Alaska earthquakes

M3.3 earthquake 129 km SE of Atka, Alaska

A magnitude 3.3 earthquake struck 129 km SE of Atka, Alaska on Sun, Feb 21, 2021, 11:20 AM HAST (21:20 UTC), 35 km (22 mi) below the surface.

A larger quake followed: M4.2 76 km ESE of Atka, Alaska. This one was a foreshock.

Map

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The earthquake

Magnitude: 3.3 (ml), minor
Local time: Sun, Feb 21, 2021, 11:20 AM HAST
UTC: 2021-02-21 21:20:57 UTC
Depth: 35.0 km (21.7 mi), shallow
Epicenter: 51.456° N, 172.748° 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 3.7 km horizontally, 2.0 km in depth
Magnitude uncertainty: ±0.15
Depth from: Operator assigned
Station coverage gap: 320°, poorly surrounded by stations
Stations used: 27

Nearby

Within 100 km, magnitude 1.5 and up: 35 in the 60 days after this one and 10 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 us6000djyw (also filed as ak0212eckodu). Read Thu, Sep 24, 2026, 4:05 PM UTC.