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
The largest event to occur this week in this region was a moderate earthquake of magnitude 5.2, 3 miles WSW of Yountville, CA at 08:36 AM UTC Sunday, 09 03, 2000 (01:36 AM PDT Sunday, Sep 03, 2000).
The largest event to occur this week in this region was a moderate earthquake of magnitude 5.2, 3 miles WSW of Yountville, CA at 08:36 AM UTC Sunday, 09 03, 2000 (01:36 AM PDT Sunday, Sep 03, 2000).
This earthquake was on an unmapped fault just west of the West Napa Fault. Its focal mechanism was the typical right-lateral strike-slip on a northwest striking fault. The quake produced a few small aftershocks reaching magnitude 2.4. It was felt throughout the northern Bay Area. Several people were injured, including a boy who was covered by fallen bricks. The earthquake was most strongly felt in the sedimentary basins like the Napa Valley, even though the epicenter was to the west under a mountain ridge. The highest intensity felt was Modified Mercalli VII, which includes effects like "difficult to stand, noticed by drivers of motor cars, weak chimneys broken, waves on ponds". The highest recorded acceleration was 33% of g (the force of gravity) at a station in the Napa Valley, a bit high for such a relatively small event.
The largest event to occur this week in this region was a minor earthquake of magnitude 3.1, 10 miles WSW of Toms Place, CA at 05:39 PM UTC Tuesday, 09 05, 2000 (10:39 AM PDT Tuesday, Sep 05, 2000).
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 2000 AUG 31 1031 15.85 37 32.73 118 26.52 9.11 31 .06 .2 .6 CHV 2.6D 86 0 NN 2000 SEP 1 1929 18.59 38 47.62 122 46.13 1.68 38 .06 .1 .3 GEY 2.5D 40 3 NN 2000 SEP 1 2000 51.93 36 1.16 121 30.43 2.13 56 .05 .2 1.1 SUR 2.3D 169 19 NN 2000 SEP 2 0800 30.44 37 59.32 122 3.33 15.63 58 .12 .2 .3 CON 2.4D 73 7 NN 2000 SEP 2 0805 52.61 39 20.95 123 1.85 8.85 35 .06 .2 .7 BAR 2.1D 58 18 NN 2000 SEP 2 2158 47.87 37 59.25 122 3.23 16.23 57 .13 .2 .3 CON 2.5D 73 7 NN 2000 SEP 2 2259 7.65 37 6.23 121 48.88 5.66 61 .09 .1 .3 LOM 2.9D 33 2 NN 2000 SEP 2 2318 14.38 37 6.16 121 48.96 5.52 55 .07 .1 .2 LOM 2.1D 33 2 NN 2000 SEP 3 0836 30.09 38 22.73 122 24.76 10.22 75 .17 .2 .4 NAP 5.2L 34 3 NN 2000 SEP 3 1344 9.69 37 35.74 118 51.91 8.12 35 .06 .2 .4 MOR 2.6D 94 2 NN 2000 SEP 3 2100 3.07 38 21.90 122 24.00 8.57 53 .11 .1 .3 NAP 2.3D 36 4 NN 2000 SEP 4 0143 8.48 39 21.48 123 2.52 8.34 47 .14 .2 .8 BAR 3.4D 57 18 WW 2000 SEP 4 0158 11.96 39 21.56 123 2.54 7.34 38 .07 .1 .8 BAR 2.3D 57 18 NN 2000 SEP 4 0427 1.18 36 39.33 121 16.46 5.45 55 .05 .1 .3 STN 2.2D 58 1 NN 2000 SEP 4 0536 5.20 39 21.47 123 2.40 9.34 48 .15 .2 .8 BAR 3.1D 48 18 NN 2000 SEP 4 0740 53.35 39 21.53 123 2.43 7.51 40 .10 .2 .8 BAR 2.2D 55 18 NN 2000 SEP 4 0946 48.55 38 22.83 122 24.12 6.38 52 .13 .1 .3 NAP 2.3D 44 4 NN 2000 SEP 4 2055 5.95 38 22.16 122 24.22 7.96 50 .11 .1 .3 NAP 2.5D 36 4 NN 2000 SEP 5 1200 25.20 38 48.14 122 46.01 1.68 20 .05 .2 .4 GEY 2.2D 56 2 WW 2000 SEP 5 1516 58.01 36 8.19 120 11.96 9.87 18 .07 .2 .4 COA 2.2D 170 12 WW 2000 SEP 5 1739 28.28 37 28.92 118 50.14 3.89 34 .06 .3 .9 MOR 3.1D 108 8 WW 2000 SEP 5 1806 52.95 37 28.95 118 50.11 3.87 30 .06 .2 1.0 MOR 3.1D 121 8 WW 2000 SEP 6 0227 18.51 38 22.24 122 23.77 5.36 39 .14 .2 .6 NAP 2.2D 36 4 WW 2000 SEP 6 0431 10.58 39 24.87 123 5.35 3.19 15 .10 .3 3.0 BAR 2.2D 88 16 WW 2000 SEP 6 1640 54.33 35 50.56 120 23.00 4.33 31 .05 .2 .3 GOL 2.5D 94 2 WW 2000 SEP 6 2318 0.76 36 0.70 121 31.14 12.86 22 .08 .4 1.2 SUR 2.1D 185 19 WW
