Abstract

Seasonal melt that forms at the surface of the Greenland Ice Sheet often eventually finds its way to the bed of the ice sheet, where it can have a significant effect on ice sheet dynamics. However, the way in which meltwater pathways from the surface to the bed are formed and maintained is not well understood. In this presentation, I will discuss the mechanics of hydrofracture, through which initial surface-to-bed connections are thought to be made. Hydrofracture of liquid water through its solid phase has unique mechanics, partly due to the low viscosity and turbulence of water, the higher density of water than ice, the melting of ice that occurs with viscous dissipation of turbulent energy, and the viscoelastic deformation of ice. A simplified model will be presented that describes the essential aspects of such hydrofracture, and the implications for glacier dynamics will be explained.