Sediment wedges not stabilizing West Antarctic Ice Sheet



The stability of the West Antarctic Ice Sheet is uncertain as climate changes. An ice sheet such as the West Antarctic Ice Sheet that is grounded well below sea level on a bed that slopes toward the interior of the sheet is believed to be unstable: When the grounding zone, where the grounded sheet transitions into floating ice, retreats inland, it can lead to massive amounts of ice becoming ungrounded and floating into the ocean unless something such as a wedge of sediment stabilizes the ice sheet. It has been proposed that such a sediment wedge stabilizes the grounding zone of the Whillans Ice Stream, one of the large ice streams flowing from the West Antarctic Ice Sheet. However, most understanding of ice sheet stability at grounding zones comes from models and remote observation rather than field-based observations.