Alaska earthquakes

M3.1 earthquake 60 km SSW of Atka, Alaska

A magnitude 3.1 earthquake struck 60 km SSW of Atka, Alaska on Tue, Aug 10, 2021, 2:40 PM HADT (23:40 UTC), 224 km (139 mi) below the surface.

A larger quake followed: M3.7 64 km SE of Adak, Alaska. This one was a foreshock.

Map

Where this earthquake was located, with the others nearby. Select one for its page.

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The earthquake

Magnitude: 3.1 (ml), minor
Local time: Tue, Aug 10, 2021, 2:40 PM HADT
UTC: 2021-08-10 23:40:31 UTC
Depth: 224.2 km (139.3 mi), intermediate-depth
Epicenter: 51.709° N, 174.595° 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 26.9 km horizontally, 20.3 km in depth
Magnitude uncertainty: ±0.09
Depth from: From location
Station coverage gap: 239°, poorly surrounded by stations
Stations used: 24

Nearby

Within 100 km, magnitude 1.5 and up: 126 in the 60 days after this one and 73 in the 30 days before it.

After

The first 60 of 126.

Before

Earthquakes today Alaska earthquakes Live radar here

Sources

From the USGS Earthquake Hazards Program and its partner networks, event us6000f8gw (also filed as ak021a7j8pfp). Read Thu, Sep 24, 2026, 3:59 AM UTC.