Landform assemblage produced by ice-grounding events on the Yermak Plateau

The landforms and sediments preserved on the Yermak Plateau (Figs 1, 2, 3) provide information on the glacial history and past dynamics of the northwestern-most sector of the Eurasian Ice Sheet (Dowdeswell et al. 2010; Gebhardt et al. 2011), as well as the exchange of ice and water between the North Atlantic and the Arctic Ocean via Fram Strait (Fig. 1a) (Jakobsson et al. 2010). Early ideas about Quaternary ice cover in the Arctic Ocean proposed the existence of a circum-Arctic ice shelf prior to the last glaciation (e.g. Mercer 1970). More recent work suggested that the major glaciations since the interglacial period of marine oxygen isotope stage (MIS) 5.5 did not extend beyond the Eurasian continental shelf edges. However, geophysical data reveal that ice extended across the Yermak Plateau prior to MIS 5.5 during the particularly extensive glaciation in MIS 6 (Dowdeswell et al. 2010; Jakobsson et al. 2010). By contrast, the presence of a grounding-zone complex beyond NW Spitsbergen (Fig. 3) implies that grounded ice did not extend onto the Yermak Plateau during the Last Glacial Maximum (LGM) (Ottesen & Dowdeswell 2009).