Alaska earthquakes

M1.9 earthquake 127 km W of Adak, Alaska

A magnitude 1.9 earthquake struck 127 km W of Adak, Alaska on Wed, Apr 4, 2018, 2:47 AM HADT (11:47 UTC), 15 km (9 mi) below the surface.

A larger quake followed: M4.5 208 km W of Adak, 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: 1.9 (ML, local (Richter)), micro
Magnitude from: Alaska Earthquake Center
Local time: Wed, Apr 4, 2018, 2:47 AM HADT
UTC: 2018-04-04 11:47:08 UTC
Depth: 15.0 km (9.3 mi), shallow
Epicenter: 51.711° N, 178.467° 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
1.9	ML, local (Richter)	Alaska Earthquake Center	Preferred · Preliminary
1.43	ML, local (Richter)	AV	Final · ±0.122 · 4 stations

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: 17

Nearby

Within 100 km, magnitude 1.5 and up: 66 in the 60 days after this one and 79 in the 30 days before it.

After

The first 60 of 66.

Before

Earthquakes today Alaska earthquakes Live radar here

Sources

From the USGS Earthquake Hazards Program and its partner networks, event ak0184bnchef (also filed as ak19213599, av61693711). Read Fri, Oct 2, 2026, 4:11 AM UTC.