M1.7 earthquake 21km ESE of Anza, CA

A magnitude 1.7 earthquake struck 21km ESE of Anza, CA on Mon, Oct 4, 2021, 4:40 PM PDT (23:40 UTC), 13 km (8 mi) below the surface.

A larger quake followed: M3.5 25km WSW of Westmorland, 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: 127 in the 60 days after this one and 81 in the 30 days before it.

The first 60 of 127.

From the USGS Earthquake Hazards Program and its partner networks, event ci40062936. Read Sun, Oct 4, 2026, 5:27 AM UTC.