Hektoria Glacier Collapse Linked to Ice‑Plain Calving

A new study documents an unprecedented collapse of Antarctica’s Hektoria Glacier — about 25 km of retreat over 15 months, including roughly 8.2 km lost in November–December 2022, with those two‑month rates nearly ten times faster than previously recorded for grounded glaciers. Researchers trace the rapid loss to the breakout of long‑standing fast ice and removal of floating ice tongues, after which the glacier thinned onto a flat “ice plain” and underwent buoyancy‑driven calving and near‑instant flotation that triggered cascading collapse. Measurements show about a sixfold increase in flow speed, roughly a fortyfold rise in thinning rates, and large calving events that produced detectable glacial earthquakes. Study authors conclude the ice‑plain calving process, rather than short‑term atmospheric or oceanic forcing alone, was the proximate cause and warn the same mechanism could destabilize other marine‑terminating glaciers, with serious implications for future sea‑level rise. Some scientists note uncertainty about grounding versus floating conditions at parts of the terminus, so further observations are needed to assess how widespread the vulnerability may be.