M3.6 earthquake 6 km W of Cobb, California

A magnitude 3.6 earthquake struck 6 km W of Cobb, California on Tue, Apr 3, 1990, 2:12 PM PDT (21:12 UTC), 1 km (1 mi) below the surface.

Map

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

Different scales measure different things and differ by a few tenths. The USGS marks one as preferred, and it is the one this page uses.

Mag.	Scale	Computed by	Notes
3.6	ML, local (Richter)	Northern California Seismic System	Preferred · Final · 0 stations
4.1	ML, local (Richter)	USGS National Earthquake Information Center	Reviewed

The USGS’s account of the effects of this earthquake.

Felt (IV) at Cobb and Loch Lomond. Also felt at Finley and The Geysers.

From the USGS event page for nc159000. U.S. Geological Survey text and figures are in the public domain.

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: 173 in the 60 days after this one and 98 in the 30 days before it.

The first 60 of 173.

From the USGS Earthquake Hazards Program and its partner networks, event nc159000 (also filed as usp00047e2). Read Sun, Oct 4, 2026, 1:35 PM UTC.