Alaska earthquakes

M2.8 earthquake 254 km W of Adak, Alaska

A magnitude 2.8 earthquake struck 254 km W of Adak, Alaska on Sun, Jul 23, 2017, 7:40 PM GMT+12 (07:40 UTC), 77 km (48 mi) below the surface.

A larger quake followed: M4.8 Rat Islands, Aleutian Islands, 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: 2.8 (ML, local (Richter)), micro
Magnitude from: USGS National Earthquake Information Center
Local time: Sun, Jul 23, 2017, 7:40 PM GMT+12
UTC: 2017-07-23 07:40:54 UTC
Depth: 77.3 km (48.0 mi), intermediate-depth
Epicenter: 51.563° N, 179.710° 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
2.8	ML, local (Richter)	USGS National Earthquake Information Center	Preferred · Reviewed
2.8	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 4.9 km horizontally, 6.2 km in depth
Stations used: 29

Nearby

Within 100 km, magnitude 1.5 and up: 134 in the 60 days after this one and 64 in the 30 days before it.

After

The first 60 of 134.

Before

Earthquakes today Alaska earthquakes Live radar here

Sources

From the USGS Earthquake Hazards Program and its partner networks, event us2000a7i9 (also filed as ak16366365, ak0179di1iuy). Read Sat, Oct 3, 2026, 1:15 AM UTC.