Shallow M5.7 earthquake hits South Sandwich Islands region

An earthquake of magnitude M5.7 struck the South Sandwich Islands region at 17:05 UTC on December 17, 2025. The event was registered at a depth of 35.0 km (21.7 miles), based on coordinates 25.2°S, 58.7°W.

The epicenter is located within the remote South Sandwich Islands region, a sparsely populated area in the southern Atlantic Ocean, well known for its seismic activity but distant from major population centers.

Critical infrastructure in the South Sandwich Islands region is extremely limited, consisting mainly of isolated research stations and maritime navigation routes. There are no significant airports, ports, or energy facilities in the immediate area.

There is no tsunami threat associated with this earthquake, based on its location and available data.

The significance index is 500 (on a scale that runs through 1 000), based on magnitude, felt reports, and estimated impact.

The South Sandwich Islands region forms part of the boundary between the South American Plate and the Scotia Plate, which is a known zone of frequent seismicity due to subduction and transform fault activity.

This information was last updated at 17:24 UTC on December 17, 2025.