Alaska earthquakes

M2.7 earthquake 271 km WSW of Adak, Alaska

A magnitude 2.7 earthquake struck 271 km WSW of Adak, Alaska on Fri, Oct 21, 2016, 8:59 PM GMT+12 (08:59 UTC), 34 km (21 mi) below the surface.

A larger quake followed: M5.6 Rat Islands, Aleutian Islands, Alaska. This one was a foreshock.

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The earthquake

Magnitude: 2.7 (ML, local (Richter)), micro
Magnitude from: USGS National Earthquake Information Center
Local time: Fri, Oct 21, 2016, 8:59 PM GMT+12
UTC: 2016-10-21 08:59:51 UTC
Depth: 34.5 km (21.4 mi), shallow
Epicenter: 51.354° N, 179.539° 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
2.7	ML, local (Richter)	USGS National Earthquake Information Center	Preferred · Reviewed
2.7	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 12.0 km horizontally, 14.8 km in depth
Depth from: From location
Station coverage gap: 203°, poorly surrounded by stations
Stations used: 8

Nearby

Within 100 km, magnitude 1.5 and up: 83 in the 60 days after this one and 45 in the 30 days before it.

After

The first 60 of 83.

Before

Earthquakes today Alaska earthquakes Live radar here

Sources

From the USGS Earthquake Hazards Program and its partner networks, event us100072i7 (also filed as ak14251928, ak016dk0nlit). Read Sat, Oct 3, 2026, 3:05 PM UTC.