Alaska earthquakes

M3.4 earthquake 157 km W of Nikolski, Alaska

A magnitude 3.4 earthquake struck 157 km W of Nikolski, Alaska on Fri, Sep 18, 2020, 2:20 PM HADT (23:20 UTC), 219 km (136 mi) below the surface.

A larger quake followed: M4.3 130 km ENE of Atka, Alaska. This one was a foreshock.

Map

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The earthquake

Magnitude: 3.4 (ml), minor
Local time: Fri, Sep 18, 2020, 2:20 PM HADT
UTC: 2020-09-18 23:20:59 UTC
Depth: 218.9 km (136.0 mi), intermediate-depth
Epicenter: 52.850° N, 171.199° 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 11.9 km horizontally, 15.2 km in depth
Magnitude uncertainty: ±0.09
Depth from: From location
Station coverage gap: 167°
Stations used: 22

Nearby

Within 100 km, magnitude 1.5 and up: 11 in the 60 days after this one and 3 in the 30 days before it.

After

Before

Earthquakes today Alaska earthquakes Live radar here

Sources

From the USGS Earthquake Hazards Program and its partner networks, event us6000c2pv (also filed as ak020c1omb7r). Read Wed, Sep 30, 2026, 4:04 AM UTC.