Alaska earthquakes

M4.8 earthquake 218 km SE of Chiniak, Alaska

A magnitude 4.8 earthquake struck 218 km SE of Chiniak, Alaska on Wed, Feb 7, 2018, 6:58 PM AKST (03:58 UTC), 18 km (11 mi) below the surface.

A larger quake followed: M5.2 228 km SE 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: 4.8 (mww), light
Local time: Wed, Feb 7, 2018, 6:58 PM AKST
UTC: 2018-02-08 03:58:01 UTC
Depth: 18.0 km (11.2 mi), shallow
Epicenter: 56.003° N, 150.237° W
Region: Alaska
Felt reports: 1
Tsunami flag: No
Status: Reviewed by a seismologist

Did you feel it?

1 person reported to the USGS what they felt; the strongest reported shaking was II, weak shaking.

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: 4.8 Mww
Nodal plane 1: Strike 266°, dip 83°, rake 3°
Nodal plane 2: Strike 175°, dip 87°, rake 173°

How well it is located

Reviewed by a seismologist.

Location uncertainty: About 5.8 km horizontally, 1.8 km in depth
Magnitude uncertainty: ±0.05
Depth from: From moment tensor inversion
Station coverage gap: 143°
Stations used: 146

Nearest places

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

Nearby

Within 100 km, magnitude 1.8 and up: at least 201 in the 60 days after this one and at least 200 in the 30 days before it.

After

The first 60 of at least 201.

Before

Earthquakes today Alaska earthquakes Live radar here

Sources

From the USGS Earthquake Hazards Program and its partner networks, event us2000cynn (also filed as ak0181sk39vs, ak18413493). Read Tue, Sep 29, 2026, 3:48 AM UTC.