2025-11-03 スウォンジー大学
＜関連情報＞
- https://www.swansea.ac.uk/press-office/news-events/news/2025/11/new-study-reveals-fastest-antarctic-glacier-retreat-in-modern-history.php
- https://www.nature.com/articles/s41561-025-01802-4
氷原の崩壊により記録的な氷河後退が発生 Record grounded glacier retreat caused by an ice plain calving process
Naomi Ochwat,Ted Scambos,Robert S. Anderson,J. Paul Winberry,Adrian Luckman,Etienne Berthier,Maud Bernat & Yulia K. Antropova
Nature Geoscience Published:03 November 2025
DOI:https://doi.org/10.1038/s41561-025-01802-4
Abstract
Understanding and predicting marine-terminating glacier instability presents one of the greatest challenges to forecasting future sea level rise. An extreme case of such instability is the Hektoria Glacier on the Eastern Antarctic Peninsula, which retreated ~25 km between January 2022 and March 2023. Here we investigate the dynamics and drivers of this retreat event primarily from analysis of geophysical data and satellite imagery. We find that retreat commenced immediately after the loss of decade-old fast ice in the Larsen B embayment and was associated with an almost 6-fold increase in flow speed and 40-fold increase in glacier thinning, relative to the period immediately before the fast ice loss. We also find that in November–December 2022, the glacier retreated a total of 8.2 ± 0.2 km in two months—a retreat rate nearly an order of magnitude faster than published values—and began with a transition from tabular iceberg calving to buoyancy-driven calving on an ice plain, a flat area where the glacier was only lightly grounded. 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. This implies that marine-terminating glaciers with ice plain bed geometry can be easily destabilized.
