Modeling Rapid Lake Drainage in Glaciers

Due to recent warming, the Greenland Ice Sheet has undergone a number of dramatic changes including an increase in the amount of surface meltwater and an increase in iceberg calving rates. These changes are in turn responsible for changes in the dynamics of the ice sheet. Understanding the physical processes by which meltwater and calving affect glacier dynamics is therefore crucial to being able to predict the future of large ice masses like the Greenland Ice Sheet. One process in particular that deserves attention is the drainage of surface meltwater lakes to the base of the ice sheet, thereby potentially lubricating the bed. Sometimes this drainage is rapid, implying turbulent flow of water and an ice sheet response that involves elastic behavior. This drainage can be understood by jointly modeling the flow of water, the expansion of a subglacial crack that fills with water, and the deformation of the ice itself (Tsai and Rice, 2010; 2012). See publications for more details.

The picture at right (from I. Joughin) is of a meltwater lake approximately 3km by 2km and 10m deep.