Constraints on the Late Weichselian ice sheet over the Barents Sea from observations of raised shorelines |
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| Institution: | 1. Faculteit Aardwetenschappen, Universiteit Utrecht, Utrecht, The Netherlands;2. On leave from Research School of Earth Sciences, Australian National University, Canberra 0200, Australia;1. Department of Arctic and Marine Biology, UiT the Arctic University of Norway, NO-9037, Tormsø, Norway;2. United States Geological Survey (Retired), 441 Ashley Dr. Underwood, WA 98651, USA;3. Akvaplan-niva AS, Fram Centre—High North Research Centre for Climate and the Environment, Hjalmar Johansens Gate 14, 9007 Tromsø, Norway;4. Norwegian Institute for Air Research, Fram Centre—High North Research Centre for Climate and the Environment, Hjalmar Johansens Gate 14, 9007 Tromsø, Norway;5. Department of Biological Sciences, University of Calgary, Calgary, Alberta, T2N1N4, Canada;1. MOE Key Laboratory of Fundamental Physical Quantities Measurement, School of Physics, Huazhong University of Science and Technology, Wuhan, PR China;2. State Key Laboratory of Geodesy and Earth’s Dynamics, Institute of Geodesy and Geophysics, Chinese Academy of Sciences, Wuhan, PR China;3. State Key Laboratory of Information Engineering in Surveying, Mapping, and Remote Sensing, Wuhan University, Wuhan, PR China;4. School of Geodesy and Geomatics, Wuhan University, Wuhan, PR China;1. Institute of Geology, Innsbruck University, Innrain 52, Innsbruck 6020, Austria;2. A.P. Karpinsky Russian Geological Research Institute (VSEGEI), Sredny prospekt 74, St.-Petersburg 199106, Russian Federation;1. State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment, Chinese Academy of Sciences, Xi’an 710061, China;2. Institute of Mineral Resources Research, China Metallurgical Geology Bureau, Beijing 101300, China;3. Shaanxi Provincial Key Laboratory of Accelerator Mass Spectrometry Technology and Application, National Center for Accelerator Mass Spectrometry in Xi’an, Xi’an 710061, China;4. Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing 100101, China;5. Center for Excellence in Tibetan Plateau Earth Sciences, Chinese Academy of Sciences, Beijing 100101, China;6. Department of Physics and Astronomy, Purdue University, West Lafayette 47907, USA;7. Department of Earth, Atmospheric, and Planetary Sciences, Purdue University, West Lafayette 47907, USA;1. W. Szafer Institute of Botany, Polish Academy of Sciences, Lubicz 46, 31-512 Kraków, Poland;2. Institute of Nature Conservation, Polish Academy of Sciences, al. A. Mickiewicza 33, 31-120 Kraków, Poland |
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| Abstract: | Direct evidence for Late Weichselian grounded glacier ice over extensive areas of the Barents Sea is based largely on indirect observations, including elevations of old shorelines on Svalbard and arguments of isostatic rebound. Such isostatic models are discussed here for two cases representing maximum and minimum ice-sheet reconstructions. In the former model the ice extends over the Kara Sea, whereas in the latter the ice is limited to the Barents Sea and island archipelagos. Comparisons of predictions with observations from a number of areas, including Spitsbergen, Nordaustlandet, Edgeøya, Kong Karls Land, Franz Josef Land, Novaya Zemlya and Finnmark, support arguments for the existence of a large ice sheet over the region at the time of the last glacial maximum. This ice sheet is likely to have had the following characteristics, conclusions that are independent of assumptions made about the Earth's rheological parameters. (i) The maximum thickness of this ice was about 1500–2000 m with the centre of the load occurring to the south and east of Kong Karls Land. (ii) The ice sheet extended out to the western edge of the continental shelf and its maximum thickness over western Spitsbergen was about 800 m. (iii) To the north of Svalberg and Frans Josef Land the ice sheet extended out to the northern shelf edge. (iv) Retreat of the grounded ice across the southern Barents Sea occurred relatively early such that this region was largely ice free by about 15,000 BP. (v) By 12,000 BP the grounded ice had retreated to the northern archipelagos and was largely gone by 10,000 BP. (vi) The ice sheet may have extended to the Kara Sea but ice thicknesses were only a fraction of those proposed in those reconstructions where the maximum ice thickness is centered on Novaya Zemlya. Models for the palaeobathymetry for the Barents Sea at the time of the last glacial maximum indicate that large parts of the Barents Sea were either very shallow or above sea level, providing the opportunity for ice growth on the emerged plateaux, as well as on the islands, but only towards the end of the period of Fennoscandian ice sheet build-up. |
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