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 1:43:17 AM (PST) on Monday, December 15, 2025.
The magnitude 2.2 event occurred 4 km (3 miles) ESE of San Ramon, CA.
The hypocentral depth is 8 km ( 5 miles).


Magnitude 2.2 - duration magnitude (Md)
Time Monday, December 15, 2025 at 1:43:17 AM (PST)
Monday, December 15, 2025 at 9:43:17 (UTC)
Distance from San Ramon, CA - 4 km (3 miles) ESE (123 degrees)
Dublin, CA - 6 km (4 miles) N (359 degrees)
Blackhawk, CA - 7 km (5 miles) SSW (200 degrees)
Diablo, CA - 9 km (5 miles) SSE (167 degrees)
Danville, CA - 9 km (6 miles) SE (141 degrees)
Coordinates 37 deg. 45.5 min. N (37.759N), 121 deg. 56.2 min. W (121.937W)
Depth 8.03 km (5.00 miles)
Quality Good
Location Quality Parameters Nst=31, Nph=31, Dmin=11.6 km, Rmss=0.07 sec, Erho=0.18 km, Erzz=0.469999999 km, Gp=56 degrees
Event ID# nc75280216
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