California earthquakes

M1.8 earthquake 5 km NE of Clipper Mills, California

A magnitude 1.8 earthquake struck 5 km NE of Clipper Mills, California on Mon, Apr 27, 1987, 2:40 PM PDT (21:40 UTC), 13 km (8 mi) below the surface.

A larger quake followed: M3.4 1 km S of Lake Almanor Country Club, 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: 1.8 (Md, duration), micro
Magnitude from: Northern California Seismic System
Local time: Mon, Apr 27, 1987, 2:40 PM PDT
UTC: 1987-04-27 21:40:26 UTC
Depth: 13.5 km (8.4 mi), shallow
Epicenter: 39.566° N, 121.113° W
Region: California
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 1.2 km horizontally, 2.6 km in depth
Magnitude uncertainty: ±0.12
Depth from: From location
Station coverage gap: 220°, poorly surrounded by stations
Stations used: 9

Nearest places

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

Nearby

Within 100 km, magnitude 1.5 and up: 25 in the 60 days after this one and 13 in the 30 days before it.

After

Before

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Sources

From the USGS Earthquake Hazards Program and its partner networks, event nc99343. Read Thu, Oct 1, 2026, 3:24 PM UTC.