In Greenland, surface melt has increased significantly in area and intensity in recent years. Melting has increased in the accumulation area, normally a region of snow accumulation. This increase in meltwater can affect the ice sheet's mass balance and ice flow dynamics. When melt occurs on the surface, meltwater may trickle down through snow a short distance vertically and then refreeze, forming thin ice layers, it may penetrate underlying snow and create pools, or it may migrate horizontally and become runoff. The fate of meltwater is not well understood because the processes of meltwater infiltration into an ice sheet have not been well measured.