How calving could affect the future of Thwaites and Pine Island Glaciers

Thwaites and Pine Island Glaciers in the Amundsen Sea Embayment, West Antarctica, are among the fastest evolving on the continent, and hold enough ice between them to raise sea levels by over a metre. In their present states, the two glaciers represent different configurations of floating ice, and therefore may not respond in the same way to changes in ocean forcing. Pine Island Ice Shelf is contained within a bay and provides a large amount of buttressing to its glacier. Thwaites Ice Shelf has two components; a heavily damaged ice tongue and a shelf which is only restrained by a single pinning point. Neither of these provide much buttressing. In our modelling experiments, we prescribe calving rates to the ice shelves of these two glaciers alongside thermal forcing from ISMIP6, to investigate the combined effects of warming oceans and continued calving on the future of the region. We demonstrate the potential impacts of adding the calving process into our model by using a range of constant calving rates. Examining the different responses can tell us how important the process is for each glacier, and how sensitive they are to changes in calving. This in turn can be used to determine whether or not significant effort should be invested in improving calving laws to more accurately predict the future shape of the ice front.