Alaska earthquakes

M2.9 earthquake 35 km W of Adak, Alaska

A magnitude 2.9 earthquake struck 35 km W of Adak, Alaska on Mon, Dec 18, 2023, 9:31 PM HAST (07:31 UTC), 5 km (3 mi) below the surface.

A larger quake followed: M4.5 125 km SW of Adak, Alaska. This one was a foreshock.

Map

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

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The earthquake

Magnitude: 2.9 (ML, local (Richter)), micro
Magnitude from: USGS National Earthquake Information Center
Local time: Mon, Dec 18, 2023, 9:31 PM HAST
UTC: 2023-12-19 07:31:38 UTC
Depth: 5.0 km (3.1 mi), shallow
Epicenter: 51.904° N, 177.146° 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
2.9	ML, local (Richter)	USGS National Earthquake Information Center	Preferred · Reviewed · ±0.105 · 12 stations
2.7	ML, local (Richter)	Alaska Earthquake Center	Preliminary
2.59	ML, local (Richter)	AV	Final · ±0.1704871634725 · 9 stations

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 1.2 km horizontally, 1.4 km in depth
Magnitude uncertainty: ±0.10
Depth from: Operator assigned
Station coverage gap: 86°
Stations used: 15

Nearby

Within 100 km, magnitude 1.5 and up: 141 in the 60 days after this one and 111 in the 30 days before it.

After

The first 60 of 141.

Before

Earthquakes today Alaska earthquakes Live radar here

Sources

From the USGS Earthquake Hazards Program and its partner networks, event us7000lk7b (also filed as av92158321, ak023g7x29sg). Read Sat, Oct 3, 2026, 3:09 AM UTC.