M1.7 earthquake 14km SE of Mammoth Lakes, CA

A magnitude 1.7 earthquake struck 14km SE of Mammoth Lakes, CA on Wed, Jul 28, 2021, 7:36 PM PDT (02:36 UTC), 4 km (2 mi) below the surface.

A larger quake followed: M3.5 27 km NNW of Benton, 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
1.66	Md, duration	Northern California Seismic System	Preferred · Final · ±0.098 · 18 stations
1.4	ML, local (Richter)	Nevada Seismological Laboratory	Preliminary · ±0.29 · 8 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: 127 in the 60 days after this one and 57 in the 30 days before it.

The first 60 of 127.

From the USGS Earthquake Hazards Program and its partner networks, event nc73601431 (also filed as nn00816746). Read Sun, Oct 4, 2026, 6:21 AM UTC.