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.

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The earthquake

Magnitude
3.4 (ml), minor
Local time
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 todayAlaska earthquakesLive 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.