M4.7 earthquake 85 km SW of Unalaska, Alaska

A magnitude 4.7 earthquake struck 85 km SW of Unalaska, Alaska on Mon, Mar 2, 1987, 9:05 PM AKST (06:05 UTC), 10 km (6 mi) below the surface.

A larger quake followed: M5.7 38 km ESE of Nikolski, Alaska. 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 1.7 and up: 27 in the 60 days after this one and 17 in the 30 days before it.

From the USGS Earthquake Hazards Program and its partner networks, event usp00032y8. Read Fri, Oct 2, 2026, 1:02 PM UTC.