Recent Earthquakes in California and Nevada


== PRELIMINARY EARTHQUAKE REPORT ==

U.S. Geological Survey, Menlo Park, California
U.C. Berkeley Seismological Laboratory, Berkeley, California


Version #0: This report supersedes any earlier reports of this event. This is a computer-generated message. This event has not yet been reviewed by a seismologist.

A micro earthquake occurred at 5:38:36 AM (PST) on Saturday, December 20, 2025.
The magnitude 1.3 event occurred 4 km (2 miles) SE of San Ramon, CA.
The hypocentral depth is 8 km ( 5 miles).


Magnitude 1.3 - duration magnitude (Md)
Time Saturday, December 20, 2025 at 5:38:36 AM (PST)
Saturday, December 20, 2025 at 13:38:36 (UTC)
Distance from San Ramon, CA - 4 km (2 miles) SE (140 degrees)
Dublin, CA - 6 km (4 miles) NNW (348 degrees)
Blackhawk, CA - 8 km (5 miles) SSW (206 degrees)
Diablo, CA - 9 km (6 miles) S (175 degrees)
Danville, CA - 9 km (6 miles) SSE (150 degrees)
Coordinates 37 deg. 45.1 min. N (37.752N), 121 deg. 56.9 min. W (121.949W)
Depth 7.72 km (4.80 miles)
Quality Fair
Location Quality Parameters Nst=6, Nph=6, Dmin=10.3 km, Rmss=0.04 sec, Erho=0.77 km, Erzz=1.78999996 km, Gp=205 degrees
Event ID# nc75283401
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For more information, see https://earthquake.usgs.gov

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