This award is for support of a project to study the processes of debris entrainment at the base of the Matanuska Glacier. Conventional theories of sediment entrainment rely on pressure- induced melting and refreezing around obstacles at the glacier sole. Evidence from preliminary work around the glacier, however, suggest that ice and sediment is underplated to the glacier base by a process of net freeze-on. Theoretical calculations for water flow in subglacial conduits indicate that conditions necessary for freezing can only exist where water flows uphill out of an overdeepening. A better understanding of this process will shed light on the factors controlling glacier movement and till genesis.
