M2.9 earthquake 29km WSW of Tecopa, CA

A magnitude 2.9 earthquake struck 29km WSW of Tecopa, CA on Sat, Jun 17, 1978, 3:31 PM PDT (22:31 UTC), 6 km (4 mi) below the surface.

A larger quake followed: M3.8 35km S of Tecopa, CA. 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
2.9	ML, local (Richter)	Southern California Seismic Network	Preferred · Final · ±0.121 · 2 stations
3.1	ML, local (Richter)	USGS National Earthquake Information Center	Reviewed

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: 10 in the 60 days after this one and 6 in the 30 days before it.

From the USGS Earthquake Hazards Program and its partner networks, event ci3340046 (also filed as usp0000v42). Read Sat, Oct 3, 2026, 2:09 PM UTC.