Northern California Seismicity Report for the week ending Feb 22, 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

• 11 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 microearthquake of magnitude 3.0, 10 miles WNW of Los Banos, CA at 03:40 AM UTC Friday, 02 16, 2001 (07:40 PM PST Thursday, Feb 15, 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 microearthquake of magnitude 3.0, 10 miles WNW of Los Banos, CA at 03:40 AM UTC Friday, 02 16, 2001 (07:40 PM PST Thursday, Feb 15, 2001).

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

The largest event to occur this week in this region was an earthquake of magnitude 1.6, 11 miles WSW of Toms Place, CA at 06:31 AM UTC Friday, 02 16, 2001 (10:31 PM PST Thursday, Feb 15, 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 FEB 16 0340 32.80 37  5.39 121  1.82  7.42 58 .10  .3  .5 ORT    3.0D 141  9 NN
2001 FEB 16 0341 48.65 37  7.57 121  0.46  0.43 32 .32  .712.0 JQN  # 2.0D 107 10 WW
2001 FEB 16 0624 52.63 37  6.76 121  0.59 11.51 54 .13  .2  .5 JQN    2.4D  84  9 NN
2001 FEB 16 0650 31.52 37  5.31 121  2.12  7.97 51 .08  .2  .5 ORT    2.4D 137  9 NN
2001 FEB 19 0438 16.03 37 35.51 122 24.86  9.56 67 .04  .1  .3 SFP    2.3D  59  7 NN
 
2001 FEB 20 0609  6.54 40 29.48 124 12.21 20.85 11 .03  .6  .3 EUR    2.2D 140 11 NN
2001 FEB 20 1603 54.00 38 25.36 122 12.58  8.80 21 .04  .2  .4 GVL    2.1D 132  4 NN
2001 FEB 20 1630 18.90 40 16.80 123 49.19 28.40 20 .07  .2  .6 MEN    2.6D  66 10 NN
2001 FEB 21 0055 12.43 35 53.66 120  8.86 18.57 16 .05  .3  .9 COA    2.2D  91 15 WW
2001 FEB 21 2109 33.65 40 36.46 122 22.51 17.38  9 .08  .6 1.0 SHA    2.3D 148 14 WW
 
2001 FEB 21 2319 11.43 40 38.21 122 23.95 22.59 13 .10  .4  .6 SHA    2.7L  78 11 WW