Alaska earthquakes

M2.7 earthquake 17 km SE of Adak, Alaska

A magnitude 2.7 earthquake struck 17 km SE of Adak, Alaska on Mon, Sep 21, 2020, 3:38 AM HADT (12:38 UTC), 80 km (50 mi) below the surface.

A larger quake followed: M4.3 68 km SSE 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: Mon, Sep 21, 2020, 3:38 AM HADT
UTC: 2020-09-21 12:38:57 UTC
Depth: 80.3 km (49.9 mi), intermediate-depth
Epicenter: 51.750° N, 176.489° 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 10.6 km horizontally, 9.2 km in depth
Magnitude uncertainty: ±0.12
Depth from: From location
Station coverage gap: 192°, poorly surrounded by stations
Stations used: 35

Nearby

Within 100 km, magnitude 1.5 and up: 134 in the 60 days after this one and 91 in the 30 days before it.

After

The first 60 of 134.

Before

Earthquakes today Alaska earthquakes Live radar here

Sources

From the USGS Earthquake Hazards Program and its partner networks, event us6000c3rs (also filed as ak020c6gsfsj). Read Sun, Sep 27, 2026, 11:08 PM UTC.