Alaska earthquakes

M4.1 earthquake 25 km SSW of Adak, Alaska

A magnitude 4.1 earthquake struck 25 km SSW of Adak, Alaska on Sun, Dec 4, 2016, 10:21 AM HAST (20:21 UTC), 70 km (43 mi) below the surface.

A larger quake followed: M4.9 107 km WSW of Adak, Alaska. This one was a foreshock.

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

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The earthquake

Magnitude
4.1 (mb, body-wave), light
Magnitude from
USGS National Earthquake Information Center
Local time
UTC
2016-12-04 20:21:01 UTC
Depth
69.5 km (43.2 mi), shallow
Epicenter
51.675° N, 176.811° 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
4.1mb, body-waveUSGS National Earthquake Information CenterPreferred · Reviewed · ±0.077 · 46 stations
4.1mb, body-waveAlaska 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 7.3 km horizontally, 9.5 km in depth
Magnitude uncertainty
±0.08
Depth from
From location
Station coverage gap
71°
Stations used
59

Nearby

Within 100 km, magnitude 1.5 and up: at least 199 in the 60 days after this one and 58 in the 30 days before it.

After

The first 60 of at least 199.

Before

Earthquakes todayAlaska earthquakesLive radar here

Sources

From the USGS Earthquake Hazards Program and its partner networks, event us10007ewl (also filed as ak14582424, ak016fkz7tkw). Read Sat, Oct 3, 2026, 3:05 PM UTC.