M1.8 earthquake 8 km S of Cobb, California

A magnitude 1.8 earthquake struck 8 km S of Cobb, California on Thu, Jul 21, 1983, 4:37 PM PDT (23:37 UTC), 0 km (0 mi) below the surface.

A larger quake followed: M3.1 5 km SW 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: 181 in the 60 days after this one and 88 in the 30 days before it.

The first 60 of 181.

From the USGS Earthquake Hazards Program and its partner networks, event nc1098968. Read Thu, Oct 1, 2026, 5:03 PM UTC.