Alaska earthquakes

M4.3 earthquake 117 km SSW of Nikolski, Alaska

A magnitude 4.3 earthquake struck 117 km SSW of Nikolski, Alaska on Mon, Sep 28, 2020, 5:15 PM AKDT (01:15 UTC), 10 km (6 mi) below the surface.

A larger quake followed: M4.9 125 km SSW of Nikolski, Alaska. This one was a foreshock.

Unalaska forecast More in Alaska

Map

Where this earthquake was located, with the others nearby. Select one for its page.

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The earthquake

Magnitude: 4.3 (mb), light
Local time: Mon, Sep 28, 2020, 5:15 PM AKDT
UTC: 2020-09-29 01:15:15 UTC
Depth: 10.0 km (6.2 mi), shallow
Epicenter: 51.968° N, 169.553° 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 5.2 km horizontally, 1.9 km in depth
Magnitude uncertainty: ±0.06
Depth from: Operator assigned
Station coverage gap: 128°
Stations used: 179

Nearest places

Distance and direction from each place to the epicenter, with its forecast.

Unalaska, AlaskaPopulation 4,491. Forecast293 kmSW

Nearby

Within 100 km, magnitude 1.5 and up: 17 in the 60 days after this one and 17 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 us6000c2d0 (also filed as ak020cjieflr). Read Tue, Sep 29, 2026, 11:21 PM UTC.