4.1

M4.1 Earthquake south of the Fiji IslandsSeptember 13, 2025

2025-09-13 17:22:40 UTC (2025-09-13) · approx. 5:22 AM UTC-12 local

MagnitudeM4.1(mb)
Time17:22 UTC5:22 AM UTC-12
Depth476.0 kmdeep-focus
Coordinates-25.648°, -179.747°
Felt byNo felt reports
Status✓ Reviewed by USGS

On September 13, 2025 at 17:22 UTC, a magnitude 4.1 deep-focus earthquake struck south of the Fiji Islands, at a depth of 476.0 km and coordinates -25.6481°, -179.7473°.

Physical scale: An earthquake of magnitude 4.1 releases seismic energy equivalent to roughly 21 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 406 m — a useful intuition for the size of the slip patch on the fault.

Map showing earthquake epicenter at -25.65°, -179.75°

Earthquake Details

Magnitude
4.1 mb
Depth
476.0 km
deep-focus
Location
-25.6481°N
-179.7473°E

Technical Information

Event ID
us6000rf4k
Event Type
earthquake
Status
✓ Reviewed
Significance
259
Stations Used
23
Azimuthal Gap
185.0°
Min Station Distance
8.126°
RMS Residual
0.67 sec
Last Updated
2025-12-03 03:58:23 UTC

Common Questions

How strong was the magnitude 4.1 earthquake south of the Fiji Islands?

The magnitude 4.1 earthquake that struck south of the Fiji Islands on September 13, 2025 at 17:22 UTC had a depth of 476.0 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 4.1 earthquakes can continue for several days and gradually diminish over time.

What should I do after an earthquake?

If you were in the affected area: check yourself and others for injuries, inspect your home for damage, and be prepared for aftershocks. For detailed guidance, see our earthquake safety guide and emergency planning resources.

Authoritative source: USGS event page (event ID: us6000rf4k). All scientific values on this page are sourced verbatim from the USGS feed.

Cite this page: EarthquakeTracker.org. (2025, September 13, 2025). M4.1 Earthquake south of the Fiji IslandsSeptember 13, 2025. Retrieved May 28, 2026 from https://www.earthquaketracker.org/earthquakes/event/us6000rf4k/