M1.7 earthquake 10km N of Foothill Ranch, CA

A magnitude 1.7 earthquake struck 10km N of Foothill Ranch, CA on Thu, May 27, 1982, 11:51 PM PDT (06:51 UTC), 6 km (3 mi) below the surface.

A larger quake followed: M1.8 1km ENE of Anza, 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: 198 in the 60 days after this one and 0 in the 30 days before it.

The first 60 of 198.

From the USGS Earthquake Hazards Program and its partner networks, event ci531573. Read Wed, Sep 23, 2026, 5:42 AM UTC.