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L'Antàrtida, molt més que gel R. Urgeles, M. Canals, A. Calafat i D. Amblās. Lempremta
del clima a l'Antàrtida: dinàmica glacial i extensió del gel durant
el darrer màxim glacial. Multibeam swath bathymetric and TOPAS sub-bottom profiler data collected from the Antarctic Peninsula margin during the last decade have allowed to obtain a better understanding of ice extent and dynamics during the Last Glacial Maximum. These data show that the continental shelf is bisected by a series of troughs almost extending to the shelf edge where water depths may be in excess of thousand meters. The troughs contain sets of subparallel lineations and other structures that are interpreted to result from the presence of former ice streams. Most of such ice streams have nowadays become confined to fjords and inner parts of the peninsula. This implies ice retreat distances up to 100 km, demonstrating the high sensitivity to climate change of the mostly marine based ice sheets and ice caps of Western Antarctica. |
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