SOUTHERN CALIFORNIA SEISMOGRAPHIC NETWORK A Cooperative Project of Caltech and the U.S. Geological Survey February 19, 1998 Weekly Earthquake Report for Southern California ------------------------------------------------ February 12 - 18, 1998 Prepared by: Kate Hutton, 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. -------------------------------- ****************************************************************** As many of you know by now, the U.S. Geological Survey in Menlo Park, the office which originates the Northern California Earthquake Report, is planning to discontinue the paper (and faxed) Report at the end of February 1998. We plan to follow their initiative. As of the beginning of March 1998, we will be replacing our weekly 'treeware' product with a Web site, which will include the same map, table, and commentary as the current Weekly Report, plus other features. The Web page will be updated more often than once per week. You will be able to get to this web site form the following home pages: http://www.gps.caltech.edu/seismo/ http://www-socal.wr.usgs.gov/ http://www.scecdc.scec.org/ http://www.trinet.org/ (The last one does not exist yet, but will soon.) There will be no paper copy or usenet distribution. We hope we are giving our Users sufficient notice to obtain World Wide Web access for themselves. At minimum, most public libraries now provide Web access, along with the capability to print copies of Web pages. ****************************************************************** This week's Report covers the time period from midnight Thursday morning, February 12, Universal Time (ie. UTC), to midnight Wednesday night, February 18, Universal Time. In local time, the period of coverage is from 4 p.m., February 11, Pacific Standard Time, to 4 p.m., February 18, Pacific Standard Time. We detected 188 earthquakes during the seven-day period covered. Note that we have decided to extend the production of the Weekly Report through February, or until we have thoroughly tested some of our newest software. We had another quiet week this week. There were no quakes above M3 in our coverage area. There was a M3.0 last Thursday in the Coalinga area, which is in the Menlo Park coverage area, and there was a M4.9 at 6:29 Wednesday morning, located in Mexico 53 miles SSW of the Imperial Valley town of Mexicali. The latter location is just off the southern edge of our Weekly Report map. The Baja quake was felt slightly in the San Diego area. 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 ------------------------------------------------------------- 2/12 6:23 am 36 14.9 120 16.0 3.0 9 mi. NE of Coalinga 2/12 8:15 am 33 8.0 117 22.4 2.2 4 mi. S of Oceanside 2/12 10:12 am 34 7.1 116 55.3 2.2 5 mi. WNW of Mt. San Gorgonio 2/12 10:49 am 32 56.7 115 43.3 2.0 8 mi. SW of Westmorland 2/12 11:28 am 34 16.2 119 7.1 2.2 6 mi. NE of Oxnard 2/13 2:39 am 35 5.7 118 18.9 2.3 7 mi. ESE of Tehachapi 2/13 10:13 am 33 58.8 117 12.9 2.2 5 mi. SSE of Loma Linda 2/13 10:30 am 32 12.0 115 45.2 2.6 35 mi. SSW of Calexico 2/13 1:48 pm 36 8.8 118 2.5 2.2 8 mi. NW of Coso Junction 2/13 5:40 pm 34 8.7 116 53.0 2.0 4 mi. NW of Mt. San Gorgonio 2/14 8:58 am 34 5.6 117 0.0 2.0 4 mi. NNE of Yucaipa 2/14 10:36 pm 36 2.2 120 39.0 2.6 15 mi. NW of Parkfield 2/15 1:26 am 33 53.3 118 44.1 2.0 8 mi. SSE of Pt. Dume 2/15 9:34 pm 32 45.5 115 30.8 2.2 3 mi. SE of El Centro 2/16 6:21 am 34 5.9 117 0.1 2.6 4 mi. NNE of Yucaipa 2/16 8:23 am 34 20.5 116 28.3 2.1 15 mi. N of Yucca Valley 2/17 11:10 am 33 4.5 114 57.1 2.5 32 mi. NW of Yuma, Arizona 2/18 3:47 am 32 6.9 116 26.7 2.5 46 mi. SE of San Ysidro 2/18 6:54 am 35 54.2 117 54.7 2.0 10 mi. SSE of Coso Junction 2/18 1:08 pm 34 33.9 119 9.4 2.0 9 mi. NNE of Ojai -------------------------------------------------------------