California earthquakes

M3.0 earthquake 8 km NE of Ridgemark, California

A magnitude 3.0 earthquake struck 8 km NE of Ridgemark, California on Thu, May 8, 1986, 7:29 PM PDT (02:29 UTC), 8 km (5 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
3.0 (ml), minor
Local time
UTC
1986-05-09 02:29:42 UTC
Depth
7.7 km (4.8 mi), shallow
Epicenter
36.875° 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 0.1 km horizontally, 0.2 km in depth
Depth from
From location
Station coverage gap
40°
Stations used
79

Nearest places

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

Nearby

Within 100 km, magnitude 1.5 and up: 184 in the 60 days after this one and 181 in the 30 days before it.

After

The first 60 of 184.

Before

Earthquakes todayCalifornia earthquakesLive radar here

Sources

From the USGS Earthquake Hazards Program and its partner networks, event nc72247 (also filed as usp0002tsw). Read Tue, Sep 29, 2026, 8:20 AM UTC.