M3.1 earthquake 22km ESE of Anza, CA

A magnitude 3.1 earthquake struck 22km ESE of Anza, CA on Sat, Feb 21, 1981, 7:09 AM PST (15:09 UTC), 5 km (3 mi) below the surface.

A larger quake followed: M3.7 6km NNE of Yucaipa, CA. This one was a foreshock.

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
3.12	ML, local (Richter)	Southern California Seismic Network	Preferred · Final · ±0.365 · 5 stations
3.3	ML, local (Richter)	USGS National Earthquake Information Center	Reviewed

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: 187 in the 60 days after this one and 168 in the 30 days before it.

The first 60 of 187.

From the USGS Earthquake Hazards Program and its partner networks, event ci3317155 (also filed as usp0001can). Read Thu, Oct 1, 2026, 7:19 PM UTC.