5.4

M5.4 Earthquake in the South Sandwich Islands region — June 10, 2025

2025-06-10 03:46:05 UTC (2025-06-10) · approx. 1:46 AM UTC-2 local

Aftershock of the M6.4 mainshock.

MagnitudeM5.4(mww)
Time03:46 UTC≈ 1:46 AM UTC-2
Depth15.2 kmshallow crustal
Coordinates-55.448°, -28.168°
Felt byNo felt reports
Status✓ Reviewed by USGS· green PAGER
green Alert— no significant casualties or damage expected

On June 10, 2025 at 03:46 UTC, a magnitude 5.4 shallow crustal earthquake struck in the South Sandwich Islands region, at a depth of 15.2 km and coordinates -55.4483°, -28.1680°. The USGS PAGER system issued a green alert level for this event, indicating no significant casualties or damage expected. This earthquake was detected by 145 seismic stations with excellent location accuracy and was assigned a USGS significance rating of 449, placing it among routine seismic activity.

Physical scale: An earthquake of magnitude 5.4 releases seismic energy equivalent to roughly 2 kilotons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 3.2 km — 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 6.4 mainshock that occurred 14 days ago in the South Sandwich Islands region. Since the mainshock, the USGS has recorded 0 aftershocks in this area. Aftershock activity is expected to continue for weeks to months as stresses on surrounding faults redistribute.

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 -55.45°, -28.17°

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 M5.4 earthquake near South Sandwich Islands region

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

Earthquake Details

Magnitude
5.4 mww
Depth
15.2 km
shallow crustal
Location
-55.4483°N
-28.1680°E
Intensity (MMI)
3.1
light

Technical Information

Event ID
us6000qj9w
Event Type
earthquake
Status
✓ Reviewed
Significance
449
Stations Used
145
Azimuthal Gap
27.0°
Min Station Distance
4.946°
RMS Residual
0.63 sec
Last Updated
2025-08-20 16:08:59 UTC

Nearby Earthquakes (Last 7 Days)

4.9
South Sandwich Islands region
2 days ago · 35.0 km deep

Common Questions

How strong was the magnitude 5.4 earthquake in the South Sandwich Islands region?

The magnitude 5.4 earthquake that struck in the South Sandwich Islands region on June 10, 2025 at 03:46 UTC had a depth of 15.2 km. For context, this was a moderate earthquake that could be widely felt.

Where did the earthquake occur?

The earthquake epicenter was located at -55.4483°, -28.1680°, which is in the South Sandwich Islands region.

Were there aftershocks?

Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 5.4 earthquakes can continue for days to weeks and gradually diminish over time.

Is this the same earthquake as the M6.4 one earlier?

No. This magnitude 5.4 earthquake is an aftershock of the larger magnitude 6.4 mainshock that occurred earlier in the South Sandwich Islands region. Aftershocks are smaller earthquakes triggered by stress changes from the mainshock.

Actions

View on USGSDid You Feel It?

Authoritative source: USGS event page (event ID: us6000qj9w). All scientific values on this page are sourced verbatim from the USGS feed.

Cite this page: EarthquakeTracker.org. (2025, June 10, 2025). M5.4 Earthquake in the South Sandwich Islands region — June 10, 2025. Retrieved August 20, 2025 from https://www.earthquaketracker.org/earthquakes/event/us6000qj9w/