The Two‐Decade Evolution of Antarctica's Hektoria Glacier and Its 2022 Rapid Retreat From Satellite Observations

Abstract

Beginning in March 2022, the Antarctic Peninsula's Hektoria Glacier experienced an unprecedented retreat of ∼23 km over 1.5 years, one of the fastest observed glacier retreats on record. Improving constraints on the drivers of such extreme events is key to understanding glacier change around the continent and future sea‐level rise. We use satellite remote sensing and reanalysis data to characterize changes in Hektoria, a former Larsen B Ice Shelf tributary, over the last ∼20 years and document a period of retreat from 2002 to 2011, and readvancement from 2011 to 2022. We find that the long‐term ice front and velocity response (2002–2022) correlated more strongly with changes in modeled ocean temperatures compared to surface air temperatures. However, the acute loss of buttressing support following fast ice collapse paired with a near‐contemporaneous extreme atmospheric river in the region likely catalyzed the unprecedented 2022–2023 retreat.