Half of Antarctic glacier vanished in just two months, scientists reveal

A glacier on the eastern Antarctic Peninsula has undergone one of the most rapid collapses ever documented, raising urgent questions about ice sheet stability across the continent.

Hektoria Glacier lost nearly half its total ice mass during a two-month period in late 2022, according to research published on Monday by scientists from the University of Colorado Boulder. The findings reveal a pace of ice loss that has stunned glaciologists and challenged assumptions about how quickly Antarctic ice can disappear.

Between January 2022 and March 2023, Hektoria retreated approximately 25 kilometers. Within that 14-month period, eight kilometers vanished between November and December 2022 alone representing close to 50 percent of the glacier disintegrating in just 60 days.

The research team used satellite imagery captured at different time intervals to document the collapse. This approach proved essential in detecting not just the extent of the retreat, but its extraordinary speed.

The glacier's underlying geography played a critical role in its rapid disintegration. Hektoria sits atop relatively flat bedrock, a feature that became significant as the ice began to thin.

As the glacier lost mass, portions of it began floating on ocean water beneath rather than remaining grounded on bedrock. This transition triggered a chain reaction. Floating ice is far less stable than grounded ice, and once Hektoria went afloat, it began breaking apart at an accelerated rate.

This process, known as marine ice sheet instability, occurs when warming ocean waters melt the underside of glaciers, thinning them until they lose contact with the seafloor. Once floating, the ice faces less resistance and can fracture more readily.

Lead author Naomi Ochwat flew over the glacier in early 2024, more than a year after the main collapse. Despite expecting significant changes based on satellite data, the reality proved shocking.

"When we flew over Hektoria in early 2024, I couldn't believe the vastness of the area that had collapsed," Ochwat said. The aerial survey confirmed what the data showed: a massive section of ancient ice had vanished in a geological instant.

Ted Scambos, a glaciologist on the research team, called the retreat "a bit of a shock." The speed of Hektoria's collapse challenges previous understanding of how quickly Antarctic glaciers can disintegrate.

"This kind of lightning-fast retreat really changes what's possible for other, larger glaciers on the continent," Scambos said. The concern extends far beyond this single glacier to ice sheets across Antarctica.

The eastern Antarctic Peninsula has experienced warming in both air and ocean temperatures in recent decades. If similar conditions develop at other Antarctic locationsparticularly where larger glaciers sit on comparable flat bedrock the consequences for global sea levels could be severe.

"If the same conditions set up in some of the other areas, it could greatly speed up sea level rise from the continent," Scambos warned.

Antarctica contains enough ice to raise global sea levels by approximately 60 meters if completely melted. While total melting would take centuries, even partial acceleration of ice loss from major glaciers would measurably impact coastal communities worldwide within decades.

Glaciers in West Antarctica, particularly in the Amundsen Sea sector, sit on similar flat or reverse-sloping bedrock that could make them vulnerable to the same rapid retreat mechanism observed at Hektoria.

The collapse demonstrates that ice sheet changes can happen far faster than gradual projections might suggest. The research underscores the importance of continuous satellite monitoring of Antarctic glaciers. Without regular observations, the precise timing and speed of Hektoria's collapse might have gone undetected.

As polar regions continue warming, scientists will watch other Antarctic glaciers closely for signs of similar instability.