Interaction of cryospheric and oceanographic processes along the central-east Greenland margin

The east Greenland margin has been influenced by oceanographic and cryospheric processes since the late Miocene when the southwards flow of the East Greenland Current (EGC) initiated together with the first advance of the ice sheets along the margin. However, the relative control of these processes over the sedimentation and their influence through time remains little understood. High-resolution single-channel seismic, chirp sub-bottom profiles and swath bathymetry data were acquired along the middle and lower slope and proximal abyssal plain off Liverpool Land, central-east Greenland margin. The main aim of our study is to identify the action of along and down slope processes in order to clarify the relative influence of the Greenland ice sheet and the oceanographic flows in the construction of the east Greenland margin.

Seismic-stratigraphic analyses have allowed us to distinguish between major sedimentary processes occurred during the Quaternary. The stratigraphic architecture reveals Mass Transport Deposits (MTDs) related to glacial influenced down-slope sedimentary processes. These are intercalated with buried contourite systems associated with bottom current along-slope sedimentary processes. The distribution of the MTDs suggests the influence of two distinguished ice stream systems. The initial phases of down-slope deposition appear to be related to distal deposition fed by an ice stream from the Scoresby Sund area to the south. The more recent down-slope deposits together with morphological analysis of the seafloor further supports that the recent activity of down-slope processes occurred in the north, linked to an ice stream from Kong Oscar Fjord area. These observations show a shift through time between the Scoresby Sund and Kong Oscar Fjord ice stream systems. The glacial influence over the margin has been interrupted by periods of stronger activity of the along-slope bottom current flow, denoting that the EGC periodically controlled the sedimentation.