4.3

M4.3 Earthquake 96 km S of Severo-Kuril’sk, RussiaSeptember 25, 2025

2025-09-25 19:39:33 UTC (2025-09-25) · approx. 5:39 AM UTC+10 local

MagnitudeM4.3(mb)
Time19:39 UTC5:39 AM UTC+10
Depth79.0 kmintermediate depth
Coordinates49.826°, 155.870°
Felt byNo felt reports
Status✓ Reviewed by USGS

On September 25, 2025 at 19:39 UTC, a magnitude 4.3 intermediate depth earthquake struck 96 km S of Severo-Kuril’sk, Russia, at a depth of 79.0 km and coordinates 49.8259°, 155.8697°.

Physical scale: An earthquake of magnitude 4.3 releases seismic energy equivalent to roughly 43 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 558 m — a useful intuition for the size of the slip patch on the fault.

This earthquake is part of an ongoing aftershock sequence following the magnitude 5.3 mainshock that occurred 13 days ago 78 km S of Severo-Kuril’sk, Russia. Since the mainshock, the USGS has recorded 1 aftershocks in this area. Aftershock activity is expected to continue for days to weeks as stresses on surrounding faults redistribute.

Map showing earthquake epicenter at 49.83°, 155.87°

Earthquake Details

Magnitude
4.3 mb
Depth
79.0 km
intermediate depth
Location
49.8259°N
155.8697°E

Technical Information

Event ID
us6000rhu9
Event Type
earthquake
Status
✓ Reviewed
Significance
284
Stations Used
40
Azimuthal Gap
137.0°
Min Station Distance
3.480°
RMS Residual
0.42 sec
Last Updated
2025-12-11 21:40:49 UTC

Common Questions

How strong was the magnitude 4.3 earthquake near Severo-Kuril’sk, Russia?

The magnitude 4.3 earthquake that struck 96 km S of Severo-Kuril’sk, Russia on September 25, 2025 at 19:39 UTC had a depth of 79.0 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 4.3 earthquakes can continue for several days and gradually diminish over time.

Is this the same earthquake as the M5.3 one earlier?

No. This magnitude 4.3 earthquake is an aftershock of the larger magnitude 5.3 mainshock that occurred earlier 78 km S of Severo-Kuril’sk, Russia. Aftershocks are smaller earthquakes triggered by stress changes from the mainshock.

Understanding This Data

Magnitude 4.3 earthquakes are often felt but rarely cause damage.

Learn more about magnitude →

Authoritative source: USGS event page (event ID: us6000rhu9). All scientific values on this page are sourced verbatim from the USGS feed.

Cite this page: EarthquakeTracker.org. (2025, September 25, 2025). M4.3 Earthquake 96 km S of Severo-Kuril’sk, RussiaSeptember 25, 2025. Retrieved December 11, 2025 from https://www.earthquaketracker.org/earthquakes/event/us6000rhu9/