Alaska earthquakes

M3.9 earthquake 49 km S of Sand Point, Alaska

A magnitude 3.9 earthquake struck 49 km S of Sand Point, Alaska on Sat, Aug 15, 2020, 4:57 PM AKDT (00:57 UTC), 40 km (25 mi) below the surface.

A larger quake followed: M5.9 68 km SE 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.

Open the live map with earthquakes

The earthquake

Magnitude: 3.9 (mwr), minor
Local time: Sat, Aug 15, 2020, 4:57 PM AKDT
UTC: 2020-08-16 00:57:43 UTC
Depth: 40.1 km (24.9 mi), shallow
Epicenter: 54.897° N, 160.362° 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: Reverse (thrust)
Moment magnitude: 3.9 Mwr
Nodal plane 1: Strike 56°, dip 78°, rake 95°
Nodal plane 2: Strike 214°, dip 13°, rake 69°

How well it is located

Reviewed by a seismologist.

Location uncertainty: About 5.1 km horizontally, 5.2 km in depth
Magnitude uncertainty: ±0.05
Depth from: From location
Station coverage gap: 98°
Stations used: 134

Nearest places

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

Sand Point, AlaskaPopulation 1,064. Forecast50 kmS

Nearby

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

After

The first 60 of at least 200.

Before

Earthquakes today Alaska earthquakes Live radar here

Sources

From the USGS Earthquake Hazards Program and its partner networks, event us6000bfe6 (also filed as ak020aiqes6i). Read Sun, Sep 27, 2026, 5:10 AM UTC.