Publication Date:
2016-06-05
Description:
Subglacial topography exerts strong controls on glacier dynamics, influencing the orientation and velocity of ice flow, as well as modulating the distribution of basal waters and sediment. Bed geometry can also provide a long-term record of geomorphic processes, allowing insight into landscape evolution, the origin of which may pre-date ice sheet inception. Here, we present evidence from ice-penetrating radar data for a large dendritic drainage network, radiating inland from Jakobshavn Isbræ, Greenland's largest outlet glacier. The size of the drainage basin is ∼ 450,000 km 2 and accounts for about 20% of the total land area of Greenland. Topographic and basin morphometric analyses of an isostatically uplifted (ice-free) bedrock topography suggests that this catchment pre-dates ice sheet initiation and has likely been instrumental in controlling the location and form of the Jakobshavn ice stream, and ice flow from the deep interior to the margin, now and over several glacial cycles.
Print ISSN:
0094-8276
Electronic ISSN:
1944-8007
Topics:
Geosciences
,
Physics
Permalink
