Marine geomorphological record of Ice Sheet development in East Greenland since the Last Glacial Maximum

Reconstructions of ice sheet development in East Greenland, since the Last Glacial Maximum (LGM), are poorly constrained. This study compiles swath bathymetric data from five expeditions, to investigate the geomorphology of three glacier outlet systems (Kejser Franz Joseph Fjord, Kong Oscar Fjord, and Scoresby Sund) and reconstruct the post-LGM ice dynamics and extent. The landforms suggest that ice streams probably reached the shelf edge, via cross-shelf troughs, in all three systems at the LGM. Off Scoresby Sund, it remains unresolved as to whether a mid-shelf grounding zone wedge marks a recessional stage or the LGM extent. In the AllerOd-BOlling interstadial, ice retreated to the fjord entrances at Kejser Franz Joseph Fjord and Kong Oscar Fjord, as documented by partly overridden terminal moraines, and most probably into the fjord at Scoresby Sund. Subsequent overriding occurred by ice readvance, probably in the Younger Dryas. Large ice-marginal deposition features, formed on the mid-shelf and at the entrance of Scoresby Sund, probably mark the maximum ice-sheet extent after the readvance. Holocene retreat was rapid, except for two phases of stabilization at the entrance of Kong Oscar Fjord. Landslide debris indicates that at least one tsunami affected Scoresby Sund at some time in the Holocene.