Alaska earthquakes

M3.8 earthquake 133 km W of Adak, Alaska

A magnitude 3.8 earthquake struck 133 km W of Adak, Alaska on Sun, Aug 16, 2020, 10:22 PM HADT (07:22 UTC), 145 km (90 mi) below the surface.

A larger quake followed: M4.8 193 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: 3.8 (mb), minor
Local time: Sun, Aug 16, 2020, 10:22 PM HADT
UTC: 2020-08-17 07:22:30 UTC
Depth: 144.9 km (90.1 mi), intermediate-depth
Epicenter: 51.941° N, 178.567° 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 9.0 km horizontally, 4.3 km in depth
Magnitude uncertainty: ±0.07
Depth from: From location
Station coverage gap: 88°
Stations used: 120

Nearby

Within 100 km, magnitude 1.5 and up: 156 in the 60 days after this one and 89 in the 30 days before it.

After

The first 60 of 156.

Before

Earthquakes today Alaska earthquakes Live radar here

Sources

From the USGS Earthquake Hazards Program and its partner networks, event us6000bifv (also filed as ak020akhwmxm). Read Tue, Sep 29, 2026, 2:15 AM UTC.