M1.5 earthquake 9 km NW of Cobb, California

A magnitude 1.5 earthquake struck 9 km NW of Cobb, California on Fri, Mar 27, 1987, 5:27 AM PST (13:27 UTC), 1 km (1 mi) below the surface.

A larger quake followed: M1.7 6 km ENE of Willits, 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: 174 in the 60 days after this one and 0 in the 30 days before it.

The first 60 of 174.

From the USGS Earthquake Hazards Program and its partner networks, event nc1148585. Read Tue, Sep 22, 2026, 8:55 PM UTC.