STRONG SEISMICITY CONTINUES NEAR EQUATOR IN ATLANTIC

 

EARTHQUAKE SUMMARY FOR SEPTEMBER 23, 2020

 

The strongest earthquake in the world today was an M 5.7 in the central mid-Atlantic. It was not felt in the area. This epicenter is at the equator, an area which in the past several days has shown strongly enhanced seismicity in Sumatra, the Central mid-Atlantic, the Galapagos Islands, the northern East Pacific Rise, among others, as noted in previous issues as:

 

"The most active zone of seismicity in the world today was the northern equatorial latitude band between about 0 and 20 degrees north. This band is especially active at this time of year because of strong meteorological ocean storms  (hurricanes and typhoons) which occur in these latitudes and are maximum in September. In the western Hemisphere this included continuing enhanced seismicity in eastern and central Mexico and in the Dominican Republic. The strongest earthquake of the day in this area, however was an M 5.4 in the Galapagos Islands area near the equator. Today is the first day of autumn when the sun reaches its zenith over equator. As has been suggested in this summary in prior issues, this can enhance vertical seismicity in latitudes where the sun reaches its zenith (is directly overhead at local solar noon). In this case that is the equator." (September 20-21, 2020)

 

Similar events of M 5.9 and 6.1 occurred near today's epicenter in the central east Pacific on March 22, 2020 - the first such activity in the area since September 11, 2013. Note that the event in March occurred, like today's on the equinox (in this case, the first day of Spring) while today's event is on the first day of Autumn." (September 21-22, 2020)

 

Today's event may also have been promoted by the occurrence of a geomagnetic storm today, the largest since early September as noted in this summary:

 

"The geomagnetic field saw disturbed conditions today. The AP level was 11.  High latitude geomagnetic field also saw active conditions with AP 29. Geomagnetic disturbances of this level can help promote enhanced seismicity at high latitudes and near the geomagnetic equator. Moderate to moderately strong events in these areas are likely in the next several days." (September 23, 2020)

 

The last earthquake within about 200 km of today's epicenter with M>=5.7 was an M 5.9 on July 23, 2018 and prior to that an M 7.1 on August 29,, 2016. Today's event occurred within about half an hour of local solar midnight and was also likely promoted by strong tidal stresses which maximize at this time. Forecast 127068 had expected today's event was likely in the central Mid-Atlantic within about 100 km of today's epicenter around September 19.

 

O: 24SEP2020 00:27:49   0.2S   18.8W Mw=5.7  EMSC   CENTRAL MID-ATLANTIC RIDGE   

O: 24SEP2020 01:01:28   0.3S   19.1W mb=4.8  EMSC   CENTRAL MID-ATLANTIC RIDGE   

P: 19SEP2020 127068     1.0S   20.0W 4.0-5.7 BAAAA  Central Mid-Atlantic       

 

An M 4.5 in the Greenland Sea followed the geomagnetic storm today. This is the strongest earthquake within about 400 km of this epicenter in the Greenland Sea since an M 4.6 on March 11 and an M 4.9 on October 29, 2019. Forecast 127546  had expected today's activity was likely within about 100 km of this epicenter around September 30. This event is at 103 degrees from the Banda M 7.0 of August 21 and was probably promoted by energy from that source.

 

O: 24SEP2020 04:44:56  79.6N    3.1E mb=4.5  EMSC   GREENLAND SEA                

P: 30SEP2020 127546    79.0N    7.0E 4.0-5.4 CAAAA  Arctic Ocean Region        

 

Unusual earthquakes occurred in eastern Europe today in Greece with M 4.6 and in Albania with M 4.3. The earthquake of M 4.6 in Greece is the strongest within about 150 km of this epicenter on March 21, 2020. A similar M 4.6 hit south of today's event on July 25, 2020 with M 4.7. Forecast 127428 expected today's event was likely around September 26.

 

NEIC reported this earthquake of M 4.6 in Greece  was felt with intensity II-III in the area(s) of Greece at Karia and Nidrion, Levkas and Vasilika, Trikala.  This event, like that in the Greenland Sea today, is at 103 degrees from the Banda M 7.0 of August 21 and was probably promoted by energy from that source.

 

O: 24SEP2020 05:10:19  38.8N   20.5E mb=4.6  EMSC   GREECE                       

P: 25SEP2020 127428    38.0N   21.0E 3.0-4.5 AAAAA  No. Greece                 

 

The earthquake in Albania of M 4.3 is the strongest within about 150 km of this epicenter in Albania since an M 4.2 on September 12. The last of larger magnitude in the area was an M 4.5 on July 26, 2020. Forecast 127497 had expected today's event in this area was likely around September 25.

 

NEIC reported this earthquake of M 4.3 in  Albania was felt with intensity II-III in the area(s) of Albania at Tirana and Vlore.  This event, like that in the Greenland Sea today, is at 103 degrees from the Banda M 7.0 of August 21 and was probably promoted by energy from that source.

 

O: 23SEP2020 23:25:10  41.0N   19.8E mb=4.3  EMSC   ALBANIA                      

P: 25SEP2020 127497    40.0N   20.0E 3.0-5.2 AAAAA  Romania/NW Turkey          

 

An M 5.3 in northern Mindanao, Philippines today was followed by a series of moderate aftershocks. It occurred within about an hour of local solar noon and may have been enhanced by strong tidal stresses which maximize at this hour as well as by effects from the geomagnetic storm today. It was near sub-solar at the time of the event. This appears to be an aftershock of the M 5.8 which occurred about 50 km southwest of today's epicenter on September 20, 2020. A similar M 5.8 hit he area on July 27, 2020. Forecast 127368 had expected today's event within about 50 km was likely around September 25.

 

NEIC reported this earthquake of M 5.3 in northern Mindanao  was felt with intensity II-III in the area(s) of northern Mindanao, Philippines at Gamut iTago and Alubijid, Caraga, Philippines. Today's event is located at the fifth node (72 degrees) from the M 7.8 in the Alaska Peninsula of July 22 and may have been promoted by energy from that source.

 

O: 23SEP2020 10:21:48   9.3N  126.8E ML=4.2  EMSC   MINDANAO, PHILIPPINES        

O: 23SEP2020 22:19:43   9.3N  127.0E mb=4.7  EMSC   PHILIPPINE ISLANDS REGION    

O: 24SEP2020 02:26:00   9.5N  126.9E Mw=5.3  EMSC   MINDANAO, PHILIPPINES        

O: 23SEP2020 23:32:56  10.1N  126.4E ML=4.0  EMSC   PHILIPPINE ISLANDS REGION    

P: 25SEP2020 127368    10.0N  127.0E 3.5-4.9 AAAAA  Luzon, Philippines         

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: 23SEP2020 10:20:23  23.2N  121.6E ML=4.1  TAI    Hualien, Taiwan              

P: 23SEP2020 127402    23.0N  122.0E 4.0-5.5 AAAAA  Taiwan                      

 

CWB reported this earthquake was felt with intensity II in Taitung and Hualien and I in Kaohsiung and Chiayi Counties, Taiwan.

 

O: 24SEP2020 00:16:17  36.6N   71.0E mb=4.3  EMSC   HINDU KUSH REGION, AFGHANISTAN

P: 25SEP2020 127418    37.0N   72.0E 3.8-5.2 AAAAA  Hindu Kush/Pakistan        

 

NEIC reported this earthquake of M 4.3 in Hindu Kush, Afghanistan  was felt with intensity II-III in the area(s) of Hindu Kush, Afghanistan at Mahmoud Raqui.

 

O: 23SEP2020 13:16:31  54.5N   83.9E mb=4.2  EMSC   SOUTHWESTERN SIBERIA, RUSSIA 

P: 29SEP2020 127525    50.0N   88.0E 3.0-4.6 CCCAA  So. Siberia                

 

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

 

INDONESIA AND PHILIPPINES

 

O: 23SEP2020 15:34:25   1.2N   93.1E ML=4.7  EMSC   OFF W COAST OF NORTHERN SUMATR

P: 23SEP2020 127326     5.0N   93.0E 4.0-5.5 ACAAA  Nicobar Islands            

 

O: 23SEP2020 22:07:55   2.2N  126.8E mb=4.7  EMSC   MOLUCCA SEA                  

O: 24SEP2020 01:34:06   2.9N  128.3E ML=4.2  EMSC   HALMAHERA, INDONESIA         

P: 28SEP2020 127324     2.0N  129.0E 4.0-5.5 BAAAA  Halmahera                  

 

O: 23SEP2020 20:59:36   3.8N  126.1E ML=4.0  EMSC   KEPULAUAN TALAUD, INDONESIA  

P: 29SEP2020 127324     4.0N  127.0E 4.0-5.7 CAAAA  Halmahera                  

 

O: 23SEP2020 16:18:02   5.0S  133.6E ML=4.2  EMSC   EAR S COAST OF PAPUA, INDONESI

O: 23SEP2020 15:08:48   7.0S  133.2E ML=4.4  EMSC   KEPULAUAN ARU REGION, INDONESI

P: 29SEP2020 127355     5.0S  134.0E 4.0-5.4 CAAAA  West Irian, PNG             

 

O: 23SEP2020 18:28:27   7.2S  129.1E mb=4.3  EMSC   KEPULAUAN BABAR, INDONESIA   

P: 25SEP2020 127354     6.0S  130.0E 4.0-5.4 ABAAA  West Irian, PNG            

 

O: 23SEP2020 10:21:48   9.3N  126.8E ML=4.2  EMSC   MINDANAO, PHILIPPINES         

O: 23SEP2020 22:19:43   9.3N  127.0E mb=4.7  EMSC   PHILIPPINE ISLANDS REGION    

O: 24SEP2020 02:26:00   9.5N  126.9E Mw=5.3  EMSC   MINDANAO, PHILIPPINES        

O: 23SEP2020 23:32:56  10.1N  126.4E ML=4.0  EMSC   PHILIPPINE ISLANDS REGION    

P: 25SEP2020 127368    10.0N  127.0E 3.5-4.9 AAAAA  Luzon, Philippines         

 

 

CENTRAL AND SOUTH AMERICA

 

O: 23SEP2020 20:42:50  12.9N   90.2W ML=4.6  EMSC   OFFSHORE EL SALVADOR         

P: 24SEP2020 127364    13.0N   91.0W 3.5-5.2 AAAAA  Guatemala                   

 

O: 23SEP2020 07:41:06  15.5N   95.8W ML=4.1  EMSC   OFFSHORE OAXACA, MEXICO      

P: 23SEP2020 127378    15.0N   96.0W 3.5-5.6 AAAAA  Oaxaca, Mexico             

 

O: 23SEP2020 11:43:21  17.7N   72.2W ML=3.2  EMSC   HAITI REGION                  

P: 24SEP2020 127386    20.0N   71.0W 3.0-4.6 ACAAA  Bahamas/No. Caribbean      

 

O: 23SEP2020 10:06:35  17.9N   67.0W Md=3.2  EMSC   PUERTO RICO REGION           

P: 25SEP2020 127380    18.0N   66.0W 3.4-4.9 AAAAA  Puerto Rico                

 

NEIC reported this earthquake of M 3.2 in  Puerto Rico was felt with intensity II-III in the area(s) of Puerto Rico at Moca.

 

O: 23SEP2020 22:03:55  19.0N   68.0W ML=3.1  EMSC   DOMINICAN REPUBLIC REGION    

P: 25SEP2020 127386    20.0N   67.0W 3.0-4.6 AAAAA  Bahamas/No. Caribbean      

 

O: 23SEP2020 22:57:02  19.7N  108.9W ML=4.1  EMSC   REVILLA GIGEDO ISLANDS REGION

P: 26SEP2020 127389    20.0N  109.0W 3.5-5.0 BAAAA  Gulf of California         

 

O: 23SEP2020 07:29:45  24.7N  109.2W ML=4.1  EMSC   GULF OF CALIFORNIA           

P: 24SEP2020 127389    24.0N  109.0W 3.5-5.3 AAAAA  Gulf of California         

 

O: 23SEP2020 23:09:23  25.1S   71.0W mb=4.2  EMSC   OFF COAST OF ANTOFAGASTA, CHIL

P: 29SEP2020 127566    26.0S   71.0W 4.0-6.0 CAAAA  Coast Central Chile        

 

 

O: 24SEP2020 01:46:28  17.9N   68.4W ML=3.0  EMSC   DOMINICAN REPUBLIC REGION

O: 23SEP2020 12:43:12  18.2N   68.8W ML=3.0  EMSC   DOMINICAN REPUBLIC REGION

O: 23SEP2020 16:39:12  18.5N   68.9W ML=3.0  EMSC   DOMINICAN REPUBLIC

O: 23SEP2020 22:03:55  19.0N   68.0W ML=3.1  EMSC   DOMINICAN REPUBLIC REGION    

P: 25SEP2020 127386    20.0N   67.0W 3.0-4.6 AAAAA  Bahamas/No. Caribbean      

 

O: 23SEP2020 10:28:55  18.5N   67.5W Md=3.2  EMSC   PUERTO RICO REGION

O: 23SEP2020 10:06:35  17.9N   67.0W Md=3.2  EMSC   PUERTO RICO REGION           

P: 25SEP2020 127380    18.0N   66.0W 3.4-4.9 AAAAA  Puerto Rico                

 

O: 24SEP2020 03:55:22  15.9N   94.1W mb=4.4  EMSC   OFFSHORE CHIAPAS, MEXICO

O: 23SEP2020 13:15:00  16.0N   96.3W ML=4.0  EMSC   OAXACA, MEXICO

O: 24SEP2020 05:53:19  16.0N   95.8W ML=4.0  EMSC   OAXACA, MEXICO

O: 23SEP2020 07:41:06  15.5N   95.8W ML=4.1  EMSC   OFFSHORE OAXACA, MEXICO      

P: 23SEP2020 127378    15.0N   96.0W 3.5-5.6 AAAAA  Oaxaca, Mexico             

 

AFRICA AND EUROPE

 

O: 24SEP2020 01:01:24  38.1N   34.0E ML=4.4  EMSC   CENTRAL TURKEY               

P: 26SEP2020 127457    37.0N   34.0E 3.5-5.1 ABAAA  Turkey                     

 

NEIC reported this earthquake of M 4.4 in Turkey was felt with intensity II-III in the area(s) of Ankara, Turkey.

 

O: 24SEP2020 05:10:19  38.8N   20.5E mb=4.6  EMSC   GREECE                       

P: 25SEP2020 127428    38.0N   21.0E 3.0-4.5 AAAAA  No. Greece                 

 

O: 23SEP2020 23:25:10  41.0N   19.8E mb=4.3  EMSC   ALBANIA                      

P: 25SEP2020 127497    40.0N   20.0E 3.0-5.2 AAAAA  Romania/NW Turkey          

 

O: 23SEP2020 21:21:24  42.9N    1.5W ML=3.1  EMSC   PYRENEES                     

P: 19SEP2020 127196    43.0N    0.0E 3.0-5.0 BABAA  France                     

 

O: 24SEP2020 04:44:56  79.6N    3.1E mb=4.5  EMSC   GREENLAND SEA                

P: 30SEP2020 127546    79.0N    7.0E 4.0-5.4 CAAAA  Arctic Ocean Region        

 

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

 

SOUTHWEST PACIFIC

 

O: 24SEP2020 01:30:54  22.2S  176.5W mb=4.6  EMSC   SOUTH OF FIJI ISLANDS        

P: 28SEP2020 127575    22.0S  179.0W 4.0-5.9 BABAA  Tonga Islands              

 

O: 23SEP2020 14:23:41  23.6S  179.9W mb=4.3  EMSC   SOUTH OF FIJI ISLANDS        

P: 25SEP2020 127575    25.0S  180.0W 4.0-5.5 ABAAA  Tonga Islands              

 

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

 

OCEAN RIDGES

 

O: 24SEP2020 00:27:49   0.2S   18.8W Mw=5.7  EMSC   CENTRAL MID-ATLANTIC RIDGE   

O: 24SEP2020 01:01:28   0.3S   19.1W mb=4.8  EMSC   CENTRAL MID-ATLANTIC RIDGE   

P: 19SEP2020 127068     1.0S   20.0W 4.0-5.7 BAAAA  Central Mid-Atlantic       

 

ZEALANDIA AND AUSTRALIA REGION

 

O: 24SEP2020 03:04:52  35.2S  178.5E mb=4.4  EMSC   OFF E. COAST OF N. ISLAND, N.Z

P: 28SEP2020 127583    35.0S  179.0E 3.0-4.4 BAAAA  North Island, N.Z.         

 

JAPAN AND KURIL ISLANDS

 

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

 

U.S./CANADA*

 

WESTERN U.S./CANADA

 

CALIFORNIA

 

O: 23SEP2020 08:06:54  33.0N  116.4W Ml=2.4  EMSC   SOUTHERN CALIFORNIA          

P: 27SEP2020 127443    33.4N  116.7W 2.5-4.5 BAAAA  So. California             

 

O: 23SEP2020 11:05:21  33.4N  118.4W Ml=2.0  EMSC   SAN PEDRO CHANNEL, CALIFORNIA

P: 26SEP2020 127444    33.6N  118.5W 2.5-4.4 BAAAA  So. California             

 

O: 24SEP2020 06:58:44  34.0N  118.1W Ml=2.5  EMSC   GREATER LOS ANGELES AREA, CALI

P: 25SEP2020 127447    33.9N  118.3W 2.5-4.4 AAAAA  So. California             

 

NEIC reported this earthquake of M 2.5 in the Los Angeles, California area was felt with intensity II-III in the area(s) of Los Angeles, California at Monterey Park, Pico Rivera, El Monte, Temple, Alhambra, Los Angeles, Whittier and Downey. 

 

O: 23SEP2020 12:24:27  34.2N  117.7W Ml=3.2  EMSC   GREATER LOS ANGELES AREA, CALI

P: 26SEP2020 127445    34.1N  117.4W 2.5-4.4 BAAAA  So. California             

 

NEIC reported this earthquake of M 3.2 in Southern California was felt with intensity II-III in the area(s) of California at Mt. Baldy, Upland, Rancho Cucamonga, Claremont, Upland, La Verne, Ontario.

 

O: 23SEP2020 19:05:40  37.2N  122.0W Md=2.2  EMSC   NORTHERN CALIFORNIA          

P: 25SEP2020 127411    37.2N  122.1W 2.5-4.4 AAAAA  Central California         

 

O: 23SEP2020 08:23:57  38.2N  117.8W ML=2.6  EMSC   NEVADA                       

P: 25SEP2020 127409    37.8N  118.2W 2.5-4.6 AAAAA  California/Nevada area     

 

O: 23SEP2020 07:19:12  41.3N  125.8W ML=2.9  EMSC   OFF COAST OF NORTHERN CALIFORN

P: 24SEP2020 127490    40.6N  124.9W 2.5-4.8 AAAAA  Off Coast of No. Calif     

 

NEIC reported this earthquake of M 3.0 in Northern California was felt with intensity II-III in the area(s) of Northern California at Arcata.

 

O: 23SEP2020 14:08:05  38.2N  118.0W ml=2.9  EMSC   NEVADA

O: 23SEP2020 21:46:16  38.2N  117.8W ml=2.0  EMSC   NEVADA

O: 23SEP2020 08:23:57  38.2N  117.8W ML=2.6  EMSC   NEVADA                       

P: 25SEP2020 127409    37.8N  118.2W 2.5-4.6 AAAAA  California/Nevada area     

 

O: 23SEP2020 14:17:44  35.7N  117.5W Ml=3.2  EMSC   SOUTHERN CALIFORNIA

O: 23SEP2020 14:45:17  35.4N  117.9W Ml=2.1  EMSC   SOUTHERN CALIFORNIA          

P: 26SEP2020 127408    36.2N  117.9W 2.5-4.4 BAAAA  California/Nevada area      

 

NEIC reported this earthquake of M 3.2 in Central California  was felt with intensity II-III in the area(s) of Central California at Ridgecrest, Trona, Inyokern.

 

ALASKA

 

O: 23SEP2020 17:07:06  62.4N  148.5W ML=3.0  EMSC   CENTRAL ALASKA                

P: 29SEP2020 127537    62.8N  149.1W 3.2-5.2 CAAAA  Central Alaska             

 

PACIFIC NORTHWESTERN U.S./WESTERN CANADA

 

O: 23SEP2020 15:16:32  47.9N  122.1W ML=2.5  EMSC   SEATTLE-TACOMA AREA, WASHINGTO

P: 24SEP2020 127504    48.4N  123.2W 2.0-4.3 AAAAA  Washington state, U.S.     

 

NEIC reported this earthquake of M 2.5 in Seattle, Washington was felt with intensity II-III in the area(s) of Seattle, Washington at Everett, Gold Bar, Sultan, Point Roberts and at Victoria, British Columbia.

 

O: 22SEP2020 23:25:47  47.3N  129.0W MB=3.7  ECAN Tofino, BC                     

P: 19SEP2020 127225    48.3N  128.5W 2.8-5.0 BAAAA  Vancouver Island area      

 

O: 22SEP2020 09:25:30  64.9N  139.5W MB=3.3  ECAN Dawson, YT                     

P: 15SEP2020 127258    65.0N  139.0W 3.0-4.8 CAAAA  Northern Alaska            

P: 29SEP2020 127541    64.0N  138.0W 3.0-4.8 CAAAA  Northern Alaska            

 

ROCKY MOUNTAINS REGION

 

No earthquakes of M>=2 were located in the Rocky Mountain region today.

 

EASTERN U.S./CANADA

 

O: 23SEP2020 19:33:46  34.8N   98.4W ML=2.0  EMSC   OKLAHOMA                     

P: 27SEP2020 127455    35.0N   97.0W 2.0-3.9 BAAAA  Southern Plains            

 

O: 22SEP2020 21:12:07  67.2N   66.7W MB=3.1  ECAN Qikiqtarjuaq, NU               

 

HAWAII

 

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