M1.7 earthquake 6 km SW of Mad River, California

A magnitude 1.7 earthquake struck 6 km SW of Mad River, California on Sat, Nov 18, 1978, 6:50 AM PST (14:50 UTC), 22 km (14 mi) below the surface.

A larger quake followed: M1.8 38 km SW of Ferndale, California. 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: 103 in the 60 days after this one and 76 in the 30 days before it.

The first 60 of 103.

From the USGS Earthquake Hazards Program and its partner networks, event nc1043421. Read Tue, Sep 22, 2026, 8:34 PM UTC.