Alaska earthquakes

M3.3 earthquake 188 km SSW of Adak, Alaska

A magnitude 3.3 earthquake struck 188 km SSW of Adak, Alaska on Thu, Dec 9, 2021, 8:49 PM HAST (06:49 UTC), 31 km (19 mi) below the surface.

A larger quake followed: M4.0 Andreanof Isl., Aleutian Islands, Alaska. This one was a foreshock.

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The earthquake

Magnitude: 3.3 (ml), minor
Local time: Thu, Dec 9, 2021, 8:49 PM HAST
UTC: 2021-12-10 06:49:40 UTC
Depth: 31.2 km (19.4 mi), shallow
Epicenter: 50.348° N, 177.814° 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 8.0 km horizontally, 15.3 km in depth
Magnitude uncertainty: ±0.10
Depth from: From location
Station coverage gap: 251°, poorly surrounded by stations
Stations used: 30

Nearby

Within 100 km, magnitude 1.5 and up: 22 in the 60 days after this one and 13 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 us7000gaft (also filed as ak021ft0qkx8). Read Thu, Sep 24, 2026, 10:04 AM UTC.