Alaska earthquakes

M3.4 earthquake 28 km SW of Adak, Alaska

A magnitude 3.4 earthquake struck 28 km SW of Adak, Alaska on Mon, Jul 16, 2018, 3:35 PM HADT (00:35 UTC), 65 km (41 mi) below the surface.

A larger quake followed: M6.5 108 km WSW of Adak, Alaska. This one was a foreshock.

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The earthquake

Magnitude: 3.4 (ML, local (Richter)), minor
Magnitude from: USGS National Earthquake Information Center
Local time: Mon, Jul 16, 2018, 3:35 PM HADT
UTC: 2018-07-17 00:35:18 UTC
Depth: 65.2 km (40.5 mi), shallow
Epicenter: 51.716° N, 176.964° 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
3.4	ML, local (Richter)	USGS National Earthquake Information Center	Preferred · Reviewed
3.4	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 10.0 km horizontally, 13.0 km in depth
Depth from: From location
Station coverage gap: 201°, poorly surrounded by stations
Stations used: 28

Nearby

Within 100 km, magnitude 1.5 and up: at least 201 in the 60 days after this one and 76 in the 30 days before it.

After

The first 60 of at least 201.

Before

Earthquakes today Alaska earthquakes Live radar here

Sources

From the USGS Earthquake Hazards Program and its partner networks, event us2000ga0k (also filed as ak19881055, ak01893gm96t). Read Thu, Oct 1, 2026, 11:05 PM UTC.