Geomorphic evidence for along-margin ice flow from Melville Bugt slope, west Greenland

In summer 2023, the Baffin Bay Deglacial Experiment (BADEX) completed a 33-day cruise focused on the west Greenland margin; the overarching goal of this project is to investigate the evolving ocean and ice conditions along the west Greenland ice sheet from the last glacial maximum through the deglaciation. The cruise collected seafloor and sub-seafloor data, as well as water and plankton samples, with the aim of establishing 1) the timing and extent of warm Atlantic water incursion along the north-western Greenland margin; 2) the phasing of the initial ice margin retreat relative to oceanic and atmospheric changes; 3) the role of local or regional ice shelves in buttressing trough-bound outlet glaciers; and 4) the influence of regional geology, geomorphology, and ice dynamics on ice-margin retreat. Here, we present results from the ~600 km of new multibeam sonar data collected on the slope just north of the Melville Bugt trough mouth fan (TMF). The margin in this area curves landward, forming a crescent-shaped, submarine amphitheater that contains a range of bathymetric features, which vary in form with water depth and their proximity to the TMF. This includes a series of contour-following ridges that occur in depths from ~1000 to ~450 meters below modern water level. These ridges are more prominent farther away from the TMF but are more numerous closer to the trough. They are interpreted to be of glaciogenic origin, potentially formed by an ice shelf, fed by the trough, that flowed to the north and grounded on the slope. These ridges and other bathymetric features, extending up to 2000 meters water depth will be discussed. These results add to our understanding of the ice margin configuration in northern Baffin Bay during and after the last glacial period.