M5.4 earthquake 105 km SSW of Nikolski, Alaska

Thursday, September 3, 2026, 20:21:14 UTC · 52.015°N, 169.194°W

A magnitude 5.4 earthquake struck 105 km SSW of Nikolski, Alaska on Thursday, September 3, 2026, 20:21:14 UTC, at a depth of 10.0 km (shallow). The USGS PAGER alert is green: low likelihood of casualties and damage. It is the strongest earthquake within 300 km since an M6.3 on September 3, 2026.

Magnitude: 5.4; Moderate · mww
Depth: 10 km; Shallow
Felt reports: 0; Did You Feel It?
Est. shaking: III; Weak (ShakeMap)
PAGER alert: Green; Impact estimate
Tsunami: No flag; USGS feed

Outlined circle: this earthquakeDashed circle: 75 km aftershock search areaColoured lines: estimated shaking intensity (USGS ShakeMap)

In context

How big was it, and why here?

Energy released

2 kilotons of TNT

That is about 1/8 of the Hiroshima bomb. It released about 4 times the energy of a magnitude 5.0.

Tectonic setting

34 km

from the nearest mapped plate boundary, between the North American and Pacific plates. Earthquakes cluster along boundaries like this one, where plates collide, pull apart or slide past each other.

Depth: shallow

10 km

Shallow earthquakes (under 70 km) produce the strongest surface shaking for their size, so they are the ones most likely to cause damage near the epicenter.

Did You Feel It?

Where it was felt

No “Did You Feel It?” reports have been published for this event yet. If you felt it, you can add your report on the USGS website.

I felt it — report to USGS ↗

USGS PAGER estimate

Who was exposed to shaking

USGS publishes PAGER impact estimates for significant earthquakes, usually within an hour. No populated area was estimated to feel noticeable shaking.

After the main event

Aftershocks within 75 km

USGS lists 152 M2.5+ earthquakes within 75 km since this event; the largest was M5.0 on September 3, 2026. Most nearby activity right after a large earthquake is aftershocks, which usually become less frequent over days and weeks.

Time after the mainshock on a logarithmic scale (first hours stretched), magnitude on the vertical axis. M2.5+ events from USGS.

Regional history

Past M5+ earthquakes within 300 km

USGS lists 739 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:

History · NOAA

Deadliest earthquakes in this area

NOAA’s significant-earthquake database lists 12 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700. The most severe:

1901M7.8
Aleutian Islands: Fox Islands
31 Dec 1901 · 141 km away
Limited damage (under $1M)tsunami
1965M6.5
Aleutian Islands: Fox Islands
2 Jul 1965 · 158 km away
Limited damage (under $1M)tsunami
1902M7.8
Aleutian Islands: Fox Islands
1 Jan 1902 · 123 km away
1907M7.8
Aleutian Islands
2 Sep 1907 · 74 km away
1929M7.8
Aleutian Islands: Fox Islands
7 Mar 1929 · 126 km away · intensity V
tsunami
1916M7.5
Aleutian Islands: Fox Islands
18 Apr 1916 · 153 km away

NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.

Nearby trackers