Abstract

If we are to predict the future contribution of the West Antarctic Ice Sheet to sea level rise, we must be able to use numerical models to predict how fast the ocean melts ice shelves. This is because the presence of ice shelves hinders the flow of ice from the ice sheet: any change in their geometry can affect the rate of discharge of previously grounded ice into the ocean. Ice shelves also play a role in the formation of deep and bottom waters that are central ingredients of the global overturning circulation. In this talk I discuss our present understanding of the controls on ice shelf basal melt rates; I will use datasets from beneath ice shelves to show under which conditions our formulations appear to do a good job, and where they seem to break down. I will then discuss the implications for our ability to predict the melt rates for extremely rapidly melting ice shelves, such as those in the Amundsen Sea Embayment.