Alaska earthquakes

M3.4 earthquake 81 km NNW of Atka, Alaska

A magnitude 3.4 earthquake struck 81 km NNW of Atka, Alaska on Sun, Feb 28, 2021, 2:22 PM HAST (00:22 UTC), 230 km (143 mi) below the surface.

A larger quake followed: M4.3 94 km NNE of Adak, Alaska. This one was a foreshock.

Map

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The earthquake

Magnitude: 3.4 (ml), minor
Local time: Sun, Feb 28, 2021, 2:22 PM HAST
UTC: 2021-03-01 00:22:15 UTC
Depth: 229.8 km (142.8 mi), intermediate-depth
Epicenter: 52.870° N, 174.685° 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 11.3 km horizontally, 11.1 km in depth
Magnitude uncertainty: ±0.10
Depth from: From location
Station coverage gap: 104°
Stations used: 29

Nearby

Within 100 km, magnitude 1.5 and up: 25 in the 60 days after this one and 14 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 us6000dw4z (also filed as ak0212r8dkpu). Read Thu, Sep 24, 2026, 10:20 AM UTC.