Alaska earthquakes

M4.7 earthquake 46 km W of Nikolski, Alaska

A magnitude 4.7 earthquake struck 46 km W of Nikolski, Alaska on Thu, Aug 30, 2018, 4:21 PM AKDT (00:21 UTC), 7 km (4 mi) below the surface.

A larger quake followed: M4.8 72 km SSE of Nikolski, 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: 4.7 (mb, body-wave), light
Magnitude from: USGS National Earthquake Information Center
Local time: Thu, Aug 30, 2018, 4:21 PM AKDT
UTC: 2018-08-31 00:21:43 UTC
Depth: 6.6 km (4.1 mi), shallow
Epicenter: 52.868° N, 169.549° W
Region: Alaska
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	mb, body-wave	USGS National Earthquake Information Center	Preferred · Reviewed · ±0.026 · 436 stations
4.7	Mw, moment	Alaska Earthquake Center	Preliminary
4.55	ML, local (Richter)	AV	Final · ±0.257 · 17 stations

Did you feel it?

No one has reported feeling this quake to the USGS.

How well it is located

Reviewed by a seismologist.

Location uncertainty: About 6.5 km horizontally, 5.0 km in depth
Magnitude uncertainty: ±0.03
Depth from: From location
Station coverage gap: 138°
Stations used: 518

Nearest places

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

Unalaska, AlaskaPopulation 4,491. Forecast229 kmWSW

Nearby

Within 100 km, magnitude 1.7 and up: 96 in the 60 days after this one and 29 in the 30 days before it.

After

The first 60 of 96.

Before

Earthquakes today Alaska earthquakes Live radar here

Sources

From the USGS Earthquake Hazards Program and its partner networks, event us2000h5tp (also filed as ak20238487, ak018b5vpx7q, av61768001). Read Thu, Oct 1, 2026, 8:48 AM UTC.