Quakewire
← All earthquakes
4.0MAG

LIGHT EARTHQUAKE

187 km SW of Nikolski, Alaska

USGS

A magnitude 4.0 earthquake struck 187 km SW of Nikolski, Alaska on 17 Sept 2026, 14:34 UTC. The hypocentre was 20 km below the surface — shallow by seismological convention. The figures have been revised 1 time since the first report. 4 other earthquakes above our reporting threshold have been recorded within 250 km in the past 30 days.

Depth
20 km

shallow

Latitude
51.78°N

170.85°W longitude

Time
14:34 UTC

17 Sept 2026

Magnitude
M4.0

ml

EPICENTRE

View the official report

MAGNITUDE 4.0

Noticeable shaking of indoor objects. Damage is unlikely.

The scale is logarithmic: this released about 32 times the energy of a magnitude 3.0, roughly the energy of 15 tonnes of TNT.

20 KM DEEP

Shallow earthquakes release their energy close to the surface, so they are felt more strongly, and do more damage, than deeper earthquakes of the same magnitude.

NEARBY IN THE PAST 30 DAYS

4 earthquakes above our reporting threshold within 250 km of this one, the largest a magnitude 6.5.

OTHER RECENT EARTHQUAKES

M4.0 earthquake — Nikolski, Alaska · Quakewire