Note: Single-source report; awaiting corroboration.
Between January 2022 and March 2023, the Hektoria Glacier on the eastern Antarctic Peninsula lost about 25 kilometers (15 miles) in length. This included a two-month period during which its terminus retreated more than 8 kilometers (5 miles)—the fastest rate of grounded glacial ice loss observed in modern history.
The glacier's rapid change was attributed to its geometry, which begins on land and extends into the sea, ending with a thick floating ice tongue. Scientists found that Hektoria lost both this floating ice tongue and an area of grounded ice over a flat plain, the latter directly contributing to sea level rise.
This retreat followed the 2002 collapse of the Larsen B ice shelf, which previously acted as a backstop for Hektoria and neighboring glaciers. After several years of thinning and retreat, landfast sea ice near Hektoria's terminus temporarily allowed the glacier to advance around 2011. However, the breakup of the landfast ice in January 2022—likely driven by large ocean swells—removed this support and triggered rapid disintegration and calving of the floating ice tongue.
The glacier's terminus stabilized in the 2022 austral winter, but satellite data showed ongoing changes in ice elevation. While Hektoria is relatively small compared to other Antarctic glaciers, scientists noted that similar dynamics in larger glaciers could have more significant consequences for sea level rise.