Alaska earthquakes

M4.2 earthquake 265 km WSW of Adak, Alaska

A magnitude 4.2 earthquake struck 265 km WSW of Adak, Alaska on Thu, Apr 19, 2018, 5:24 AM GMT+12 (17:24 UTC), 10 km (6 mi) below the surface.

A larger quake followed: M4.4 296 km SW of Adak, Alaska. This one was a foreshock.

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The earthquake

Magnitude: 4.2 (mb, body-wave), light
Magnitude from: USGS National Earthquake Information Center
Local time: Thu, Apr 19, 2018, 5:24 AM GMT+12
UTC: 2018-04-18 17:24:40 UTC
Depth: 10.0 km (6.2 mi), shallow
Epicenter: 50.773° N, 179.980° 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
4.2	mb, body-wave	USGS National Earthquake Information Center	Preferred · Reviewed · ±0.061 · 74 stations
4.2	mb, body-wave	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 7.2 km horizontally, 2.0 km in depth
Magnitude uncertainty: ±0.06
Depth from: Operator assigned
Station coverage gap: 217°, poorly surrounded by stations
Stations used: 69

Nearby

Within 100 km, magnitude 1.5 and up: 56 in the 60 days after this one and 20 in the 30 days before it.

After

Before

Earthquakes today Alaska earthquakes Live radar here

Sources

From the USGS Earthquake Hazards Program and its partner networks, event us1000dn7e (also filed as ak0184ywb3c5, ak19242521). Read Fri, Oct 2, 2026, 3:17 AM UTC.