Washington earthquakes

M3.4 earthquake Olympic Peninsula, Washington

A magnitude 3.4 earthquake struck in the Olympic Peninsula, Washington on Thu, Dec 28, 1978, 4:18 AM PST (12:18 UTC), 40 km (25 mi) below the surface.

A larger quake followed: M3.5 4 km SSW of Fall City, Washington. This one was a foreshock.

Skokomish forecast More in Washington

Map

Where this earthquake was located, with the others nearby. Select one for its page.

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The earthquake

Magnitude: 3.4 (md), minor
Local time: Thu, Dec 28, 1978, 4:18 AM PST
UTC: 1978-12-28 12:18:58 UTC
Depth: 40.3 km (25.0 mi), shallow
Epicenter: 47.308° N, 123.159° W
Region: Washington
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 0.8 km horizontally, 0.5 km in depth
Magnitude uncertainty: ±0.09
Depth from: From location
Station coverage gap: 92°
Stations used: 16

Nearest places

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

Nearby

Within 100 km, magnitude 1.5 and up: 9 in the 60 days after this one and 4 in the 30 days before it.

After

Before

Earthquakes today Washington earthquakes Live radar here

Sources

From the USGS Earthquake Hazards Program and its partner networks, event uw10848623. Read Tue, Sep 22, 2026, 7:05 AM UTC.