Holocene deglaciation history of King George Island as one example for future changes of the West Antarctic Ice Sheet, Antarctica

• Main Authors: Kuhn, Gerhard, Hass, Christian, Wittenberg, Nina, Wölfl, Anne-Cathrin, Tiedemann, Ralf
• Format: Conference Object
• Language: unknown
• Published: Korea Polar Research Institute 2012
• Subjects: Antarctic; King George Island; South Shetland Islands; West Antarctic Ice Sheet; Potter Cove; Admiralty Bay; Marian; Maxwell Bay; Ezcurra; Marian Cove; Ezcurra Inlet; Collins Harbor; Antarc*; Antarctica; Ice cap; Ice Sheet; Polar Research; Sea ice
• Online Access: https://epic.awi.de/id/eprint/30647/; https://hdl.handle.net/10013/epic.39588

Marine sediments in Maxwell Bay, a 500 m deep bay between Nelson and King George Island (KGI), record high-resolution Holocene environmental changes. Sediment, mineralogical, geochemical and biological compositions and the grain size of the terrigenous particles have been investigated for reconstructions of biological palaeoproductivity, sea-ice coverage, melt water inflow and the deglaciation history of the surrounding land areas. Reliable age determinations of sediments are rare but increased in number during the last years. First correlations of the local results to regional or global climate signals are possible and demonstrate the exceptional value of this region for past, recent and prognostic environmental studies. The concentration of multidisciplinary research from many nations in this small area provides a solid base for comprehensive data assimilation. We would try to establish a multi-, inter- and transdisciplinary (MIT) research project to integrate and complete the results from marine sediments with those from lakes, from glaciological studies, glacial exhumation, age determinations and from geomorphological studies and raised Holocene beaches in the King George Island area. We will start with a compilation of available data in the area of the South Shetland Islands and finish the studies of sediment characterization in Potter Cove. To detect, discriminate and interpret regional and local environmental processes and effects from global trends we need comparisons from other bays and therefore one goal is to map Marian Cove, Collins Harbor and Ezcurra Inlet at Admiralty Bay with identical hydroacoustic methods we have used in Potter Cove and compare this with ground truth surface sediment sampling for a combined geo- and biological characterization. Results on meltwater discharge, characterized by granulometric and sedimentological analysis, variations in geochemical processes and, changes in organic and inorganic accumulation rates that co-vary with global climate periods like the Medieval Climate Optimum and the Little Ice Age were described recently from sediment cores we collected in Maxwell Bay. There are discrepancies discovered between recent changes of glacial retreats and former ones during warmer Holocene periods, that might be related to a different sea level and changes from tide water glaciers to land based glaciers. Only a detailed palaeoglaciological and bedrock reconstruction of the KGI ice cap in combination with reconstructed regional past sea levels will answer questions related also to the West Antarctic Ice Sheet stability in the past and under future warmer climate conditions.