10Be exposure age constraints on the Late Weichselian ice‐sheet geometry and dynamics in inter‐ice‐stream areas,western Svalbard |
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| Authors: | Jon Y Landvik Edward J Brook Lyn Gualtieri Henriette Linge Grant Raisbeck Otto Salvigsen Françoise Yiou |
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| Institution: | 1. Norwegian University of Life Sciences, Department of Plant and Environmental Sciences, , P.O. Box 5003, ?s, Norway;2. Oregon State University, Department of Geosciences, , Corvallis, OR, 97330 USA;3. Seattle University, , College of Science and Engineering, Seattle, WA, 98122 USA;4. Department of Earth Science, University of Bergen, , Bergen, Norway;5. Centre de Spectrométrie Nucléaire et de Spectrométrie de Masse (CSNSM), , F‐91405 Campus Orsay, France;6. University of Oslo, Department of Geosciences, , Oslo, Norway |
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| Abstract: | The Late Weichselian ice sheet of western Svalbard was characterized by ice streams and inter‐ice‐stream areas. To reconstruct its geometry and dynamics we investigated the glacial geology of two areas on the island of Prins Karls Forland and the Mitrahalvøya peninsula. Cosmogenic 10Be surface exposure dating of glacial erratics and bedrock was used to constrain past ice thickness, providing minimum estimates in both areas. Contrary to previous studies, we found that Prins Karls Forland experienced a westward ice flux from Spitsbergen. Ice thickness reached >470 m a.s.l., and warm‐based conditions occurred periodically. Local deglaciation took place between 16 and 13 ka. At Mitrahalvøya, glacier ice draining the Krossfjorden basin reached >300 m a.s.l., and local deglaciation occurred at c. 13 ka. We propose the following succession of events for the last deglaciation. After the maximum glacier extent, ice streams in the cross‐shelf troughs and fjords retreated, tributary ice streams formed in Forlandsundet and Krossfjorden, and, finally, local ice caps were isolated over both Prins Karls Forland and Mitrahalvøya and their adjacent shelves. |
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