Due to unforeseen circumstances summaries for the period January 15-19 were not provided. These are being compiled and can be found in the "Previous Week's Summary" section as they are available.

 

STRONG SUB-SOLAR QUAKE HITS WESTERN INDONESIA

 

EARTHQUAKE SUMMARY FOR JANUARY 21, 2019

 

A strong earthquake of M 6.4 hit south of Sumbawa, Indonesia today. It was reported felt with intensity II in Mataram, Indonesia by NEIC. This event occurred within about an hour of local solar noon, a prime time for high tidal stresses which can help promote seismicity. The epicenter was nearly sub-solar at the time of the earthquake. This region of Indonesia had been expected in previous issues of this report to see tidal triggering at this time as:

 

"The full moon arrived at 05:16 UT on January 21, 2019. This is an especially powerful tidal event as the moon is a supermoon (closest to earth) and this

will be a total lunar eclipse. Longitudes which will experience maximum tidal stresses at this time are near 80 West and 100 East longitudes and include in the west western South America and Central America and portions of the East Pacific Rise and central U.S. In the east this maximum passes through western Indonesia including southeast Asia and Sumatra, Indonesia. These are most likely to see tidal tiggering at this time, bu many regions can see tidal triggering at this time." (January 21, 2019)

 

The mainshock of M 6.4 was preceded by an M 6.0 several hours earlier which was felt with intensity II in Bali, Indonesia. The M 6.4 is the strongest earthquake within about 200 km of today's epicenter in at least 30 years. The most recent nearby event was an M 6.6 about 250 km to the northwest of this on November 8, 2009.  Forecast 113098 had expected this earthquake was likely within about 100 km around January 22. This epicenter is located at 100 degrees from the Anchorage, Alaska quake (M 7.0) of November 30, 2018 and at 105 degrees from the South Sandwich Islands M 7.1 of December 11, 2018 and was probably promoted by concentrated seismic energy from these events. Energy from large earthquakes is returned to the surface after reflection and refraction off the core-mantle boundary to areas between 100 and 106 degrees on the surface from the mainshock and is often associated with enhanced seismicity in this distance range..

 

O: 22JAN2019 00:56:54  10.3S  118.9E mb=4.5  ANSS   SSW of Kahale Indonesia      

O: 21JAN2019 23:59:22  10.3S  119.1E mw=6.0  ANSS   SSW of Bogorawatu Indonesia  

O: 22JAN2019 01:57:00  10.4S  119.1E mb=4.8  ANSS   SSW of Bogorawatu Indonesia  

O: 22JAN2019 00:08:31  10.4S  119.1E mb=4.9  ANSS   SSW of Bogorawatu Indonesia  

O: 22JAN2019 05:10:03  10.5S  119.0E mw=6.4  ANSS   SSW of Bogorawatu Indonesia  

P: 22JAN2019 113098    11.0S  118.0E 4.0-5.7 AAAAA  So. of Indonesia           

 

The strongest earthquake in the U.S. or Canada today was an M 5.2 in the Alaska Peninsula.

NEIC reported it was widely felt up to about 500 km from the epicenter with light to moderate shaking of intensity II-III in Alaska at King Salmon, Kodiak, Homer, Cooper Landing, and Anchorage. The last earthquake in the Alaska Peninsula with M>=5.2 within about 150 km of today's epicenter occurred May 11, 2018 about 100 km south of today's epicenter. Forecast 113074 expected activity in this area was likely around January 25.

 

O: 22JAN2019 04:43:19  58.3N  155.4W mw=5.2  ANSS   Alaska Peninsula             

P: 25JAN2019 113074    60.1N  153.4W 3.2-5.0 BBAAA  Central Alaska              

 

An earthquake of M 4.5 in Guadeloupe preceded that activity in Sumbawa, Indonesia. The Guadeloupe epicenter occurred within about an hour of local solar noon and was nearly antipodal to the subsequent activity in Indonesia. NEIC reported the event in Guadeloupe was felt with intensity VI in Terre-de-Bas; Baie-Mahault and  and II-III in Petit-Bourg, Guadeloupe. The last earthquake of M>=4.5 within about 200 km of this epicenter in the region of Guadeloupe occurred as an M 4.5 on April 28, 2018 and prior to that an M 4.6 on September 15, 2017. The last of significantly larger magnitude was an M 5.8 on February 3, 2017. Forecast 112958 had expected this activity was likely around January 24, 2019 within about 50 km of the epicenter.

 

O: 21JAN2019 14:42:48  15.8N   61.7W mb=4.5  ANSS   S of Terre-de-Bas Guadeloupe 

P: 24JAN2019 112958    16.0N   62.0W 3.0-5.1 BAAAA  Leeward Islands            

 

An M 5.8 also occurred today off the south coast of Oaxaca, Mexico. NEIC reported it was felt with intensity IV in Oaxaca at Kadani, Guichicovi, and in Tuxtla Gutierrez, Chiapas, Mexico. Lesser shaking of II-III was reported in Oaxaca at Matias Romero, Huatulco, Pochutia, Puerto Escondido and at Coatepec, Veracrus and Mexico City. This earthquake occurred within minutes of local solar midnight, a time when tidal forces are at maximum and was probably enhanced by these. This is the strongest earthquake within about 150 km of this epicenter since an M 6.1 on September 23, 2017, an aftershock of an M 8.1 of September 8, 2017. Forecast 112787 had expected this earthquake was likely around January 18 within about 100 km of the epicenter.

 

O: 21JAN2019 11:57:17  15.6N   94.7W mw=5.8  ANSS   Francisco del Mar Mexico     

P: 18JAN2019 112787    15.0N   94.0W 3.5-5.4 BAAAA  Chiapas, 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: 22JAN2019 03:19:26  22.2N  121.4E ML=4.8  TAI    Hualien, Taiwan              

O: 22JAN2019 03:19:28  22.2N  121.4E mr=4.9  ANSS   Taitung City Taiwan          

 

CWB reported this earthquake was felt with intensity V in Taitung; III in Pingtung and I in Chiayi, Nantou, Kaohsiung and Yunlin Counties, Taiwan.

 

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

 

INDONESIA AND PHILIPPINES

 

O: 21JAN2019 16:47:48   4.5N  126.9E mw=5.0  ANSS   ESE of Sarangani Philippines 

P: 16JAN2019 112771     5.0N  128.0E 4.0-5.6 BAAAA  Halmahera                  

 

O: 22JAN2019 00:56:54  10.3S  118.9E mb=4.5  ANSS   SSW of Kahale Indonesia      

O: 21JAN2019 23:59:22  10.3S  119.1E mw=6.0  ANSS   SSW of Bogorawatu Indonesia  

O: 22JAN2019 01:57:00  10.4S  119.1E mb=4.8  ANSS   SSW of Bogorawatu Indonesia  

O: 22JAN2019 00:08:31  10.4S  119.1E mb=4.9  ANSS   SSW of Bogorawatu Indonesia  

O: 22JAN2019 05:10:03  10.5S  119.0E mw=6.4  ANSS   SSW of Bogorawatu Indonesia  

P: 22JAN2019 113098    11.0S  118.0E 4.0-5.7 AAAAA  So. of Indonesia           

 

CENTRAL AND SOUTH AMERICA

 

O: 22JAN2019 00:41     30.2S   71.2W mb=4.4  GUC    Coquimbo at Coquimbo, La Seren

O: 22JAN2019 00:36     30.2S   71.2W mb=4.2  GUC    Coquimbo at Coquimbo, La Seren

P: 23JAN2019 113117    30.0S   72.0W 4.0-5.6 AAAAA  Coast Central Chile        

 

CSN reported this earthquake of M 4.4 was felt with intensity IV in  Coquimbo at Coquimbo, La Serena, Monte Patria, Ovalle, Paiguano, Rio Hurtado and Cicuna, Chile.

CSN reported this earthquake of M 4.2 was felt with intensity IV in  Coquimbo at Coquimbo, La Serena, Monte Patria and Vicuna and III in Paiguano, La Higuera and Andacollo, Chil.

 

O: 21JAN2019 20:27     33.9S   70.3W mb=4.9  GUC    Maule at Romeral; III in Curic

P: 20JAN2019 112904    32.0S   67.0W 4.0-5.6 ABCAA  Central Chile              

 

CSN reported this earthquake was felt with intensity IV in  Maule at Romeral; III in Curico, Sagrada Familia and Talca and II in Pencahue and Rio Claro; in O'Higgins with IV in Placilla and III in Machali, Mostazal, Rancagua and Requinoa, and in Biobio in Concepcion, Chile with intensity III.

 

O: 21JAN2019 11:57:17  15.6N   94.7W mw=5.8  ANSS   Francisco del Mar Mexico     

P: 18JAN2019 112787    15.0N   94.0W 3.5-5.4 BAAAA  Chiapas, Mexico            

 

O: 21JAN2019 14:42:48  15.8N   61.7W mb=4.5  ANSS   S of Terre-de-Bas Guadeloupe 

P: 24JAN2019 112958    16.0N   62.0W 3.0-5.1 BAAAA  Leeward Islands            

 

O: 22JAN2019 00:04:51  18.8N   64.7W md=3.3  ANSS   Town British Virgin Islands  

P: 20JAN2019 112790    19.0N   65.0W 3.0-5.2 AAAAA  Leeward Islands            

 

O: 21JAN2019 07:06:29  19.1N   67.8W md=3.2  ANSS   Punta Cana Dominican Republic

P: 19JAN2019 112800    20.0N   67.0W 3.0-4.7 AAAAA  Bahamas/No. Caribbean      

 

O: 22JAN2019 00:41:20  30.1S   71.5W mb=4.6  ANSS   SW of Coquimbo Chile         

O: 21JAN2019 19:08:38  31.8S   72.3W mb=4.7  ANSS   W of Illapel Chile           

P: 23JAN2019 113117    30.0S   72.0W 4.0-5.6 AAAAA  Coast Central Chile        

 

NEIC reported this earthquake of M 4.6 in Coquimbo, Chile was felt with intensity III-IV in the area(s) of Coquimbo, Chile at La Serena, Ovalle, and Vicuna.

 

O: 21JAN2019 20:27:34  33.9S   70.3W mb=4.8  ANSS   Puente Alto Chile            

P: 23JAN2019 113115    32.0S   67.0W 4.0-5.7 ABCAA  Central Chile              

 

NEIC reported this earthquake of M 4.8 in Central Chile was felt with intensity II-III in the area(s) of O'Higgins, Chile at Machali and Rancagua and in Santiago.

 

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

 

AFRICA AND EUROPE

 

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

 

SOUTHWEST PACIFIC

 

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

 

OCEAN RIDGES

 

O: 21JAN2019 08:18:05  31.0N   41.4W mb=4.9  ANSS   North Atlantic Ridge         

P: 20JAN2019 112819    31.0N   41.0W 4.0-5.6 AAAAA  No. Mid-Atlantic Ridge     

 

O: 22JAN2019 06:41:09  41.4N   29.2W mb=4.9  ANSS   Cruz das Flores Portugal

 

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: 21JAN2019 11:30:35  29.0N  141.9E mb=4.7  ANSS   N of Chichi-shima Japan      

P: 20JAN2019 112828    34.0N  143.0E 4.0-5.8 ACAAA  So. of Honshu              

 

U.S./CANADA*

 

WESTERN U.S./CANADA

 

CALIFORNIA

 

O: 22JAN2019 01:50:34  32.9N  115.5W ml=3.1  ANSS   SSE of Brawley CA            

P: 15JAN2019 112825    32.9N  116.4W 2.5-4.6 CAAAA  So. California             

 

NEIC reported this earthquake of M 3.1 in Southern California was felt with intensity II-III in the area(s) of Brawley, Imperial, El Cajon, Moreno Valley and Hawthorne, California.

 

O: 21JAN2019 09:13:30  34.0N  118.4W ml=2.1  ANSS   NNW of Inglewood CA          

P: 21JAN2019 113011    34.0N  118.7W 2.5-4.6 AAAAA  So. California             

 

O: 22JAN2019 04:31:29  34.1N  117.3W ml=2.4  ANSS   San Bernardino CA            

P: 19JAN2019 112826    35.0N  117.7W 2.5-4.6 BAAAA  So. California             

 

O: 22JAN2019 05:25:04  36.0N  121.0W md=2.0  ANSS   San Ardo CA                  

P: 17JAN2019 112808    37.7N  121.7W 2.5-4.6 BBAAA  Central California         

 

O: 21JAN2019 14:24:38  36.1N  117.6W ml=2.0  ANSS   Coso Junction CA             

P: 19JAN2019 112826    35.0N  117.7W 2.5-4.6 ABAAA  So. California             

 

O: 21JAN2019 18:22:36  37.6N  118.8W ml=3.0  ANSS   Mammoth Lakes CA             

P: 23JAN2019 112986    37.7N  118.7W 2.5-4.7 AAAAA  California/Nevada area     

 

O: 21JAN2019 16:19:18  39.5N  123.4W md=2.7  ANSS   NNE of Brooktrails CA        

P: 19JAN2019 112808    39.7N  123.7W 2.5-4.6 AAAAA  Central California         

 

ALASKA

 

O: 22JAN2019 04:43:19  58.3N  155.4W mw=5.2  ANSS   Alaska Peninsula             

P: 25JAN2019 113074    60.1N  153.4W 3.2-5.0 BBAAA  Central Alaska             

 

O: 22JAN2019 00:45:32  59.8N  153.2W ml=3.0  ANSS   Southern Alaska              

P: 25JAN2019 113074    60.1N  153.4W 3.2-5.0 BAAAA  Central Alaska             

 

NEIC reported this earthquake of M 3.0 in Southern Alaska was felt with intensity II-III in the area(s) of Homer and Anchorage, Alaska.

 

O: 22JAN2019 02:25:15  69.6N  144.3W ml=3.2  ANSS   Northern Alaska              

P: 25JAN2019 113079    69.4N  145.5W 3.2-5.0 BAAAA  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: 21JAN2019 21:01:26  37.9N  113.7W ml=2.5  ANSS   N of Enterprise Utah         

P: 19JAN2019 112832    38.3N  112.2W 2.0-4.1 AABAA  Utah area                  

P: 19JAN2019 112832    38.7N  112.6W 2.0-4.3 AAAAA  Utah area                  

 

EASTERN U.S./CANADA

 

No earthquakes of M>=1 were located in the Eastern U.S. or Canada today.

 

HAWAII

 

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