Abstract

Ice shelf collapse could trigger widespread retreat of marine-based portions of the Antarctic ice sheet. However, little is known about the processes that control the stability of ice shelves. Recent observations have revealed that ice shelves have topographic features that span a spectrum of wavelengths, including basal channels and crevasses. Here we use ground-penetrating radar data to quantify patterns of roughness within and between ice shelves. We find that roughness follows a power-law with scaling exponent approximately constant between ice shelves. However, the magnitude of roughness varies by over an order of magnitude between different ice shelves. Critically, we find that roughness strongly correlates with basal melt rate, suggesting that increased basal melt not only leads to deeper melt channels, but also increased fracturing, rifting and de-creased ice shelf stability. This hints that the mechanical stability of ice shelves may be more tightly controlled by ocean forcing than previously thought.