Alaska earthquakes

M4.3 earthquake 115 km SSW of False Pass, Alaska

A magnitude 4.3 earthquake struck 115 km SSW of False Pass, Alaska on Sun, Mar 5, 2023, 5:59 PM AKST (02:59 UTC), 44 km (28 mi) below the surface.

A larger quake followed: M4.5 Unimak Island region, Alaska. This one was a foreshock.

Akutan 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: 4.3 (mwr), light
Local time: Sun, Mar 5, 2023, 5:59 PM AKST
UTC: 2023-03-06 02:59:36 UTC
Depth: 44.5 km (27.6 mi), shallow
Epicenter: 53.863° N, 163.912° W
Region: Alaska
Strongest shaking: II, weak shaking
Tsunami flag: No
Status: Reviewed by a seismologist

Shaking

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

Strongest estimated: II, weak shaking
Peak ground acceleration: 0.1% of gravity
Peak ground velocity: -2.2 cm/s
Map: Automatic

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

Did you feel it?

No one has reported feeling this quake to the USGS.

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: 4.3 Mwr
Nodal plane 1: Strike 127°, dip 54°, rake -8°
Nodal plane 2: Strike 222°, dip 84°, rake -143°

How well it is located

Reviewed by a seismologist.

Location uncertainty: About 4.6 km horizontally, 6.4 km in depth
Magnitude uncertainty: ±0.07
Depth from: From location
Station coverage gap: 153°
Stations used: 93

Nearest places

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

Akutan, AlaskaPopulation 1,040. Forecast125 kmESE

Nearby

Within 100 km, magnitude 1.5 and up: 131 in the 60 days after this one and 60 in the 30 days before it.

After

The first 60 of 131.

Before

Earthquakes today Alaska earthquakes Live radar here

Sources

From the USGS Earthquake Hazards Program and its partner networks, event us7000jhk3 (also filed as ak0232zjh5db). Read Wed, Sep 30, 2026, 3:59 AM UTC.