Abstract

In January 2022 the landfast sea ice that had been present in the Larsen-B Embayment for the previous 11 years disintegrated. Major changes to the dynamic and calving behaviour of the largest ocean-terminating glaciers in the region quickly followed including the speed up of Hektoria, Green, and Crane glaciers by approximately 20%–50% between February and the end of 2022, following a decade of gradual slow-down. Circumstantially, this is attributable to their transition into tidewater glaciers following the loss of their ice shelves after the landfast sea ice evacuation. However, a question remains as to whether the landfast sea ice could have had a direct influence on the dynamics of these glaciers, or the stability of their ice shelves, through a buttressing effect akin to that of confined ice shelves on grounded ice streams. Using a mixture of remote sensing observations and diagnostic modelling, we explore this possibility and conclude that sea ice likely exerts its influence through other mechanisms.