Hektoria Glacier, located on the eastern side of the Antarctic Peninsula. Today, it’s in the news, primarily due to its startlingly rapid shrinkage — currently unfolding at a rate that’s the fastest ever observed. The extent of the glacier is around 300 km2. That’s almost ten times bigger than the entire local government area of the City of Sydney! This significant retreat raises concerns about the potential implications for global sea levels as it continues to display unprecedented changes.
The glacier fed into the Larsen B ice shelf until its calving driven collapse in 2002. Between January 2022 and March 2023, it retreated at a staggering rate of 25 kilometers. The concerning pattern was most prominent in the months over the summer. Astonishingly, this was the retreat of 8 kilometers in a single month, from November to December 2022—never seen before in modern glaciology!
Unique Geological Characteristics
Hektoria Glacier’s remarkable retreat is due to its exceptional geographic location sitting over an “ice plain.” This broad, flat region means the glacier is only moderately grounded, leaving it more vulnerable to rapid change. In 2022, the collapse of attached landfast sea ice was responsible for faster retreat rates.
Ice plains occur at more locations than just Hektoria Glacier. In recent years, scientists have observed similar structures elsewhere in Antarctica, including the Ross Ice Shelf and Thwaites Glacier. Geoscientists are cautioning lawmakers against ignoring the geological realities. This information is crucial for understanding how glaciers will move in the future and modeling how that movement will affect global sea levels.
“Hence, we conclude that in this case, retreat primarily resulted from an ice plain calving process, rather than atmospheric or oceanic conditions as suggested previously,” – report.
Implications for Global Sea Levels
The incredibly fast retreat of Hektoria Glacier should sound alarm bells for scientists about the stability of some of the much larger glaciers in Antarctica. Poul Christoffersen, a glaciologist at the Institute for Marine and Antarctic Studies, stressed how significant these changes are. He is currently based at the University of Tasmania.
“It is definitely or unarguably a very fast retreat that they’re documenting,” – Poul Christoffersen.
He pointed out that while Hektoria Glacier is relatively small by Antarctic standards, its behavior may reflect a broader trend. Similar retreats on much bigger glaciers would have truly catastrophic consequences for worldwide sea level rise.
“Some people call that the ‘Arctic-ification’ or ‘Greenland-ification’ of Antarctica, meaning that the glaciers are showing signs or characteristics of glaciers elsewhere in the Earth that are typically warmer,” – Poul Christoffersen.
Future Considerations
As researchers continue to study Hektoria Glacier, they emphasize the importance of documenting the bedrock geometry beneath glaciers throughout Antarctica. Such information is vital for evaluating potential instabilities and incorporating rapid buoyancy-driven retreat into predictive models concerning the fate of the Antarctic ice sheet.
“Therefore, it is imperative to document the bedrock geometry beneath the glaciers around Antarctica to evaluate the potential for this type of instability to occur and incorporate rapid buoyancy-driven retreat in models predicting the fate of the Antarctic ice sheet,” – report.
