HR: 08:30h
AN: C41D-03    [Abstracts]
TI: Artificial Variability in Radar-Derived Accumulation Rates: Effects of Differential Deposition
AU: * Hamilton, G S
EM: gordon.hamilton@maine.edu
AF: Climate Change Institute, University of Maine, 303 Bryand Global Sciences Ctr,, Orono, ME 04469 United States
AU: Arcone, S A
EM: Steven.A.Arcone@erdc.usace.army.mil
AF: US Army, Cold Regions Research and Engineering Laboratory, 72 Lyme Road, Hanover, NH 03755 United States
AU: Spikes, V B
EM: vbs@earthscienceagency.com
AF: Earth Science Agency LLC, PO Box 2858, 275 Kingsbury Grade, Stateline, NV 89449 United States
AB: Katabatic winds interact with surface topography to re-distribute snow at local scales on polar ice sheets. The historical record of snowfall is further modified by ice flow away from the original site of deposition. These processes complicate the use of ice cores and other point measurements for studying spatial patterns in accumulation rate and for identifying climate-related (temporal) changes in snowfall. We have been using GPR to obtain spatially-extensive estimates of accumulation rates across large portions of the West Antarctic Ice Sheet. The controlling factor for near-surface estimates of accumulation rate is surface slope, while at depth, historical averages are also controlled by ice dynamics. We discuss a high-resolution, 177 km-long radar profile recorded to 56 m depth in central West Antarctica, which contains strata that vary in depth by as much as 30 m. We present three profiles of accumulation rates vs distance. The rates become more variable with depth, and demonstrate the difficulty of deriving meaningful accumulation estimates for ice sheet mass balance studies.
DE: 9310 Antarctica
DE: 1827 Glaciology (1863)
DE: 0600 ELECTROMAGNETICS
SC: Cryosphere [C]
MN: 2004 AGU Fall Meeting