California earthquakes

M3.4 earthquake 2 km SSW of Sattley, California

A magnitude 3.4 earthquake struck 2 km SSW of Sattley, California on Tue, May 21, 1985, 8:42 PM PDT (03:42 UTC), 3 km (2 mi) below the surface.

A larger quake followed: M3.5 17 km NNW of Stagecoach, Nevada. This one was a foreshock.

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Map

Where this earthquake was located, with the others nearby. Select one for its page.

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The earthquake

Magnitude
3.4 (ML, local (Richter)), minor
Magnitude from
Northern California Seismic System
Local time
UTC
1985-05-22 03:42:13 UTC
Depth
3.1 km (1.9 mi), shallow
Epicenter
39.597° N, 120.442° W
Tsunami flag
No
Status
Reviewed by a seismologist

Magnitude estimates

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.ScaleComputed byNotes
3.4ML, local (Richter)Northern California Seismic SystemPreferred · Final · 0 stations
3.3ML, local (Richter)USGS National Earthquake Information CenterReviewed

What happened

The USGS’s account of the effects of this earthquake.

Felt (IV) at Calpine, (III) at Blairsden and Sierra City.

From the USGS event page for nc48203. U.S. Geological Survey text and figures are in the public domain.

Did you feel it?

No one has reported feeling this quake to the USGS.

How well it is located

Reviewed by a seismologist.

Location uncertainty
About 0.3 km horizontally, 1.6 km in depth
Depth from
From location
Station coverage gap
56°
Stations used
39

Nearest places

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

Nearby

Within 100 km, magnitude 1.5 and up: 21 in the 60 days after this one and 4 in the 30 days before it.

After

Before

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Sources

From the USGS Earthquake Hazards Program and its partner networks, event nc48203 (also filed as usp0002f2h). Read Sat, Oct 3, 2026, 11:35 AM UTC.