83 km SSW of Nikolski, Alaska

3 Sept 2026, 14:22:44 · 21 days ago

Magnitude: 4.2 ML
Depth: 17.4 km
UTC: 3 Sept 2026, 11:22:44
Coordinates: 52.250°N 169.355°W
Preferred source: USGS
Sources: USGS, EMSC
Felt reports: 0
Revision: Reviewed by an analyst
Nearest active fault: No mapped active fault within 50 kmGEM Global Active Faults (Styron & Pagani 2020), CC BY-SA 4.0

Expected intensity

MMI II ≤ 64 km
MMI III ≤ 29 km
MMI IV ≤ 11 km
MMI V ≤ 5.0 km

Rings show the expected Modified Mercalli (MMI) intensity from the Akkar–Sandıkkaya–Bommer (2014) ground-motion model converted with Worden et al. (2012). Real shaking depends on soil and building.

Felt reports

No reports yet.

Did you feel it? Report

Source comparison

Latest solution of each source. Differences are to the preferred solution.

Source	Magnitude	Time	Δ time	Depth	Δ location	Place
EMSC	4.2ML	3 Sept 2026, 14:22:44	±0.0 s	17.4 km	0.0 km	FOX ISLANDS, ALEUTIAN ISLANDS
USGS ★	4.2ML	3 Sept 2026, 14:22:44	—	17.4 km	—	83 km SSW of Nikolski, Alaska

Aftershock forecast

The chance of an aftershock of magnitude 4 or more in the next 7 days is 1%, and of magnitude 5 or more 0.1%.

The chance of an aftershock of magnitude 3 or more in the next 24 hours is 2%.

A larger earthquake followed this one; this one may have been a foreshock. Go to the larger earthquake

Magnitude	1 day	1 week	1 month
M ≥ 3	2%≈ 0.02	10%≈ 0.10	26%≈ 0.32
M ≥ 4	0.2%≈ <0.01	1%≈ 0.01	3%≈ 0.03
M ≥ 5	<0.1%≈ 0.00	0.1%≈ <0.01	0.3%≈ <0.01
M ≥ 6	0%≈ 0.00	<0.1%≈ 0.00	<0.1%≈ 0.00

≈ expected number of aftershocks

2 aftershocks recorded so far within 10 km (2 of M3.2 or more).

Computed: 24 Sept 2026, 18:03. Method: Reasenberg-Jones (generic, Bayesian a-value update); regime ANSR-SHALCON; generic parameters Page et al. (2016) via USGS OpenSHA GenericRJ_ParametersFetch.json. Probabilities are updated with the recorded aftershocks on every request. (b = 1, p = 0.98, c = 0.018 days, a = -1.786)

This is a statistical forecast, not an earthquake prediction. Actual aftershock activity can differ; follow AFAD for official statements.

Aftershocks

Earthquakes within 20 km of the epicentre in the first 30 days.

Count: 12