Alaska earthquakes

M4.6 earthquake 271 km ESE of Chiniak, Alaska

A magnitude 4.6 earthquake struck 271 km ESE of Chiniak, Alaska on Tue, Feb 6, 2018, 6:16 AM AKST (15:16 UTC), 10 km (6 mi) below the surface.

A larger quake followed: M5.4 252 km ESE of Chiniak, Alaska. This one was a foreshock.

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Map

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

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The earthquake

Magnitude: 4.6 (mwr), light
Local time: Tue, Feb 6, 2018, 6:16 AM AKST
UTC: 2018-02-06 15:16:23 UTC
Depth: 10.0 km (6.2 mi), shallow
Epicenter: 56.404° N, 148.402° W
Region: Alaska
Tsunami flag: Yes: a large quake in an oceanic region
Status: Reviewed by a seismologist

Tsunami

The USGS flags a quake this large in an oceanic region. The flag does not mean a tsunami happened; the tsunami warning centers decide that, and their messages are below when they issued any.

Current tsunami warnings: tsunami.gov. Warnings in force in the US also appear on our alerts pages.

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: Oblique normal
Moment magnitude: 4.6 Mwr
Nodal plane 1: Strike 341°, dip 84°, rake -139°
Nodal plane 2: Strike 246°, dip 49°, rake -8°

How well it is located

Reviewed by a seismologist.

Location uncertainty: About 6.8 km horizontally, 1.9 km in depth
Magnitude uncertainty: ±0.04
Depth from: Operator assigned
Station coverage gap: 138°
Stations used: 70

Nearest places

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

Nearby

Within 100 km, magnitude 1.6 and up: at least 202 in the 60 days after this one and at least 200 in the 30 days before it.

After

The first 60 of at least 202.

Before

Earthquakes today Alaska earthquakes Live radar here

Sources

From the USGS Earthquake Hazards Program and its partner networks, event us1000chh4 (also filed as ak18371148, at00p3qifd, ak0181pfwtza). Read Tue, Sep 29, 2026, 8:45 AM UTC.