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@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
The largest event to occur this week in this region was a microearthquake of magnitude 2.9 8 miles WSW of Toms Place, CA at 01:57 PM UTC Monday, Sep 13, 1999 (06:57 AM PDT Monday, Sep 13, 1999).
The largest event to occur this week in this region was a microearthquake of magnitude 2.4 5 miles WNW of San Juan Bautista, CA at 11:34 AM UTC Monday, Sep 13, 1999 (04:34 AM PDT Monday, Sep 13, 1999).
The largest event to occur this week in this region was a microearthquake of magnitude 2.9 8 miles WSW of Toms Place, CA at 01:57 PM UTC Monday, Sep 13, 1999 (06:57 AM PDT Monday, Sep 13, 1999).
The low level of seismicity in the Long Valley region reflects the loss on Monday, 9/13/99, of telemetry from 16 of the 24 seismic stations that we operate in this region. The telemetry to Menlo Park utilizes the FAA microwave system, which is under repair. We expect telemetry to be restored 9/17/99.
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 N RMS ERH ERZ LOC PREF YR MON DA HRMN SEC DEG MIN DEG MIN KM RD S SEC KM KM REMKS MAG 99 SEP 9 1107 33.21 37 31.59 118 48.23 7.35 31 .04 .2 .6 MOR 2.1D 99 SEP 9 1149 17.99 36 50.65 121 34.11 4.86 53 .12 .2 .3 SJB 2.3D 99 SEP 9 1615 7.44 37 31.70 118 48.13 7.05 31 .04 .2 .5 MOR 2.1D 99 SEP 10 1602 25.67 40 32.80 122 14.28 22.97 16 .06 .4 .8 SHA 2.6D 99 SEP 10 1732 38.54 37 36.11 118 54.80 7.49 26 .04 .2 .4 SHE 2.2D 99 SEP 11 645 51.96 39 7.20 123 29.40 5.80 23 .09 .2 .8 PAR 2.1D 99 SEP 11 738 58.52 40 32.94 122 14.35 22.14 16 .05 .3 .7 SHA 2.4D 99 SEP 11 1701 49.83 40 33.13 122 14.16 23.15 17 .07 .3 .8 SHA 2.6D 99 SEP 11 2151 35.04 40 17.53 121 23.42 5.17 16 .03 .3 .8 ALM 2.4D 99 SEP 13 1134 58.51 36 52.61 121 36.63 12.16 45 .08 .2 .3 SJB 2.4D 99 SEP 13 1357 42.13 37 32.13 118 48.85 5.19 29 .05 .2 .5 MOR 2.9D 99 SEP 14 1658 22.41 38 48.19 122 46.30 0.08 15 .38 .9 2.0 GEY # 2.1D
