California earthquakes

M1.7 earthquake 26 km W of Volta, California

A magnitude 1.7 earthquake struck 26 km W of Volta, California on Thu, Dec 11, 1986, 2:27 AM PST (10:27 UTC), 4 km (3 mi) below the surface.

A larger quake followed: M4.2 9 km ENE of Morgan Hill, California. 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
1.7 (md), micro
Local time
UTC
1986-12-11 10:27:18 UTC
Depth
4.1 km (2.5 mi), shallow
Epicenter
37.083° N, 121.219° 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 0.2 km horizontally, 0.8 km in depth
Magnitude uncertainty
±0.11
Depth from
From location
Station coverage gap
107°
Stations used
50

Nearest places

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

Nearby

Within 100 km, magnitude 1.5 and up: 173 in the 60 days after this one and 78 in the 30 days before it.

After

The first 60 of 173.

Before

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Sources

From the USGS Earthquake Hazards Program and its partner networks, event nc89929. Read Mon, Sep 28, 2026, 3:21 AM UTC.