A geomorphological overview of glacial landforms on the Icelandic continental shelf

摘要

The availability of a bathymetric database that covers about 80% of the Icelandic shelf has made it possible to produce a geomorphological map of the glacial landforms. The digital elevation model of the bathymetry was analyzed as a series of shaded relief images. Trough edges, bulging trough mouths, moraines, eskers, melt water channels, streamlined bedrock and streamlined drift, mostly hitherto unmapped, distributed all around the island have been identified. Moraines are found on the shelf, within troughs and inside fjords. Streamlined landforms are always confined to the bottom of troughs. Troughs appear to have been cut by ice streams draining an ice sheet that likely covered the entire shelf. At the shelf break, most troughs terminate with contours that bulge in a convex-outwards fashion. This suggests that an ice stream eroded, transported and finally deposited large amounts of sediment at the trough mouth. Overall, the glacial morphology of the shelf highlights a radial pattern that indicates a main ice divide near the centre of Iceland.