M1.6 earthquake 4 km S of Cobb, California

A magnitude 1.6 earthquake struck 4 km S of Cobb, California on Mon, Dec 2, 1985, 1:55 AM PST (09:55 UTC), 2 km (1 mi) below the surface.

A larger quake followed: M3.6 8 km WSW of Kelseyville, 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: 178 in the 60 days after this one and 120 in the 30 days before it.

The first 60 of 178.

From the USGS Earthquake Hazards Program and its partner networks, event nc1133396. Read Tue, Sep 29, 2026, 10:39 PM UTC.