STRONG AFTERSHOCK IN KERMADEC ISLANDS, NEW ZEALAND

 

EARTHQUAKE SUMMARY FOR JULY 24, 2021

 

The strongest earthquake in the world today was an M 6.0-6.1 in the Kermadec Islands, New Zealand. NEIC reported this earthquake of M 6.1 in the Kermadec Islands was felt with intensity II-III in the area(s) of the Tonga Islands and possibly in North Island, New Zealand. This is not a classical aftershock of the M 8.1 to the northwest of March 4, 2021. It represents a new mainshock. It is the strongest earthquake within about 150 km of this epicenter since an M 6.5 on June 20, 2021 and prior to that an M 6.1 on April 29, 2021. This event was probably promoted by high tidal stresses with the full moon today. It occurred within about an hour of local solar midnight, a time when such stresses area maximized. Forecast 135887 had expected today's event in this region was likely around July 23.

 

The tidal forecast for seismicity with the current full moon reads:

 

"The full moon arrived on July 24 at 02:37 UT. Longitudes which are at local solar midnight at this time are near 40 West and those at local solar noon near 140 East. These include, in the west, the Atlantic Ocean basin and in the east, the western Pacific subduction zone including Japan and portions of Eastern Indonesia and the Philippines. These areas are currently active and could see a strong earthquake in the next week." (July 22-24, 2021)

 

O: 24JUL2021 12:51:27  30.2S  176.8W Mw=6.0  EMSC   KERMADEC ISLANDS REGION      

O: 24JUL2021 12:51:27  30.2S  176.8W Mw=6.1  ANSS   KERMADEC ISLANDS REGION      

P: 23JUL2021 135887    30.0S  178.0W 4.0-5.5 AAAAA  No. Kermadec Islands       

 

A moderate earthquake of M 5.4 was widely felt in the southern Gulf of California today. NEIC reported maximum intensity V at Cullacan, Sinaloa, Mexico and II-III in Baja California at Los Cabos, Cabo San Lucas, La Paz and Tlalnepantla. An aftershock of M 4.6 was reported with intensity II in Cabo San Lucas, Baja, California. A similar M 5.4 hit the area on April 4, 2021 but the last of larger magnitude within about 150 km of today's epicenters was an M 5.5 n October 8, 2018. Forecast 135707 had expected today's event within about 25 km was likely around July 25.

 

O: 25JUL2021 04:25:57  23.9N  108.5W mb=4.6  EMSC   GULF OF CALIFORNIA

O: 25JUL2021 03:38:57  23.9N  108.7W Mw=5.4  EMSC   GULF OF CALIFORNIA           

P: 25JUL2021 135707    24.0N  109.0W 3.5-5.0 AAAAA  Gulf of California         

 

The strongest seismicity in the U.S. or Canada today was a pair of events of  M 4.0 and 4.2 in the central Andreanof Island, Aleutians, Alaska.  They were not reported felt in this remote area. An M 4.9 quake hit this area on July 11 and these may be aftershocks of that activity. These were expected within about 100 km around July 26 in forecast 135923.

 

O: 24JUL2021 18:11:03  51.3N  176.5W mb=4.2  EMSC   ANDREANOF ISLANDS, ALEUTIAN IS.

O: 24JUL2021 13:30:06  51.3N  176.6W mb=4.0  EMSC   ANDREANOF ISLANDS, ALEUTIAN IS

P: 26JUL2021 135823    51.6N  177.6W 3.5-5.1 AAAAA  Andreanoff Isls, Aleutians 

 

An unusual earthquake of M 3.0-3.2 hit Southern Texas today.  It may have been promoted by high tidal stresses as it occurred within about an hour of local solar midnight. While an M 3.1 hit about 100 km northeast of this on July 21, 2021, the last earthquake of M>=3.2 in this region of Texas within about 100 km was an M 3.4 on April 10, 2021. Forecast 135714 had expected today's event within about 150 km was likely around July 26.

 

O: 24JUL2021 08:08:43  28.6N   98.7W mb=3.0  EMSC   SOUTHERN TEXAS                

P: 26JUL2021 135714    28.0N   97.0W 3.0-4.4 AABAA  Northern Mexico            

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: 24JUL2021 16:23:50  32.9N  102.3E mb=4.4  EMSC   WESTERN SICHUAN, CHINA       

P: 25JUL2021 135712    32.0N  101.0E 4.0-5.7 AAAAA  Myanmar                    

 

O: 24JUL2021 11:21:11  37.4N   71.3E mb=4.4  EMSC   HINDU KUSH REGION, AFGHANISTAN

O: 24JUL2021 23:11:22  37.4N   71.9E mb=4.4  EMSC   TAJIKISTAN                   

P: 25JUL2021 135741    37.0N   71.0E 3.8-5.6 AAAAA  Hindu Kush/Pakistan        

 

O: 24JUL2021 09:10:17  55.9N  113.6E mb=4.4  EMSC   BURYATIYA, RUSSIA            

P: 28JUL2021 135838    55.0N  113.0E 3.0-4.4 BAAAA  So. Siberia                

 

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

 

INDONESIA AND PHILIPPINES

 

O: 24JUL2021 21:42:19   0.2N   96.6E mb=4.3  EMSC   NIAS REGION, INDONESIA       

P: 17JUL2021 135410     2.0N   96.0E 4.0-5.6 CBAAA  Nicobar Islands            

 

O: 24JUL2021 08:04:14   0.4S  134.3E ML=4.0  EMSC   NEAR N COAST OF PAPUA, INDONES

P: 26JUL2021 135677     3.0S  135.0E 4.0-5.4 ACAAA  West Irian, PNG            

 

O: 24JUL2021 13:07:23   2.9N  126.6E Mw=5.3  EMSC   MOLUCCA SEA                  

P: 28JUL2021 135662     3.0S  128.0E 4.0-5.4 BABAA  Ceram area                 

 

O: 24JUL2021 10:58:23   5.4S  148.5E mb=4.2  EMSC   NEW BRITAIN REGION, P.N.G.   

P: 24JUL2021 135667     3.0S  146.0E 4.0-5.6 ACCAA  New Ireland                

 

O: 24JUL2021 17:12:02   6.6S  129.8E mb=4.7  EMSC   BANDA SEA                    

P: 28JUL2021 135660     7.0S  129.0E 4.0-5.5 BAAAA  Banda Sea                   

 

O: 24JUL2021 19:49:41   6.8S  147.9E mb=4.8  EMSC   EASTERN NEW GUINEA REG., P.N.G

P: 16JUL2021 135420     6.0S  149.0E 4.0-5.4 CAAAA  New Ireland                

 

O: 24JUL2021 07:17:25   7.3S  126.7E mb=4.3  EMSC   KEPULAUAN BARAT DAYA, INDONESI

P: 24JUL2021 135660     7.0S  127.0E 4.0-5.4 AAAAA  Banda Sea                  

 

O: 25JUL2021 04:32:26   8.6S  118.3E mb=4.3  EMSC   SUMBAWA REGION, INDONESIA    

P: 25JUL2021 135676     8.0S  117.0E 4.0-5.4 AABAA  Sumbawa Island area        

P: 28JUL2021 135676     9.0S  118.0E 4.0-5.4 BAAAA  Sumbawa Island area        

 

CENTRAL AND SOUTH AMERICA

 

O: 25JUL2021 00:41:59  11.2N   86.8W mb=4.3  EMSC   NEAR COAST OF NICARAGUA

O: 25JUL2021 00:03:53  11.2N   86.8W mb=4.6  EMSC   NEAR COAST OF NICARAGUA      

P: 19JUL2021 135450    12.0N   88.0W 3.5-5.2 CAAAA  Nicaragua                  

 

O: 24JUL2021 09:29:52  15.6N   96.0W ML=4.0  EMSC   OFFSHORE OAXACA, MEXICO      

P: 25JUL2021 135682    16.0N   94.0W 3.5-5.1 AABAA  Chiapas, Mexico            

 

O: 25JUL2021 05:21:32  16.0N   92.2W Mw=5.0  EMSC   CHIAPAS, MEXICO              

P: 24JUL2021 135682    15.0N   93.0W 3.5-5.2 AAAAA  Chiapas, Mexico            

 

NEIC reported this earthquake of M 5.0 in Chiapas, Mexico was felt with intensity VI in the area(s) of Chiapas, Mexico at Frontera Comalapa.

 

O: 24JUL2021 10:35:59  18.2N  103.4W ML=4.0  EMSC   OFFSHORE MICHOACAN, MEXICO   

P: 28JUL2021 135691    18.0N  104.0W 3.5-5.5 BAAAA  Michoacan, Mexico          

 

O: 24JUL2021 23:23:17  27.9S   67.0W mb=4.4  EMSC   CATAMARCA, ARGENTINA         

P: 25JUL2021 135872    28.0S   67.0W 4.0-5.6 AAAAA  Argentina                  

 

O: 24JUL2021 13:55:57  34.4S   73.5W mb=4.9  EMSC   OFF COAST OF O'HIGGINS, CHILE

P: 25JUL2021 135883    34.0S   70.0W 4.0-5.5 AACAA  Central Chile              

 

NEIC reported this earthquake of M 4.9 in O'Higgins, Chile  was felt with intensity II-III in the area(s) of Valparaiso, Chile.

 

 

O: 25JUL2021 04:25:57  23.9N  108.5W mb=4.6  EMSC   GULF OF CALIFORNIA

O: 25JUL2021 03:38:57  23.9N  108.7W Mw=5.4  EMSC   GULF OF CALIFORNIA           

P: 25JUL2021 135707    24.0N  109.0W 3.5-5.0 AAAAA  Gulf of California         

 

AFRICA AND EUROPE

 

O: 24JUL2021 21:56:54  35.2N   25.2E mb=4.1  EMSC   CRETE, GREECE                

P: 24JUL2021 135740    34.0N   25.0E 3.0-4.8 ABAAA  Crete                      

 

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

 

SOUTHWEST PACIFIC

 

O: 24JUL2021 13:19:57   8.0S  156.4E mb=5.1  EMSC   SOLOMON ISLANDS              

P: 16JUL2021 135428     9.0S  158.0E 4.0-5.4 CABAA  Solomon Islands            

 

NEIC reported this earthquake of M 5.1 in the Solomon Islands was felt with intensity V in the area(s) of the Solomon Islands at Gizo.

 

O: 25JUL2021 00:21:23  16.0S  174.0W mb=4.6  EMSC   TONGA                        

P: 24JUL2021 135869    16.0S  175.0W 4.0-5.7 AAAAA  Tonga Islands              

 

O: 24JUL2021 16:45:46  24.0S  179.2W mb=4.3  EMSC   SOUTH OF FIJI ISLANDS        

P: 29JUL2021 135880    23.0S  177.0W 4.0-5.7 BABAA  Tonga Islands              

 

O: 24JUL2021 16:36:46  21.9S  170.9E Mw=5.0  EMSC   SOUTHEAST OF LOYALTY ISLANDS 

P: 28JUL2021 135874    22.0S  170.0E 4.0-5.6 BAAAA  Loyalty Islands            

 

OCEAN RIDGES

 

No significant (M>=5) or unusual earthquakes were reported on Ocean Ridges today.

 

 

ZEALANDIA AND AUSTRALIA REGION

 

O: 24JUL2021 12:51:27  30.2S  176.8W Mw=6.0  EMSC   KERMADEC ISLANDS REGION      

P: 23JUL2021 135887    30.0S  178.0W 4.0-5.5 AAAAA  No. Kermadec Islands       

 

O: 25JUL2021 06:30:11  34.3S  179.7E ML=4.0  EMSC   SOUTH OF KERMADEC ISLANDS    

P: 30JUL2021 135886    37.0S  179.0E 3.5-4.9 BCAAA  E. of North Islands N.Z.   

 

JAPAN AND KURIL ISLANDS

 

O: 24JUL2021 23:22:51  25.9N  125.5E mb=4.7  EMSC   SOUTHWESTERN RYUKYU ISL., JAPA

P: 23JUL2021 135716    26.0N  125.0E 4.0-5.6 AAAAA  Ryukyu Islands             

 

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

 

U.S./CANADA*

 

WESTERN U.S./CANADA

 

CALIFORNIA

 

O: 24JUL2021 21:35:17  30.8N  114.2W ML=3.6  EMSC   GULF OF CALIFORNIA

O: 24JUL2021 19:33:11  31.1N  114.9W ML=4.3  EMSC   BAJA CALIFORNIA, MEXICO

O: 24JUL2021 20:59:48  30.6N  114.1W ML=3.9  EMSC   GULF OF CALIFORNIA           

P: 25JUL2021 135761    30.9N  114.3W 2.5-4.6 AAAAA  So. California              

 

O: 25JUL2021 01:48:29  32.5N  118.2W ML=2.6  EMSC   OFF COAST OF CALIFORNIA      

P: 26JUL2021 135763    32.4N  118.2W 2.5-4.8 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 at El Cajon. 

 

O: 25JUL2021 06:44:37  33.5N  116.6W Ml=2.0  EMSC   SOUTHERN CALIFORNIA          

P: 26JUL2021 135764    33.4N  116.7W 2.5-4.9 AAAAA  So. California             

 

O: 24JUL2021 11:51:07  36.5N  121.8W Md=2.2  EMSC   CENTRAL CALIFORNIA           

P: 23JUL2021 135733    36.7N  121.4W 2.5-4.6 AAAAA  Central California         

 

O: 24JUL2021 22:28:37  37.2N  120.0W Md=2.2  EMSC   CENTRAL CALIFORNIA           

P: 24JUL2021 135734    37.1N  121.5W 2.5-4.6 AABAA  Central California         

 

O: 25JUL2021 06:22:32  38.2N  117.9W ml=2.0  EMSC   NEVADA

O: 24JUL2021 18:07:42  37.5N  118.8W Md=2.2  EMSC   CENTRAL CALIFORNIA           

P: 29JUL2021 135726    37.5N  118.6W 2.5-4.8 BAAAA  California/Nevada area     

 

O: 24JUL2021 17:42:38  37.9N  117.1W ml=2.2  EMSC   NEVADA                       

P: 28JUL2021 135725    37.2N  117.3W 2.5-5.1 BAAAA  California/Nevada area     

 

O: 25JUL2021 02:19:14  39.7N  122.9W Md=2.4  EMSC   NORTHERN CALIFORNIA

O: 25JUL2021 02:35:28  39.7N  122.8W ML=2.6  EMSC   NORTHERN CALIFORNIA

O: 24JUL2021 08:54:23  39.5N  122.0W Md=2.3  EMSC   NORTHERN CALIFORNIA          

O: 24JUL2021 13:37:11  39.7N  122.9W Md=2.6  EMSC   NORTHERN CALIFORNIA          

P: 19JUL2021 135551    40.0N  123.0W 2.5-4.6 BAAAA  Northern California        

P: 25JUL2021 135736    39.0N  123.1W 2.5-4.6 AAAAA  Central California         

 

O: 24JUL2021 23:06:06  40.3N  124.5W ML=2.5  EMSC   OFFSHORE NORTHERN CALIFORNIA 

P: 27JUL2021 135807    40.7N  124.6W 2.5-4.5 BAAAA  Off Coast of No. Calif     

 

ALASKA

 

O: 24JUL2021 18:11:03  51.3N  176.5W mb=4.2  EMSC   ANDREANOF ISLANDS, ALEUTIAN IS.

O: 24JUL2021 13:30:06  51.3N  176.6W mb=4.0  EMSC   ANDREANOF ISLANDS, ALEUTIAN IS

P: 26JUL2021 135823    51.6N  177.6W 3.5-5.1 AAAAA  Andreanoff Isls, Aleutians 

 

PACIFIC NORTHWESTERN U.S./WESTERN CANADA

 

O: 24JUL2021 23:41:50  60.1N  140.7W ML=2.9  EMSC   SOUTHERN YUKON TERRITORY, CANA

P: 23JUL2021 135845    61.0N  138.0W 3.2-5.2 AABAA  Central Alaska             

 

ROCKY MOUNTAINS REGION

 

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

 

EASTERN U.S./CANADA

 

O: 24JUL2021 10:48:45  36.3N   89.5W Md=2.0  EMSC   TENNESSEE                    

P: 25JUL2021 135747    36.7N   89.7W 2.0-4.0 AAAAA  New Madrid area            

 

O: 24JUL2021 08:08:43  28.6N   98.7W mb=3.0  EMSC   SOUTHERN TEXAS               

P: 26JUL2021 135714    28.0N   97.0W 3.0-4.4 AABAA  Northern Mexico            

 

O: 24JUL2021 11:12:53  36.5N   98.8W ML=2.3  EMSC   OKLAHOMA                      

P: 26JUL2021 135778    36.0N   98.0W 2.0-4.1 AAAAA  Southern Plains            

 

HAWAII

 

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