Alaska earthquakes

M4.2 earthquake 289 km SE of Chiniak, Alaska

A magnitude 4.2 earthquake struck 289 km SE of Chiniak, Alaska on Sat, Jan 27, 2018, 7:44 PM AKST (04:44 UTC), 10 km (6 mi) below the surface.

A larger quake followed: M5.1 233 km SE of Chiniak, 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: 4.2 (Mww, W-phase moment), light
Magnitude from: USGS National Earthquake Information Center
Local time: Sat, Jan 27, 2018, 7:44 PM AKST
UTC: 2018-01-28 04:44:03 UTC
Depth: 10.0 km (6.2 mi), shallow
Epicenter: 55.628° N, 149.217° W
Region: Alaska
Felt reports: 1
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	Mww, W-phase moment	USGS National Earthquake Information Center	Preferred · Reviewed · ±0.11 · 8 stations
4.2	Mw, moment	Alaska Earthquake Center	Preliminary
4.0	Mwr, regional moment	USGS National Earthquake Information Center	Moment tensor · Reviewed

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: Reverse (thrust)
Moment magnitude: 4.2 Mww
Nodal plane 1: Strike 292°, dip 31°, rake 85°
Nodal plane 2: Strike 118°, dip 59°, rake 93°

How well it is located

Reviewed by a seismologist.

Location uncertainty: About 5.2 km horizontally, 1.8 km in depth
Magnitude uncertainty: ±0.11
Depth from: Operator assigned
Station coverage gap: 148°
Stations used: 202

Nearby

Within 100 km, magnitude 1.5 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 us2000cqjl (also filed as ak18214986, ak0181adow92). Read Fri, Oct 2, 2026, 3:05 PM UTC.