HR: 0800h
AN: C21C-1128    [Abstracts]
TI: Sediment Transport in Subglacial Channels: Simulation of the Physical Processes Behind Esker Formation
AU: * Wilschut, F
EM: fwilschut@eos.ubc.ca
AF: Department of Earth and Ocean Sciences, University of British Columbia, 2219 Main Mall, Vancouver, BC V6T 1Z4 Canada
AU: Clarke, G K
EM: clarke@eos.ubc.ca
AF: Department of Earth and Ocean Sciences, University of British Columbia, 2219 Main Mall, Vancouver, BC V6T 1Z4 Canada
AB: Eskers are sinuous ridges consisting of sand and gravel that is transported and deposited in ice-walled conduits. A new model that describes the erosion, transport and deposition of a sediment mixture containing sand, granules and pebbles in a subglacial channel is used to explore physical processes controlling the formation of eskers. This model combines the mathematical description of the evolution of subglacial channels based on the balance laws of continuum mechanics with standard fluvial sediment transport equations. First, the effects of changes in the bed elevation by erosion and deposition of sediment on the evolution of subglacial channels are highlighted. We discuss the influence of till grain-size distribution and sediment supply to the channel on the spatial variation and composition of sediment deposits along the channel. Finally, we investigate the importance of seasonal variations in the meltwater supply to the channel and the role of water storage reservoirs feeding the channel. Results of our experiments are compared with well-studied field examples of eskers.
DE: 0726 Ice sheets
DE: 0744 Rivers (0483, 1856)
DE: 0798 Modeling
DE: 1827 Glaciology (0736, 0776, 1863)
DE: 1862 Sediment transport (4558)
SC: Cryosphere [C]
MN: Fall Meeting 2005