Alaska earthquakes

M5.3 earthquake 139 km ESE of Nikolski, Alaska

A magnitude 5.3 earthquake struck 139 km ESE of Nikolski, Alaska on Mon, Sep 23, 2019, 9:51 AM AKDT (17:51 UTC), 10 km (6 mi) below the surface.

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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: 5.3 (Mww, W-phase moment), moderate
Magnitude from: USGS National Earthquake Information Center
Local time: Mon, Sep 23, 2019, 9:51 AM AKDT
UTC: 2019-09-23 17:51:10 UTC
Depth: 10.0 km (6.2 mi), shallow
Epicenter: 52.533° N, 166.907° 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
5.3	Mww, W-phase moment	USGS National Earthquake Information Center	Preferred · Reviewed · ±0.05 · 39 stations
5.35	Mw, moment	ISC-GEM global catalog	Final · ±0.1
5.3	Mww, W-phase moment	Alaska Earthquake Center	Preliminary

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: 5.3 Mww
Nodal plane 1: Strike 245°, dip 30°, rake 91°
Nodal plane 2: Strike 64°, dip 60°, rake 89°

How well it is located

Reviewed by a seismologist.

Location uncertainty: About 4.7 km horizontally, 1.8 km in depth
Magnitude uncertainty: ±0.05
Depth from: Operator assigned
Station coverage gap: 170°
Stations used: 114

Nearest places

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

Unalaska, AlaskaPopulation 4,491. Forecast151 kmS

Nearby

Within 100 km, magnitude 2.3 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 us60005mbn (also filed as ak019c87dmyu, iscgem616494075). Read Fri, Oct 2, 2026, 6:45 PM UTC.