Alaska earthquakes

M3.9 earthquake 138 km WNW of Adak, Alaska

A magnitude 3.9 earthquake struck 138 km WNW of Adak, Alaska on Tue, Jul 7, 2020, 10:05 PM HADT (07:05 UTC), 180 km (112 mi) below the surface.

A larger quake followed: M5.2 52 km WNW of Adak, Alaska. This one was a foreshock.

Map

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The earthquake

Magnitude: 3.9 (mb), minor
Local time: Tue, Jul 7, 2020, 10:05 PM HADT
UTC: 2020-07-08 07:05:39 UTC
Depth: 179.6 km (111.6 mi), intermediate-depth
Epicenter: 52.271° N, 178.550° 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 8.2 km horizontally, 4.6 km in depth
Magnitude uncertainty: ±0.12
Depth from: From location
Station coverage gap: 49°
Stations used: 67

Nearby

Within 100 km, magnitude 1.5 and up: 93 in the 60 days after this one and 35 in the 30 days before it.

After

The first 60 of 93.

Before

Earthquakes today Alaska earthquakes Live radar here

Sources

From the USGS Earthquake Hazards Program and its partner networks, event us7000ajws (also filed as ak0208qcb4oe). Read Tue, Sep 29, 2026, 2:34 PM UTC.