Alaska earthquakes

M3.8 earthquake 28 km E of Sand Point, Alaska

A magnitude 3.8 earthquake struck 28 km E of Sand Point, Alaska on Wed, Sep 20, 2017, 1:37 AM AKDT (09:37 UTC), 69 km (43 mi) below the surface.

A larger quake followed: M4.5 84 km ESE of Sand Point, Alaska. This one was a foreshock.

Sand Point forecastMore in Alaska

Map

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

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The earthquake

Magnitude
3.8 (mb, body-wave), minor
Magnitude from
USGS National Earthquake Information Center
Local time
UTC
2017-09-20 09:37:07 UTC
Depth
69.1 km (42.9 mi), shallow
Epicenter
55.337° N, 160.054° W
Region
Alaska
Strongest shaking
III, weak shaking
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.ScaleComputed byNotes
3.8mb, body-waveUSGS National Earthquake Information CenterPreferred · Reviewed · ±0.18 · 8 stations
3.7ML, local (Richter)Alaska Earthquake CenterPreliminary

Shaking

The USGS ShakeMap: shaking estimated from seismic stations and the quake’s size, on the Modified Mercalli intensity scale.

Strongest estimated
III, weak shaking
Map
Automatic
USGS ShakeMap: estimated shaking intensity around the epicenter
Estimated shaking intensity. Map: USGS ShakeMap.

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, 7.7 km in depth
Magnitude uncertainty
±0.18
Depth from
From location
Station coverage gap
99°
Stations used
98

Nearest places

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

Nearby

Within 100 km, magnitude 1.5 and up: 28 in the 60 days after this one and 33 in the 30 days before it.

After

Before

Earthquakes todayAlaska earthquakesLive radar here

Sources

From the USGS Earthquake Hazards Program and its partner networks, event us2000arir (also filed as ak16867839, ak017c33x4h6). Read Thu, Oct 1, 2026, 10:01 PM UTC.