East Antarctic Ice Sheet Instability in the Vestfold Hills, Prydz Bay Region, Antarctica - History and Control

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The project proposed contributes to an international initiative, which aims at a better understanding of modern and past East Antarctic Ice Sheet Instabilities (EASI), complementing existing findings with new samples and data from three expeditions with the R.V. "Polarstern" (EASI-1, -2 and -3). Focus of the project is put on the ice-free coastal area of Vestfold Hills at the eastern margin of Prydz Bay. In this so-called ´oasis´, field work shall be carried out during the expedition EASI-2 (Nov. 2023 - Jan. 2024), with the recovery of sediment cores from a fjord and several lakes, as well as geomorphological investigations. Based on a multi-disciplinary analysis of the sample and data sets obtained, supported by geodetic and paleobiological investigations by other EASI projects, the glacial history of the Vestfold Hills shall be reconstructed in unprecedented spatial and temporal detail. The reconstructions shall comprise the ice retreat and possible readvances since the Last Glacial Maximum (LGM), but also the controversial extend of the ice coverage during the LGM and possible ice-free settings prior to the LGM. Besides, the forcing mechanisms for the reconstructed glacial history shall for the first time be investigated systematically, evaluating the factors that influence the ice mass balance via calving as well as subaereal and subaquatic melting. This on the one hand concerns the postglacial variations in local temperature and relative sea level, whose reconstructions shall be improved by the new sediment records. On the other hand, it concerns the history of sea-ice coverage and ocean currents on the adjacent continental shelf, which will be reconstructed by other EASI projects. And finally, it concerns potential impacts by the glaciological and morphological characteristics of the oasis, which shall be evaluated by comparisons with the respective characteristics and individual climatic and environmental histories in other East Antarctic oases.