M4.3 earthquake 38 km SW of Ferndale, California

A magnitude 4.3 earthquake struck 38 km SW of Ferndale, California on Mon, Mar 30, 1981, 4:38 AM PST (12:38 UTC), 25 km (16 mi) below the surface.

A larger quake followed: M4.6 58 km WSW of Ferndale, California. 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
4.3	ML, local (Richter)	Northern California Seismic System	Preferred · Final · 0 stations
4.4	mb, body-wave	USGS National Earthquake Information Center	Reviewed · 6 stations

The USGS’s account of the effects of this earthquake.

FELT (IV) AT PETROLIA AND RIO DELL. ALSO FELT AT LOLETA.

From the USGS event page for nc1061874. U.S. Geological Survey text and figures are in the public domain.

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: 186 in the 60 days after this one and 61 in the 30 days before it.

The first 60 of 186.

From the USGS Earthquake Hazards Program and its partner networks, event nc1061874 (also filed as usp0001cy9). Read Sun, Oct 4, 2026, 4:14 PM UTC.