HR: 10:50h
AN: C21D-03 INVITED     [PDF]
TI: Tracking Isochronal Radar Reflections Across West Antarctica
AU: * Spikes, V B
EM: vandy.spikes@maine.edu
AF: Climate Change Institute, University of Maine, 5790 BGSC, Room 303, Orono, ME 04469-5790 United States
AU: Arcone, S A
EM: steven.a.arcone@erdc.usace.army.mil
AF: USACE Engineer Research and Development Center, Cold Regions Research and Engineering Laboratory, 72 Lyme Road, Hanover, NH 03755-1290 United States
AU: Hamilton, G S
EM: gordon.hamilton@maine.edu
AF: Climate Change Institute, University of Maine, 5790 BGSC, Room 303, Orono, ME 04469-5790 United States
AB: We used a 400 MHz radar profiling system to resolve and track individual horizons within firn along the 1999 to 2002 International Trans Antarctic Scientific Expedition (ITASE - U.S.A. component) traverses across West Antarctica. Nearly 5000 km of radar data ranging in depth from 56 m to 135 m were collected while traveling between ice core sites. Throughout the dataset we observe continuous reflections that are caused by density variations related to summer melt layers and wind crusts. By tracking such horizons between dated ice cores we demonstrate that the isochronal accuracy of each continuous reflection is less than 1 year. This result highlights the vertical resolution of our radar system which is about 30 times greater than that provided by standard radio echo sounders. This result also justifies the use of these horizons for determining historical snow accumulation rates along survey lines. The benefits of using this continuous measurement approach are that it reveals the spatial and temporal patterns of snow accumulation over large regions and it produces an accurate spatial mean. These data are currently being used to update continental-scale datasets of Antarctic surface mass balance and to improve mass balance estimates of the West Antarctic Ice Sheet.
UR: http://www.geology.um.maine.edu/user/blue_spikes/research.htm
DE: 0694 Instrumentation and techniques
DE: 1620 Climate dynamics (3309)
DE: 1827 Glaciology (1863)
DE: 1854 Precipitation (3354)
DE: 1863 Snow and ice (1827)
SC: Cryosphere [C]
MN: 2003 Fall Meeting