California earthquakes

M2.4 earthquake 6 km NE of Ridgemark, California

A magnitude 2.4 earthquake struck 6 km NE of Ridgemark, California on Thu, May 1, 1986, 12:17 AM PDT (07:17 UTC), 4 km (3 mi) below the surface.

A larger quake followed: M4.7 18 km SSE of Tres Pinos, 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
2.4 (md), micro
Local time
UTC
1986-05-01 07:17:38 UTC
Depth
4.2 km (2.6 mi), shallow
Epicenter
36.851° N, 121.305° 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, 0.4 km in depth
Magnitude uncertainty
±0.31
Depth from
From location
Station coverage gap
100°
Stations used
24

Nearest places

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

Nearby

Within 100 km, magnitude 1.5 and up: 177 in the 60 days after this one and 186 in the 30 days before it.

After

The first 60 of 177.

Before

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Sources

From the USGS Earthquake Hazards Program and its partner networks, event nc71590. Read Wed, Sep 30, 2026, 7:05 PM UTC.