Alaska earthquakes

M3.5 earthquake 259 km W of Adak, Alaska

A magnitude 3.5 earthquake struck 259 km W of Adak, Alaska on Tue, Aug 4, 2020, 10:23 PM GMT+12 (10:23 UTC), 82 km (51 mi) below the surface.

A larger quake followed: M4.6 294 km WSW 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: 3.5 (ml), minor
Local time: Tue, Aug 4, 2020, 10:23 PM GMT+12
UTC: 2020-08-04 10:23:26 UTC
Depth: 82.2 km (51.1 mi), intermediate-depth
Epicenter: 51.650° N, 179.625° E
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 12.7 km horizontally, 7.2 km in depth
Magnitude uncertainty: ±0.12
Depth from: From location
Station coverage gap: 131°
Stations used: 31

Nearby

Within 100 km, magnitude 1.5 and up: 166 in the 60 days after this one and 59 in the 30 days before it.

After

The first 60 of 166.

Before

Earthquakes today Alaska earthquakes Live radar here

Sources

From the USGS Earthquake Hazards Program and its partner networks, event us6000bhe4 (also filed as ak0209z1pmrj). Read Tue, Sep 29, 2026, 12:38 AM UTC.