Alaska earthquakes

M3.7 earthquake 34 km W of Cantwell, Alaska

A magnitude 3.7 earthquake struck 34 km W of Cantwell, Alaska on Thu, Sep 20, 2018, 10:42 AM AKDT (18:42 UTC), 101 km (63 mi) below the surface.

A larger quake followed: M3.9 64 km N of Petersville, Alaska. This one was a foreshock.

Healy forecast More in Alaska

Map

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

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The earthquake

Magnitude: 3.7 (ML, local (Richter)), minor
Magnitude from: Alaska Earthquake Center
Local time: Thu, Sep 20, 2018, 10:42 AM AKDT
UTC: 2018-09-20 18:42:46 UTC
Depth: 100.8 km (62.6 mi), intermediate-depth
Epicenter: 63.341° N, 149.622° 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
3.7	ML, local (Richter)	Alaska Earthquake Center	Preferred · Preliminary
3.7	ML, local (Richter)	USGS National Earthquake Information Center	Reviewed

Did you feel it?

No one has reported feeling this quake to the USGS.

How well it is located

Reviewed by a seismologist.

Stations used: 248

Nearest places

Distance and direction from each place to the epicenter, with its forecast.

Nearby

Within 100 km, magnitude 1.5 and up: 194 in the 60 days after this one and 79 in the 30 days before it.

After

The first 60 of 194.

Before

Earthquakes today Alaska earthquakes Live radar here

Sources

From the USGS Earthquake Hazards Program and its partner networks, event ak018c39b6e8 (also filed as ak20259703, us2000hhrq). Read Thu, Oct 1, 2026, 11:23 AM UTC.