The Hektoria Glacier, whose area is comparable to that of Philadelphia, is located on the Antarctic Peninsula — a narrow mountain chain protruding from the mainland. Typically, glaciers like Hektoria, which lie on the seabed and do not float, retreat by no more than a few hundred meters per year. However, research shows that from November to December 2022, the glacier retreated by a staggering 8 kilometers.
This data was obtained by chance. Researchers from the University of Colorado Boulder were conducting observations in the bay as part of another project. They were studying sea ice known as "fast ice," which was attached to the land and not exposed to wind and tides. During the data analysis, Naomi Ochwat, one of the study's authors and a research associate at the university, noticed that Hektoria had lost a significant amount of ice in a short period. This prompted her and her colleagues to investigate the situation further by analyzing satellite images and data collected during flights, identifying several factors that contributed to such rapid retreat.
In 2011, the bay was filled with fast ice, which stabilized the surrounding glaciers and allowed them to advance inward, forming thick floating ice tongues. However, in 2022, this fast ice detached from its base, leading to the destabilization of the glaciers and their retreat.
Ice plains can accelerate the glacier retreat process, as the reduction in its mass causes the ice to begin to rise, and water seeps beneath it through cracks, creating pressure and causing large icebergs to calve — a phenomenon known as calving. When one iceberg calves, it creates pressure on the glacier behind it, which can lead to subsequent calving events.
The authors of the study warn that if other large glaciers begin to retreat at a similar rate, it could have "catastrophic consequences for sea level rise." Antarctica contains enough ice to raise global sea levels by approximately 59 meters.
Naomi Ochwat emphasizes that climate change has become an important factor in the retreat of Hektoria. The loss of sea ice in the ocean near the glacier, likely caused by rising water temperatures, has allowed waves to reach the fast ice and break it apart, leaving the glacier vulnerable.
Ted Scambos, one of the study's authors and a senior research scientist at the Earth Sciences and Observations Center at the University of Colorado Boulder, notes that Hektoria is a relatively small glacier compared to other Antarctic formations, and its partial disappearance will not have a significant impact on sea levels on a global scale. However, he adds that this is a "smaller relative" of some giant glaciers that may face a similar process.
The next step for scientists is to more accurately determine which areas of Antarctica are susceptible to this process. If a massive glacier begins to rapidly disintegrate, "it could lead to a sharp rise in sea level," concludes Ochwat.
