M1.8 earthquake 8km NNE of Round Valley, CA

A magnitude 1.8 earthquake struck 8km NNE of Round Valley, CA on Sun, Dec 19, 2021, 5:08 AM PST (13:08 UTC), 6 km (4 mi) below the surface.

A larger quake followed: M4.8 8km ESE of Deep Springs, 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
1.75	Md, duration	Northern California Seismic System	Preferred · Final · ±0.13 · 19 stations
1.5	ML, local (Richter)	Nevada Seismological Laboratory	Reviewed · ±0.34 · 4 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: 174 in the 60 days after this one and 83 in the 30 days before it.

The first 60 of 174.

From the USGS Earthquake Hazards Program and its partner networks, event nc73665741 (also filed as nn00830197). Read Sun, Oct 4, 2026, 6:40 AM UTC.