M1.8 earthquake 38 km NNE of Amboy, Washington

A magnitude 1.8 earthquake struck 38 km NNE of Amboy, Washington on Tue, Jul 31, 1984, 2:22 AM PDT (09:22 UTC), -1 km (-1 mi) below the surface.

A larger quake followed: M3.1 12 km S of Morton, Washington. This one was a foreshock.

Map

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

No one has reported feeling this quake to the USGS.

Reviewed by a seismologist.

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

Within 100 km, magnitude 1.5 and up: 72 in the 60 days after this one and 23 in the 30 days before it.

The first 60 of 72.

From the USGS Earthquake Hazards Program and its partner networks, event uw10179263. Read Fri, Oct 2, 2026, 10:41 PM UTC.