Polar desert sandar, Antarctica

Abstract

Abstract Because the climatic severity of Antarctic polar desert environments strongly inhibits glaciofluvial processes, outwash sediments are not as conspicuous as in parts of Iceland and Arctic Canada. However, in the Antarctic “dry valleys” numerous, small sandar, both active and relict, attest to the longterm effectiveness of low-magnitude, meltwater discharges in ancient polar desert landscapes. Many parts of these valley systems have been free of glacier ice for at least 0.5 m.y. and glacier responses are extremely slow. Thus, small discharge events may have been repeated many thousands to tens of thousands of times for each sandur system. In this manner significant bodies of outwash sediments have accumulated. Very slow acting glaciofluvial processes typify Antarctic sandar, in contrast to the more pronounced meltwater and rainstorm peakflows, including jokulhlaups, which largely shape their Arctic counterparts.