COMMEMORATING 25 YEARS SINCE LANDERS, CALIFORNIA EARTHQUAKE (M 7.8)

 

EARTHQUAKE SUMMARY FOR JUNE 27, 2017

 

It was a very quiet date in global seismicity today. The largest events of M 4.9 each were located in Hindu Kush, Afghanistan and in Halmahera, Indonesia. Neither of these was damaging and both were felt with light intensity. As often happens in mid-summer seismicity was on the increase in the central U.S. where light earthquakes of M 2.0-2.1 occurred in Illinois and Arkansas as well as the ongoing seismicity in Oklahoma and Kansas. The minor swarm in the Truckee area of Northern California continued at a reduced level. A second minor swarm including an M 2.5 occurred near Landers, California marking 25 years since an M 7.8 at that epicenter.

 

June 28, 2017 is the 25th anniversary of an earthquake of M 7.8 in Southern California which occurred June 28, 1992. The following excerpt from the history section of this report describes that event:

 

" 6 28 11 57 35 1992  34.190 -116.540  10 7.8   So. California

 

The largest earthquake in California in 40 years, this event killed one at Yucca Valley and two others by heart attacks. More than 400 were injured.  Considerable damage occurred to buildings (bowling alley, residences, stores) in the Landers and Yucca Valley area. The maximum intensity of this earthquake was IX. It apparently triggered a second strong event several hours later in  the Big Bear area east of Los Angeles. Estimated cost was $92 million U.S. dollars. Felt in Utah, Arizona, New Mexico, Colorado, Nevada. Surface faulting was observed in the Barstow and Joshua Tree area with more than 5 meters  horizontal displacement and up to 1.0 meters vertical displacement. Seiche was observed from Washington, Colorado and Texas." (June 28, 2016)

 

The author was working in Colorado at the time of this earthquake. Personal recollection of that Sunday? morning may be of interest to readers. It was a hot morning and sleep was fitful. About 6 o'clock I was awakened by the howling of a local dog (Ransom by name) who had made a stand outside my bedroom window. I couldn't get back to sleep because of the  incessant howling, barking and whining Ransom was making. He had never done this before in the years we had been neighbors. So eventually I got up and tried to calm him down, which seemed to work. Because of the heat and disruption I couldn't get back to sleep so I turned on the television and caught the first reports of a major earthquake in southern California. Surface waves from this event would have arrived about the time Ransom started his outburst and major seiche was observed in the area where I was living. I speculate Ransom felt the local effects and was frightened having not felt this before, and needed to tell the world about it, and my bedroom was right next door. It was at the time when automatic web data was just beginning. Initial locations gave the location near Baker, California, a small hamlet in the California Desert which few had ever heard of. But at first, the quake was known as the Baker quake only later to be designated as the Landers earthquake after a somewhat larger town near the epicenter. We used to kid James Lander, founder of the National Earthquake Information Center (NEIC) that he finally had an earthquake named after him (this was not the case but the kidding was in fun anyway).

 

A minor swarm of earthquakes occurred today in the Yucca Valley/Landers area within about 10 km of the epicenter of June 28, 1992 event. The largest of these was M 2.5 within about 10 km of the epicenter of the 1992 event but was not

felt in this remote area. The area experienced a long period of quiet following the M 7.8 in 1992. The last earthquake of M>=2.5 within about 20 km of the  1992 mainshock occurred as an M 3.0 on April 7, 2017 and prior to that an M 3.5 on June 16, 2016 and an M 2.7 on August 3, 2015, the only three such earthquakes  in the past two years in the area. Statistically stronger aftershocks tend to occur about the same time of year, probably due to climate effects. The largest aftershock since 2000 was the M 3.5 in 2016. Forecast 108422 had expected this activity was likely at the end of June.

 

 

O: 27JUN2017 01:00:16  34.3N  116.4W ml=2.0  ANSS   Yucca Valley CA

O: 27JUN2017 01:24:43  34.3N  116.4W ml=2.5  ANSS   Yucca Valley CA

O: 28JUN2017 00:34:13  34.3N  116.5W ml=2.1  ANSS   Yucca Valley CA

O: 28JUN2017 00:34:13  34.3N  116.5W ML=2.1  EMSC   SOUTHERN CALIFORNIA          

P: 23JUN2017 108422    34.3N  116.5W 2.5-4.6 BAAAA  So. California             

 

The strongest earthquake in the U.S. or Canada today occurred within about 45 minutes of local solar noon in the Fox Islands, Aleutians, Alaska with M 4.0. This event was not reported felt. An M 5.8 hit near this epicenter on May 24 and this is probably an aftershock of that earthquake. Forecast 108489 had  expected today's event was likely around June 28.

 

O: 27JUN2017 23:45:26  53.2N  166.7W ML=4.0  EMSC   FOX ISLANDS, ALEUTIAN ISLANDS

P: 28JUN2017 108489    52.5N  166.5W 3.5-4.9 AAAAA  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: 28JUN2017 03:50:41  36.6N   70.9E mb=4.9  EMSC   HINDU KUSH REGION, AFGHANISTAN

P: 27JUN2017 108396    36.0N   72.0E 3.8-5.2 AAAAA  Hindu Kush/Pakistan        

 

O: 27JUN2017 23:10:36  41.7N   72.7E mb=3.9  EMSC   KYRGYZSTAN                   

P: 30JUN2017 108453    41.0N   73.0E 4.0-5.4 BAAAA  Kirgizstan/Xinjiang        

 

O: 28JUN2017 00:57:35  52.7N  160.6E mb=4.0  EMSC   OFF EAST COAST OF KAMCHATKA  

P: 27JUN2017 108488    52.0N  161.0E 4.0-5.5 AAAAA  E. of Kamchatka            

 

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

 

INDONESIA AND PHILIPPINES

 

O: 27JUN2017 14:55:30   1.4N  126.8E mb=4.9  EMSC   MOLUCCA SEA                  

O: 27JUN2017 14:55:29  01.5N  126.8E MS=5.1  BMG  Felt with intensity III

P: 26JUN2017 108301     2.0N  128.0E 4.0-5.6 AAAAA  Halmahera                  

 

BMG reported this earthquake was felt with intensity III in Ternate, Jailolo and II in Tobelo, Halmahera, Indonesia.

 

CENTRAL AND SOUTH AMERICA

 

O: 27JUN2017 19:14     17.2S   69.9W mb=3.5  IGP    W of Capaso-Puno, Peru.      

P: 25JUN2017 108531    17.0S   69.0W 4.0-5.6 AAAAA  So. Peru/Bolivia           

 

O: 27JUN2017 22:13:47   4.3S   80.0W mb=4.6  EMSC   PERU-ECUADOR BORDER REGION   

P: 25JUN2017 108311     4.0S   80.0W 4.0-5.4 AAAAA  Ecuador                    

 

O: 27JUN2017 13:38:44  19.9S   69.2W ML=4.0  EMSC   TARAPACA, CHILE              

P: 27JUN2017 108540    21.0S   69.0W 4.0-5.7 ABAAA  Coast No. Chile            

 

O: 28JUN2017 00:44:40  28.0S   66.6W mb=4.6  EMSC   CATAMARCA, ARGENTINA         

P: 23JUN2017 108538    28.0S   67.0W 4.0-5.4 BAAAA  Argentina                  

 

O: 27JUN2017 03:18:54  14.5N   92.0W ML=4.2  UNAM  l SURESTE de CD HIDALGO, CHIS *

P: 25JUN2017 108336    14.0N   92.0W 3.5-5.5 AAAAA  Guatemala                  

 

O: 27JUN2017 23:27:12  19.2N  105.1W ML=4.0  UNAM  l OESTE de CIHUATLAN, JAL *: 19

O: 27JUN2017 22:46:01  19.2N  105.1W ML=4.2  UNAM  l OESTE de CIHUATLAN, JAL *: 19

P: 26JUN2017 108343    19.0N  104.0W 3.5-5.2 AAAAA  Michoacan, Mexico          

 

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

 

AFRICA AND EUROPE

 

O: 28JUN2017 01:49:48  38.9N   26.3E mb=4.0  EMSC   NEAR THE COAST OF WESTERN TURK

P: 29JUN2017 108376    39.0N   27.0E 3.0-4.8 AAAAA  Aegean Sea                 

 

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

 

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

 

 

ZEALANDIA AND AUSTRALIA REGION

 

O: 28JUN2017 02:05:27  37.1S  179.0E MS=4.1  GEONET Felt with weak intensity

P: 25JUN2017 108556    38.0S  176.0E 3.0-4.5 BABAA  North Island, N.Z.         

 

GEONET reported this earthquake was felt with weak intensity in the area NE of Te Araroa, North Island, New Zealand. There was one felt report for weak shaking from the Wellington area which was probably incorrect.

 

O: 27JUN2017 14:26:15  39.4S  174.8E MS=4.1  GEONET Felt with light intensity

P: 24JUN2017 108556    39.0S  174.0E 3.0-4.5 AAAAA  North Island, N.Z.         

 

GEONET reported this earthquake was felt with light intensity west of Taumarunui and in southwestern North Island and northern South Island. Light to moderate intensity was reported throughout much of southern and western North Island and northern South Island. More than 118 people reported feeling this earthquake with weak or light intensity; 7 with moderate; 1 with strong and none with extreme shaking.

 

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: 28JUN2017 04:26:47  33.2N  115.9W ML=2.0  EMSC   SOUTHERN CALIFORNIA          

O: 27JUN2017 12:47:13  33.2N  116.1W ML=2.8  EMSC   SOUTHERN CALIFORNIA          

P: 30JUN2017 108420    33.7N  116.1W 2.5-4.4 BAAAA  So. California             

 

O: 27JUN2017 18:37:23  33.7N  117.9W ML=2.0  EMSC   GREATER LOS ANGELES AREA, CALI

O: 27JUN2017 19:35:07  33.9N  118.0W ML=2.0  EMSC   GREATER LOS ANGELES AREA, CALI

P: 29JUN2017 108423    33.9N  118.3W 2.5-4.5 AAAAA  So. California             

 

O: 28JUN2017 03:07:29  34.2N  117.0W ML=2.3  EMSC   SOUTHERN CALIFORNIA          

P: 26JUN2017 108422    33.9N  116.9W 2.5-4.5 AAAAA  So. California             

 

O: 27JUN2017 01:00:16  34.3N  116.4W ml=2.0  ANSS   Yucca Valley CA

O: 27JUN2017 01:24:43  34.3N  116.4W ml=2.5  ANSS   Yucca Valley CA

O: 28JUN2017 00:34:13  34.3N  116.5W ml=2.1  ANSS   Yucca Valley CA

O: 28JUN2017 00:34:13  34.3N  116.5W ML=2.1  EMSC   SOUTHERN CALIFORNIA          

P: 23JUN2017 108422    34.3N  116.5W 2.5-4.6 BAAAA  So. California             

 

O: 27JUN2017 16:28:06  34.6N  117.9W Ml=2.0  EMSC   SOUTHERN CALIFORNIA          

P: 29JUN2017 108423    33.9N  118.3W 2.5-4.5 AAAAA  So. California              

 

O: 28JUN2017 03:01:23  39.3N  122.8W MD=2.2  EMSC   NORTHERN CALIFORNIA          

P: 27JUN2017 108389    38.5N  122.7W 2.5-4.4 AAAAA  Central California         

 

O: 27JUN2017 12:43:42  39.5N  120.3W ML=2.3  EMSC   NORTHERN CALIFORNIA          

O: 27JUN2017 10:35:46  39.5N  120.3W ML=2.8  EMSC   NORTHERN CALIFORNIA          

O: 27JUN2017 12:14:10  39.5N  120.3W ML=3.2  EMSC   NORTHERN CALIFORNIA          

O: 27JUN2017 16:17:38  39.5N  120.4W ML=2.8  EMSC   NORTHERN CALIFORNIA          

P: 29JUN2017 108391    39.8N  120.6W 2.5-4.4 AAAAA  Central California         

 

NEIC reported these earthquakes on the California-Nevada border  were felt with intensity IV in Truckee, California and II-III in the area(s) of Foresthill, Nevada City, Kings Beach, Grass Valley, South Lake Tahoe, Placerville, Sierraville and Citrus Heights, California.

 

ALASKA

 

O: 27JUN2017 23:45:26  53.2N  166.7W ML=4.0  EMSC   FOX ISLANDS, ALEUTIAN ISLANDS

P: 28JUN2017 108489    52.5N  166.5W 3.5-4.9 AAAAA  Fox Islands, Aleutians      

 

O: 27JUN2017 19:47:14  59.7N  136.4W Ml=3.2  EMSC   SOUTHEASTERN ALASKA          

O: 27JUN2017 19:47:13  59.8N  136.6W ML=3.4  NRCA  106 km WNW of Haines

P: 25JUN2017 108501    59.0N  136.0W 3.0-4.6 AAAAA  Southeast Alaska           

 

O: 28JUN2017 04:46:12  61.3N  146.8W Ml=3.3  EMSC   SOUTHERN ALASKA              

P: 28JUN2017 108510    63.2N  145.5W 3.2-5.1 ABAAA  Central Alaska             

 

PACIFIC NORTHWESTERN U.S./WESTERN CANADA

 

O: 27JUN2017 20:05:12  47.2N  122.2W ML=2.2  EMSC   SEATTLE-TACOMA AREA, WASHINGTO

P: 29JUN2017 108480    47.5N  121.8W 2.0-4.0 AAAAA  Washington state, U.S.     

 

ROCKY MOUNTAINS REGION

 

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

 

EASTERN U.S./CANADA

 

O: 27JUN2017 15:44:33  36.4N   93.0W md=0.9  ANSS   NE of Harrison Arkansas

O: 27JUN2017 15:43:46  36.4N   93.0W md=2.0  ANSS   NNE of Harrison Arkansas

O: 27JUN2017 15:43:46  36.4N   93.0W MD=2.0  EMSC   ARKANSAS                     

P: 22JUN2017 108403    36.0N   93.0W 2.0-3.9 BAAAA  New Madrid area            

 

O: 27JUN2017 17:18:42  35.7N   97.4W mb=2.4  EMSC   OKLAHOMA                     

O: 27JUN2017 14:57:53  35.8N   96.7W mb=2.7  EMSC   OKLAHOMA                     

P: 27JUN2017 108429    35.0N   97.0W 2.0-3.9 AAAAA  Southern Plains            

 

NEIC reported this earthquake of M 2.7 in Oklahoma was felt with intensity II-III in the area(s) of Stroud, Oklahoma.

 

O: 27JUN2017 15:42:53  36.5N   99.0W mb=2.3  EMSC   OKLAHOMA                     

P: 26JUN2017 108430    37.0N   98.0W 2.0-3.9 AAAAA  Southern Plains            

 

O: 27JUN2017 16:01:34  37.8N   88.8W md=2.0  ANSS   Johnston City Illinois

O: 27JUN2017 16:01:34  37.8N   88.8W Md=2.1  EMSC   ILLINOIS                     

P: 27JUN2017 108405    38.0N   87.0W 2.0-4.1 AABAA  New Madrid area            

 

 

O: 27JUN2017 05:41:14  44.4N   70.2W ml=1.3  ANSS   NNE of Livermore Maine       

P: 29JUN2017 108460    44.0N   71.0W 2.0-4.3 AAAAA  New England                

P: 30JUN2017 108454    44.0N   70.0W 2.0-4.1 BAAAA  Maine                      

 

HAWAII

 

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