HR: 1340h
AN: C33C-0360    [Abstracts]
TI: Relating GPR to In Situ and Stratigraphically Determined Accumulation Rates at South Pole Station
AU: * Laatsch, J G
EM: Laatsch@ldeo.columbia.edu
AF: US Army Cold Regions Research and Engineering Laboratory, 72 Lyme Rd., Hanover, NH 03755 United States
AU: * Laatsch, J G
EM: Laatsch@ldeo.columbia.edu
AF: Lamont Doherty Earth Observatory of Columbia University, P.O. Box 1000, Palisades, NY 10964 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 Rd., Hanover, NH 03755 United States
AU: Bell, R E
EM: Robinb@ldeo.columbia.edu
AF: Lamont Doherty Earth Observatory of Columbia University, P.O. Box 1000, Palisades, NY 10964 United States
AB: Spatial and temporal variation in accumulation rates is poorly constrained yet is a primary indicator of climate trends on ice sheets. Several methods have been used to obtain accumulation rate data with varying strengths and weaknesses. The principal mechanisms of quantifying accumulation rate data have been through stratigrpahic analysis of ice cores, or through in situ accumulation stake measurements. In situ measurements have a severely limited temporal scope and often inadequate spatial resolution to be relevant to meso-scale climate reconstructions. Stratigrpahic analysis allows for more developed temporal resolution and time series length, but is not a direct measurement and also represents a small spatial area. We propose that ground penetrating radar can be an effective tool to bridge the gap between the limited spatial signature of ice cores and dearth of in situ measurements. South Pole Station has the highest density of in situ accumulation rate measurements both temporally and spatially. One of the most notable examples of this is the accumulation stake network maintained at South Pole Station by The Ohio State University. We conducted a land based traverse along two lines of this accumulation grid while operating a 400MHz ground penetrating radar unit. By identifying significant isochrones within the radar data we have determined the relative accumulation rate for the years between the isochrones. This technique facilitates a high density of data collection with relative ease and also allows for the accumulation rate record to be extended beyond the limited amount of time for which there is in situ data. By performing this experiment at South Pole we can relate the geophysical data to direct measurements of accumulation rate as well as accumulation rates determined from stratigraphic analysis of snow pits and cores in the vicinity.
DE: 9310 Antarctica
DE: 1827 Glaciology (1863)
SC: Cryosphere [C]
MN: 2004 AGU Fall Meeting