2023 156738 32.5N 104.6W 2.0-4.1 AAAAA SW U.S.A
EASTERN U.S./CANADA
O: 21SEP2023 08:39:09 47.4N 70.4W MB=0.5 ECAN of Baie-Saint-Paul, QC
P: 22SEP2023 156778 47.0N 70.0W 2.0-4.1 AAAAA Maine
O: 21SEP2023 22:41:40 79.6N 18.4W mb=4.7 EMSC EASTERN GREENLAND
O: 21SEP2023 22:41:40 79.6N 18.6W mb=4.7 ANSS eastern Greenland"
P: 22SEP2023 156842 71.0N 8.0W 3.5-5.2 ACAAA Jan Mayen Isl. area
O: 21SEP2023 10:59:21 34.5N 97.8W ML=2.2 EMSC OKLAHOMA
O: 21SEP2023 11:15:30 34.5N 97.8W ML=2.1 EMSC OKLAHOMA
O: 21SEP2023 12:48:05 34.5N 97.8W ML=2.0 EMSC OKLAHOMA
O: 21SEP2023 13:57:06 34.5N 97.8W ML=2.0 EMSC OKLAHOMA
O: 21SEP2023 21:29:07 34.5N 97.8W ML=3.0 EMSC OKLAHOMA
O: 21SEP2023 07:24:26 34.5N 97.8W ML=3.0 EMSC OKLAHOMA
P: 22SEP2023 156755 34.0N 97.0W 2.0-4.1 AAAAA Southeast U.S.
NEIC reported this earthquake of M 3.0 in Oklahoma was felt with intensity V in the area(s) of Duncan, Oklahoma.
O: 21SEP2023 12:42:46 35.1N 95.5W ML=2.4 EMSC OKLAHOMA
P: 22SEP2023 156757 35.0N 96.0W 2.0-4.3 AAAAA Southern Plains
O: 21SEP2023 11:55:07 64.0N 88.1W MB=3.4 ECAN of Chesterfield Inlet, NU
O: 21SEP2023 11:55:07 64.0N 88.1W ML=3.4 EMSC NUNAVUT, CANADA
P: 26SEP2023 156837 65.0N 86.0W 2.5-3.9 BAAAA Nunavit/Hudson Bay, Canada
HAWAII
No earthquakes of M>=3 were located in Hawaii.
STRONG QUAKES IN EAST PACIFIC RISE; PRINCE EDWARD ISLANDS
EARTHQUAKE SUMMARY FOR SEPTEMBER 20, 2023
The largest earthquake in the world today was an M 6.0 in the northern East Pacific Rise south of Oaxaca, Mexico where was reported felt with intensity II. It was followed by a strong aftershock of M 5.7 and a moderate event of M 4.6 and preceded by an M 4.6 foreshock and an M 5.2 foreshock seconds before the mainshock. The last earthquake of M>=6 within about 200 km of today's epicenters occurred as an M 6.1 on March 22, 2020 and a similar event of M 6.0-6.1 on September 11, 2013. The only event of M>=6.0-6.1 in the area in the past 35 years was an M 6.33 on August 15, 1997. At the time of the event of March 22, 2020, this summary noted:
"The strongest earthquakes in the world today were an M 6.1 in the Central East Pacific Rise and an M 5.6 in the Central Mid-Atlantic Ridge. Neither of these were reported felt in these remote areas. The event in the Central East Pacific Rise is the largest within about 250 km of that epicenter since an M 6.1 on September 11, 2013 and a similar M 6.1 on August 4, 2007. The maximum sized earthquakes in the region in the past 30 years have been about M 6.1." (March 22, 2020)
Forecast 156391 had expected today's activity within about 100 km of these epicenters was likely around September 16. This activity is at the fifth node (72 degrees) from the M 7.7 in the Loyalty Islands of May 19, 2023 and near 103 degrees from the M 6.8 in Morocco of September 8, 2023 and may have been promoted by energy from those sources.
O: 20SEP2023 14:46:00 4.5S 105.8W Mw=6.0 EMSC CENTRAL EAST PACIFIC RISE
O: 20SEP2023 15:03:37 4.6S 105.9W Mw=5.7 EMSC CENTRAL EAST PACIFIC RISE
O: 20SEP2023 15:28:25 4.6S 106.2W mb=4.6 EMSC CENTRAL EAST PACIFIC RISE
O: 20SEP2023 14:45:29 4.5S 105.7W mb=5.2 EMSC CENTRAL EAST PACIFIC RISE
P: 16SEP2023 156391 5.0S 105.0W 4.0-5.5 BAAAA No. East Pacific Rise
An M 5.8 in the Prince Edward Island region of the South Indian Ocean also occurred today. It was not reported felt in this remote area. This epicenter is near the antipode of the M 6.0 in Vancouver, Canada of September 17, 2023 and may have been promoted by antipodal energy associated with that event. An earthquake of M 5.9 hit the Prince Edward Islands about 300 km east of today's epicenter on August 14, 2023. At the time this summary noted:
"An M 5.9 also occurred in the Prince Edward Islands of the south Indian Ocean. It was not reported felt in this remote area. Several hours earlier an M 4.9 occurred in the Southeast Indian Ridge. Neither of these event was reported felt. Both events occurred about an hour after local solar noon and may have been promoted by strong tidal stresses associated with the new moon of August 16. As noted in this and previous issues of this summary this event in the Prince Edward Islands is near the longitude of maximum tidal stress with today's new moon (see above).
The earthquake in the Prince Edward Islands is a aftershock of an M 6.8 on May 21, 2023. At the time this summary noted:
"The strongest earthquake in the world today was an M 6.8 in the Prince Edward Islands of the South Indian Ocean. It was not reported felt in this remote area.
This is the strongest earthquake in the Prince Edward Islands region within about 300 km of these epicenters in at least 35 years. The largest previous earthquake in this time frame in this area was an M 6.3 exactly 25 years ago today on May 21, 1998 within about 200 km of today's epicenter." (May 21, 2023, August 14, 2023)
Today's event is at 102 degrees from the M 7.7 in the Loyalty Islands of May 19 and may have been promoted by energy from that source.
O: 20SEP2023 19:22:34 44.9S 35.4E Mw=5.8 EMSC PRINCE EDWARD ISLANDS REGION
The strongest earthquake in the U.S. or Canada today was an M 5.4 in the Alaska Peninsula Alaska. NEIC reported it was felt with intensity V in Sand Point and King Cove and III in False Pass, Alaska. This is the strongest earthquake in the region of the Alaska Peninsula since an M 5.6 on August 3, 2023. At the time this summary noted:
"The strongest earthquake in the world, the U.S. or Canada today was an M 5.6 in the Unimak Island area of Alaska. NEIC reported it was felt with intensity IV in Sand Point, King Cove and II-III in False Pass, Chignik Lagoon, Alaska. This is the strongest aftershock to date of the M 7.2-7.4 of July 16, 2023 in the Alaska Peninsula about 50 km east of today's epicenter. It is the second largest earthquake in this area since an M 6.1 on July 28 and July 29, 2020. In the past 15 years many of the strongest earthquakes in this region have occurred in mid- to late-July and early August, perhaps indicating a seasonal triggering component. All events in the region with M>=6 since 2008 have occurred in late July including an M 6.1 on July 16, 2011; an M 6.0 on July 19, 2018; an M 6.1 on July 28, 2020 and an M 7.2 on July 16, 2023." (August 3, 2023)
This event occurred near local solar noon and may have been promoted by strong tidal stresses which maximize near this hour. forecast 156562 had expected enhanced seismicity in this region in mid-September.
O: 21SEP2023 01:14:00 55.0N 160.5W Mw=5.4 EMSC ALASKA PENINSULA
P: 14SEP2023 156562 54.3N 161.7W 3.5-4.9 CAAAA Unimak Islands, Aleutians
An unusually large earthquake of M 3.8 hit the central Nunavut, Canada region today. It was not reported felt in this remote area. The last earthquake with M>=3.8 within about 200 km of today's epicenter in Nunavut, Canada occurred more than 10 years ago on March 10, 2012 with M 4.2.
Forecast 156574 had expected today's event was likely in mid-September within
about 100 km of this epicenter. This activity is at 144 degrees from the Prince Edward Islands and at the third node (120 degrees) from the M 7.1 in Java of August 28, 2023 and at 103 degrees from recent strong earthquakes in Tonga and may have been promoted by energy from those sources.
O: 20SEP2023 14:22:14 64.9N 88.2W ML=3.8 EMSC NUNAVUT, CANADA
O: 20SEP2023 14:22:14 64.9N 88.2W MB=3.8 ECAN of Naujaat, NU
P: 12SEP2023 156574 65.0N 86.0W 2.5-4.0 CAAAA Nunavit/Hudson Bay, Canada
An earthquake of M 4.4 also shook the northern Dominican Republic today.
NEIC reported this earthquake of M 4.4 in the Dominican Republic was felt with intensity II-III in the area(s) of the Dominican Republic with V in Mao Valverde; IV in Moncion Santiago Rodriguez, Villa Bisono, Santiago and lesser shaking in Altamira, Villa Gonzalez, Imbert, Puerto Plata, among others. The last earthquake of larger magnitude within the Dominican Republic was an M 4.8 on May 18, 2023. Forecast 156422 had expected today's event was likely within about 50 km around September 20.
O: 20SEP2023 07:00:41 19.6N 70.8W mb=4.4 EMSC DOMINICAN REPUBLIC
P: 20SEP2023 156422 20.0N 71.0W 3.0-4.6 AAAAA Bahamas/No. Caribbean
OTHER GLOBAL EARTHQUAKE ACTIVITY
For most events there are two listings. The first line is the observed event starting with "O:" for Observed. There follows the date, month and year, the time in UT hours:minutes:seconds, the latitude and longitude, the given magnitude and the reporting agency followed by the geographic location. The second line starts with "P:" This is the forecast event as forecast in our summaries normally more than a month in advance. Magnitudes may vary in response to updated seismic watches and daily variations due to tidal and other influences. This line has the forecast date, month and year, the forecast number, latitude, longitude and forecast magnitude range. This is followed by a comparison between the forecast and the event. The comparison includes letters A-D. The first is number of days difference from predicted (A:up to 2, B3-5; C:6-10; D:more than 10), Difference in latitude (A:up to 1 degree; B:1-2 degrees; C:2-4 degrees; D:more than 4 degrees); longitude (same comparison as with latitude); magnitude (A: within forecast range; B: higher than forecast range; C: lower than forecast range; D: no comparison possible). The last letter is a stand in for a future comparison which needs to be done statistically after a large number of forecasts have been made. In previous data, an excellent match is generally AAAAA; a good match as one or two B's; a fair match has several B's and C's and a poor match is one which contains a number of C's or D's.
ASIA
O: 21SEP2023 06:34:25 36.1N 68.4E mb=4.1 EMSC HINDU KUSH REGION, AFGHANISTAN
P: 8SEP2023 156182 36.0N 71.0E 3.8-5.2 DABAA Hindu Kush/Pakistan
INDONESIA AND PHILIPPINES
O: 21SEP2023 04:07:11 1.0N 98.2E mb=4.8 EMSC NIAS REGION, INDONESIA
P: 15SEP2023 156377 1.0N 98.0E 4.0-5.6 CAAAA So. Sumatera
O: 20SEP2023 18:00:43 1.2S 134.4E ML=4.4 EMSC NEAR N COAST OF PAPUA, INDONES
P: 17SEP2023 156394 2.0S 139.0E 4.0-5.4 BACAA West Irian, PNG
O: 20SEP2023 20:33:34 3.8N 125.7E ML=4.4 EMSC KEPULAUAN SANGIHE, INDONESIA
P: 17SEP2023 156372 5.0N 128.0E 4.0-5.4 BBCAA Halmahera
No significant (M>=5) or unusual earthquakes were reported in Indonesia or the Philippines today.
CENTRAL AND SOUTH AMERICA
O: 20SEP2023 07:42:30 8.8S 79.8W ML=4.0 EMSC NEAR COAST OF NORTHERN PERU
P: 19SEP2023 156392 9.0S 80.0W 4.0-5.6 AAAAA No. Peru
O: 20SEP2023 19:04:30 9.1N 84.9W ML=4.3 EMSC COSTA RICA
P: 20SEP2023 156368 8.0N 83.0W 3.5-4.9 ABBAA Costa Rica
O: 20SEP2023 07:17:30 10.9N 86.5W ML=4.0 EMSC OFF COAST OF COSTA RICA
P: 11SEP2023 156414 11.0N 86.0W 3.5-5.2 CAAAA Nicaragua
P: 16SEP2023 156368 9.0N 86.0W 3.5-4.9 BBAAA Costa Rica
O: 20SEP2023 21:50:24 14.7N 94.6W ML=4.2 EMSC OFF COAST OF CHIAPAS, MEXICO
O: 20SEP2023 06:50:08 15.7N 93.9W ML=4.1 EMSC OFFSHORE CHIAPAS, MEXICO
O: 20SEP2023 14:28:33 15.9N 93.6W ML=4.1 EMSC CHIAPAS, MEXICO
P: 14SEP2023 156402 16.0N 94.0W 3.5-5.5 CAAAA Chiapas, Mexico
O: 20SEP2023 18:42:51 16.6N 100.5W ML=4.0 EMSC OFFSHORE GUERRERO, MEXICO
P: 14SEP2023 156418 16.0N 100.0W 3.5-5.6 CAAAA Oaxaca, Mexico
O: 21SEP2023 03:55:25 17.1N 94.1W ML=4.1 EMSC OAXACA, MEXICO
P: 12SEP2023 156402 17.0N 95.0W 3.5-5.3 CAAAA Chiapas, Mexico
O: 20SEP2023 19:59:16 17.7N 102.1W ML=4.4 EMSC OFFSHORE GUERRERO, MEXICO
P: 19SEP2023 156412 18.0N 103.0W 3.5-5.2 AAAAA Michoacan, Mexico
O: 20SEP2023 20:38:39 18.7N 72.7W ML=3.9 EMSC HAITI REGION
P: 15SEP2023 156422 19.0N 73.0W 3.0-4.6 BAAAA Bahamas/No. Caribbean
O: 21SEP2023 04:30:05 19.5N 65.5W MD=3.7 EMSC PUERTO RICO REGION
P: 17SEP2023 156408 19.0N 65.0W 3.0-4.9 BAAAA Leeward Islands
O: 20SEP2023 07:00:41 19.6N 70.8W mb=4.4 EMSC DOMINICAN REPUBLIC
P: 20SEP2023 156422 20.0N 71.0W 3.0-4.6 AAAAA Bahamas/No. Caribbean
O: 20SEP2023 14:49:01 24.2S 67.5W mb=4.7 EMSC SALTA, ARGENTINA
P: 18SEP2023 156591 23.0S 67.0W 4.0-5.8 ABAAA Argentina
O: 20SEP2023 09:59:02 25.0S 70.2W mb=4.4 EMSC ANTOFAGASTA, CHILE
P: 13SEP2023 156595 24.0S 69.0W 4.0-5.6 CAAAA Coast No. Chile
AFRICA AND EUROPE
No significant (M>=5) or unusual earthquakes were reported in Europe today.
SOUTHWEST PACIFIC
O: 20SEP2023 09:32:32 14.7S 167.9E Mw=5.0 EMSC VANUATU
P: 16SEP2023 156590 16.0S 168.0E 4.0-5.4 BBAAA Vanuatu Islands
O: 20SEP2023 08:50:27 18.0S 178.6W mb=4.6 EMSC FIJI REGION
P: 15SEP2023 156588 17.0S 177.0W 4.0-5.6 BABAA Tonga Islands
O: 20SEP2023 11:00:35 22.9S 172.2E mb=4.6 EMSC SOUTHEAST OF LOYALTY ISLANDS
P: 17SEP2023 156602 23.0S 173.0E 4.0-5.6 BAAAA Tonga/Fiji
P: 20SEP2023 156596 23.0S 170.0E 4.0-5.5 AABAA Loyalty Islands
OCEAN RIDGES
O: 20SEP2023 14:46:00 4.5S 105.8W Mw=6.0 EMSC CENTRAL EAST PACIFIC RISE
O: 20SEP2023 15:03:37 4.6S 105.9W Mw=5.7 EMSC CENTRAL EAST PACIFIC RISE
O: 20SEP2023 15:28:25 4.6S 106.2W mb=4.6 EMSC CENTRAL EAST PACIFIC RISE
O: 20SEP2023 14:45:29 4.5S 105.7W mb=5.2 EMSC CENTRAL EAST PACIFIC RISE
P: 16SEP2023 156391 5.0S 105.0W 4.0-5.5 BAAAA No. East Pacific Rise
O: 20SEP2023 19:22:34 44.9S 35.4E Mw=5.8 EMSC PRINCE EDWARD ISLANDS REGION
O: 21SEP2023 02:14:14 71.7N 11.3W Mw=3.5 EMSC JAN MAYEN ISLAND REGION
P: 14SEP2023 156578 71.0N 7.0W 3.5-5.2 CAAAA Jan Mayen Isl. area
ZEALANDIA AND AUSTRALIA REGION
O: 21SEP2023 01:17:52 45.0S 167.5E ML=3.9 EMSC SOUTH ISLAND OF NEW ZEALAND
O: 21SEP2023 01:17:52 45.0S 167.5E MS=4.0 GEONET South Island, N.Z.
P: 19SEP2023 156620 45.0S 167.0E 3.0-4.9 AAAAA So. Island, N.Z.
GEONET reported this earthquake was felt with weak intensity in the area southwest of Te Anau, South Island. 7 reports of felt intensity came from the area east and north of the epicenter with 6 weak, 0 light, 1 moderate, 0 strong, 0 severe and 0 extreme shaking.
JAPAN AND KURIL ISLANDS
O: 20SEP2023 14:00:15 40.2N 142.4E mb=4.4 EMSC NEAR EAST COAST OF HONSHU, JAP
P: 18SEP2023 156508 41.0N 142.0E 3.5-5.6 AAAAA Hokkaido, Japan
O: 20SEP2023 22:17:32 46.8N 146.3E mb=4.6 EMSC NORTHWEST OF KURIL ISLANDS
P: 20SEP2023 156535 45.0N 146.0E 3.5-5.4 ABAAA So. Kurils
U.S./CANADA*
WESTERN U.S./CANADA
CALIFORNIA
O: 21SEP2023 05:21:50 36.0N 120.6W MD=2.2 EMSC CENTRAL CALIFORNIA
P: 16SEP2023 156444 36.4N 121.1W 2.5-4.5 BAAAA Central California
O: 21SEP2023 05:06:57 38.9N 122.4W MD=2.2 EMSC NORTHERN CALIFORNIA
P: 17SEP2023 156445 39.0N 123.1W 2.5-4.6 BAAAA Central California
O: 20SEP2023 13:40:27 39.3N 117.3W ML=2.4 EMSC NEVADA
P: 17SEP2023 156504 40.2N 119.6W 2.5-4.7 BABAA California/Nevada area
O: 20SEP2023 17:01:12 39.4N 122.6W MD=2.6 EMSC NORTHERN CALIFORNIA
P: 17SEP2023 156445 39.0N 123.1W 2.5-4.6 BAAAA Central California
NEIC reported this earthquake of M 2.6 in Northern California was felt with intensity II-III in the area(s) of Northern California in Elk Creek and Willows.
O: 20SEP2023 22:47:27 39.7N 120.6W ML=2.8 EMSC NORTHERN CALIFORNIA
O: 20SEP2023 13:58:27 39.7N 120.6W MD=2.1 EMSC NORTHERN CALIFORNIA
P: 20SEP2023 156446 39.4N 120.5W 2.5-4.4 AAAAA Central California
NEIC reported this earthquake of M 2.8 in Northern California was felt with intensity II-III in the area(s) of Northern California in Portola and Citrus Heights.
ALASKA
O: 20SEP2023 13:50:01 51.8N 178.5E ML=3.7 EMSC RAT ISLANDS, ALEUTIAN ISLANDS
P: 18SEP2023 156557 51.0N 178.0E 4.0-5.6 AAAAA Rat Islands
O: 21SEP2023 01:14:00 55.0N 160.5W Mw=5.4 EMSC ALASKA PENINSULA
P: 14SEP2023 156562 54.3N 161.7W 3.5-4.9 CAAAA Unimak Islands, Aleutians
O: 20SEP2023 23:15:47 63.0N 150.9W ML=3.3 EMSC CENTRAL ALASKA
P: 15SEP2023 156571 63.3N 151.0W 3.2-5.5 BAAAA Central Alaska
PACIFIC NORTHWESTERN U.S./WESTERN CANADA
No events of M>=2 were located in the northwestern U.S. or western Canada today.
ROCKY MOUNTAINS REGION
O: 20SEP2023 19:15:32 37.3N 104.5W ML=2.8 EMSC COLORADO
P: 17SEP2023 156449 37.1N 104.7W 2.0-3.9 BAAAA Colorado area
NEIC reported this earthquake of M 2.8 in Southern Colorado was felt with intensity II-III in the area(s) of Southern Colorado in Trinidad (IV) and Model.
O: 20SEP2023 17:09:47 31.7N 104.4W ML=2.1 EMSC WESTERN TEXAS
O: 20SEP2023 16:09:55 31.5N 104.2W ML=2.8 EMSC WESTERN TEXAS
P: 16SEP2023 156474 31.4N 104.2W 2.0-4.1 BAAAA SW U.S.A
EASTERN U.S./CANADA
O: 20SEP2023 10:27:11 34.5N 97.8W ML=3.0 EMSC OKLAHOMA
P: 17SEP2023 156492 35.0N 96.0W 2.0-4.3 BABAA Southern Plains
NEIC reported this earthquake of M 2.9 in Oklahoma was felt with intensity II-III in the area(s) of Oklahoma in Duncan, Norman and Oklahoma City.
O: 20SEP2023 14:22:14 64.9N 88.2W ML=3.8 EMSC NUNAVUT, CANADA
O: 20SEP2023 14:22:14 64.9N 88.2W MB=3.8 ECAN of Naujaat, NU
P: 12SEP2023 156574 65.0N 86.0W 2.5-4.0 CAAAA Nunavit/Hudson Bay, Canada
HAWAII
No earthquakes of M>=3 were located in Hawaii.
STRONG EARTHQUAKE SHAKES CENTRAL SOUTH ISLAND, NEW ZEALAND
EARTHQUAKE SUMMARY FOR SEPTEMBER 19, 2023
The strongest earthquake in the world today was an M 5.6-6.2 in central South Island, New Zealand. NEIC reported it was felt with maximum intensity V in Canterbury at Rolleston and IV in Oamaru, Timaru, Lincoln, Christchurch with lesser shaking of II-III in Ashburton, Lyttelton, Te Puru-Thornton Bay, Waikato and Denedin Otago. GEONET reported it at M 6.2 and that it was felt with light intensity in the area of Central South Island, New Zealand. Of 14338 felt reports 4779 reports of light and 6786 of weak intensity with 1749 of moderate shaking and 169 with strong 2 with severe and 11 with extreme intensity came from the area. The last earthquake within about 150 km of this epicenter with M>=5.6 occurred on February 14, 2016 with M 5.8. The last of M>=6.2 was the Christchurch earthquake of M 7.0 of September 3, 2010 about 100 km north of today's epicenter. Forecast 156620 had expected a moderate earthquake in this area of South Island was likely around September 17.
O: 20SEP2023 01:18:23 43.7S 171.1E ML=3.8 EMSC SOUTH ISLAND OF NEW ZEALAND
O: 19SEP2023 21:14:49 43.7S 171.1E MS=6.2 GEONET South Island, New Zealand
O: 19SEP2023 21:14:50 43.7S 171.1E Mw=5.6 EMSC SOUTH ISLAND OF NEW ZEALAND
P: 17SEP2023 156620 44.0S 169.0E 3.0-5.1 AABAA So. Island, N.Z.
An unusual earthquake of M 4.5 hit near the northern coast of Libya today. This appears to be part of an activation of the northern African and Western Europe area which in the past several days included an M 6.8 in Morocco and an M 5.1 in northern Italy among others. Moderate earthquakes in this region of Libya area rare. The last earthquake in Libya within about 150 km of this epicenter was an M 4.5 on November 16, 2005, the only such quake in this area in at least 35 years. Forecast 156438 had expected today's event was likely in mid-September to the north of today's epicenter.
O: 20SEP2023 01:33:09 32.5N 24.6E mb=4.5 EMSC NEAR COAST OF LIBYA
P: 16SEP2023 156438 35.0N 25.0E 3.0-4.9 BCAAA Aegean Sea
The strongest earthquake in the U.S. or Canada today was an M 4.4 in the Alaska Peninsula Alaska. NEIC reported it was felt with intensity III in Sand Point, Alaska.
An earthquake of M 4.4 also shook the northern Dominican Republic today. The last earthquake of larger magnitude within the Dominican Republic was an M 4.8 on May 18, 2023. Forecast 156422 had expected today's event was likely within about 50 km around September 20.
O: 20SEP2023 07:00:41 19.6N 70.8W mb=4.4 EMSC DOMINICAN REPUBLIC
P: 20SEP2023 156422 20.0N 71.0W 3.0-4.6 AAAAA Bahamas/No. Caribbean
OTHER GLOBAL EARTHQUAKE ACTIVITY
For most events there are two listings. The first line is the observed event starting with "O:" for Observed. There follows the date, month and year, the time in UT hours:minutes:seconds, the latitude and longitude, the given magnitude and the reporting agency followed by the geographic location. The second line starts with "P:" This is the forecast event as forecast in our summaries normally more than a month in advance. Magnitudes may vary in response to updated seismic watches and daily variations due to tidal and other influences. This line has the forecast date, month and year, the forecast number, latitude, longitude and forecast magnitude range. This is followed by a comparison between the forecast and the event. The comparison includes letters A-D. The first is number of days difference from predicted (A:up to 2, B3-5; C:6-10; D:more than 10), Difference in latitude (A:up to 1 degree; B:1-2 degrees; C:2-4 degrees; D:more than 4 degrees); longitude (same comparison as with latitude); magnitude (A: within forecast range; B: higher than forecast range; C: lower than forecast range; D: no comparison possible). The last letter is a stand in for a future comparison which needs to be done statistically after a large number of forecasts have been made. In previous data, an excellent match is generally AAAAA; a good match as one or two B's; a fair match has several B's and C's and a poor match is one which contains a number of C's or D's.
ASIA
No significant (M>=5) or unusual earthquakes were reported in Asia today.
INDONESIA AND PHILIPPINES
O: 20SEP2023 02:31:38 1.6N 126.3E ML=4.1 EMSC MOLUCCA SEA
P: 17SEP2023 156374 1.0N 126.0E 4.0-5.6 BAAAA Mindanao, Philippines
O: 19SEP2023 20:09:36 9.0S 112.3E ML=4.3 EMSC SOUTH OF JAVA, INDONESIA
P: 20SEP2023 156396 6.0S 113.0E 4.0-5.6 ACAAA So. of Bali
O: 19SEP2023 21:10:54 10.8N 144.1E mb=4.8 EMSC SOUTH OF MARIANA ISLANDS
P: 15SEP2023 156420 12.0N 143.0E 4.0-5.4 BBAAA So. Marianas/Guam
NEIC reported this earthquake of M 4.8 in Guam was felt with intensity II-III in the area(s) of Guam in Tamuning.
CENTRAL AND SOUTH AMERICA
O: 20SEP2023 05:55:57 8.4N 83.0W ML=4.1 EMSC PANAMA-COSTA RICA BORDER REGION
O: 19SEP2023 23:37:44 8.4N 82.9W ML=4.0 EMSC PANAMA-COSTA RICA BORDER REGIO
P: 20SEP2023 156368 8.0N 83.0W 3.5-4.9 AAAAA Costa Rica
O: 20SEP2023 07:42:30 8.8S 79.8W ML=4.0 EMSC NEAR COAST OF NORTHERN PERU
P: 19SEP2023 156392 9.0S 80.0W 4.0-5.6 AAAAA No. Peru
O: 20SEP2023 07:17:30 10.9N 86.5W ML=4.0 EMSC OFF COAST OF COSTA RICA
P: 15SEP2023 156414 12.0N 87.0W 3.5-5.1 ABAAA Nicaragua
P: 16SEP2023 156368 9.0N 86.0W 3.5-4.9 ABAAA Costa Rica
O: 20SEP2023 06:25:12 14.5N 92.7W ML=4.0 EMSC OFFSHORE CHIAPAS, MEXICO
P: 17SEP2023 156406 14.0N 92.0W 3.5-5.2 BAAAA Guatemala
O: 20SEP2023 06:50:08 15.7N 93.9W ML=4.1 EMSC OFFSHORE CHIAPAS, MEXICO
P: 17SEP2023 156401 14.0N 94.0W 3.5-5.6 BBAAA Chiapas, Mexico
O: 20SEP2023 02:25:47 16.3N 98.3W ML=4.4 EMSC OAXACA, MEXICO
P: 14SEP2023 156418 16.0N 100.0W 3.5-5.6 CABAA Oaxaca, Mexico
O: 19SEP2023 18:40:29 18.0N 101.8W ML=4.1 EMSC GUERRERO, MEXICO
P: 17SEP2023 156412 18.0N 101.0W 3.5-5.1 AAAAA Michoacan, Mexico
NEIC reported this earthquake of M 4.2 in Guerrero, Mexico was felt with intensity II-III in the area(s) of Guerrero, Mexico in Acapulco.
O: 19SEP2023 23:44:27 18.5N 73.9W ML=3.3 EMSC HAITI REGION
P: 15SEP2023 156422 19.0N 73.0W 3.0-4.6 BAAAA Bahamas/No. Caribbean
O: 20SEP2023 04:32:39 19.1N 65.6W MD=3.5 EMSC PUERTO RICO REGION
O: 19SEP2023 22:02:03 19.2N 65.5W MD=3.3 EMSC PUERTO RICO REGION
O: 19SEP2023 22:35:00 19.1N 65.5W MD=3.7 EMSC PUERTO RICO REGION
P: 17SEP2023 156408 19.0N 65.0W 3.0-4.9 AAAAA Leeward Islands
O: 20SEP2023 03:41:32 19.9N 71.8W ML=3.2 EMSC DOMINICAN REPUBLIC REGION
O: 20SEP2023 07:00:41 19.6N 70.8W mb=4.4 EMSC DOMINICAN REPUBLIC
P: 20SEP2023 156422 20.0N 71.0W 3.0-4.6 AAAAA Bahamas/No. Caribbean
O: 19SEP2023 22:18:38 22.0N 107.9W ML=4.1 EMSC OFF COAST OF SINALOA, MEXICO
P: 16SEP2023 156425 24.0N 109.0W 3.5-5.2 BBAAA Gulf of California
AFRICA AND EUROPE
O: 20SEP2023 01:33:09 32.5N 24.6E mb=4.5 EMSC NEAR COAST OF LIBYA
P: 16SEP2023 156438 35.0N 25.0E 3.0-4.9 BCAAA Aegean Sea
O: 20SEP2023 09:17:43 31.2N 8.2W ML=3.4 EMSC MOROCCO
P: 15SEP2023 156458 31.0N 8.0W 3.5-5.3 BAAAA Morocco/Spain
NEIC reported this earthquake of M 4.6 in Poland was felt with intensity IV in the area(s) of Poland in Lubin and Glogow.
SOUTHWEST PACIFIC
O: 20SEP2023 09:32:32 14.7S 167.9E Mw=5.0 EMSC VANUATU
P: 16SEP2023 156590 16.0S 168.0E 4.0-5.4 BBAAA Vanuatu Islands
O: 20SEP2023 08:50:27 18.0S 178.6W mb=4.6 EMSC FIJI REGION
P: 15SEP2023 156588 17.0S 177.0W 4.0-5.6 BABAA Tonga Islands
O: 20SEP2023 05:42:43 20.8S 178.3W mb=4.6 EMSC FIJI REGION
P: 17SEP2023 156587 19.0S 173.0W 4.0-5.9 BBCAA Tonga Islands
OCEAN RIDGES
O: 20SEP2023 00:27:17 36.6S 97.0W mb=4.9 EMSC WEST CHILE RISE
ZEALANDIA AND AUSTRALIA REGION
O: 20SEP2023 01:18:23 43.7S 171.1E ML=3.8 EMSC SOUTH ISLAND OF NEW ZEALAND
O: 19SEP2023 21:14:49 43.7S 171.1E MS=6.2 GEONET South Island, New Zealand
O: 19SEP2023 21:14:50 43.7S 171.1E Mw=5.6 EMSC SOUTH ISLAND OF NEW ZEALAND
P: 17SEP2023 156620 44.0S 169.0E 3.0-5.1 AABAA So. Island, N.Z.
JAPAN AND KURIL ISLANDS
O: 19SEP2023 22:01:05 31.4N 141.8E mb=4.4 EMSC IZU ISLANDS, JAPAN REGION
O: 19SEP2023 22:17:47 30.9N 142.0E Mw=5.2 EMSC IZU ISLANDS, JAPAN REGION
P: 18SEP2023 156469 32.0N 141.0E 4.0-5.4 AAAAA Off East Coast Honshu
O: 20SEP2023 00:49:12 40.3N 145.1E mb=4.7 EMSC OFF EAST COAST OF HONSHU, JAPA
P: 18SEP2023 156490 39.0N 143.0E 4.0-5.4 ABBAA So. of Honshu
U.S./CANADA*
WESTERN U.S./CANADA
CALIFORNIA
O: 20SEP2023 04:56:47 31.4N 115.4W ML=3.1 EMSC BAJA CALIFORNIA, MEXICO
P: 20SEP2023 156477 32.6N 116.1W 2.5-4.8 ABAAA So. California
NEIC reported this earthquake of M 3.1 in Greater Los Angeles, California was felt with intensity II-III in the area(s) of Greater Los Angeles, California in Fontana, Rancho Cucamonga, Rialto, Bloomington, and others.
O: 20SEP2023 01:40:30 35.4N 118.5W ML=2.1 EMSC CENTRAL CALIFORNIA
P: 17SEP2023 156486 35.3N 118.6W 2.5-4.6 BAAAA So. California
O: 20SEP2023 02:39:38 38.2N 117.8W ML=3.3 EMSC NEVADA
P: 16SEP2023 156442 38.2N 118.2W 2.5-4.5 BAAAA California/Nevada area
NEIC reported this earthquake of M 3.1 in Northern California was felt with intensity II-III in the area(s) of Northern California in Patterson, Newman, Tracy, Modesto, Turlock, Delhi, Pleasanton, Los Banos, Stockton, Atwater among others.
O: 20SEP2023 00:03:37 40.9N 124.2W MD=2.8 EMSC OFFSHORE NORTHERN CALIFORNIA
P: 19SEP2023 156526 40.5N 125.8W 2.5-4.6 AAAAA Off Coast of No. Calif
NEIC reported this earthquake of M 2.9 in northern California was felt with intensity II-III in the area(s) of northern California in Arcata, Bayside, McKinleyville, Eureka and Korbel.
ALASKA
O: 20SEP2023 06:15:47 59.9N 152.8W ML=3.2 EMSC SOUTHERN ALASKA
P: 18SEP2023 156568 60.2N 153.2W 3.2-5.2 AAAAA Central Alaska
NEIC reported this earthquake of M 3.3 in Southern Alaska was felt with intensity II-III in the area(s) of Southern Alaska in Willow, Talkeetna, Chugiak, Anchorage.
O: 19SEP2023 22:17:51 69.2N 144.6W ML=3.2 EMSC NORTHERN ALASKA
PACIFIC NORTHWESTERN U.S./WESTERN CANADA
No events of M>=2 were located in the northwestern U.S. or western Canada today.
ROCKY MOUNTAINS REGION
O: 20SEP2023 00:58:52 31.7N 104.4W ML=2.0 EMSC WESTERN TEXAS
P: 16SEP2023 156474 31.4N 104.2W 2.0-4.1 BAAAA SW U.S.A
O: 20SEP2023 06:11:04 32.1N 101.1W ML=2.2 EMSC WESTERN TEXAS
O: 20SEP2023 01:29:57 32.5N 102.1W ML=2.8 EMSC WESTERN TEXAS
P: 17SEP2023 156475 31.4N 102.2W 2.0-4.1 BBAAA SW U.S.A
O: 20SEP2023 05:52:10 38.0N 104.7W ML=2.2 EMSC COLORADO
P: 17SEP2023 156449 37.1N 104.7W 2.0-3.9 BAAAA Colorado area
EASTERN U.S./CANADA
NEIC reported an earthquake of M 2.6 in Southern Nebraska was felt with intensity II-III in the area(s) of Southern Nebraska in Blue Hill.
O: 20SEP2023 00:55:41 34.5N 97.7W ML=2.1 EMSC OKLAHOMA
O: 19SEP2023 22:30:03 34.5N 97.8W ML=2.9 EMSC OKLAHOMA
P: 14SEP2023 156492 34.0N 97.0W 2.0-4.4 BAAAA Southern Plains
NEIC reported this earthquake of M 2.7 in Oklahoma was felt with intensity II-III in the area(s) of Oklahoma in Oklahoma City.
O: 20SEP2023 03:17:36 46.9N 66.0W MB=1.8 ECAN of Red Bank, NB
P: 14SEP2023 156506 46.0N 66.0W 2.0-4.5 AAAAA E. of Maine
O: 19SEP2023 19:11:18 51.2N 90.8W MB=2.0 ECAN of Osnaburgh 63B, ON
O: 19SEP2023 01:07:23 49.3N 67.6W MB=2.1 ECAN of Godbout, QC
P: 11SEP2023 156513 49.3N 67.5W 2.0-4.2 CAAAA Maine
O: 18SEP2023 11:18:26 45.1N 66.3W MB=2.0 ECAN of Musquash, NB
P: 14SEP2023 156506 46.0N 66.0W 2.0-4.5 BAAAA E. of Maine
O: 18SEP2023 11:02:59 45.3N 71.2W MB=2.0 ECAN of Chartierville, QC
P: 14SEP2023 156520 44.0N 73.0W 2.0-4.3 BBBAA New England
O: 18SEP2023 09:31:57 41.8N 81.0W MB=2.2 ECAN of Cleveland, OH
P: 14SEP2023 156528 41.8N 81.4W 2.0-3.9 BAAAA Ohio/Lake Erie
HAWAII
No earthquakes of M>=3 were located in Hawaii.
MODERATE QUAKE SHAKES NORTHERN CALIFORNIA EAST OF SAN FRANCISCO
EARTHQUAKE SUMMARY FOR SEPTEMBER 18, 2023
The strongest earthquake in the U.S. or Canada today was an M 4.5 in Northern California east of the San Francisco, California Bay. This event was widely felt throughout much of central and northern California. NEIC gave maximum intensity IV was felt in California in Patterson, Newman, Crows Landing, Modesto, Tracy with III in Livermore, Ceres, Manteca, San Francisco and as far as southern California. The mainshock was preceded by an M 4.0 foreshock, among others of smaller magnitude and by a number of felt aftershocks of M>=3. The aftershocks were generally felt in the Patterson, Newman, Livermore, Tracy, Morgan Hill, Modesto, Ripon and San Jose area with intensity II-III but the M 4.0 foreshock was felt with intensity IV in Patterson. This largest event in the series may have been triggered by an M1.1 class solar flare which coincided with it. The preliminary parameters from SWPC for this flare are:
Flare # START MAX END CLASS DATE Flux (Jm-2)
-------------------------------------------------------------------------
XXXX 0344 0400 0410 M1.1 (September 19, 2023) 1.1E-02
This is the first M-class solar flare in the past three days.
The earthquakes in California also occurred at the height of the strongest geomagnetic storm since September 2 and may have been promoted by changes in the geomagnetic field associated with that storm. This summary noted in this regard:
"The geomagnetic field saw minor storm conditions today. The AP level was 30. High latitudes saw major storm conditions with AP 49. Middle latitudes were at active conditions with AP 21. This is the strongest disturbance in the geomagnetic field since AP reached 38 on September 2 with high latitude AP 59 on that date. This storm is expected to intensity on September 19, 2023. Some initial seismic enhancement is likely with a stronger intense period around September 21-22." (September 19, 2023)
Today's event in Northern California is the first of M>=4.5 within about 100 km of today's epicenter since an M 5.1 about 50 km southwest of this on October 25, 2022 and may be a regional aftershock of that event. At the time this summary noted in this regard:
"Another actor promoting this earthquake at this time was a Tropical Cyclone making slope-fall off Virginia at this time. This summary had noted the possible effect on the western edge of the North American plate in the previous issues as:
"A tropical cyclone may be forming in the North Atlantic east of Georgia and South Carolina. This system is expected by NHC to reach Tropical Depression status in the next day at 40% likelihood. It is not expected to make landfall but is near the continental slope and could affect seismicity in the western North American Plate. This system is currently near 35N 65W." (October 23-24, 2022)
The last earthquake in the San Jose/San Francisco, California area with equal or larger magnitude than M 5.1 occurred on October 31, 2007 with M 5.5. Other earthquakes of M>=5 hit the area with M 5.2 on August 12, 1998, January 16, 1993 and April 18, 1990. At the time of the M 5.5 on October 31, 2007 ..." (October 25, 2022)
The last earthquake in the San Jose/San Francisco, California area with equal or larger magnitude than M 5.1 occurred on October 31, 2007 with M 5.5. Other earthquakes of M>=5 hit the area with M 5.2 on August 12, 1998, January 16, 1993 and April 18, 1990. At the time of the M 5.5 on October 31, 2007 this summary noted in this regard:
"A strongly felt earthquake hit the San Francisco Bay region tonight with M 5.6. ... The earthquake in the San Francisco Bay region was preceded several hours earlier by an event of M 2.9 which hit to the northwest and may have set up the conditions for the larger earthquake. ... The earthquake was generally felt within about 300 km of the epicenter with lesser intensities. This was the strongest earthquake to hit the San Francisco area since the World Series earthquake in October, 1989 (M 7.0). While pictures fell from walls and items fell from shelves throughout much of the area no immediate reports of major damage or casualties were available. The earthquake appears to have occurred on the Calaveras Fault. A contributing factor for the occurrence of this earthquake at this time may have been the strong geomagnetic storms which occurred late on October 25 and again this morning. The storms occurred while San Francisco was sub-solar and the effects were maximized. It is common for storms such as this to have their maximum effect on seismicity 4.5-5.0 days following the onset. The earthquake in San Francisco did occur five days after the onset of this storm which was the strongest to occur at mid-latitudes in the past month and the second strongest to occur in the past three months (Kp 36)." (October 31, 2007)
The factors noted in the previous strong activity in this area were all prevalent today including the landfall of Hurricane Lee in the northeastern U.S. and eastern Canada and a strong geomagnetic storm and may be notable for triggering in this region.
Forecast 156444 had expected enhanced seismicity was likely in this region in mid-September.
O: 19SEP2023 00:15:32 37.4N 121.3W Mw=4.0 EMSC NORTHERN CALIFORNIA
O: 19SEP2023 03:44:30 37.4N 121.3W Mw=3.5 EMSC NORTHERN CALIFORNIA
O: 19SEP2023 04:40:58 37.4N 121.3W ML=3.1 EMSC NORTHERN CALIFORNIA
O: 19SEP2023 04:48:37 37.4N 121.3W MD=2.1 EMSC NORTHERN CALIFORNIA
O: 19SEP2023 05:25:20 37.4N 121.2W ML=3.2 EMSC NORTHERN CALIFORNIA
O: 19SEP2023 04:13:10 37.5N 121.2W Mw=4.5 EMSC NORTHERN CALIFORNIA
P: 13SEP2023 156444 38.0N 122.3W 2.5-4.4 CAAAA Central California
P: 16SEP2023 156444 36.4N 121.1W 2.5-4.5 BBAAA Central California
The earthquake in California was preceded by an M 3.4 in southern Nebraska. This event was reported felt with intensity II-III in Nebraska at Blue Hill, Guide Rock, Hastings, Grand Island, Fremont and South Sioux City. Earthquakes in Nebraska often precede significant earthquakes in northern and central California as previously noted in this summary. Fore example a slightly smaller event near this epicenter in Nebraska of August 22, 2023 caused the following note to be published in this summary:
"A pair of light earthquakes of M 2.9 and 2.7 occurred today south of Lincoln and Hastings, Nebraska. NEIC reported they were felt with intensity IV in Nebraska at Ashton. Earthquakes in this region of Nebraska often precede stronger events on the North American-Pacific tectonic plate boundary. In the current situation with Hurricane Hilary and accompanying M 5.1 in Southern California this possibility may be somewhat mitigated. This is the third earthquake of M 2.9 in this region of Nebraska in the current year. These follow an M 3.7 on July 17, 2022 southeast of today's epicenter - the only event of M>2.9 in Nebraska in the past 3 years. At the time of the M 3.7 this summary noted:
"An unusual M 3.8 earthquake occurred on the Nebraska-Kansas border south of Lincoln and Grand Island, Nebraska near Superior. NEIC reported this earthquake of M 3.8 in Nebraska was felt with intensity IV-V in the area(s) of Nebraska at Superior, Guide Rock and in Mankato Kansas, with lesser shaking in Hardy, Red Cloud, Deshler, Glenvil, Nebraska and in Kansas at Webber, Smith Center, Republic. This is the strongest earthquake in southern Nebraska within about 150 km of this epicenter since an M 3.8 on May 6, 2021. The only event of larger magnitude in this area in the past 30 years was an M 4.5 on June 22, 2019. Earthquakes in Nebraska and South Dakota often precede strong earthquakes along the western rim of North America and with a strong coming geomagnetic storm this is a possibility. When the event occurred on May 6, 2021 this summary noted in this regard:
"A series of light earthquakes also occurred today in the region of northern
Kansas. This included an M 3.8 and aftershocks of M 3.0, 3.1 and 3.1. An M 3.8 in northern Kansas today was widely felt. NEIC reported this earthquake and aftershocks of M 3.1 in Kansas was felt with intensity IV in the area(s) of Kansas at Formoso, Courtland, Burr Oak, Hope and II-III in Jewel, Randall, Webber, Mankato, Belleville, Concordia, and Bend, Herington and Ramona. Other aftershocks of M 3.1 and 3.0 in Kansas were felt with intensity IV in Formoso and possibly in Sylvan Grove and in Peru, Nebraska. This is the strongest earthquake within about 100 km of this epicenter in the past year. An M 4.5 occurred about 150 km southeast of this in Kansas on January 19, 2020. Forecast 133547 had expected today's activity in northern Kansas was likely around May 4." (May 7, 2021)
When the M 4.5 hit on June 23, 2019 it was noted as:
"As noted in previous issues of this summary, moderate earthquakes in the area of Kansas, Nebraska and South Dakota are often followed within hour by moderate to strong quakes along the western boundary of North America - often in the regions off the coast of Oregon and Washington and this appears to be the case in this instance." (June 23, 2019, July 17, 2022, August 22, 2023)
At M 3.4 this is the strongest earthquake in Nebraska recorded in the past three years. The last event in Nebraska with M>=3.4 within about 200 km of this epicenter was an M 3.6 on July 26, 2022.
Forecast 156493 had expected regional seismic enhancement was likely in Nebraska and northern Kansas around September 16.
O: 18SEP2023 14:34:40 40.2N 98.3W ML=3.4 EMSC NEBRASKA
P: 16SEP2023 156493 38.0N 98.0W 2.0-4.3 ABAAA Southern Plains
Three moderately strong earthquakes occurred in the region of Japan today - an M 6.4-6.8 in the Ryukyu Islands, an M 5.8 in the Izu Islands south of Tokyo and an M 5.5 off the coast of northeastern Honshu. The strongest earthquake of the day in the world was the M 6.4-6.8 in the Ryukyu Islands near Okinawa, Japan. NEIC reported it was felt with maximum intensity IV in Okinawa at Naha and Urasoe with III in Tomigusuku, Yomitan, Chatan, Okinawa, Ginowan, Ishikawa, Gushikawa and Nago among others. CWB reported this earthquake at M 6.8 was felt with intensity I in Hualien, Yilan, Nantou, Taichung, Changhua, Taitung, Yunlin, and Chiayi Counties, Taiwan. Only two earthquakes of M>=6.4 have been recorded within about 250 km of today's epicenter in the past 35 years - an M 6.5 on March 2, 2014 and an M 6.9 on November 8, 2011. Today's earthquake was simultaneous with the beginning of flare 190 and may have been promoted by SFE from that flare.
Flare # START MAX END CLASS DATE Flux (Jm-2)
-------------------------------------------------------------------------
190 1321 1338 1359 C1.5 (September 18, 2023) 3.3E-03
Forecast 156431 had expected today's event within about 100 km was likely in mid-September. This epicenter is located near 103 degrees from the M 6.8 in Morocco of September 8 and was probably promoted by energy from that source.
O: 18SEP2023 13:21:24 26.5N 125.3E Mw=6.4 ANSS NORTHEAST OF TAIWAN
O: 18SEP2023 13:21:24 26.5N 125.3E Mw=6.3 EMSC NORTHEAST OF TAIWAN
O: 18SEP2023 13:21:19 26.8N 126.0E Mw=6.8 CWB NORTHEAST OF TAIWAN
P: 13SEP2023 156431 26.0N 125.0E 4.0-5.4 BAAAA Ryukyu Islands
P: 19SEP2023 156431 25.0N 124.0E 4.0-5.6 ABAAA Ryukyu Islands
An M 5.8 also occurred in the Izu Islands south of southeastern Honshu, Japan today. A similar M 5.8 occurred on February 5, 2023 and an M 6.3 in the Izu Islands was recorded on January 16, 2023. At the time of that event this summary noted:
"The strongest earthquake in the world today was an M 6.3 in the Izu Islands, Japan. NEIC reported it was felt with intensity II-III in Japan at Shizuoka, Kanagawa, Tokyo, Chiba, Fukushima and Okinawa Prefectures. This follows an M 5.2 in the area yesterday. In the previous summary it had been noted in this regard:
"The strongest earthquake in the world today was an M 5.2 in the Izu Islands of Southeastern Japan. Today's event was reported by JMA to have been lightly felt in southeastern Honshu, Japan. The last earthquake in the Izu Islands of significantly larger magnitude in this area of Izu Islands occurred on August 4, 2022 with M 5.7 after similar activity on July 31, 2022." (January 16, 2023)
Forecast 156469 ad expected today's activity within about 50 km was likely around September 18.
O: 18SEP2023 11:31:11 29.7N 139.1E mb=4.5 EMSC IZU ISLANDS, JAPAN REGION
O: 19SEP2023 06:22:38 31.0N 142.0E Mw=5.8 EMSC IZU ISLANDS, JAPAN REGION
O: 18SEP2023 21:33:29 31.5N 141.8E mb=4.5 EMSC IZU ISLANDS, JAPAN REGION
O: 19SEP2023 00:00:17 31.5N 142.0E mb=4.6 EMSC IZU ISLANDS, JAPAN REGION
P: 18SEP2023 156469 32.0N 141.0E 4.0-5.4 AAAAA Off East Coast Honshu
The earthquake off the northern coast of Honshu, Japan of M 5.5 followed a similar M 5.5 on September 8, 2023. At the time this summary noted in this regard:
"An M 5.5 was also reported off the east coast of northern Honshu, Japan today. NEIC reported it was felt with intensity II-III in Iwate, Miyagi, Fukushima, Aomori, Saitama and Tokyo Prefectures, Japan.
... Enhanced seismicity in Honshu and off eastern Honshu, Japan had been expected at this time in this summary due to the passage of Tropical Storm Kirogi through the area at this time. This was emphasized in the September 5, issue of this summary as:
"NEIC reported this earthquake of M 4.9 near Tokyo, Japan was felt with intensity II-III in the area(s) of Honshu, Japan in Chiba, Ibaraki, Tokyo, Saitama, Kanagawa Prefectures. This follows smaller events yesterday which was reported in this summary in the previous issue as:
"... An interesting earthquake of M 4.1 hit off the east coast of Honshu, Japan.
This event occurred near local solar noon and may have been promoted by geomagnetic and tidal stresses which maximize near this hour. Tropical Storm Kirogi passed over this epicenter at the time of the earthquake." (September 8, 2023)
Forecast 156471 had expected today's event within about 50 km was likely around September 18 off northern Japan.
O: 18SEP2023 19:33:04 38.5N 141.6E Mw=5.5 EMSC NEAR EAST COAST OF HONSHU, JAP
P: 18SEP2023 156471 39.0N 142.0E 4.0-5.5 AAAAA Off East Coast Honshu
The mainshock in the Vancouver area yesterday has been reanalyzed. The current magnitude is given as M 6.0. This event was probably promoted by strong geomagnetic and weather-related stresses (see previous issues of this summary. This summary noted this event in the previous issue as:
"The strongest earthquake in the world today was an M 5.6-5.9 west of Vancouver Island, British Columbia, Canada. NEIC reported it was felt with light shaking I-III in British Columbia at Parksville, Gibsons, Vancouver and perhaps as far as Oregon and Northern California. Foreshocks of M 4.5 and 4.3 preceded the mainshock and may have been felt lightly in the epicentral area." (September 18, 2023)
Forecast 156546 had expected this event within about 15 km was likely in mid-September.
O: 17SEP2023 11:28:08 50.6N 130.5W MB=6.0 ECAN of Port Hardy, BC
O: 17SEP2023 15:19:49 50.7N 130.5W MB=4.5 ECAN of Port Hardy, BC
P: 13SEP2023 156546 50.5N 130.4W 3.0-4.9 BAAAA British Colombia
OTHER GLOBAL EARTHQUAKE ACTIVITY
For most events there are two listings. The first line is the observed event starting with "O:" for Observed. There follows the date, month and year, the time in UT hours:minutes:seconds, the latitude and longitude, the given magnitude and the reporting agency followed by the geographic location. The second line starts with "P:" This is the forecast event as forecast in our summaries normally more than a month in advance. Magnitudes may vary in response to updated seismic watches and daily variations due to tidal and other influences. This line has the forecast date, month and year, the forecast number, latitude, longitude and forecast magnitude range. This is followed by a comparison between the forecast and the event. The comparison includes letters A-D. The first is number of days difference from predicted (A:up to 2, B3-5; C:6-10; D:more than 10), Difference in latitude (A:up to 1 degree; B:1-2 degrees; C:2-4 degrees; D:more than 4 degrees); longitude (same comparison as with latitude); magnitude (A: within forecast range; B: higher than forecast range; C: lower than forecast range; D: no comparison possible). The last letter is a stand in for a future comparison which needs to be done statistically after a large number of forecasts have been made. In previous data, an excellent match is generally AAAAA; a good match as one or two B's; a fair match has several B's and C's and a poor match is one which contains a number of C's or D's.
ASIA
O: 18SEP2023 16:31:57 35.8N 59.2E ML=4.0 EMSC NORTHEASTERN IRAN
P: 12SEP2023 156489 31.0N 57.0E 3.8-5.4 CCBAA So. Iran
NEIC reported this earthquake of M 3.8 in Northeastern Iran was felt with intensity II-III in the area(s) of Northeastern Iran in Meshed Khorasan-e Razavi.
O: 19SEP2023 05:28:37 37.4N 73.2E mb=4.6 EMSC HINDU KUSH REGION, AFGHANISTAN
P: 20SEP2023 156452 39.0N 72.0E 3.8-5.2 ABAAA Hindu Kush/Pakistan
O: 19SEP2023 00:57:34 43.2N 78.5E mb=4.5 EMSC EASTERN KAZAKHSTAN
P: 12SEP2023 156512 41.0N 77.0E 4.0-5.4 CCAAA Kirgizstan/Xinjiang
O: 18SEP2023 13:37:40 54.0N 159.8E mb=4.6 EMSC NEAR EAST COAST OF KAMCHATKA
P: 16SEP2023 156551 54.0N 158.0E 4.0-5.8 AABAA Kamchatka
P: 17SEP2023 156548 52.0N 161.0E 4.0-5.4 ABAAA E. of Kamchatka
No significant (M>=5) or unusual earthquakes were reported in Asia today.
INDONESIA AND PHILIPPINES
O: 19SEP2023 04:09:56 1.3N 128.1E ML=4.2 EMSC HALMAHERA, INDONESIA
P: 19SEP2023 156371 1.0N 128.0E 4.0-5.4 AAAAA Halmahera
O: 18SEP2023 16:40:41 3.6S 149.7E mb=4.6 EMSC BISMARCK SEA
P: 16SEP2023 156389 4.0S 151.0E 4.0-5.4 AAAAA New Ireland
O: 18SEP2023 17:27:35 4.3S 134.1E ML=4.4 EMSC NEAR S COAST OF PAPUA, INDONES
P: 17SEP2023 156394 2.0S 139.0E 4.0-5.4 ACCAA West Irian, PNG
O: 18SEP2023 17:57:30 5.1S 102.0E mb=4.4 EMSC SOUTHWEST OF SUMATRA, INDONESI
P: 12SEP2023 156398 6.0S 102.0E 4.0-5.5 CAAAA So. of Sumatera
O: 19SEP2023 04:32:09 6.3N 127.1E mb=5.0 EMSC PHILIPPINE ISLANDS REGION
P: 16SEP2023 156366 7.0N 126.0E 4.0-5.4 BAAAA Central Philippines
P: 18SEP2023 156372 8.0N 127.0E 4.0-5.5 ABAAA Halmahera
O: 18SEP2023 20:12:57 8.5S 109.0E ML=4.1 EMSC JAVA, INDONESIA
P: 14SEP2023 156397 8.0S 108.0E 4.0-5.4 BAAAA So. of Java
P: 18SEP2023 156586 10.0S 109.0E 4.0-5.4 ABAAA So. of Java
O: 18SEP2023 11:02:06 13.0N 121.1E mb=4.8 EMSC MINDORO, PHILIPPINES
P: 18SEP2023 156409 13.0N 122.0E 3.5-4.9 AAAAA Luzon, Philippines
NEIC reported this earthquake of M 4.8 in Mindoro, Philippines was felt with intensity II-III in the area(s) of Mindoro, Philippines in San Jose, Southern Tagalog.
CENTRAL AND SOUTH AMERICA
O: 18SEP2023 22:33:48 4.9S 80.8W ML=4.0 EMSC PERU-ECUADOR BORDER REGION
P: 8SEP2023 156108 4.0S 80.0W 4.0-5.8 CAAAA Ecuador
O: 18SEP2023 10:02:53 7.1N 72.0W mb=4.5 EMSC APURE, VENEZUELA
P: 18SEP2023 156367 7.0N 73.0W 4.0-5.4 AAAAA Colombia
O: 18SEP2023 08:38:14 14.1N 92.1W ML=4.3 EMSC OFFSHORE GUATEMALA
O: 18SEP2023 12:26:28 14.0N 92.5W ML=4.2 EMSC OFFSHORE GUATEMALA
P: 17SEP2023 156406 14.0N 92.0W 3.5-5.2 AAAAA Guatemala
O: 18SEP2023 17:20:23 15.2N 94.5W ML=4.0 EMSC OFF COAST OF CHIAPAS, MEXICO
O: 18SEP2023 22:05:31 14.7N 94.6W ML=4.0 EMSC OFF COAST OF CHIAPAS, MEXICO
P: 17SEP2023 156401 14.0N 94.0W 3.5-5.6 AAAAA Chiapas, Mexico
O: 18SEP2023 08:35:11 18.1N 71.4W ML=3.0 EMSC DOMINICAN REPUBLIC
O: 18SEP2023 08:59:05 18.1N 71.4W ML=3.0 EMSC DOMINICAN REPUBLIC
P: 20SEP2023 156422 20.0N 71.0W 3.0-4.6 ABAAA Bahamas/No. Caribbean
O: 19SEP2023 01:04:56 18.2N 69.0W ML=3.0 EMSC DOMINICAN REPUBLIC REGION
P: 17SEP2023 156419 18.0N 69.0W 3.4-5.1 AAAAA Puerto Rico
O: 18SEP2023 17:01:22 19.2N 66.7W MD=3.6 EMSC PUERTO RICO REGION
O: 19SEP2023 03:53:59 17.9N 67.0W MD=3.0 EMSC PUERTO RICO REGION
P: 16SEP2023 156422 20.0N 68.0W 3.0-4.6 AABAA Bahamas/No. Caribbean
O: 19SEP2023 02:37:19 18.7N 64.1W MD=3.6 EMSC VIRGIN ISLANDS REGION
O: 19SEP2023 01:53:16 19.6N 64.6W MD=3.8 EMSC VIRGIN ISLANDS REGION
P: 17SEP2023 156408 19.0N 65.0W 3.0-4.9 AAAAA Leeward Islands
O: 19SEP2023 06:49:36 17.5N 72.5W ML=3.1 EMSC HAITI REGION
O: 18SEP2023 16:33:56 20.0N 73.6W ML=3.7 EMSC HAITI REGION
P: 15SEP2023 156422 19.0N 73.0W 3.0-4.6 BAAAA Bahamas/No. Caribbean
O: 18SEP2023 16:20:15 20.7S 67.3W mb=4.3 EMSC POTOSI, BOLIVIA
P: 20SEP2023 156591 21.0S 68.0W 4.0-6.2 AAAAA Argentina
NEIC reported this earthquake of M 4.1 in Northern Chile was felt with intensity II-III in the area(s) of Northern Chile in Iquique, Tarapaca.
AFRICA AND EUROPE
No significant (M>=5) or unusual earthquakes were reported in Europe today.
SOUTHWEST PACIFIC
O: 18SEP2023 22:40:59 10.0S 160.9E mb=4.9 EMSC SOLOMON ISLANDS
P: 16SEP2023 156589 11.0S 163.0E 4.0-5.5 AABAA Vanuatu Islands
O: 19SEP2023 03:28:22 13.2S 167.2E mb=4.9 EMSC VANUATU
P: 11SEP2023 156589 12.0S 166.0E 4.0-5.4 CBAAA Vanuatu Islands
O: 18SEP2023 15:19:27 14.3S 167.4E mb=4.7 EMSC VANUATU
O: 18SEP2023 19:44:40 14.7S 167.4E mb=4.8 EMSC VANUATU
P: 16SEP2023 156590 16.0S 168.0E 4.0-5.4 ABAAA Vanuatu Islands
OCEAN RIDGES
O: 18SEP2023 16:49:31 55.9S 129.1W mb=5.2 EMSC PACIFIC-ANTARCTIC RIDGE
O: 18SEP2023 17:06:04 55.4S 128.7W mb=4.8 EMSC PACIFIC-ANTARCTIC RIDGE
P: 16SEP2023 156622 56.0S 122.0W 4.0-5.7 AACAA Pacific-Antarctic Ridge
O: 18SEP2023 22:02:35 64.4N 20.7W ML=3.6 EMSC ICELAND
P: 10SEP2023 156303 66.0N 17.0W 3.0-4.5 CBBAA Iceland area
ZEALANDIA AND AUSTRALIA REGION
No earthquakes of M>=4 were recorded in the regions of Zealandia or Australia
today. GeoNet did not report any felt events in the area.
JAPAN AND KURIL ISLANDS
O: 18SEP2023 13:21:24 26.5N 125.3E Mw=6.3 EMSC NORTHEAST OF TAIWAN
O: 18SEP2023 13:21:19 26.8N 126.0E Mw=6.8 CWB NORTHEAST OF TAIWAN
P: 13SEP2023 156431 26.0N 125.0E 4.0-5.4 BAAAA Ryukyu Islands
P: 19SEP2023 156431 25.0N 124.0E 4.0-5.6 ABAAA Ryukyu Islands
O: 19SEP2023 04:35:30 29.3N 129.2E ML=4.3 EMSC RYUKYU ISLANDS, JAPAN
P: 18SEP2023 156427 29.0N 131.0E 4.0-5.6 AABAA Kyushu Japan
O: 18SEP2023 11:31:11 29.7N 139.1E mb=4.5 EMSC IZU ISLANDS, JAPAN REGION
O: 19SEP2023 06:22:38 31.0N 142.0E Mw=5.8 EMSC IZU ISLANDS, JAPAN REGION
O: 18SEP2023 21:33:29 31.5N 141.8E mb=4.5 EMSC IZU ISLANDS, JAPAN REGION
O: 19SEP2023 00:00:17 31.5N 142.0E mb=4.6 EMSC IZU ISLANDS, JAPAN REGION
P: 18SEP2023 156469 32.0N 141.0E 4.0-5.4 AAAAA Off East Coast Honshu
O: 18SEP2023 20:32:10 33.2N 138.3E mb=4.1 EMSC IZU ISLANDS, JAPAN REGION
P: 18SEP2023 156448 34.0N 137.0E 3.5-4.9 AAAAA Central/So. Honshu Japan
O: 18SEP2023 19:33:04 38.5N 141.6E Mw=5.5 EMSC NEAR EAST COAST OF HONSHU, JAP
P: 18SEP2023 156471 39.0N 142.0E 4.0-5.5 AAAAA Off East Coast Honshu
U.S./CANADA*
WESTERN U.S./CANADA
CALIFORNIA
O: 18SEP2023 08:16:27 31.4N 114.4W ML=3.3 EMSC GULF OF CALIFORNIA
O: 18SEP2023 08:29:55 31.4N 114.5W ML=3.7 EMSC GULF OF CALIFORNIA
O: 18SEP2023 22:27:46 30.6N 114.6W ML=3.6 EMSC GULF OF CALIFORNIA
P: 14SEP2023 156426 30.0N 114.0W 3.5-5.1 BAAAA Gulf of California
O: 18SEP2023 19:12:50 31.4N 115.5W ML=3.2 EMSC BAJA CALIFORNIA, MEXICO
P: 20SEP2023 156477 32.6N 116.1W 2.5-4.8 ABAAA So. California
O: 19SEP2023 04:50:24 34.0N 117.0W ML=2.6 EMSC SOUTHERN CALIFORNIA
O: 19SEP2023 04:14:09 34.8N 117.4W ML=2.3 EMSC SOUTHERN CALIFORNIA
P: 18SEP2023 156481 34.1N 117.4W 2.5-4.6 AAAAA So. California
NEIC reported this earthquake of M 2.6 in Southern California was felt with intensity II-III in the area(s) of Southern California in Yucaipa, Calimesa, Banning, Forest Falls and Redlands.
O: 18SEP2023 23:25:34 36.2N 120.8W MD=2.9 EMSC CENTRAL CALIFORNIA
P: 16SEP2023 156444 36.4N 121.1W 2.5-4.5 AAAAA Central California
NEIC reported this earthquake of M 3.0 in Central California was felt with intensity II-III in the area(s) of Central California in San Ardo, Hollister, Los Banos, Dos Palos, Lost Hills, Alameda and Ione.
O: 19SEP2023 00:15:32 37.4N 121.3W Mw=4.0 EMSC NORTHERN CALIFORNIA
O: 19SEP2023 03:44:30 37.4N 121.3W Mw=3.5 EMSC NORTHERN CALIFORNIA
O: 19SEP2023 04:40:58 37.4N 121.3W ML=3.1 EMSC NORTHERN CALIFORNIA
O: 19SEP2023 04:48:37 37.4N 121.3W MD=2.1 EMSC NORTHERN CALIFORNIA
O: 19SEP2023 05:25:20 37.4N 121.2W ML=3.2 EMSC NORTHERN CALIFORNIA
O: 19SEP2023 04:13:10 37.5N 121.2W Mw=4.5 EMSC NORTHERN CALIFORNIA
P: 13SEP2023 156444 38.0N 122.3W 2.5-4.4 CAAAA Central California
P: 16SEP2023 156444 36.4N 121.1W 2.5-4.5 BBAAA Central California
O: 18SEP2023 21:02:27 38.8N 122.8W MD=2.1 EMSC NORTHERN CALIFORNIA
P: 17SEP2023 156445 39.0N 123.1W 2.5-4.6 AAAAA Central California
O: 18SEP2023 15:06:40 39.2N 120.1W MD=2.0 EMSC NORTHERN CALIFORNIA
O: 18SEP2023 15:14:54 39.2N 120.1W MD=2.0 EMSC NORTHERN CALIFORNIA
O: 18SEP2023 10:11:37 39.5N 120.2W MD=1.7 EMSC NORTHERN CALIFORNIA
O: 18SEP2023 08:04:48 39.2N 120.1W MD=2.0 EMSC NORTHERN CALIFORNIA
P: 20SEP2023 156446 39.4N 120.5W 2.5-4.4 AAAAA Central California
O: 19SEP2023 02:50:17 40.4N 125.2W ML=3.3 EMSC OFFSHORE NORTHERN CALIFORNIA
P: 19SEP2023 156526 40.5N 125.8W 2.5-4.6 AAAAA Off Coast of No. Calif
NEIC reported this earthquake of M 3.3 off the coast of Northern California was felt with intensity II-III in the area(s) of Northern California in Fortuna.
ALASKA
O: 18SEP2023 07:03:12 52.0N 174.2W ML=3.8 EMSC ANDREANOF ISLANDS, ALEUTIAN IS
P: 17SEP2023 156543 50.6N 174.7W 3.5-4.9 ABAAA Andreanoff Isls, Aleutians
O: 18SEP2023 21:36:56 55.5N 158.0W ML=3.2 EMSC ALASKA PENINSULA
P: 15SEP2023 156541 54.8N 158.7W 3.5-5.1 BAAAA Alaska Peninsula
PACIFIC NORTHWESTERN U.S./WESTERN CANADA
O: 17SEP2023 11:28:08 50.6N 130.5W MB=6.0 ECAN of Port Hardy, BC
O: 17SEP2023 15:19:49 50.7N 130.5W MB=4.5 ECAN of Port Hardy, BC
P: 13SEP2023 156546 50.5N 130.4W 3.0-4.9 BAAAA British Colombia
ROCKY MOUNTAINS REGION
No earthquakes of M>=2 were located in the Rocky Mountain region today.
EASTERN U.S./CANADA
O: 18SEP2023 23:11:34 34.9N 97.3W ML=2.5 EMSC OKLAHOMA
P: 14SEP2023 156492 34.0N 97.0W 2.0-4.4 BAAAA Southern Plains
P: 17SEP2023 156492 35.0N 96.0W 2.0-4.3 AAAAA Southern Plains
O: 18SEP2023 14:34:40 40.2N 98.3W ML=3.4 EMSC NEBRASKA
P: 16SEP2023 156493 38.0N 98.0W 2.0-4.3 ABAAA Southern Plains
O: 16SEP2023 07:19:10 47.6N 70.2W MB=1.1 ECAN of La Malbaie, QC
O: 16SEP2023 04:56:40 47.1N 70.9W MB=1.5 ECAN of Beaupré, QC
O: 15SEP2023 10:45:39 46.9N 71.0W MB=1.6 ECAN of Château-Richer, QC
O: 16SEP2023 16:21:32 47.7N 70.2W MB=1.8 ECAN of Clermont, QC
P: 16SEP2023 156521 47.3N 70.5W 2.0-4.0 AAAAA New England
O: 16SEP2023 20:29:43 46.8N 65.9W MB=1.8 ECAN of Blackville, NB
P: 14SEP2023 156506 46.0N 66.0W 2.0-4.5 AAAAA E. of Maine
O: 18SEP2023 09:31:57 41.8N 81.0W MB=2.2 ECAN of Cleveland, OH
O: 17SEP2023 17:04:37 41.8N 81.1W MB=2.4 ECAN of Cleveland, OH
P: 14SEP2023 156528 41.8N 81.4W 2.0-3.9 BAAAA Ohio/Lake Erie
HAWAII
No earthquakes of M>=3 were located in Hawaii.
MODERATELY STRONG QUAKE SHAKES VANCOUVER ISLAND, BRITISH COLUMBIA, CANADA
EARTHQUAKE SUMMARY FOR SEPTEMBER 17, 2023
The strongest earthquake in the world today was an M 5.6-5.9 west of Vancouver Island, British Columbia, Canada. NEIC reported it was felt with light shaking I-III in British Columbia at Parksville, Gibsons, Vancouver and perhaps as far as Oregon and Northern California. Foreshocks of M 4.5 and 4.3 preceded the mainshock and may have been felt lightly in the epicentral area.
This enhanced seismicity in British Columbia, Canada had been anticipated in this summary in the past several issues. It began two days ago with a strong series of moderate quakes as described at the time in this summary:
"A series of light to moderate earthquake with maximum events of M 4.2 occurred today in the region near Vancouver, British Columbia, Canada. These events centered near local solar noon and were probably promoted by the new moon tidal stresses today which maximized near this time as noted in this and previous issues of this summary:
"The New Moon will arrive at 01:40 UT on September 15. Longitudes which will be at local solar midnight at this time are near 25 West while those at local solar noon are near 155 East. These include the same areas identified as probable area of tidal triggering with the Full Moon of August 31. This forecast identified these at the time as: "These zones include the central Atlantic and Iceland and western Europe in the west and the Kuril Islands, Japan and portions of eastern Indonesia and the Vanuatu Islands in the east. These areas are the most likely to see tidal triggering in the next week. Such events often occur near local solar midnight and noon. A major earthquake is considered likely with this full moon in the next week." (September 13-15, 2023)
and continued in the previous issues of this summary as:
"The strong swarm of earthquakes yesterday in the area of Vancouver Island, British Columbia ceased abruptly today with only a minor earthquake recorded in the area. This swarm coincided with landfall of Hurricane Lee in Maine and Nova Scotia, Canada. This storm has been called a summer "nor'easter" because of its strength and characteristics. This summary has taken a clear stance on the likely connection between nor'easters and coincidental major activity in the northwestern U.S. and southwestern Canada as typified by the summary of January 29, 2022:
" ... a major nor'easter is beginning to progress up the eastern coast of the U.S. It may hit the Boston area with record snows today and on Saturday, January 29, 2022. Such nor'easters are often associated with a strong enhancement of seismicity along the western North American tectonic plate. A precautionary seismic watch is being called by this summary for this region through February 2, 2022." (January 27, 2022)
and more recently:
"The strongest earthquakes in the U.S. or Canada today occurred as an M 4.3 near Vancouver Island and as an M 3.8 in the Queen Charlotte Islands area of British Columbia. These were not reported felt. This may related to a nor'easter hitting the northeastern U.S. at this time. Larger earthquakes in the Vancouver and Queen Charlotte Island area of Canada often occur in conjunction with strong nor'easters on the opposite side of the North American Plate." (March 14, 2023)
A stronger earthquake in the Vancouver or Queen Charlotte region is possible with landfall of Hurricane Lee today in Nova Scotia and Newfoundland.
Hurricane Lee has been described in this and previous issues of this summary as:
"Hurricane Lee continued today in the area of north of Nova Scotia with winds up to 50 kts (category 1 hurricane). It is expected to track to the north and east and may enhance seismicity in the Northeast U.S and Quebec, Canada as it makes landfall in that area around of Nova Scotia on September 17 in the next week. Interactions with the North American Plate may also trigger moderate to strong seismic enhancement in areas of coastal western Canada and northwestern U.S. at this time. Coastal flooding in Maine is considered marginal by NHC but more intense effects are possible along the coasts of eastern Canada." (September 16-17, 2023)
The last earthquake of M>=5.9 within about 100 km of today's epicenters in Vancouver was an M 6.3 on December 25, 2019, part of a series of events in the area that started with two of M 6.0 on December 23, 2019. At the time this summary noted:
"Other factors which probably affected the timing of the activity in Vancouver, Canada probably included strong meteorological storms which dropped up to 12 inches on areas of the southeast U.S. and in Washington State and British Columbia and the geomagnetic storm of December 19-20.
...
The last earthquake in the Vancouver Island area of M>=6 was an M 6.5 on July 4, 2019 with the regional seismic activation of early July, 2019. A swarm hit southeast of today's events on October 22, 2018 (M 6.8, 6.5, 6.5) and in January, 2008 (M 6.4, 6.0 ..) and September 2013 (M 6.0, 6.0, 6.1)." (December 23, 2019)
An M 6.0 was also recorded in the Vancouver area about 150 km southeast of today's event on April 13, 2023.
Forecast 156546 had expected today's event within about 10 km was likely in mid-September.
O: 17SEP2023 11:28:13 50.8N 130.2W Mw=5.6 EMSC VANCOUVER ISLAND, CANADA REGION
O: 17SEP2023 11:28:08 50.6N 130.5W MB=5.9 ECAN of Port Hardy, BC
O: 17SEP2023 15:19:50 50.8N 130.3W ML=4.3 EMSC VANCOUVER ISLAND, CANADA REGION
O: 17SEP2023 15:19:49 50.7N 130.5W MB=4.3 ECAN of Port Hardy, BC
O: 17SEP2023 09:58:57 50.6N 130.5W MB=5.0 ECAN of Port Hardy, BC
O: 17SEP2023 09:59:03 50.8N 129.8W Mw=4.5 EMSC VANCOUVER ISLAND, CANADA REGIO
P: 13SEP2023 156546 50.5N 130.4W 3.0-4.9 BAAAA British Colombia
An unusually large M 5.1 struck the area of Northern Italy today. NEIC reported it was felt with maximum intensity IV in San Godenzo, Toscana, Brisighella Emilia-Romagna, Castrocaro Terme and Terra del Sole and Forli with lesser shaking in Borgo, San Lornzo, Scarperia, Riolo Terme, Pontassieve and Imola among others. This is the strongest earthquake in northern Italy within about 200 km of this epicenter since an M 5.6 about 200 km to the east on November 9, 2022 but the last within about 100 km of today's epicenter was an 6.1 on May 20, 2012 and an M 5.5 aftershock on May 29, 2012. At the time of the May 20, 2012 event this summary noted:
"Three strong earthquakes of M 5.8-6.1 hit in the world today and were probably triggered by tidal forces associated with the upcoming solar eclipse which will occur later today. The most widely felt and damaging of today's events occurred as an M 6.1 in northern Italy ...
The last earthquake in northern Italy of similar or larger magnitude (and the only such event in the past 22 years) was an M 6.4 on September 26, 1997." (May 20, 2012)
Today's event in Italy occurred near Florence but was reported by the press to have not caused any significant damage in the area. Forecast 156503 had expected today's event within about 100 km was likely around September 15.
O: 18SEP2023 03:10:14 44.0N 11.7E Mw=5.1 ANSS NORTHERN ITALY
O: 18SEP2023 03:10:14 44.0N 11.6E Mw=5.1 EMSC NORTHERN ITALY
P: 15SEP2023 156503 45.0N 12.0E 3.0-5.2 BAAAA Austria
OTHER GLOBAL EARTHQUAKE ACTIVITY
For most events there are two listings. The first line is the observed event starting with "O:" for Observed. There follows the date, month and year, the time in UT hours:minutes:seconds, the latitude and longitude, the given magnitude and the reporting agency followed by the geographic location. The second line starts with "P:" This is the forecast event as forecast in our summaries normally more than a month in advance. Magnitudes may vary in response to updated seismic watches and daily variations due to tidal and other influences. This line has the forecast date, month and year, the forecast number, latitude, longitude and forecast magnitude range. This is followed by a comparison between the forecast and the event. The comparison includes letters A-D. The first is number of days difference from predicted (A:up to 2, B3-5; C:6-10; D:more than 10), Difference in latitude (A:up to 1 degree; B:1-2 degrees; C:2-4 degrees; D:more than 4 degrees); longitude (same comparison as with latitude); magnitude (A: within forecast range; B: higher than forecast range; C: lower than forecast range; D: no comparison possible). The last letter is a stand in for a future comparison which needs to be done statistically after a large number of forecasts have been made. In previous data, an excellent match is generally AAAAA; a good match as one or two B's; a fair match has several B's and C's and a poor match is one which contains a number of C's or D's.
ASIA
O: 17SEP2023 06:49:53 24.3N 90.2E ML=3.9 EMSC BANGLADESH
P: 19SEP2023 156429 26.0N 93.0E 4.0-5.4 ABBAA Myanmar
NEIC reported this earthquake of M 4.0 in Bangladesh was felt with intensity II-III in the area(s) of Bangladesh with IV in Dacca and II in Dhamrai and Maimansingh.
O: 17SEP2023 19:03:10 27.3N 87.4E ML=3.7 EMSC NEPAL
P: 20SEP2023 156501 30.0N 88.0E 3.8-5.4 BCAAA Xizang
O: 17SEP2023 16:23:35 38.8N 71.7E mb=4.6 EMSC TAJIKISTAN
P: 20SEP2023 156452 39.0N 72.0E 3.8-5.2 BAAAA Hindu Kush/Pakistan
O: 17SEP2023 23:18:54 55.3N 164.7E mb=4.5 EMSC KOMANDORSKIYE OSTROVA REGION
P: 13SEP2023 156552 55.0N 164.0E 4.0-5.9 BAAAA Komandorsky Isl
No significant (M>=5) or unusual earthquakes were reported in Asia today.
INDONESIA AND PHILIPPINES
O: 18SEP2023 00:50:38 0.1S 123.5E ML=4.2 EMSC SULAWESI, INDONESIA
P: 14SEP2023 156374 1.0N 124.0E 4.0-5.5 BBAAA Mindanao, Philippines
O: 17SEP2023 19:33:32 3.3N 128.1E ML=4.1 EMSC NORTH OF HALMAHERA, INDONESIA
P: 15SEP2023 156371 3.0N 128.0E 4.0-5.4 AAAAA Halmahera
O: 17SEP2023 22:20:40 5.2S 147.1E mb=4.1 EMSC EASTERN NEW GUINEA REG., P.N.G
P: 16SEP2023 156390 5.0S 148.0E 4.0-5.4 AAAAA New Ireland
O: 17SEP2023 07:27:33 6.3S 103.8E ML=3.9 EMSC SOUTHWEST OF SUMATRA, INDONESI
P: 15SEP2023 156398 7.0S 104.0E 4.0-5.4 AAAAA So. of Sumatera
O: 17SEP2023 20:49:09 7.5N 126.2E ML=4.1 EMSC MINDANAO, PHILIPPINES
P: 16SEP2023 156366 7.0N 126.0E 4.0-5.4 AAAAA Central Philippines
O: 17SEP2023 10:56:15 8.4S 127.8E mb=4.4 EMSC EAST TIMOR REGION
P: 14SEP2023 156379 7.0S 127.0E 4.0-5.4 BBAAA Banda Sea
O: 18SEP2023 02:54:05 13.2N 120.4E mb=4.9 EMSC MINDORO, PHILIPPINES
P: 18SEP2023 156409 13.0N 122.0E 3.5-4.9 AABAA Luzon, Philippines
NEIC reported this earthquake of M 4.9 in Mindoro, Philippines was felt with intensity II-III in the area(s) of Mindoro, Philippines in San Jose, Southern Tagalog.
No significant (M>=5) or unusual earthquakes were reported in Indonesia or the Philippines today.
CENTRAL AND SOUTH AMERICA
O: 17SEP2023 14:58:00 13.3N 90.2W ML=4.2 EMSC OFFSHORE EL SALVADOR
P: 15SEP2023 156406 14.0N 90.0W 3.5-5.4 AAAAA Guatemala
O: 18SEP2023 04:03:24 14.4N 93.5W ML=4.0 EMSC OFF COAST OF CHIAPAS, MEXICO
P: 17SEP2023 156401 14.0N 94.0W 3.5-5.6 AAAAA Chiapas, Mexico
O: 18SEP2023 02:25:22 16.3N 98.3W ML=4.1 EMSC OAXACA, MEXICO
P: 14SEP2023 156418 16.0N 100.0W 3.5-5.6 BABAA Oaxaca, Mexico
O: 17SEP2023 07:55:24 17.7N 81.6W mb=4.2 EMSC CAYMAN ISLANDS REGION
NEIC reported this earthquake of M 4.2 in the Cayman Islands was felt with intensity II-III in the area(s) of the Cayman Islands in Grand Cayman at George Town, Bodden Town and West Bay.
O: 17SEP2023 14:30:17 18.9N 66.8W MD=3.3 EMSC PUERTO RICO REGION
P: 17SEP2023 156408 19.0N 65.0W 3.0-4.9 AABAA Leeward Islands
O: 17SEP2023 06:54:38 19.0N 68.4W MD=3.6 EMSC DOMINICAN REPUBLIC REGION
P: 16SEP2023 156422 20.0N 68.0W 3.0-4.6 AAAAA Bahamas/No. Caribbean
O: 17SEP2023 19:52:22 27.6N 111.6W ML=3.4 EMSC GULF OF CALIFORNIA
P: 20SEP2023 156426 28.0N 112.0W 3.5-5.1 BAAAA Gulf of California
O: 17SEP2023 20:03:44 28.2S 71.2W mb=4.6 EMSC OFFSHORE ATACAMA, CHILE
P: 15SEP2023 156594 29.0S 70.0W 4.0-5.7 AAAAA Coast Central Chile
O: 18SEP2023 01:37:23 31.6S 71.8W ML=3.2 EMSC OFFSHORE COQUIMBO, CHILE
P: 20SEP2023 156605 31.0S 72.0W 4.0-5.5 AAAAA Central Chile
No significant (M>=5) or unusual earthquakes were reported in Central or South America today.
AFRICA AND EUROPE
O: 17SEP2023 18:09:29 5.4S 34.9E mb=4.3 EMSC TANZANIA
P: 12SEP2023 156386 6.0S 36.0E 4.0-5.5 AAAAA Indian Ocean
O: 17SEP2023 16:33:55 31.2N 8.1W mb=3.5 EMSC MOROCCO
O: 17SEP2023 23:06:19 31.2N 8.8W ML=3.5 EMSC MOROCCO
P: 15SEP2023 156458 31.0N 8.0W 3.5-5.3 AAAAA Morocco/Spain
O: 18SEP2023 03:10:14 44.0N 11.6E Mw=5.1 EMSC NORTHERN ITALY
P: 15SEP2023 156503 45.0N 12.0E 3.0-5.2 BAAAA Austria
SOUTHWEST PACIFIC
O: 17SEP2023 11:53:59 10.2S 161.4E Mw=5.0 EMSC SOLOMON ISLANDS
P: 16SEP2023 156589 11.0S 163.0E 4.0-5.5 AABAA Vanuatu Islands
O: 17SEP2023 12:58:44 15.6S 168.2E mb=4.6 EMSC VANUATU
P: 16SEP2023 156590 16.0S 168.0E 4.0-5.4 AAAAA Vanuatu Islands
OCEAN RIDGES
O: 18SEP2023 06:24:06 22.4S 69.0E mb=4.7 EMSC MID-INDIAN RIDGE
P: 13SEP2023 156598 29.0S 62.0E 4.0-5.6 BCCAA So. Indian Ocean
O: 17SEP2023 22:54:38 56.0S 27.1W mb=5.1 EMSC SOUTH SANDWICH ISLANDS REGION
P: 14SEP2023 156623 55.0S 28.0W 4.0-5.9 BAAAA So. Sandwich Islands
ZEALANDIA AND AUSTRALIA REGION
No earthquakes of M>=4 were recorded in the regions of Zealandia or Australia
today. GeoNet did not report any felt events in the area.
JAPAN AND KURIL ISLANDS
O: 18SEP2023 03:43:22 28.6N 129.9E mb=4.7 EMSC RYUKYU ISLANDS, JAPAN
P: 16SEP2023 156432 28.0N 128.0E 4.0-5.4 AABAA Ryukyu Islands
P: 18SEP2023 156427 29.0N 131.0E 4.0-5.6 AAAAA Kyushu Japan
U.S./CANADA*
WESTERN U.S./CANADA
CALIFORNIA
O: 17SEP2023 16:52:11 31.4N 115.6W ML=3.3 EMSC BAJA CALIFORNIA, MEXICO
P: 13SEP2023 156477 30.8N 116.2W 2.5-4.8 BAAAA So. California
O: 17SEP2023 16:54:47 37.6N 122.5W md=2.3 ANSS E of Pacifica CA
P: 13SEP2023 156444 38.0N 122.3W 2.5-4.4 BAAAA Central California
O: 17SEP2023 19:04:42 38.4N 122.2W MD=2.1 EMSC NORTHERN CALIFORNIA
O: 18SEP2023 06:20:53 38.8N 122.8W Mw=3.5 EMSC NORTHERN CALIFORNIA
O: 17SEP2023 16:54:05 38.8N 122.8W MD=2.1 EMSC NORTHERN CALIFORNIA
P: 17SEP2023 156445 39.0N 123.1W 2.5-4.6 AAAAA Central California
NEIC reported this earthquake of M 3.5 in the California Geysers was felt with intensity II-III in the area(s) of the California Geysers with IV in Nice, Kelseyville and lesser shaking in Middletown, Cloverdale, Healdsburg, Lowe Lake, Calistoga, Windsor, Santa Rosa among others.
O: 18SEP2023 04:17:37 39.2N 120.1W ML=3.2 EMSC NORTHERN CALIFORNIA
P: 20SEP2023 156446 39.4N 120.5W 2.5-4.4 AAAAA Central California
NEIC reported this earthquake of M 3.4 in Northern California and Nevada was felt with intensity II-III in the area(s) of Northern California and Nevada in California at Carnelian Bay, Tahoe Vista, Kings Beach, Olympic Valley, Tahoe City, Truckee, Incline Village, Tahoma and in Nevada in Glenbrook among others.
ALASKA
O: 17SEP2023 20:16:52 57.1N 155.5W ML=3.0 EMSC ALASKA PENINSULA
P: 15SEP2023 156541 54.8N 158.7W 3.5-5.1 ACBAA Alaska Peninsula
O: 18SEP2023 06:09:43 60.3N 152.7W ML=3.4 EMSC SOUTHERN ALASKA
P: 18SEP2023 156568 60.2N 153.2W 3.2-5.2 AAAAA Central Alaska
NEIC reported this earthquake of M 3.4 in Southern Alaska was felt with intensity II-III in the area(s) of Southern Alaska in West Kenai Peninsula.
PACIFIC NORTHWESTERN U.S./WESTERN CANADA
O: 17SEP2023 11:28:13 50.8N 130.2W Mw=5.6 EMSC VANCOUVER ISLAND, CANADA REGION
O: 17SEP2023 11:28:08 50.6N 130.5W MB=5.9 ECAN of Port Hardy, BC
O: 17SEP2023 15:19:50 50.8N 130.3W ML=4.3 EMSC VANCOUVER ISLAND, CANADA REGION
O: 17SEP2023 15:19:49 50.7N 130.5W MB=4.3 ECAN of Port Hardy, BC
O: 17SEP2023 09:58:57 50.6N 130.5W MB=5.0 ECAN of Port Hardy, BC
O: 17SEP2023 09:59:03 50.8N 129.8W Mw=4.5 EMSC VANCOUVER ISLAND, CANADA REGIO
P: 13SEP2023 156546 50.5N 130.4W 3.0-4.9 BAAAA British Colombia
O: 17SEP2023 07:08:53 47.7N 121.9W ML=2.5 EMSC PUGET SOUND REGION, WASHINGTON
P: 19SEP2023 156539 48.9N 122.1W 2.0-3.9 ABAAA Washington state, U.S.
NEIC reported this earthquake of M 2.5 in Washington State was felt with intensity II-III in the area(s) of Washington State with maximum intensity IV in Seattle and lesser shaking in Fall City, Snoqualmie, Carnation, North Bend, Gold Bar, Bellevue, Spanaway among others.
ROCKY MOUNTAINS REGION
O: 17SEP2023 20:20:29 35.4N 113.2W ML=2.8 EMSC ARIZONA
P: 20SEP2023 156473 34.7N 111.0W 2.0-4.3 BABAA SW U.S.A
NEIC reported this earthquake of M 2.8 in Arizona was felt with intensity II-III in the area(s) of Arizona in Prescott Valley.
O: 17SEP2023 13:15:52 44.3N 114.8W ML=2.2 EMSC SOUTHERN IDAHO
P: 17SEP2023 156515 44.4N 115.1W 2.0-4.1 AAAAA Montana/Idaho
O: 17SEP2023 07:43:09 48.1N 115.2W ML=2.7 EMSC WESTERN MONTANA
P: 19SEP2023 156517 47.7N 117.4W 2.0-3.9 AABAA Montana/Idaho
EASTERN U.S./CANADA
O: 17SEP2023 21:58:32 35.9N 97.2W ML=2.1 EMSC OKLAHOMA
P: 14SEP2023 156493 36.0N 97.0W 2.0-4.4 BAAAA Southern Plains
P: 17SEP2023 156492 35.0N 96.0W 2.0-4.3 AAAAA Southern Plains
HAWAII
No earthquakes of M>=3 were located in Hawaii.