Alaska earthquakes

M4.7 earthquake 172 km E of Atka, Alaska

A magnitude 4.7 earthquake struck 172 km E of Atka, Alaska on Fri, Apr 10, 2026, 3:39 PM HADT (00:39 UTC), 63 km (39 mi) below the surface.

A larger quake followed: M5.6 172 km ENE of Atka, 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: 4.7 (Mwr, regional moment), light
Magnitude from: USGS National Earthquake Information Center
Local time: Fri, Apr 10, 2026, 3:39 PM HADT
UTC: 2026-04-11 00:39:54 UTC
Depth: 62.9 km (39.1 mi), shallow
Epicenter: 52.127° N, 171.675° W
Region: Alaska
Strongest shaking: III, weak shaking
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
4.7	Mwr, regional moment	USGS National Earthquake Information Center	Preferred · Reviewed · ±0.058 · 29 stations
5.2	ML, local (Richter)	Alaska Earthquake Center	Reviewed · ±0.2 · 68 stations

Shaking

The USGS ShakeMap: shaking estimated from seismic stations and the quake’s size, on the Modified Mercalli intensity scale.

Strongest estimated: III, weak shaking
Peak ground acceleration: 1.2% of gravity
Peak ground velocity: 0.5 cm/s
Map: Automatic

USGS ShakeMap: estimated shaking intensity around the epicenter — Estimated shaking intensity. Map: USGS ShakeMap.

Did you feel it?

No one has reported feeling this quake to the USGS.

Fault motion and ground failure

How the rock slipped, from the moment tensor, and the USGS estimate of landslides and liquefaction.

Faulting: Strike-slip
Moment magnitude: 4.7 Mwr
Nodal plane 1: Strike 115°, dip 60°, rake 8°
Nodal plane 2: Strike 21°, dip 83°, rake 150°

How well it is located

Reviewed by a seismologist.

Location uncertainty: About 6.7 km horizontally, 5.8 km in depth
Magnitude uncertainty: ±0.06
Depth from: From location
Station coverage gap: 138°
Stations used: 83

Nearby

Within 100 km, magnitude 1.7 and up: 44 in the 60 days after this one and 16 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 us6000sp8g (also filed as aka2026hbpyvr). Read Thu, Oct 1, 2026, 6:56 AM UTC.