Alaska earthquakes

M3.6 earthquake 71 km SSW of Adak, Alaska

A magnitude 3.6 earthquake struck 71 km SSW of Adak, Alaska on Wed, Aug 11, 2021, 8:25 PM HADT (05:25 UTC), 35 km (22 mi) below the surface.

A larger quake followed: M4.8 128 km WSW 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: 3.6 (ml), minor
Local time: Wed, Aug 11, 2021, 8:25 PM HADT
UTC: 2021-08-12 05:25:39 UTC
Depth: 35.0 km (21.7 mi), shallow
Epicenter: 51.312° N, 177.127° 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 2.6 km horizontally, 2.0 km in depth
Magnitude uncertainty: ±0.09
Depth from: Operator assigned
Station coverage gap: 204°, poorly surrounded by stations
Stations used: 40

Nearby

Within 100 km, magnitude 1.5 and up: 175 in the 60 days after this one and 24 in the 30 days before it.

After

The first 60 of 175.

Before

Earthquakes today Alaska earthquakes Live radar here

Sources

From the USGS Earthquake Hazards Program and its partner networks, event us7000f2tt (also filed as ak021aajicme). Read Thu, Sep 24, 2026, 8:38 AM UTC.