A major earthquake with a preliminary magnitude of 7.8 struck beneath the Drake Passage early today, rattling one of the planet’s most remote and storm-swept stretches of ocean and triggering tsunami advisories for parts of southern South America and several sub-Antarctic territories. The U.S. Geological Survey said the quake occurred at 09:15 GMT at an estimated depth of 18 kilometers and located roughly 280 kilometers south of Cape Horn, placing it near complex plate boundaries between the Scotia and Antarctic plates.

Because the epicenter lies well offshore, initial reports indicated no immediate, widespread destruction on land. “We have not received confirmed reports of structural damage or casualties,” Chile’s national emergency office, ONEMI, said in a statement. Still, Chilean authorities ordered precautionary evacuations of low-lying coastal communities in the Magallanes region and advised maritime operators to avoid the Drake Passage until further notice. The Argentine navy issued similar cautions for Tierra del Fuego and the South Atlantic coast.

The U.S.-based Pacific Tsunami Warning Center and the Intergovernmental Oceanographic Commission of UNESCO issued advisories assessing the potential for tsunami waves to affect southern Chile, the Falkland Islands, South Georgia and the South Sandwich Islands, and portions of the Antarctic Peninsula. The PTWC said initial wave heights were expected to be variable and could be higher near bays and inlets, where local bathymetry amplifies surge. “We are monitoring tide gauges and satellite observations. Local authorities should take precautions,” a PTWC bulletin said.

Antarctic research stations and vessels in the region activated contingency protocols. The British Antarctic Survey reported that staff at Rothera and other bases were accounted for and that coastal installations were being inspected for damage. “Conditions in the Drake Passage can change rapidly. Our priority is safety and ensuring continuous communications with partner agencies,” a BAS spokesperson said. Several research ships and commercial vessels reported heavy swells and reduced visibility, complicating maneuvers in an already treacherous corridor used by Antarctic logistics and international shipping.

Seismologists noted that although the Drake Passage is remote, the geological forces at play are significant. The area sits where the Scotia Plate interacts with surrounding plates, producing both transform and subduction-related stress. “A quake of this size in this tectonic setting is capable of generating tsunamis, and the Southern Ocean’s configuration can funnel energy toward coastlines,” said Dr. Elena Márquez, a seismologist at the University of Chile.

Beyond immediate emergency concerns, the quake underscores broader international coordination challenges in the Southern Ocean. Coastal communities in Chile and Argentina, dependent fishing fleets and international Antarctic programs must rely on rapid information sharing across national and scientific institutions. Under the Antarctic Treaty, parties are obliged to cooperate in emergencies, a framework being tested as teams assess potential impacts on remote stations and wildlife habitats.

Authorities urged residents and mariners in affected zones to follow official directives and avoid returning to evacuated shorelines until warnings are lifted. Monitoring will continue through tidal and seismic networks, satellite altimetry and aerial reconnaissance where weather permits. The coming hours and days will be crucial in determining whether this powerful undersea quake produces localized coastal damage or remains, for now, mainly a reminder of the Southern Ocean’s volatile geology and the precariousness of human activity at the edge of the Antarctic.