Alaska earthquakes

M4.8 earthquake 220 km WSW of Adak, Alaska

A magnitude 4.8 earthquake struck 220 km WSW of Adak, Alaska on Sun, Feb 21, 2021, 5:02 AM HAST (15:02 UTC), 10 km (6 mi) below the surface.

A larger quake followed: M5.4 185 km WSW of Adak, Alaska. This one was a foreshock.

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The earthquake

Magnitude: 4.8 (mb), light
Local time: Sun, Feb 21, 2021, 5:02 AM HAST
UTC: 2021-02-21 15:02:33 UTC
Depth: 10.0 km (6.2 mi), shallow
Epicenter: 50.825° N, 179.311° 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 5.0 km horizontally, 1.8 km in depth
Magnitude uncertainty: ±0.04
Depth from: Operator assigned
Station coverage gap: 128°
Stations used: 136

Nearby

Within 100 km, magnitude 1.8 and up: 43 in the 60 days after this one and 46 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 us6000djwu (also filed as ak0212e8w2is, iscgem619843775). Read Sat, Sep 26, 2026, 3:39 AM UTC.