Alaska earthquakes

M2.9 earthquake 70 km NE of Adak, Alaska

A magnitude 2.9 earthquake struck 70 km NE of Adak, Alaska on Mon, Sep 20, 2021, 9:54 AM HADT (18:54 UTC), 228 km (141 mi) below the surface.

A larger quake followed: M3.8 37 km ENE of Adak, 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: 2.9 (ml), micro
Local time: Mon, Sep 20, 2021, 9:54 AM HADT
UTC: 2021-09-20 18:54:55 UTC
Depth: 227.6 km (141.4 mi), intermediate-depth
Epicenter: 52.389° N, 176.044° W
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 23.1 km horizontally, 8.2 km in depth
Magnitude uncertainty: ±0.15
Depth from: From location
Station coverage gap: 281°, poorly surrounded by stations
Stations used: 21

Nearby

Within 100 km, magnitude 1.5 and up: 65 in the 60 days after this one and 50 in the 30 days before it.

After

The first 60 of 65.

Before

Earthquakes today Alaska earthquakes Live radar here

Sources

From the USGS Earthquake Hazards Program and its partner networks, event us6000fv3h (also filed as ak021c39druu). Read Thu, Sep 24, 2026, 7:11 AM UTC.