Alaska earthquakes

M2.5 earthquake 114 km W of Adak, Alaska

A magnitude 2.5 earthquake struck 114 km W of Adak, Alaska on Tue, Sep 28, 2021, 11:31 PM HADT (08:31 UTC), 137 km (85 mi) below the surface.

A larger quake followed: M3.1 135 km WSW of Adak, Alaska. This one was a foreshock.

Map

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The earthquake

Magnitude: 2.5 (ml), micro
Local time: Tue, Sep 28, 2021, 11:31 PM HADT
UTC: 2021-09-29 08:31:53 UTC
Depth: 136.7 km (85.0 mi), intermediate-depth
Epicenter: 52.062° N, 178.265° 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 6.9 km horizontally, 8.3 km in depth
Magnitude uncertainty: ±0.12
Depth from: From location
Station coverage gap: 175°
Stations used: 20

Nearby

Within 100 km, magnitude 1.5 and up: 97 in the 60 days after this one and 42 in the 30 days before it.

After

The first 60 of 97.

Before

Earthquakes today Alaska earthquakes Live radar here

Sources

From the USGS Earthquake Hazards Program and its partner networks, event us7000fpkk (also filed as ak021chz4mhi). Read Thu, Sep 24, 2026, 9:21 AM UTC.