Modelling the Impact of Surface Melt on Antarctic Ice Shelf Stability

Floating ice shelves modulate the flow of ice towards the ocean, and are vulnerable to changes in both the atmosphere and ocean. The formation of surface meltwater has been linked with the disintegration of many ice shelves in the Antarctic Peninsula over the last several decades. The most notable ice shelf collapse occurred in 2002, when significant meltwater lake coverage was observed on the surface of the Larsen B Ice Shelf before its collapse, resulting in the loss of an area of ice over twenty times the size of Cardiff over a period of just a few weeks. Such collapse can affect ocean circulation and temperature, and cause a loss of habitat. The loss of ice shelves removes their buttressing effect on the grounded ice sheet, which has in the past led to an observed acceleration of glaciers that previously fed into the ice shelves, and a corresponding rise in sea level.

Understanding the surface hydrology of ice shelves is thus an essential first step to reliably project future sea level rise from ice sheet melt. Surface hydrology processes are poorly represented in ice sheet and climate models, despite the importance of surface meltwater production and transport to ice shelf stability. As a result of this, projections of future sea level rise under a changing climate still vary over an order of magnitude.