M4.3 earthquake 45 km SW of Unalaska, Alaska

A magnitude 4.3 earthquake struck 45 km SW of Unalaska, Alaska on Fri, Feb 27, 1987, 1:12 AM AKST (10:12 UTC), 10 km (6 mi) below the surface.

A larger quake followed: M4.6 71 km SW of Unalaska, 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 1.5 and up: 38 in the 60 days after this one and 4 in the 30 days before it.

From the USGS Earthquake Hazards Program and its partner networks, event usp00032ub. Read Tue, Sep 22, 2026, 10:41 AM UTC.