M3.3 earthquake 2 km WNW of Biola, California

A magnitude 3.3 earthquake struck 2 km WNW of Biola, California on Sat, Jul 9, 1977, 7:01 AM PDT (14:01 UTC), 2 km (1 mi) below the surface.

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
3.3	ML, local (Richter)	Northern California Seismic System	Preferred · Final · 0 stations
3.71	ML, local (Richter)	Southern California Seismic Network	Reviewed · ±0.139 · 6 stations

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: 47 in the 60 days after this one and 19 in the 30 days before it.

From the USGS Earthquake Hazards Program and its partner networks, event nc1035757 (also filed as ci3333816). Read Sat, Oct 3, 2026, 1:19 PM UTC.