SPATIAL-DISTRIBUTION OF SNOW IN WESTERN DRONNING MAUD LAND, EAST ANTARCTICA, MAPPED BY A GROUND-BASED SNOW RADAR

During the austral summer 1993/1994, the spatial distribution of snow was mapped by a ground-based snow radar (800-2300 MHz) in western Dron ning Maud Land, East Antarctica. Snow radar soundings were performed a long continuous profiles extending from the ice shelf up to the polar plateau, a total distance of 1040 km. The high-resolution radar regist rations revealed subsurface layering in the uppermost 12 m of the snow pack. The travel time record was translated into snow accumulation exp ressed in water equivalents, based on an empirical relationship betwee n wave speed and firn density. A good knowledge on snow density variat ions with depth is essential for the variability studies. Generally, t he snow layering was well developed in the coastal area and less well developed on the polar plateau. High spatial variability in snow accum ulation was observed on a regional as well as on a local scale. The va riability was very high in areas with large surface slopes, such as th e grounding zone and around nunataks. The highest variability was reco rded in the nunatak area, where the standard deviation reached 59% of the spatial average accumulation. On the smooth high-altitude plateau, variations in accumulation were less pronounced. However, here the st andard deviation exceeded 22% of the average accumulation rate. Provid ed that the snow radar soundings are supported by dating of reference horizons along the travel route, this is a good method to obtain the a ccumulation rate and pattern for large areas with a high spatial resol ution.