Alaska earthquakes

M3.3 earthquake 82 km S of Unalaska, Alaska

A magnitude 3.3 earthquake struck 82 km S of Unalaska, Alaska on Mon, Sep 11, 2017, 9:17 PM AKDT (05:17 UTC), 26 km (16 mi) below the surface.

A larger quake followed: M4.6 109 km S of Unalaska, Alaska. This one was a foreshock.

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Map

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

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The earthquake

Magnitude
3.3 (ML, local (Richter)), minor
Magnitude from
USGS National Earthquake Information Center
Local time
UTC
2017-09-12 05:17:33 UTC
Depth
25.6 km (15.9 mi), shallow
Epicenter
53.143° N, 166.723° 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.ScaleComputed byNotes
3.3ML, local (Richter)USGS National Earthquake Information CenterPreferred · Reviewed · ±0.148 · 6 stations
2.5ML, local (Richter)Alaska Earthquake CenterPreliminary

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 5.5 km horizontally, 8.9 km in depth
Magnitude uncertainty
±0.15
Stations used
25

Nearest places

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

Nearby

Within 100 km, magnitude 1.5 and up: 100 in the 60 days after this one and 67 in the 30 days before it.

After

The first 60 of 100.

Before

Earthquakes todayAlaska earthquakesLive radar here

Sources

From the USGS Earthquake Hazards Program and its partner networks, event us2000aq5g (also filed as ak16820908, ak017bpt4dom). Read Thu, Oct 1, 2026, 7:48 PM UTC.