Alaska earthquakes

M2.7 earthquake 96 km SSE of Atka, Alaska

A magnitude 2.7 earthquake struck 96 km SSE of Atka, Alaska on Mon, Sep 20, 2021, 1:23 AM HADT (10:23 UTC), 35 km (22 mi) below the surface.

A larger quake followed: M3.4 64 km SSE of Atka, Alaska. This one was a foreshock.

Map

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The earthquake

Magnitude: 2.7 (ml), micro
Local time: Mon, Sep 20, 2021, 1:23 AM HADT
UTC: 2021-09-20 10:23:00 UTC
Depth: 35.0 km (21.7 mi), shallow
Epicenter: 51.362° N, 173.840° 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 7.0 km horizontally, 2.0 km in depth
Magnitude uncertainty: ±0.15
Depth from: Operator assigned
Station coverage gap: 288°, poorly surrounded by stations
Stations used: 23

Nearby

Within 100 km, magnitude 1.5 and up: 57 in the 60 days after this one and 44 in the 30 days before it.

After

Before

Earthquakes today Alaska earthquakes Live radar here

Sources

From the USGS Earthquake Hazards Program and its partner networks, event us6000fv3c (also filed as ak021c34fjq0). Read Thu, Sep 24, 2026, 7:06 AM UTC.