Ocean-induced melt volume directly paces ice loss from Pine Island Glacier

The spatial distribution of ocean-induced melting beneath buttressing ice shelves is often cited as an important factor controlling Antarctica's sea-level contribution. Using numerical simulations, we investigate the relative sensitivity of grounded-ice loss to the spatial distribution and overall volume of ice-shelf melt over two centuries. Contrary to earlier work, we find only minor sensitivity to melt distribution (<6%), with a linear dependence of ice loss on the total melt. Thus, less complex models that need not reproduce the detailed melt distribution may simplify the projection of future sea level. The linear sensitivity suggests a contribution of up to 5.1 cm from Pine Island Glacier over the next two centuries given anticipated levels of ocean warming, provided its ice shelf does not collapse because of other causes.

Automated summary

The study shows that ocean-induced melting beneath buttressing ice shelves is crucial for Antarctica's sea-level contribution, but grounded-ice loss is only minimally sensitive to the spatial distribution, with the main factor being the total melt volume. This linear sensitivity suggests a potential sea-level rise contribution from Pine Island Glacier of up to 5.1 cm over the next two centuries without the collapse of its ice shelf due to other factors.