May 5, 1994 Weekly Earthquake Report for Southern California ------------------------------------------------ April 28 - May 4, 1994 Prepared by: Nick Scheckel & Debbie Wells, Seismological Laboratory (kate@bombay.gps.caltech.edu) Lucy Jones, U.S. Geological Survey California Institute of Technology This document is a commentary on current seismic activity. The earthquakes discussed have been detected and processed automatically. All epicenters and magnitudes have been reviewed to exclude obvious blunders; however, they must still be considered preliminary. For further information, please contact the authors or the Caltech Public Relations Office at 818-395-6326. For daily updates, call our Earthquake Information Hotline: 818-395-6977. -------------------------------- This week's Report covers the time period from midnight Thursday morning, April 28, Pacific Daylight Time, to midnight Wednesday night, May 5, Pacific Daylight Time. We recorded 388 earthquakes this week. Three events were felt, with the week's largest quake, a M3.6 Northridge aftershock on Tuesday night. There was one other Northridge aftershock that was felt (a M3.2 on Monday) and a Landers/Big Bear aftershock (M2.9) felt on Tuesday afternoon. All three events were expected aftershocks. No significant earthquakes occurred in other parts of southern California. The table lists the quakes 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 Daylight Time listed. Table 1 ------- Date Time N Lat. W Long. Mag ------------------------------------------------------------- 4/28 2:11 am 35 29.9 120 4.2 2.0 10 mi. NNW of Simmler 4/28 9:00 am 34 29.8 116 30.8 2.1 26 mi. N of Yucca Valley 4/28 9:35 am 33 57.2 116 19.7 2.9 9 mi. E of Desert Hot Springs 4/28 10:04 am 34 20.5 116 27.7 2.8 15 mi. N of Yucca Valley 4/28 3:19 pm 34 15.5 118 42.2 2.4 1 mi. SSE of Simi Valley 4/28 5:12 pm 35 59.1 119 48.2 2.3 33 mi. ENE of Cholame 4/28 5:17 pm 34 19.8 118 27.4 2.3 3 mi. NNW of San Fernando 4/28 9:46 pm 34 27.8 116 29.4 2.1 23 mi. N of Yucca Valley 4/29 5:40 am 34 20.2 116 28.2 2.2 15 mi. N of Yucca Valley 4/29 5:48 am 34 14.6 118 45.2 2.0 3 mi. SW of Simi Valley 4/29 6:14 am 36 7.5 118 10.2 2.2 12 mi. W of south end of Haiwee Reservoir 4/29 11:57 am 34 16.7 118 35.3 2.3 4 mi. NW of Northridge 4/30 3:15 am 34 26.3 120 44.9 2.3 11 mi. SSW of Pt. Arguello 4/30 8:59 pm 34 19.1 118 35.1 2.2 5 mi. SW of Newhall 5/1 7:04 am 34 38.0 116 33.4 2.3 25 mi. ENE of Lucerne Valley 5/1 7:08 am 34 16.1 118 36.1 2.5 4 mi. N of Canoga Park 5/1 11:23 am 33 53.6 117 3.3 2.2 5 mi. WSW of Beaumont 5/1 6:32 pm 33 10.5 116 6.7 2.1 2 mi. NNE of Ocotillo Wells 5/1 8:39 pm 34 58.8 116 57.0 2.0 7 mi. NNE of Barstow 5/1 9:04 pm 34 7.4 116 23.4 2.2 3 mi. E of Yucca Valley 5/2 6:14 am 34 18.2 118 32.4 2.1 4 mi. N of Northridge 5/2 7:44 am 34 59.3 119 20.4 2.7 12 mi. SSE of Taft 5/2 11:02 am 34 15.3 118 28.9 2.1 3 mi. SW of San Fernando 5/2 12:46 pm 33 56.0 117 3.4 2.0 4 mi. W of Beaumont 5/2 2:00 pm 34 22.5 118 38.4 2.0 4 mi. SW of Magic Mtn. 5/2 3:40 pm 34 14.9 118 28.2 2.2 2 mi. SW of San Fernando 5/2 5:30 pm 34 10.8 118 34.0 3.2 2 mi. ESE of Canoga Park; FELT 5/2 7:17 pm 34 2.1 116 18.9 2.4 9 mi. SE of Yucca Valley 5/2 11:34 pm 34 15.3 118 35.4 2.0 3 mi. NNE of Canoga Park 5/3 2:21 am 32 43.7 115 29.9 2.2 4 mi. N of Calexico 5/3 5:25 am 35 0.6 116 57.6 2.3 9 mi. NNE of Barstow 5/3 7:20 am 34 19.6 118 31.5 2.0 3 mi. S of Newhall 5/3 8:11 am 34 21.9 118 32.0 2.4 1 mi. SSW of Newhall 5/3 10:08 am 34 35.7 116 37.1 2.4 21 mi. ENE of Lucerne Valley 5/3 11:46 am 34 18.0 118 24.0 2.0 2 mi. ENE of San Fernando 5/3 3:13 pm 34 15.0 118 28.4 2.0 2 mi. SW of San Fernando 5/3 3:49 pm 34 8.2 116 50.2 2.8 2 mi. NNW of Mt. San Gorgonio; FELT 5/3 5:06 pm 35 7.1 118 35.5 2.0 8 mi. W of Tehachapi 5/3 5:20 pm 34 25.0 116 28.5 2.0 20 mi. N of Yucca Valley 5/3 6:48 pm 33 12.0 119 10.8 2.2 19 mi. SSW of Santa Barbara Is. (highest pt.) 5/3 7:40 pm 34 3.6 116 22.5 2.0 5 mi. SE of Yucca Valley 5/3 9:09 pm 34 19.6 118 27.7 3.6 3 mi. NNW of San Fernando; FELT 5/3 9:11 pm 34 19.7 118 28.1 2.0 3 mi. NNW of San Fernando 5/4 4:34 am 34 21.2 118 39.4 2.3 5 mi. NNE of Simi Valley 5/4 9:13 am 33 57.3 116 19.7 2.6 9 mi. E of Desert Hot Springs 5/4 9:24 am 34 27.8 116 30.3 2.1 24 mi. N of Yucca Valley 5/4 12:54 pm 34 31.2 116 31.5 2.2 28 mi. N of Yucca Valley 5/4 4:12 pm 35 34.2 118 20.7 2.0 8 mi. ESE of the town of Lake Isabella 5/4 4:47 pm 34 12.3 119 31.3 2.5 11 mi. N of Santa Cruz Is. (E end) ------------------------------------------------------------- Figure 1. A map of southern California showing the earthquakes recorded during the past week by the Caltech/USGS Seismic Network. Major faults are marked, as well as the metropolitan areas of Los Angeles (L.A.), Palm Springs (P.S.), San Diego (S.D.), and Santa Barbara (S.B.). The circles denote the earthquakes, the size of the circle indicating the magnitude.