Alaska earthquakes

M3.1 earthquake 83 km E of Adak, Alaska

A magnitude 3.1 earthquake struck 83 km E of Adak, Alaska on Sun, Aug 15, 2021, 11:11 PM HADT (08:11 UTC), 73 km (46 mi) below the surface.

A larger quake followed: M3.4 64 km SE of Adak, Alaska. This one was a foreshock.

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The earthquake

Magnitude
3.1 (ml), minor
Local time
UTC
2021-08-16 08:11:06 UTC
Depth
73.4 km (45.6 mi), intermediate-depth
Epicenter
51.793° N, 175.425° 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 9.0 km horizontally, 18.5 km in depth
Magnitude uncertainty
±0.15
Depth from
From location
Station coverage gap
206°, poorly surrounded by stations
Stations used
40

Nearby

Within 100 km, magnitude 1.5 and up: 127 in the 60 days after this one and 72 in the 30 days before it.

After

The first 60 of 127.

Before

Earthquakes todayAlaska earthquakesLive radar here

Sources

From the USGS Earthquake Hazards Program and its partner networks, event us7000f78p (also filed as ak021ah7cytv). Read Thu, Sep 24, 2026, 10:10 AM UTC.