California earthquakes

M1.7 earthquake 36 km WNW of Samoa, California

A magnitude 1.7 earthquake struck 36 km WNW of Samoa, California on Sat, Oct 28, 1978, 2:33 PM PDT (21:33 UTC), 13 km (8 mi) below the surface.

A larger quake followed: M4.2 64 km W of Ferndale, 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
1.7 (md), micro
Local time
UTC
1978-10-28 21:33:41 UTC
Depth
12.8 km (8.0 mi), shallow
Epicenter
40.928° N, 124.599° 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 9.3 km horizontally, 3.6 km in depth
Depth from
From location
Station coverage gap
309°, poorly surrounded by stations
Stations used
4

Nearest places

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

Nearby

Within 100 km, magnitude 1.5 and up: 139 in the 60 days after this one and 95 in the 30 days before it.

After

The first 60 of 139.

Before

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Sources

From the USGS Earthquake Hazards Program and its partner networks, event nc1043055. Read Mon, Sep 28, 2026, 11:43 PM UTC.