Alaska earthquakes

M3.8 earthquake 128 km SW of Adak, Alaska

A magnitude 3.8 earthquake struck 128 km SW of Adak, Alaska on Sun, Aug 9, 2020, 5:42 PM HADT (02:42 UTC), 26 km (16 mi) below the surface.

A larger quake followed: M4.8 193 km WSW of Adak, Alaska. This one was a foreshock.

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The earthquake

Magnitude
3.8 (mb), minor
Local time
UTC
2020-08-10 02:42:36 UTC
Depth
26.1 km (16.2 mi), shallow
Epicenter
51.227° N, 178.173° 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 4.9 km horizontally, 12.0 km in depth
Magnitude uncertainty
±0.12
Depth from
From location
Station coverage gap
209°, poorly surrounded by stations
Stations used
50

Nearby

Within 100 km, magnitude 1.5 and up: 175 in the 60 days after this one and 95 in the 30 days before it.

After

The first 60 of 175.

Before

Earthquakes todayAlaska earthquakesLive radar here

Sources

From the USGS Earthquake Hazards Program and its partner networks, event us7000bdq0 (also filed as ak020a8uabww). Read Mon, Sep 28, 2026, 10:22 PM UTC.