3.9

M3.9 Earthquake 167 km WSW of Nikolski, AlaskaSeptember 16, 2026

2026-09-16 08:28:51 UTC (8 hours ago) · approx. 9:28 PM UTC-11 local

MagnitudeM3.9(ml)
Time08:28 UTC9:28 PM UTC-11
Depth90.5 kmintermediate depth
Coordinates52.374°, -171.157°
Felt byNo felt reports
Status✓ Reviewed by USGS

On September 16, 2026 at 08:28 UTC, a magnitude 3.9 intermediate depth earthquake struck 167 km WSW of Nikolski, Alaska, at a depth of 90.5 km and coordinates 52.3740°, -171.1570°.

Physical scale: An earthquake of magnitude 3.9 releases seismic energy equivalent to roughly 11 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 296 m — a useful intuition for the size of the slip patch on the fault.

Map showing earthquake epicenter at 52.37°, -171.16°

ShakeMap — predicted shaking intensity

Modeled ground-motion intensity contoured on the Modified Mercalli scale (MMI). Computed by the USGS from the moment-tensor solution and regional ground-motion prediction equations.

USGS ShakeMap intensity contours for the M3.9 earthquake near 167 km WSW of Nikolski, Alaska

Source: U.S. Geological Survey ShakeMap. View interactive ShakeMap on USGS

Earthquake Details

Magnitude
3.9 ml
Depth
90.5 km
intermediate depth
Location
52.3740°N
-171.1570°E
Intensity (MMI)
2.3
weak

Technical Information

Event ID
aka2026sjepok
Event Type
earthquake
Status
✓ Reviewed
Significance
234
Stations Used
52
Azimuthal Gap
197.0°
Min Station Distance
0.900°
RMS Residual
0.60 sec
Last Updated
2026-09-16 15:43:42 UTC

Common Questions

How strong was the magnitude 3.9 earthquake near Nikolski, Alaska?

The magnitude 3.9 earthquake that struck 167 km WSW of Nikolski, Alaska on September 16, 2026 at 08:28 UTC had a depth of 90.5 km. For context, this was a minor earthquake typically detected only by instruments.

Were there aftershocks?

Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 3.9 earthquakes can continue for several days and gradually diminish over time.

Understanding This Data

Magnitude 3.9 earthquakes are typically only recorded by instruments.

Learn more about magnitude →

Authoritative source: USGS event page (event ID: aka2026sjepok). All scientific values on this page are sourced verbatim from the USGS feed.

Cite this page: EarthquakeTracker.org. (2026, September 16, 2026). M3.9 Earthquake 167 km WSW of Nikolski, AlaskaSeptember 16, 2026. Retrieved September 16, 2026 from https://www.earthquaketracker.org/earthquakes/event/aka2026sjepok/