California earthquakes

M1.8 earthquake 16 km ESE of Ruth, California

A magnitude 1.8 earthquake struck 16 km ESE of Ruth, California on Wed, Mar 22, 1978, 2:49 AM PST (10:49 UTC), 45 km (28 mi) below the surface.

A larger quake followed: M3.0 14 km ESE of Ruth, California. This one was a foreshock.

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

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The earthquake

Magnitude
1.8 (md), micro
Local time
UTC
1978-03-22 10:49:45 UTC
Depth
44.7 km (27.8 mi), shallow
Epicenter
40.196° N, 123.156° W
Tsunami flag
No
Status
Reviewed by a seismologist

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 12.0 km horizontally, 6.3 km in depth
Depth from
From location
Station coverage gap
316°, poorly surrounded by stations
Stations used
8

Nearest places

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

Nearby

Within 100 km, magnitude 1.5 and up: 54 in the 60 days after this one and 39 in the 30 days before it.

After

Before

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Sources

From the USGS Earthquake Hazards Program and its partner networks, event nc1039424. Read Tue, Sep 22, 2026, 12:11 PM UTC.