Multi-decadal collapse of East Antarctica’s Conger–Glenzer Ice Shelf

Abstract

Antarctica is currently losing net mass to the ocean primarily from West Antarctica and the Antarctic Peninsula, which together hold ~5.5 m of sea level rise potential. Yet, the East Antarctic Ice Sheet stores almost ten times more ice, and its evolution contributes significant uncertainty to sea level rise projections, mainly due to insufficient process-scale observations. Here we report the collapse of the Conger–Glenzer Ice Shelf in East Antarctica that culminated with its March 2022 disintegration. We use a combination of observations to document its evolution over four stages spanning 25 years, starting 1997–2000 when small calving events isolated it from the Shackleton Ice Shelf. In 2011, it retreated from a central pinning point, followed by relative calving quiescence for a decade; the remaining ~1,200 km2 of the ice shelf disintegrated over a few days in mid-March 2022. These observations of the Conger–Glenzer Ice Shelf collapse shed light on the processes involved, in particular, the impacts of ocean and atmospheric warming and extreme weather events. Ice shelf collapses, rare in the satellite record so far, have substantial implications for the stability of the Antarctic ice sheet and its contribution to future sea level rise. Satellite observations reveal that the Conger–Glenzer Ice Shelf collapse in East Antarctica occurred in four stages spanning a period of 25 years, culminating in its rapid disintegration in March 2022.