Northern California Seismicity Report for the week ending Apr 19, 2001

This report provides a brief summary of earthquake activity recorded by the U.S. Geological Survey Northern California Seismic Network in Menlo Park and the University of California Berkeley Seismological Laboratory. It is automatically generated each Wednesday shortly after midnight, Universal time (UT). UT (ie., Greenwich Mean Time) is 8 hours ahead of PST or 7 hours ahead of PDT.

Because it is not possible to review all of the earthquakes before this report is generated, it may contain errors. Please report errors or provide suggestions and comments to ncsn@andreas.wr.usgs.gov

The report no longer includes maps showing earthquakes for the entire US or world. Those maps are now available from the U.S.G.S. National Earthquake Information Center. In addition, all earthquake data can be retrieved from the Northern California Earthquake Data Center.

Please note that some of the earthquake data in this report have been reviewed by seismic analysts. Consequently, the parameters that describe the hypocenter, magnitude, origin time, and solution statistics may differ slightly from the information contained on the real-time earthquake web page. The differences reflect revised arrival times at seismic stations and the analysts' decisions to include or exclude information from seismic stations.

The minimum magnitude ( M) values in the following bullets reflect the smallest earthquake which the network can routinely record within the region. During the previous seven-day period ending at midnight (UT) Wednesday, our seismic networks recorded

• 24 M >2.0 earthquakes in Northern and Central California (map) (within dashed polygon of figure).

The largest event to occur this week in this region was a minor earthquake of magnitude 3.5, 6 miles E of Watsonville, CA at 10:01 AM UTC Thursday, 04 12, 2001 (03:01 AM PDT Thursday, Apr 12, 2001).

• 17 M >1.2 earthquakes in the San Francisco Bay area (map).

The largest event to occur this week in this region was a minor earthquake of magnitude 3.5, 6 miles E of Watsonville, CA at 10:01 AM UTC Thursday, 04 12, 2001 (03:01 AM PDT Thursday, Apr 12, 2001).

• 8 M >1.2 earthquakes in the Long Valley region (map).

The largest event to occur this week in this region was a microearthquake of magnitude 2.1, 9 miles ENE of Mammoth Lakes, CA at 10:11 PM UTC Tuesday, 04 17, 2001 (03:11 PM PDT Tuesday, Apr 17, 2001).

The following table provides a listing of all M >2 earthquakes that occurred this week. An explanation of the entries in the table is available.

---ORIGIN TIME (UT)--- -LAT N-- --LON W-- DEPTH  N RMS ERH ERZ LOC    PREF AZ MIN S. PAGE   1
YEAR MON DA HRMN  SEC  DEG MIN  DEG  MIN    KM  RD SEC  KM  KM REMKS  MAG  GAP DS PF

2001 APR 12 1001 32.55 36 54.91 121 38.63  5.46 74 .11  .2  .3 SJB    3.5L  42  2 NN
2001 APR 13 0215 59.71 38 48.36 122 46.64  2.83 32 .05  .2  .3 GEY    2.3D  92  2 NN
2001 APR 13 0248 42.86 35 57.33 120 30.10 10.05 51 .07  .2  .2 MID    3.4L  45  0 NN
2001 APR 13 0834  8.90 38 50.02 122 49.22  2.03 44 .12  .2  .4 GEY    3.4L  56  4 NW
2001 APR 13 1423 37.42 37 36.47 118 53.14  4.42 32 .08  .2  .3 SHE    2.0D  92  1 NN
 
2001 APR 13 2104 47.49 36 53.23 121 24.86  8.00 68 .07  .1  .3 HOL    2.7D  31  4 NN
2001 APR 13 2134 40.96 39 29.81 122 56.76 10.88 24 .06  .2  .4 BAR    2.2D  48  1 NN
2001 APR 13 2350 58.41 38 52.94 123 40.07  9.64 27 .09  .8  .6 PAR    3.0D 233 15 NN
2001 APR 14 0334 24.58 37 12.09 119  0.72 15.10 55 .08  .2  .9 KAI    3.1D  70 24 NN
2001 APR 14 0754 28.26 40 18.07 123 23.41 26.33 22 .07  .3  .9 MEN    2.2D  51 19 NN
 
2001 APR 14 0840 11.77 39 29.47 122 56.26 15.07 58 .21  .2  .4 BAR    3.3L  48  1 NN
2001 APR 14 1307  3.64 36 18.50 120 52.92  5.26 44 .07  .2  .3 BIT    2.0D  49  4 NN
2001 APR 14 1456 28.74 37  5.05 121  2.17  6.01 53 .10  .2  .6 ORT    2.8D 133  8 WW
2001 APR 14 1607 44.01 37 59.84 121 51.05 18.41 64 .12  .2  .2 GRN    2.4D 124 15 NN
2001 APR 15 0156 55.61 36  1.53 120 34.59  5.22 33 .05  .2  .3 SLA    2.4D  87  5 WW
 
2001 APR 15 1024 37.69 36 55.20 121 39.98 10.89 78 .09  .1  .3 SJB    2.6D  47  1 NN
2001 APR 16 0808 44.74 36 14.71 120 48.08  7.32 54 .09  .2  .3 BIT    3.0D  74  3 NN
2001 APR 16 1437 58.60 38 48.45 122 48.56  2.22 38 .06  .1  .3 GEY    2.8D  32  1 NN
2001 APR 16 2105 52.16 39 48.62 122 52.14  1.77 31 .30  .416.6 SAC  # 3.2D  74 21 WW
2001 APR 17 0318 52.27 38 49.42 122 48.15  3.30 30 .06  .2  .6 GEY    2.4D  41  2 WW
 
2001 APR 17 0411 52.56 38 47.83 122 43.93  3.09 18 .07  .2  .6 GEY    2.2D  54  3 WW
2001 APR 17 2211 16.70 37 41.73 118 48.64  4.01 27 .07  .2  .5 EMO    2.1D  98  2 WW
2001 APR 18 0138  7.14 39 20.72 123 15.03  3.15 11 .06  .3 8.6 MAA -  2.0D  65 12 WW
2001 APR 18 0833  7.81 38 46.40 122 43.26  2.22 17 .05  .3  .4 GEY    2.0D  62  0 WW