Alaska earthquakes

M3.2 earthquake 122 km S of Unalaska, Alaska

A magnitude 3.2 earthquake struck 122 km S of Unalaska, Alaska on Wed, Feb 21, 2018, 7:58 PM AKST (04:58 UTC), 5 km (3 mi) below the surface.

A larger quake followed: M4.3 135 km SSE of Unalaska, 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: 3.2 (ML, local (Richter)), minor
Magnitude from: USGS National Earthquake Information Center
Local time: Wed, Feb 21, 2018, 7:58 PM AKST
UTC: 2018-02-22 04:58:58 UTC
Depth: 5.0 km (3.1 mi), shallow
Epicenter: 52.778° N, 166.721° W
Region: Alaska
Tsunami flag: No
Status: Reviewed by a seismologist

Magnitude estimates

Different scales measure different things and differ by a few tenths. The USGS marks one as preferred, and it is the one this page uses.

Mag.	Scale	Computed by	Notes
3.2	ML, local (Richter)	USGS National Earthquake Information Center	Preferred · Reviewed · ±0.148 · 6 stations
2.8	ML, local (Richter)	Alaska Earthquake Center	Preliminary

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 4.3 km horizontally, 2.0 km in depth
Magnitude uncertainty: ±0.15
Depth from: Operator assigned
Station coverage gap: 213°, poorly surrounded by stations
Stations used: 29

Nearest places

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

Unalaska, AlaskaPopulation 4,491. Forecast123 kmS

Nearby

Within 100 km, magnitude 1.5 and up: 73 in the 60 days after this one and 29 in the 30 days before it.

After

The first 60 of 73.

Before

Earthquakes today Alaska earthquakes Live radar here

Sources

From the USGS Earthquake Hazards Program and its partner networks, event us2000d9wh (also filed as ak18483825, ak0182fq7ola). Read Thu, Oct 1, 2026, 3:25 AM UTC.