Alaska earthquakes

M2.7 earthquake 48 km WSW of Adak, Alaska

A magnitude 2.7 earthquake struck 48 km WSW of Adak, Alaska on Thu, Feb 18, 2021, 8:40 AM HAST (18:40 UTC), 81 km (50 mi) below the surface.

A larger quake followed: M4.4 44 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: 2.7 (ml), micro
Local time: Thu, Feb 18, 2021, 8:40 AM HAST
UTC: 2021-02-18 18:40:51 UTC
Depth: 81.0 km (50.3 mi), intermediate-depth
Epicenter: 51.722° N, 177.286° 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 7.2 km horizontally, 5.2 km in depth
Magnitude uncertainty: ±0.13
Depth from: From location
Station coverage gap: 185°, poorly surrounded by stations
Stations used: 23

Nearby

Within 100 km, magnitude 1.5 and up: 163 in the 60 days after this one and 94 in the 30 days before it.

After

The first 60 of 163.

Before

Earthquakes today Alaska earthquakes Live radar here

Sources

From the USGS Earthquake Hazards Program and its partner networks, event us7000dfdm (also filed as ak02129caho2). Read Fri, Sep 25, 2026, 5:43 PM UTC.