M2.8 earthquake 11km WSW of Anza, CA

A magnitude 2.8 earthquake struck 11km WSW of Anza, CA on Thu, Feb 5, 1981, 10:57 AM PST (18:57 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
2.8	ML, local (Richter)	Southern California Seismic Network	Preferred · Final · ±0.258 · 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: 185 in the 60 days after this one and 139 in the 30 days before it.

The first 60 of 185.

From the USGS Earthquake Hazards Program and its partner networks, event ci12254191 (also filed as usp0001c1t). Read Sat, Oct 3, 2026, 4:34 AM UTC.