3.7

M3.7 Earthquake 73 km SW of Nikolski, AlaskaSeptember 3, 2025

2025-09-03 21:18:42 UTC (2025-09-03) · approx. 10:18 AM UTC-11 local

MagnitudeM3.7(mb)
Time21:18 UTC10:18 AM UTC-11
Depth39.2 kmshallow crustal
Coordinates52.424°, -169.536°
Felt byNo felt reports
Status✓ Reviewed by USGS

On September 3, 2025 at 21:18 UTC, a magnitude 3.7 shallow crustal earthquake struck 73 km SW of Nikolski, Alaska, at a depth of 39.2 km and coordinates 52.4238°, -169.5357°.

Physical scale: An earthquake of magnitude 3.7 releases seismic energy equivalent to roughly 5.4 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 215 m — a useful intuition for the size of the slip patch on the fault.

Map showing earthquake epicenter at 52.42°, -169.54°

Earthquake Details

Magnitude
3.7 mb
Depth
39.2 km
shallow crustal
Location
52.4238°N
-169.5357°E

Technical Information

Event ID
us6000rd5m
Event Type
earthquake
Status
✓ Reviewed
Significance
211
Stations Used
27
Azimuthal Gap
176.0°
Min Station Distance
0.688°
RMS Residual
0.98 sec
Last Updated
2025-11-30 23:39:41 UTC

Common Questions

How strong was the magnitude 3.7 earthquake near Nikolski, Alaska?

The magnitude 3.7 earthquake that struck 73 km SW of Nikolski, Alaska on September 3, 2025 at 21:18 UTC had a depth of 39.2 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 3.7 earthquakes can continue for several days and gradually diminish over time.

Understanding This Data

Magnitude 3.7 earthquakes are typically only recorded by instruments.

Learn more about magnitude →

Authoritative source: USGS event page (event ID: us6000rd5m). All scientific values on this page are sourced verbatim from the USGS feed.

Cite this page: EarthquakeTracker.org. (2025, September 3, 2025). M3.7 Earthquake 73 km SW of Nikolski, AlaskaSeptember 3, 2025. Retrieved November 30, 2025 from https://www.earthquaketracker.org/earthquakes/event/us6000rd5m/