Alaska earthquakes

M4.3 earthquake 146 km SSE of Sand Point, Alaska

A magnitude 4.3 earthquake struck 146 km SSE of Sand Point, Alaska on Wed, Oct 21, 2020, 3:34 AM AKDT (11:34 UTC), 26 km (16 mi) below the surface.

A larger quake followed: M5.3 203 km S of Sand Point, Alaska. This one was a foreshock.

Sand Point 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 (mwr), light
Local time: Wed, Oct 21, 2020, 3:34 AM AKDT
UTC: 2020-10-21 11:34:52 UTC
Depth: 25.8 km (16.0 mi), shallow
Epicenter: 54.102° N, 159.713° 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: 4.3 Mwr
Nodal plane 1: Strike 353°, dip 80°, rake -167°
Nodal plane 2: Strike 260°, dip 78°, rake -11°

How well it is located

Reviewed by a seismologist.

Location uncertainty: About 2.9 km horizontally, 5.8 km in depth
Magnitude uncertainty: ±0.09
Depth from: From location
Station coverage gap: 163°
Stations used: 111

Nearest places

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

Sand Point, AlaskaPopulation 1,064. Forecast146 kmSSE

Nearby

Within 100 km, magnitude 1.5 and up: at least 202 in the 60 days after this one and at least 200 in the 30 days before it.

After

The first 60 of at least 202.

Before

Earthquakes today Alaska earthquakes Live radar here

Sources

From the USGS Earthquake Hazards Program and its partner networks, event us6000calf (also filed as ak020dk2ajt4). Read Sun, Sep 27, 2026, 6:34 PM UTC.