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Geoscience seminar - Martin Margolds, Charles University, Department of Physical Geography and Geoecology, 128 43, Prague, Czech Republic

The configuration of Northern Hemisphere ice sheets through the Quaternary

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Time

Thursday 21 November 2019,  at 14:15 - 15:00

Knowledge of the extent, volume and timing of Quaternary ice sheets is fundamental to studies of sea-level change, Earth rheology, global climate, landscape evolution, sedimentation, palaeoecology, genetic diversity and Anthropology. The last few decades have seen unprecedented growth in the size and diversity of empirical datasets used to reconstruct and date palaeo-ice sheet extent, together with major improvements in our ability to simulate their dynamics in numerical models. However, the vast majority of these reconstructions focus on ice sheet deglaciation from the Last Glacial Maximum (LGM) and there have been very few attempts at constraining pre-LGM ice-sheet extent. Here, we evaluate and integrate data and modelling of pre-LGM ice sheets to produce the first self-consistent time-slice reconstructions of Northern Hemisphere ice-sheet extent spanning the entire Quaternary, including min-max bounds. We use these reconstructions to produce new independent estimates of relative sea level during each time slice. Our results are discussed in terms of their implications for ice-free refugia and migration corridors, long-term landscape evolution, and the synchrony/asynchrony in the extent of Northern Hemisphere ice sheets for major marine isotope stages spanning the Quaternary.