Alaska earthquakes

M3.9 earthquake 73 km NNE of Adak, Alaska

A magnitude 3.9 earthquake struck 73 km NNE of Adak, Alaska on Sat, Oct 15, 2016, 2:40 PM HADT (23:40 UTC), 194 km (121 mi) below the surface.

A larger quake followed: M5.0 44 km ESE of Adak, Alaska. This one was a foreshock.

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 (mb, body-wave), minor
Magnitude from: USGS National Earthquake Information Center
Local time: Sat, Oct 15, 2016, 2:40 PM HADT
UTC: 2016-10-15 23:40:49 UTC
Depth: 194.2 km (120.6 mi), intermediate-depth
Epicenter: 52.492° N, 176.245° 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.	Scale	Computed by	Notes
3.9	mb, body-wave	USGS National Earthquake Information Center	Preferred · Reviewed · ±0.133 · 15 stations
3.3	ML, local (Richter)	Alaska Earthquake Center	Preliminary

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 15.1 km horizontally, 9.7 km in depth
Magnitude uncertainty: ±0.13
Depth from: From location
Station coverage gap: 148°
Stations used: 27

Nearby

Within 100 km, magnitude 1.5 and up: 23 in the 60 days after this one and 21 in the 30 days before it.

After

Before

Earthquakes today Alaska earthquakes Live radar here

Sources

From the USGS Earthquake Hazards Program and its partner networks, event us20007g1s (also filed as ak14212549, ak016dac8y7f). Read Sun, Oct 4, 2026, 3:13 PM UTC.