Alaska earthquakes

M4.2 earthquake 250 km W of Adak, Alaska

A magnitude 4.2 earthquake struck 250 km W of Adak, Alaska on Sun, Oct 16, 2016, 9:28 AM GMT+12 (21:28 UTC), 184 km (114 mi) below the surface.

A larger quake followed: M5.3 Rat Islands, Aleutian Islands, Alaska. This one was a foreshock.

Map

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The earthquake

Magnitude: 4.2 (mb, body-wave), light
Magnitude from: USGS National Earthquake Information Center
Local time: Sun, Oct 16, 2016, 9:28 AM GMT+12
UTC: 2016-10-15 21:28:08 UTC
Depth: 183.7 km (114.1 mi), intermediate-depth
Epicenter: 52.072° N, 179.739° E
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
4.2	mb, body-wave	USGS National Earthquake Information Center	Preferred · Reviewed · ±0.108 · 24 stations
4.2	mb, body-wave	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 10.2 km horizontally, 9.0 km in depth
Magnitude uncertainty: ±0.11
Station coverage gap: 161°
Stations used: 26

Nearby

Within 100 km, magnitude 1.5 and up: 44 in the 60 days after this one and 31 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 us20007fnq (also filed as ak14254309, ak016daazf5b). Read Sat, Oct 3, 2026, 4:03 PM UTC.