Alaska earthquakes

M3.9 earthquake 250 km W of Adak, Alaska

A magnitude 3.9 earthquake struck 250 km W of Adak, Alaska on Sat, Sep 11, 2021, 2:06 AM GMT+12 (14:06 UTC), 131 km (81 mi) below the surface.

A larger quake followed: M5.1 Rat Islands, Aleutian Islands, Alaska. This one was a foreshock.

Map

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

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The earthquake

Magnitude: 3.9 (mb), minor
Local time: Sat, Sep 11, 2021, 2:06 AM GMT+12
UTC: 2021-09-10 14:06:04 UTC
Depth: 131.1 km (81.4 mi), intermediate-depth
Epicenter: 51.859° N, 179.723° E
Region: Alaska
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 5.8 km horizontally, 5.4 km in depth
Magnitude uncertainty: ±0.07
Depth from: From location
Station coverage gap: 117°
Stations used: 97

Nearby

Within 100 km, magnitude 1.5 and up: 89 in the 60 days after this one and 80 in the 30 days before it.

After

The first 60 of 89.

Before

Earthquakes today Alaska earthquakes Live radar here

Sources

From the USGS Earthquake Hazards Program and its partner networks, event us7000fbuh (also filed as ak021bmnc653). Read Fri, Sep 25, 2026, 6:38 PM UTC.