Alaska earthquakes

M4.2 earthquake 81 km SE of Atka, Alaska

A magnitude 4.2 earthquake struck 81 km SE of Atka, Alaska on Fri, May 21, 2021, 11:56 PM HADT (08:56 UTC), 41 km (26 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: 4.2 (mb), light
Local time: Fri, May 21, 2021, 11:56 PM HADT
UTC: 2021-05-22 08:56:11 UTC
Depth: 41.4 km (25.7 mi), shallow
Epicenter: 51.693° N, 173.329° 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 3.8 km horizontally, 10.3 km in depth
Magnitude uncertainty: ±0.16
Depth from: From location
Station coverage gap: 140°
Stations used: 56

Nearby

Within 100 km, magnitude 1.5 and up: 56 in the 60 days after this one and 17 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 us7000e5a5 (also filed as ak0216izesgg). Read Thu, Sep 24, 2026, 10:10 AM UTC.