Alaska earthquakes

M3.1 earthquake 68 km SE of Atka, Alaska

A magnitude 3.1 earthquake struck 68 km SE of Atka, Alaska on Fri, Apr 23, 2021, 12:42 AM HADT (09:42 UTC), 35 km (22 mi) below the surface.

A larger quake followed: M5.1 75 km SE of Atka, Alaska. This one was a foreshock.

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The earthquake

Magnitude: 3.1 (ml), minor
Local time: Fri, Apr 23, 2021, 12:42 AM HADT
UTC: 2021-04-23 09:42:03 UTC
Depth: 35.0 km (21.7 mi), shallow
Epicenter: 51.833° N, 173.404° 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 5.6 km horizontally, 2.0 km in depth
Magnitude uncertainty: ±0.12
Depth from: Operator assigned
Station coverage gap: 210°, poorly surrounded by stations
Stations used: 26

Nearby

Within 100 km, magnitude 1.5 and up: 29 in the 60 days after this one and 43 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 us7000e4mz (also filed as ak021571c4ok). Read Thu, Sep 24, 2026, 10:35 AM UTC.