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 minor earthquake of magnitude 3.5, 5 miles WSW of Lake Pillsbury, CA at 11:51 PM UTC Wednesday, 05 24, 2000 (04:51 PM PDT Wednesday, May 24, 2000).
A swarm of earthquakes, all less tham M 3.5, continued in a small cluster near Pillsbury lake about 17 miles east of Willits. The cluster is on an unnamed fault parallel to and between the San Andreas fault to the west and the Bartlett Springs fault to the east. The largest events are of similar magnitude: M 3.0 on 5/19, M 3.3 and M 3.3 on 5/21, and M 3.5 on 5/24.
The largest event to occur this week in this region was a microearthquake of magnitude 2.9, 3 miles SSW of Gilroy, CA at 08:37 PM UTC Sunday, 05 21, 2000 (01:37 PM PDT Sunday, May 21, 2000).
The largest event to occur this week in this region was a microearthquake of magnitude 2.0, 7 miles W of Toms Place, CA at 09:46 PM UTC Tuesday, 05 23, 2000 (02:46 PM PDT Tuesday, May 23, 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 MAY 18 0120 55.44 39 24.17 123 4.48 5.84 28 .08 .2 1.2 BAR 2.0D 53 16 NN 2000 MAY 18 0208 50.91 39 23.65 123 3.45 0.02 44 .24 .2 2.2 BAR # 2.8D 58 16 NN 2000 MAY 18 0303 30.56 39 23.20 123 3.81 5.43 36 .08 .1 .9 BAR 2.3D 56 17 NN 2000 MAY 18 0553 45.02 39 23.15 123 3.71 5.81 30 .07 .2 1.0 BAR 2.2D 57 17 NN 2000 MAY 18 0949 9.87 39 23.00 123 3.02 1.22 28 .21 .3 9.3 BAR # 2.5D 58 16 WW 2000 MAY 18 1624 54.69 39 22.85 123 3.30 5.26 43 .12 .2 .8 BAR 3.1D 58 17 NN 2000 MAY 18 1657 45.68 39 23.36 123 3.46 3.29 21 .07 .2 2.0 BAR 2.1D 58 16 NN 2000 MAY 18 1841 2.49 39 23.17 123 3.91 5.55 30 .07 .1 1.1 BAR 2.2D 56 17 NN 2000 MAY 18 2146 23.00 36 49.62 121 32.90 5.13 50 .10 .2 .3 SJB 2.5D 26 3 NN 2000 MAY 19 0041 54.49 36 49.53 121 33.04 6.66 53 .08 .2 .3 SJB 2.2D 26 3 NN 2000 MAY 19 1213 36.22 39 23.56 123 4.10 6.74 41 .08 .1 .6 BAR 2.9D 56 16 NN 2000 MAY 19 1301 35.34 36 49.67 121 33.22 6.03 47 .09 .2 .4 SJB 2.8D 25 4 NN 2000 MAY 20 0212 57.17 39 23.41 123 3.63 5.77 35 .09 .1 .9 BAR 2.7D 51 16 NN 2000 MAY 20 0216 51.81 39 23.42 123 3.59 5.57 20 .08 .3 1.2 BAR 2.2D 57 16 WW 2000 MAY 20 0634 54.21 39 23.52 123 4.04 3.51 12 .08 .3 2.8 BAR 2.1D 93 16 WW 2000 MAY 20 0723 14.32 36 49.53 121 32.80 5.29 52 .10 .2 .3 SJB 2.7D 26 3 NN 2000 MAY 20 1458 27.44 39 18.54 122 49.50 4.03 13 .02 .3 1.8 BAR 2.2D 105 19 WW 2000 MAY 20 1953 54.19 38 49.46 122 48.36 4.88 40 .05 .1 .4 GEY 2.6D 32 2 NN 2000 MAY 21 0014 29.49 39 23.17 123 3.75 5.29 26 .08 .2 1.1 BAR 2.0D 57 17 NN 2000 MAY 21 0507 2.82 37 46.42 122 35.33 6.62 49 .04 .2 .4 SFP 2.1D 167 8 NN 2000 MAY 21 0521 54.78 36 50.40 121 34.35 7.63 56 .09 .2 .3 SJB 2.8D 33 2 NN 2000 MAY 21 1004 31.87 39 23.10 123 3.34 6.58 40 .09 .2 .7 BAR 3.4D 57 16 NN 2000 MAY 21 1612 3.75 39 22.18 123 3.11 8.23 49 .15 .2 .6 BAR 3.5D 63 17 NN 2000 MAY 21 1934 37.48 39 22.32 123 3.22 6.78 36 .09 .1 .7 BAR 3.0D 57 17 NN 2000 MAY 21 2037 25.78 36 57.95 121 35.74 7.60 76 .15 .2 .4 SAR 2.9D 26 1 NN 2000 MAY 22 1246 30.36 40 38.17 123 50.30 21.54 24 .06 .2 .2 EUR 3.2D 92 14 NN 2000 MAY 22 1321 51.00 38 46.45 122 43.28 2.04 15 .05 .2 .3 GEY 2.0D 58 0 WW 2000 MAY 22 1944 44.61 36 49.42 121 32.67 5.22 50 .10 .2 .3 SJB 2.3D 37 3 NN 2000 MAY 22 2010 13.33 36 0.84 120 34.27 5.26 50 .07 .2 .2 SLA 2.7D 44 5 NN 2000 MAY 22 2013 9.43 36 0.74 120 34.38 5.18 39 .06 .2 .2 SLA 2.3D 86 5 NN 2000 MAY 23 1235 6.85 37 42.68 122 6.37 6.04 67 .09 .1 .2 HAY 2.6D 67 2 NN 2000 MAY 23 2146 2.64 37 33.43 118 48.41 5.60 25 .06 .4 .5 MOR 2.0D 147 4 WW 2000 MAY 24 2251 3.40 39 22.27 123 3.30 4.49 25 .08 .2 1.6 BAR 2.4D 57 17 WW 2000 MAY 24 2351 19.86 39 22.50 123 2.78 5.59 44 .12 .2 .8 BAR 3.5L 58 17 WW
