Bedrock morphology reveals paleo subglacial drainage network in the Northeast Baffin Bay

• Main Authors: Slabon, Patricia, Dorschel, Boris, Jokat, Wilfried, Freire, Francis
• Format: Conference Object
• Language: unknown
• Published: 2017
• Subjects: Baffin Bay; Baffin; Greenland; Ice Sheet
• Online Access: https://epic.awi.de/id/eprint/46186/; https://hdl.handle.net/10013/epic.3de5aa1b-a3a7-421c-b119-112c10310935

The availability of high-resolution bathymetry on the northeast Baffin Bay is limited in the Melville Bay, Northeast Baffin Bay, due to its remote location. At present, there are only few studies that mapped the glacial imprint from past glacials on the Northwest Greenland continental shelf. This study provides a compilation of the most recent high-resolution bathymetry from Melville Bay, northeast Baffin Bay. It presents a more detailed picture of the crystalline bedrock basement on the inner continental shelf that allows a more detailed analysis of its morphology towards glacial and fluvial landforms. The newly-compiled data show an extensive paleo sub-glacial channel network that spans from the crystalline basement of the Melville Bay Fault towards the modern ice-streams of the Greenland Ice Sheet. We focus on three areas of higher data coverage to analyse them for glacial geomorphology and paleo ice-flow patterns. These channels describe a dendritic drainage pattern. They are overdeepened and u-shaped near the coast and become narrow and more v-shaped seawards. They are located in a highly fractured crystalline bedrock. Most channels follow zones of weakness in the bedrock that are parallel or subparallel to the major fault axes in the Baffin Bay. The channels show typical characteristics for both fluvial and glacial erosion that give evidence for varying glaciofluvial impact. The channel network forms the onset zone of the large paleo-ice streams that occupied the Melville Bay cross-shelf troughs during past glacials. Differences in underlying geology are depicted in varying channel characteristics. We interpret the channel network as subglacial drainage network that developed underneath the paleo-ice sheet off Northwest Greenland. It provides morphological indications for the pathways of ice and meltwater of the Greenland ice-sheet across the crystalline basement into the Baffin Bay.