Alaska earthquakes

M3.4 earthquake 64 km SSE of Atka, Alaska

A magnitude 3.4 earthquake struck 64 km SSE of Atka, Alaska on Tue, Sep 21, 2021, 2:03 AM HADT (11:03 UTC), 35 km (22 mi) below the surface.

A larger quake followed: M3.6 33 km SSW of Atka, 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: 3.4 (ml), minor
Local time: Tue, Sep 21, 2021, 2:03 AM HADT
UTC: 2021-09-21 11:03:08 UTC
Depth: 35.0 km (21.7 mi), shallow
Epicenter: 51.643° N, 173.918° 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 2.7 km horizontally, 2.0 km in depth
Magnitude uncertainty: ±0.09
Depth from: Operator assigned
Station coverage gap: 205°, poorly surrounded by stations
Stations used: 34

Nearby

Within 100 km, magnitude 1.5 and up: 61 in the 60 days after this one and 48 in the 30 days before it.

After

The first 60 of 61.

Before

Earthquakes today Alaska earthquakes Live radar here

Sources

From the USGS Earthquake Hazards Program and its partner networks, event us6000fvzg (also filed as ak021c4sg1y6). Read Thu, Sep 24, 2026, 3:11 AM UTC.