M1.8 earthquake Northern California

A magnitude 1.8 earthquake struck in Northern California on Mon, Jul 27, 1981, 5:37 AM PDT (12:37 UTC), 2 km (1 mi) below the surface.

A larger quake followed: M1.9 6 km WSW of Cobb, California. This one was a foreshock.

Map

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

No one has reported feeling this quake to the USGS.

Reviewed by a seismologist.

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

Within 100 km, magnitude 1.5 and up: 108 in the 60 days after this one and 56 in the 30 days before it.

The first 60 of 108.

From the USGS Earthquake Hazards Program and its partner networks, event nc1065982. Read Tue, Sep 22, 2026, 9:40 PM UTC.