M4.5 earthquake 134 km SSE of Old Harbor, Alaska

A magnitude 4.5 earthquake struck 134 km SSE of Old Harbor, Alaska on Thu, Apr 13, 1978, 3:59 AM GMT-10 (13:59 UTC), 33 km (21 mi) below the surface.

A larger quake followed: M4.9 68 km SSE of Old Harbor, 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: 6 in the 60 days after this one and 8 in the 30 days before it.

From the USGS Earthquake Hazards Program and its partner networks, event usp0000u2w. Read Tue, Sep 22, 2026, 5:45 AM UTC.