4.2

M4.2 Earthquake 114 km SW of Nikolski, AlaskaSeptember 3, 2025

2025-09-03 20:07:40 UTC (2025-09-03) · approx. 9:07 AM UTC-11 local

MagnitudeM4.2(mb)
Time20:07 UTC9:07 AM UTC-11
Depth26.2 kmshallow crustal
Coordinates52.131°, -169.899°
Felt byNo felt reports
Status✓ Reviewed by USGS

On September 3, 2025 at 20:07 UTC, a magnitude 4.2 shallow crustal earthquake struck 114 km SW of Nikolski, Alaska, at a depth of 26.2 km and coordinates 52.1314°, -169.8992°.

Physical scale: An earthquake of magnitude 4.2 releases seismic energy equivalent to roughly 30 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 476 m — a useful intuition for the size of the slip patch on the fault.

Map showing earthquake epicenter at 52.13°, -169.90°

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 M4.2 earthquake near 114 km SW of Nikolski, Alaska

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

Earthquake Details

Magnitude
4.2 mb
Depth
26.2 km
shallow crustal
Location
52.1314°N
-169.8992°E
Intensity (MMI)
2.1
weak

Technical Information

Event ID
us7000qtlc
Event Type
earthquake
Status
✓ Reviewed
Significance
271
Stations Used
75
Azimuthal Gap
141.0°
Min Station Distance
0.663°
RMS Residual
0.98 sec
Last Updated
2025-11-30 23:39:40 UTC

Common Questions

How strong was the magnitude 4.2 earthquake near Nikolski, Alaska?

The magnitude 4.2 earthquake that struck 114 km SW of Nikolski, Alaska on September 3, 2025 at 20:07 UTC had a depth of 26.2 km. For context, this was a light earthquake commonly felt near the epicenter.

Were there aftershocks?

Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 4.2 earthquakes can continue for several days and gradually diminish over time.

Understanding This Data

Magnitude 4.2 earthquakes are often felt but rarely cause damage.

Learn more about magnitude →

Authoritative source: USGS event page (event ID: us7000qtlc). All scientific values on this page are sourced verbatim from the USGS feed.

Cite this page: EarthquakeTracker.org. (2025, September 3, 2025). M4.2 Earthquake 114 km SW of Nikolski, AlaskaSeptember 3, 2025. Retrieved November 30, 2025 from https://www.earthquaketracker.org/earthquakes/event/us7000qtlc/