California earthquakes

M2.7 earthquake 7 km W of Cobb, California

A magnitude 2.7 earthquake struck 7 km W of Cobb, California on Wed, Dec 30, 1981, 10:29 AM PST (18:29 UTC), 0 km (0 mi) below the surface.

A larger quake followed: M3.5 16 km E of Lower Lake, California. This one was a foreshock.

Cobb forecastMore in California

Map

Where this earthquake was located, with the others nearby. Select one for its page.

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The earthquake

Magnitude
2.7 (md), micro
Local time
UTC
1981-12-30 18:29:11 UTC
Depth
0.4 km (0.3 mi), shallow
Epicenter
38.810° N, 122.808° W
Tsunami flag
No
Status
Reviewed by a seismologist

Did you feel it?

No one has reported feeling this quake to the USGS.

How well it is located

Reviewed by a seismologist.

Location uncertainty
About 0.1 km horizontally, 0.4 km in depth
Magnitude uncertainty
±0.12
Depth from
From location
Station coverage gap
34°
Stations used
31

Nearest places

Distance and direction from each place to the epicenter, with its forecast.

Nearby

Within 100 km, magnitude 1.5 and up: 148 in the 60 days after this one and 45 in the 30 days before it.

After

The first 60 of 148.

Before

Earthquakes todayCalifornia earthquakesLive radar here

Sources

From the USGS Earthquake Hazards Program and its partner networks, event nc1070812. Read Tue, Sep 22, 2026, 11:36 AM UTC.