Alaska earthquakes

M3.7 earthquake 64 km NNE of Adak, Alaska

A magnitude 3.7 earthquake struck 64 km NNE of Adak, Alaska on Sun, Feb 28, 2021, 12:03 AM HAST (10:03 UTC), 226 km (140 mi) below the surface.

A larger quake followed: M4.4 61 km WSW of Atka, Alaska. This one was a foreshock.

Map

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The earthquake

Magnitude: 3.7 (mb), minor
Local time: Sun, Feb 28, 2021, 12:03 AM HAST
UTC: 2021-02-28 10:03:19 UTC
Depth: 225.8 km (140.3 mi), intermediate-depth
Epicenter: 52.381° N, 176.186° 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 12.8 km horizontally, 6.7 km in depth
Magnitude uncertainty: ±0.17
Depth from: From location
Station coverage gap: 130°
Stations used: 61

Nearby

Within 100 km, magnitude 1.5 and up: 60 in the 60 days after this one and 25 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 us7000dkgy (also filed as ak0212pqoi2a). Read Thu, Sep 24, 2026, 10:21 AM UTC.