SOUTHERN CALIFORNIA SEISMOGRAPHIC NETWORK A Cooperative Project of Caltech and the U.S. Geological Survey November 13, 1997 Weekly Earthquake Report for Southern California ------------------------------------------------ November 6 - 12, 1997 Prepared by: Nick Scheckel, Seismological Laboratory (kate@bombay.gps.caltech.edu) Lucy Jones, U. S. Geological Survey California Institute of Technology For further information, please contact the authors, or the Caltech Public Relations Office at 626-395-6327. For daily updates, call our Earthquake Information Hotline: 626-395-6977. -------------------------------- ***************************************************************** If you receive this Report by FAX and if you have recently had a change of AREA CODE, please notify us ASAP. We have no other way to know which fax numbers need to be changed!! Actually, if your area code is 818 and it HASN'T changed, it would be helpful to know that, too. ***************************************************************** This week's Report covers the time period from midnight Thursday morning, November 6, Universal Time (ie. UTC), to midnight Wednesday night, November 12, Universal Time. In local time, the period of coverage is from 4 p.m., November 5, Pacific Standard Time, to 4 p.m., November 12, Pacific Standard Time. We detected 183 earthquakes during the seven-day period covered. These Weekly Reports should not be used for archival purposes. Further data processing often changes the magnitudes slightly and, especially during times of high seismicity, sometimes changes the estimates of total seismicity. For the best earthquake catalog currently available, see: http://scec.gps.caltech.edu/catalog-search.html The largest earthquake of the week, a M3.8, occurred Wednesday evening in the northern region of the Landers aftershock zone (M7.3, June 28th, 1992). The earthquake resulted from strike- slip faulting like most Landers aftershocks. It was large enough to be felt but we received no calls. The only event (officially) felt was a M2.9 Tuesday morning offshore of Newport Beach. It was too small to constrain its focal mechanism. It occurred near the southern extension of the Palos Verdes fault that cuts across the peninsula of Palos Verdes. The only other M3.0 earthquake of the week was an aftershock to the Ridgecrest mainshock (M5.8, September 20th, 1995), it struck Friday morning. Table 1 lists the quakes this week that were M2.0 or larger in the central part of the coverage area. Times are local times; if you want Greenwich Mean Time, add 7 hrs to the Pacific Daylight Time or 8 hrs to the Pacific Standard Time listed. Table 1 ------- Date Time N Lat. W Long. Mag ------------------------------------------------------------- 11/ 5 5:13 pm 35 46.0 117 39.0 2.4 10 mi. N of Ridgecrest 11/ 5 6:10 pm 33 52.0 117 49.9 2.0 1 mi. SW of Yorba Linda 11/ 5 8:25 pm 32 33.9 118 7.3 2.2 21 mi. SE of San Clemente Is. (SE tip) 11/ 5 8:33 pm 34 58.7 116 57.0 3.8 7 mi. NNE of Barstow 11/ 5 9:34 pm 35 8.4 117 8.2 2.0 18 mi. NNW of Barstow 11/ 6 7:41 am 34 20.6 119 17.6 2.1 4 mi. N of Ventura 11/ 6 7:24 pm 33 49.2 115 33.4 2.2 4 mi. WSW of Eagle Mtn. 11/ 7 12:07 am 32 1.1 116 18.6 2.0 52 mi. SSW of Ocotillo 11/ 7 8:32 am 35 44.8 117 37.3 3.0 8 mi. NNE of Ridgecrest 11/ 7 10:43 pm 33 2.9 117 52.4 2.4 29 mi. SSW of Dana Point 11/ 7 11:24 pm 33 10.5 116 2.7 2.0 5 mi. ENE of Ocotillo Wells 11/ 8 4:15 am 35 56.5 119 50.3 2.2 29 mi. ENE of Cholame 11/ 8 8:30 am 32 16.1 115 13.4 2.9 31 mi. SSE of Calexico 11/ 8 11:49 am 33 55.5 120 19.0 2.3 7 mi. SSE of San Miguel Is. 11/ 8 8:20 pm 33 55.3 120 18.3 2.6 8 mi. SSE of San Miguel Is. 11/ 9 12:33 am 36 8.3 120 4.7 2.6 15 mi. E of Coalinga 11/ 9 3:12 am 34 10.4 116 49.9 2.1 5 mi. N of Mt. San Gorgonio 11/ 9 7:42 am 33 11.3 116 1.0 2.0 6 mi. SSW of Salton City 11/11 8:29 am 33 29.5 118 3.6 2.9 11 mi. SW of Newport Beach FELT 11/11 8:46 am 32 46.8 115 33.9 2.0 1 mi. SW of El Centro 11/11 12:09 pm 33 52.7 117 47.3 2.1 1 mi. ESE of Yorba Linda 11/12 6:41 am 34 1.3 116 19.5 2.1 7 mi. S of Joshua Tree 11/12 6:47 am 34 35.8 116 37.4 2.0 21 mi. ENE of Lucerne Valley 11/12 8:39 am 36 24.1 117 52.5 2.1 10 mi. NE of Olancha 11/12 8:48 am 36 22.2 118 4.9 2.0 7 mi. NW of Olancha 11/12 1:36 pm 36 6.9 120 5.8 2.6 14 mi. E of Coalinga -------------------------------------------------------------