Geophys. Res. Lett. http://doi.org/78h (2015)

Credit: Marion Bougamont

The glaciers of West Antarctica, including the Ross Sea ice streams, have shown a gain in mass over recent years. This is due to the slowdown of the glaciers' flow to the sea. Changes in ice flow are related to internal ice-sheet instabilities such as processes at the base of the glaciers including temperature change, hydrology and lateral shear. What is not known is whether the current gain in mass will persist.

Marion Bougamont of the Scott Polar Research Institute, University of Cambridge, UK, and colleagues use a 3D ice-sheet model to investigate the various factors affecting ice flow along the Siple Coast, West Antarctica, for 250 years. By considering the various processes together, the authors identify the tributaries of the currently dormant Kamb Ice Stream, one of six major ice streams in the region, as a source of regional instability. This instability could lead to major restructuring of flow in the coming decades, with net loss within two centuries. This loss of ice would result in an additional 5 mm of sea-level rise by 2100.