Activation of existing surface crevasses has limited impact on grounding line flux of Antarctic Ice Streams

Recent studies have identified widespread vulnerable ice shelf regions in Antarctica which are both highly buttressed and susceptible to crevasse hydrofracturing, raising concern for potential crevasse driven ice-shelf collapse and future sea level rise. Here, we employ the finite element ice flow model, Úa, to investigate whether crevasses which have propagated through the entire ice column have a significant impact on upstream flow and quantify their contribution to sea level rise. We find a large variability in the response of ice shelves to this perturbation, with changes in grounding line flux as large as 155% for the Filchner-Ronne and 46% for the Ross, when compared to the present day. Crevasses located close to the grounding lines contribute most of this change. When compared to a second perturbation in which ice shelves are completely removed, however, the response is relatively small for all modelled ice shelves.