Queen Maud Land

The right part of this ERS-1 SAR image, gathered on 16-1-1992, shows peaks of the Heimefront Range in Queen Maud Land of Antarctica, about 300 km inland from the coast of the Weddell Sea. The escarpment of the Heimefront Range separates the plateau of the Amundsen Ice, situated south of the mountains, from the ice stream Veststraumen which moves from the upper right to the lower left part of the image.
The highest peaks of the mountain group Sivorgfjella, visible near the lower right corner of the image, rise to 2700 m above sea level, about 2000 m higher than the ice surface in the lower left corner. Veststraumen transports ice from the Heimefront Range and from Amundsen Ice towards Rijser-Larsen Ice Shelf at the Weddell Coast. The streamlines, visible as linear features, indicate the direction of ice motion.

Gentle undulations of the ice surface, related to subsurface topography, result in large-scale wave-like structures with orientation of the ridges approximately perpendicular to the flow direction. Along the edge of the mountains the flowlines change from south-westerly to westerly direction.
Near the central right margin of the image a major ice stream, called Aubertisen, collects ice from two tributaries coming down from the plateau. Thin parallel lines, approximately perpendicular to the low lines, correspond to crevasses. Major crevasse zones can be seen near the confluence of the two ice streams and along the margin of the mountain slopes.

Another major crevasse zone in the lower left part of the image is related to disturbances of ice motion due to bedrock elevations. North of Veststraumen, in the upper left part of the image, lies the ice plateau Ritscherflya where the ice shows only little motion.
Variations of image brightness in this region are related to subtle variations of surface topography and snow morphology. The highest parts of the mountain groups Sivorgfjella and Milorgfjella along the right margin of the image terminate with steep cliffs of rock and ice facing towards north-west (left). These cliffs appear elongated because they are facing away from the radar. Rough, partly wind eroded ice surfaces below the cliffs, covered with blocks of ice avalanches and crevasses, appear as zones of remarkably bright radar return.

H. Rott, Innsbruck, Austria

Keywords: ESA European Space Agency - Agence spatiale europeenne, observation de la terre, earth observation, satellite remote sensing, teledetection, geophysique, altimetrie, radar, chimique atmospherique, geophysics, altimetry, radar, atmospheric chemistry