M1.6 earthquake 18km ESE of Anza, CA

A magnitude 1.6 earthquake struck 18km ESE of Anza, CA on Fri, Feb 21, 2003, 3:29 AM PST (11:29 UTC), 13 km (8 mi) below the surface.

A larger quake followed: M5.0 6km N of Big Bear City, CA. 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: at least 199 in the 60 days after this one and 121 in the 30 days before it.

The first 60 of at least 199.

From the USGS Earthquake Hazards Program and its partner networks, event ci13935708. Read Mon, Oct 5, 2026, 2:57 AM UTC.