Alaska earthquakes

M4.5 earthquake 151 km S of False Pass, Alaska

A magnitude 4.5 earthquake struck 151 km S of False Pass, Alaska on Sun, Aug 23, 2020, 2:40 PM AKDT (22:40 UTC), 35 km (22 mi) below the surface.

A larger quake followed: M4.7 156 km SSE of Akutan, Alaska. This one was a foreshock.

Akutan 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: 4.5 (mwr), light
Local time: Sun, Aug 23, 2020, 2:40 PM AKDT
UTC: 2020-08-23 22:40:41 UTC
Depth: 35.0 km (21.7 mi), shallow
Epicenter: 53.501° N, 163.718° 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.

Fault motion and ground failure

How the rock slipped, from the moment tensor, and the USGS estimate of landslides and liquefaction.

Faulting: Strike-slip
Moment magnitude: 4.5 Mwr
Nodal plane 1: Strike 141°, dip 14°, rake -11°
Nodal plane 2: Strike 242°, dip 87°, rake -103°

How well it is located

Reviewed by a seismologist.

Location uncertainty: About 5.4 km horizontally, 1.9 km in depth
Magnitude uncertainty: ±0.04
Depth from: Operator assigned
Station coverage gap: 164°
Stations used: 213

Nearest places

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

Akutan, AlaskaPopulation 1,040. Forecast152 kmESE

Nearby

Within 100 km, magnitude 1.5 and up: 71 in the 60 days after this one and 87 in the 30 days before it.

After

The first 60 of 71.

Before

Earthquakes today Alaska earthquakes Live radar here

Sources

From the USGS Earthquake Hazards Program and its partner networks, event us6000bjj5 (also filed as ak020auo63fj). Read Sat, Sep 26, 2026, 4:30 PM UTC.