Alaska earthquakes

M3.9 earthquake 151 km WSW of Adak, Alaska

A magnitude 3.9 earthquake struck 151 km WSW of Adak, Alaska on Sun, Aug 2, 2020, 4:58 AM HADT (13:58 UTC), 35 km (22 mi) below the surface.

A larger quake followed: M4.6 125 km W of Adak, Alaska. This one was a foreshock.

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The earthquake

Magnitude: 3.9 (mb), minor
Local time: Sun, Aug 2, 2020, 4:58 AM HADT
UTC: 2020-08-02 13:58:59 UTC
Depth: 35.0 km (21.7 mi), shallow
Epicenter: 51.145° N, 178.480° 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 4.0 km horizontally, 2.0 km in depth
Magnitude uncertainty: ±0.12
Depth from: Operator assigned
Station coverage gap: 141°
Stations used: 72

Nearby

Within 100 km, magnitude 1.5 and up: 191 in the 60 days after this one and 87 in the 30 days before it.

After

The first 60 of 191.

Before

Earthquakes today Alaska earthquakes Live radar here

Sources

From the USGS Earthquake Hazards Program and its partner networks, event us6000b8cl (also filed as ak0209vsmsvy). Read Tue, Sep 29, 2026, 2:14 AM UTC.