Alaska earthquakes

M4.5 earthquake Alaska Peninsula

A magnitude 4.5 earthquake struck in the Alaska Peninsula on Tue, Mar 28, 2017, 12:59 PM AKDT (20:59 UTC), 46 km (28 mi) below the surface.

Womens Bay forecast More in Alaska

Map

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

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The earthquake

Magnitude: 4.5 (Mw, moment), light
Magnitude from: Alaska Earthquake Center
Local time: Tue, Mar 28, 2017, 12:59 PM AKDT
UTC: 2017-03-28 20:59:58 UTC
Depth: 45.6 km (28.3 mi), shallow
Epicenter: 56.312° N, 156.240° W
Region: Alaska
Felt reports: 1
Strongest shaking: III, weak shaking
PAGER alert: Green
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
4.5	Mw, moment	Alaska Earthquake Center	Preferred · Preliminary
4.5	Mwr, regional moment	USGS National Earthquake Information Center	Reviewed · ±0.053 · 34 stations

Shaking

The USGS ShakeMap: shaking estimated from seismic stations and the quake’s size, on the Modified Mercalli intensity scale.

Strongest estimated: III, weak shaking
Map: Automatic

USGS ShakeMap: estimated shaking intensity around the epicenter — Estimated shaking intensity. Map: USGS ShakeMap.

Did you feel it?

1 person reported to the USGS what they felt; the strongest reported shaking was I, not felt shaking.

Estimated impact

The USGS PAGER system estimates deaths and economic losses from the shaking and the population and buildings exposed to it.

Alert level: Green: little or no damage or loss of life expected

Fault motion and ground failure

How the rock slipped, from the moment tensor, and the USGS estimate of landslides and liquefaction.

Faulting: Oblique reverse
Moment magnitude: 4.5 Mwr
Nodal plane 1: Strike 186°, dip 80°, rake 143°
Nodal plane 2: Strike 284°, dip 54°, rake 12°

How well it is located

Reviewed by a seismologist.

Stations used: 148

Nearest places

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

Womens Bay, AlaskaPopulation 719. Forecast264 kmWSW

Nearby

Within 100 km, magnitude 1.5 and up: 48 in the 60 days after this one and 14 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 ak0174080mt2 (also filed as ak15644458, us20008ve9). Read Sun, Oct 4, 2026, 6:50 PM UTC.