M2.5 earthquake 37km WSW of Tecopa, CA

A magnitude 2.5 earthquake struck 37km WSW of Tecopa, CA on Tue, May 4, 2021, 6:31 AM PDT (13:31 UTC), 1 km (1 mi) below the surface.

A larger quake followed: M3.6 24km NNE of Trona, 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
2.55	ML, local (Richter)	Southern California Seismic Network	Preferred · Final · ±0.124 · 106 stations
2.3	ML, local (Richter)	USGS National Earthquake Information Center	Reviewed · ±0.039 · 88 stations

1 person reported to the USGS what they felt; the strongest reported shaking was I, not felt shaking.

Reviewed by a seismologist.

Distance and direction from each place to the epicenter, with its forecast.

Within 100 km, magnitude 1.5 and up: 118 in the 60 days after this one and 55 in the 30 days before it.

The first 60 of 118.

From the USGS Earthquake Hazards Program and its partner networks, event ci39640111 (also filed as us7000dzzr). Read Sat, Oct 3, 2026, 3:04 PM UTC.