4.7

M4.7 Earthquake in the South Sandwich Islands regionSeptember 16, 2025

2025-09-16 09:33:02 UTC (2025-09-16) · approx. 7:33 AM UTC-2 local

MagnitudeM4.7(mb)
Time09:33 UTC7:33 AM UTC-2
Depth133.0 kmintermediate depth
Coordinates-58.815°, -26.444°
Felt byNo felt reports
Status✓ Reviewed by USGS

On September 16, 2025 at 09:33 UTC, a magnitude 4.7 intermediate depth earthquake struck in the South Sandwich Islands region, at a depth of 133.0 km and coordinates -58.8145°, -26.4439°. This earthquake was detected by 48 seismic stations with excellent location accuracy and was assigned a USGS significance rating of 340, placing it among routine seismic activity.

Physical scale: An earthquake of magnitude 4.7 releases seismic energy equivalent to roughly 169 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 1.1 km — a useful intuition for the size of the slip patch on the fault.

The epicenter is located in South Sandwich Islands, a region characterized by the South Sandwich Trench, one of Earth's most remote subduction zones.

Learn more: Magnitude scale · Aftershock sequences

Map showing earthquake epicenter at -58.81°, -26.44°

Earthquake Details

Magnitude
4.7 mb
Depth
133.0 km
intermediate depth
Location
-58.8145°N
-26.4439°E

Technical Information

Event ID
us6000rfug
Event Type
earthquake
Status
✓ Reviewed
Significance
340
Stations Used
48
Azimuthal Gap
68.0°
Min Station Distance
16.066°
RMS Residual
0.60 sec
Last Updated
2025-12-03 03:58:44 UTC

Common Questions

How strong was the magnitude 4.7 earthquake in the South Sandwich Islands region?

The magnitude 4.7 earthquake that struck in the South Sandwich Islands region on September 16, 2025 at 09:33 UTC had a depth of 133.0 km. For context, this was a light earthquake commonly felt near the epicenter.

Where did the earthquake occur?

The earthquake epicenter was located at -58.8145°, -26.4439°, which is in the South Sandwich Islands region.

Were there aftershocks?

Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 4.7 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: us6000rfug). All scientific values on this page are sourced verbatim from the USGS feed.

Cite this page: EarthquakeTracker.org. (2025, September 16, 2025). M4.7 Earthquake in the South Sandwich Islands regionSeptember 16, 2025. Retrieved May 28, 2026 from https://www.earthquaketracker.org/earthquakes/event/us6000rfug/