Alaska earthquakes

M3.9 earthquake 298 km W of Adak, Alaska

A magnitude 3.9 earthquake struck 298 km W of Adak, Alaska on Sat, Dec 18, 2021, 2:14 PM GMT+12 (02:14 UTC), 132 km (82 mi) below the surface.

A larger quake followed: M5.2 Rat Islands, Aleutian Islands, Alaska. This one was a foreshock.

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The earthquake

Magnitude: 3.9 (mb), minor
Local time: Sat, Dec 18, 2021, 2:14 PM GMT+12
UTC: 2021-12-18 02:14:58 UTC
Depth: 132.0 km (82.0 mi), intermediate-depth
Epicenter: 51.856° N, 179.030° E
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 6.8 km horizontally, 4.7 km in depth
Magnitude uncertainty: ±0.19
Depth from: From location
Station coverage gap: 125°
Stations used: 44

Nearby

Within 100 km, magnitude 1.5 and up: 196 in the 60 days after this one and 105 in the 30 days before it.

After

The first 60 of 196.

Before

Earthquakes today Alaska earthquakes Live radar here

Sources

From the USGS Earthquake Hazards Program and its partner networks, event us6000gekx (also filed as ak021g66g5ot). Read Sat, Sep 26, 2026, 7:13 AM UTC.