This award supports the acquisition of high resolution ground-penetrating radar (GPR) profiles as part of the ITASE-2 traverse, along a route in East Antarctica from Victoria Land to South Pole Station. The project will collect profiles of the firn stratigraphy to aid in the selection of coring sites, measure spatially averaged snow accumulation rates and determine the ice dynamics that cause the stratigraphy. The radar profiles from the GPR work will be correlated with ice core stratigraphy and GPS data obtained by others as part of the traverse. GPR will also be used for crevasse detection and traverse route safety but this is considered routine, based on experience from prior work.. The major GPR findings in stratigraphic dynamics from ITASE I are: 1) most 400-MHz horizons are separate and distinct wavelets that extend over 500 km; 2) horizons appear to be caused by the density contrasts across clusters of thin, double-layers of hoar and ice; and 3) the folding can be caused by differential accumulation processes and the interaction between differential wavelength and ice speed, all tempered by radar velocity pulldown. effects. This proposal is based on the hypothesis that the same processes that generate and fold reflection horizons in the relatively greater and warmer accumulation zone of West Antarctica, are also at work in the relatively lesser and far colder accumulation zone of East Antarctica, and will be detected despite the fact that the accumulation rates, in cm of firn at any density, are far less than the vertical resolution of the radar. The major objectives of this project are to test this hypothesis by searching for thin layer signatures, and evidence of folding caused by differential accumulation dynamics. Evidence will also be sought of tectonic folding, most likely caused by convergence within feeder areas for the glaciers of the Transantarctic Mountains, and of the small scale continuity of horizons. For each of the two field years, the funding will also support a student for 4 months, minor equipment purchases, travel, editing, publications and supplies. The student will be a temporary employee of USA CRREL to support him or her during the summer months.
