Contribution of ice-shelf melt, calving and damage to the evolution of Pine Island and Thwaites glaciers

In the last decades, Pine Island Glacier (PIG) and Thwaites Glacier (TG) are observed to be losing ice with increasing rates, contributing to sea-level rise. To estimate their potential sea-level contribution in the future, it’s essential to understand the mechanisms driving the dynamical changes at present. Various processes have been suggested to influence the dynamics of PIG and TG, including ocean driven sub-ice-shelf melting, iceberg calving, basal sliding and ice fracturing/damage. However, the relative importance of these physical processes for past and future changes of the glaciers remains uncertain. In this study, we use the abundant remote-sensing observations acquired in the recent decades (1996-2023) to quantitatively constrain and perturb an ice-sheet model. By simulating the ice discharge and spatial changes in ice thickness of the glaciers through sensitivity experiments, we quantify the relative impact of the above mentioned processes on the dynamics of PIG and TG.