Assessment of the importance of ice‐shelf buttressing to ice‐sheet flow

Abstract

Reduction or loss of a restraining ice shelf will cause speed‐up of flow from contiguous ice streams, contributing to sea‐level rise, with greater changes from ice streams that are wider, have stickier beds, or have higher driving stress. Loss of buttressing offsetting half of the tendency for ice‐stream/ice‐shelf spreading for an ice stream similar to Pine Island Glacier, West Antarctica is modeled to contribute at least 1 mm of sea‐level rise over a few decades. These results come from a new, simple model that includes relevant stresses in a boundary‐layer formulation, and allows rapid estimation of ice‐shelf impacts for a wide range of configurations.