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- March 30, 1995
-
- Weekly Earthquake Report for Southern California
- ------------------------------------------------
- March 23 - 29, 1995
-
- 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 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, March 23, Pacific Standard Time, to midnight
- Wednesday night, March 29, 1995, Pacific Standard Time. We
- recorded 288 earthquakes of M1.0 or larger during the 7-day
- period covered.
- Although the total number of events this week was almost
- the same as past weeks, there were a number of felt and
- potentially feelable quakes. This variation is statistically
- expected, by the way. Rather like throwing five "heads" in a
- row while tossing coins; it's not common, but it does happen
- occasionally.
- Two Northridge aftershocks, a M3.0 on Friday evening and
- a M2.6 on Saturday afternoon, were both felt in the San Fernando
- area. The focal mechanism of the M3.0 was what we have come to
- expect from the Northridge aftershock zone: thrust on an east-
- striking fault. Also, a Lander/Big Bear aftershock (M2.8) was
- felt in the Big Bear area on Sunday afternoon.
- On Monday morning, a M3.3 was felt in the Desert Hot
- Springs area. This quake was located a few miles west of the
- Landers aftershock zone, and is not considered an aftershock.
- It occurred on a north-striking normal fault. We commonly see
- clusters of small, normal-faulting earthquakes in this region.
- They are thought to be associated with the many small normal
- faults of the Little San Bernardino Mountains.
- There were three other M3+ events that apparently went
- unnoticed by the public. These were: a M3.0 on Sunday afternoon
- in the Grapevine area, a M3.0 Landers aftershock (with the
- expected strike-slip mechanism) late Sunday night, and a M3.2
- just before noon on Tuesday, just south of the U.S./Mexican
- border.
- The table 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
- -------------------------------------------------------------
- 3/23 12:30 am 32 28.0 115 26.5 2.7 14 mi. SSE of Calexico
- 3/23 6:02 am 33 42.2 116 44.3 2.0 3 mi. SSW of Idyllwild
- 3/23 9:25 am 33 58.9 116 22.1 2.1 7 mi. E of Desert Hot
- Springs
- 3/23 5:53 pm 34 14.3 116 50.2 2.2 2 mi. SSE of Big Bear City
- 3/23 10:42 pm 32 45.2 115 26.6 2.2 6 mi. NE of Calexico
- 3/23 10:43 pm 32 44.5 115 26.1 2.4 "
- 3/23 10:44 pm 32 44.9 115 26.1 2.2 "
- 3/23 10:45 pm 32 44.3 115 26.0 2.3 "
- 3/24 4:17 am 34 24.6 116 28.4 2.2 20 mi. N of Yucca Valley
- 3/24 4:28 am 34 13.7 118 36.2 2.1 1 mi. N of Canoga Park
- 3/24 5:15 am 33 59.9 119 11.9 2.3 10 mi. S of Port Hueneme
- 3/24 2:23 pm 34 7.7 116 23.1 2.1 3 mi. E of Yucca Valley
- 3/24 3:00 pm 34 21.3 118 46.8 2.1 6 mi. NW of Simi Valley
- 3/24 6:10 pm 34 17.8 118 26.9 2.1 1 mi. NNW of San Fernando
- 3/24 6:58 pm 34 18.4 116 26.8 2.7 13 mi. N of Yucca Valley
- 3/24 7:30 pm 32 27.7 115 26.3 2.1 14 mi. SSE of Calexico
- 3/24 8:08 pm 34 18.0 118 27.3 3.0 1 mi. NW of San Fernando
- FELT
- 3/24 8:24 pm 34 17.8 118 27.0 2.5 "
- 3/24 9:47 pm 35 1.8 118 8.0 2.1 2 mi. SE of Mojave
- 3/24 10:33 pm 34 17.7 118 26.7 2.4 Under San Fernando
- 3/25 12:00 am 33 54.1 118 18.4 2.0 Gardena area
- 3/25 7:49 am 34 47.2 116 17.8 2.0 35 mi. SSW of Baker
- 3/25 1:40 pm 34 16.2 118 27.3 2.6 1 mi. SW of San Fernando
- FELT
- 3/25 3:37 pm 33 18.8 116 18.5 2.4 5 mi. NE of Borrego
- Springs
- 3/25 5:54 pm 34 18.1 118 26.5 2.4 1 mi. N of San Fernando
- 3/25 10:46 pm 32 29.1 115 28.3 2.0 12 mi. S of Calexico
- 3/26 5:17 am 32 31.7 116 10.6 2.0 17 mi. SW of Ocotillo
- 3/26 6:41 am 32 29.6 115 27.5 2.0 12 mi. S of Calexico
- 3/26 8:49 am 34 9.2 116 25.6 2.0 2 mi. NNE of Yucca Valley
- 3/26 12:49 pm 35 2.1 119 1.0 3.0 3 mi. WNW of the I5/99
- interchange
- 3/26 12:49 pm 34 58.7 119 0.0 2.5 "
- 3/26 1:18 pm 35 0.1 119 0.8 2.3 "
- 3/26 2:01 pm 34 19.1 116 45.6 2.8 6 mi. NE of Big Bear City
- FELT
- 3/26 4:23 pm 35 50.8 117 37.7 2.0 15 mi. N of Ridgecrest
- 3/26 11:11 pm 34 37.6 116 38.7 3.0 21 mi. NE of Lucerne
- Valley
- 3/27 7:34 am 33 21.3 116 25.9 2.2 7 mi. NNW of Borrego
- Springs
- 3/27 8:26 am 33 59.3 116 26.5 3.3 3 mi. ENE of Desert Hot
- Springs; FELT
- 3/27 8:42 am 34 21.3 118 41.9 2.0 5 mi. N of Simi Valley
- 3/27 12:15 pm 32 23.9 115 28.1 2.4 18 mi. S of Calexico
- 3/27 1:17 pm 34 18.9 116 45.3 2.1 6 mi. ENE of Big Bear
- City
- 3/27 2:13 pm 34 27.5 116 31.3 2.5 23 mi. N of Yucca Valley
- 3/27 3:26 pm 34 1.2 118 59.4 2.1 3 mi. WSW of Leo Carrillo
- State Beach
- 3/27 5:26 pm 33 21.3 116 25.8 2.2 7 mi. NNW of Borrego
- Springs
- 3/27 9:36 pm 35 19.1 119 24.8 2.9 12 mi. N of Taft
- 3/27 10:38 pm 33 35.3 116 37.4 2.2 3 mi. NE of Anza
- 3/27 11:07 pm 33 20.9 116 25.6 2.3 7 mi. NNW of Borrego
- Springs
- 3/28 8:37 am 32 26.0 115 28.1 2.1 16 mi. S of Calexico
- 3/28 10:44 am 33 7.7 116 0.9 2.6 6 mi. E of Ocotillo Wells
- 3/28 11:13 am 32 29.4 115 28.4 3.2 12 mi. S of Calexico
- 3/28 6:03 pm 34 14.2 118 29.1 2.0 2 mi. E of Northridge
- 3/28 9:36 pm 33 25.9 119 0.2 2.0 4 mi. SE of Santa Barbara
- Is.
- 3/28 9:50 pm 33 20.7 116 15.3 2.0 9 mi. NE of Borrego
- Springs
- 3/29 12:32 am 35 21.1 117 32.9 2.4 19 mi. SSE of Ridgecrest
- 3/29 4:07 pm 33 43.8 118 39.9 2.0 14 mi. WSW of Palos
- Verdes Point
- 3/29 5:36 pm 32 28.4 115 27.0 2.1 13 mi. S of Calexico
- -------------------------------------------------------------