Abstract:
The Antarctic megadune research was conducted during two field seasons, one in
November 2002 and the other in December 2003 through January 2004. The megadune
field site is located on the East Antarctic Plateau, southeast of Vostok
station. The objectives of this multi-facetted research are to determine the
physical characteristics of the firn across the dunes including
... typical climate
indicators such as stable isotopes and major chemical species and to install
instruments to measure the time variation of near-surface wind and temperature
with depth, to test and refine hypotheses for megadune formation. It is
important to improve our current understanding of the megadunes because of
their extreme nature, their broad extent, and their potential impact on the
climate record. Megadunes are a manifestation of an extreme terrestrial climate
and may provide insight on past terrestrial climate or on processes active on
other planets.
Snow megadunes are undulating variations in accumulation and surface texture
with wavelengths of 2 to 5 km and amplitudes up to 5 meters. The features cover
500,000 km2 of the East Antarctic plateau, occurring in areas of
moderate regional slope and low accumulation on the flanks of the ice sheet
between 2500 and 3800 meters elevation. Landsat images and aerial photography
indicate the dunes consist of alternating surfaces of glaze and rough sastrugi,
with gradational boundaries. This pattern is oriented perpendicular to the mean
wind direction, as modeled in katabatic wind studies. Glaze surfaces cover the
leeward faces and troughs; rough sastrugi cover the windward faces and crests.
The megadune pattern is crossed by smooth to eroded wind-parallel longitudinal
dunes. Wind-eroded longitudinal dunes form spectacular 1-meter-high sastrugi in
nearby areas.
This data set contains firn physical properties measured in two meter snow pits
and from deeper, 12- to 30-m firn cores. The physical properties measured in
the snow pits include density, permeability and microstructure (grain size and
pore size). The physical properties measured on firn cores include density,
permeability, diffusivity and microstructure. The data are provided in
space-delimited ASCII text files and Microsoft Excel formats. 
