M1.6 earthquake 5 km SW of Cobb, California

A magnitude 1.6 earthquake struck 5 km SW of Cobb, California on Sat, Oct 11, 1986, 5:21 AM PDT (12:21 UTC), 3 km (2 mi) below the surface.

A larger quake followed: M4.0 4 km SW of Sea Ranch, 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: 148 in the 60 days after this one and 80 in the 30 days before it.

The first 60 of 148.

From the USGS Earthquake Hazards Program and its partner networks, event nc85441. Read Tue, Sep 29, 2026, 8:58 AM UTC.