ICE FOOT DEVELOPMENT AT TEMPERATE TIDEWATER MARGINS IN ALASKA

The presence of an ice foot at the base of temperate tidewater ice cli ffs has been debated for nearly 100 years. This paper presents evidenc e demonstrating ice feet at tidewater margins in Glacier Bay, Alaska. Ice feet are likely sources of many submarine icebergs originating at the ice margin. The cause of ice foot development is unclear, but may represent a change in fracture behavior near the bed where higher debr is concentrations affect fracture propagation and calving. Ice foot fo rmation can be favored by englacial discharge and sediment ramps along the glacier margin that can cause differential melting of the ice cli ff. The presence of ice feet is important to understanding ice-proxima l sediment dynamics because they are a primary source of debris-rich i cebergs and their calving affects sediment redistribution patterns.