European Facility For Airborne Research

European Facility For Airborne Research Sept. 24, 2018, 04:59

Document

Description
Title Transition of flow regime along a marine-terminating outlet glacier in East Antarctica
Type Publication
Abstract:

We present results of a multi-methodological approach to characterize the flow regime of West Ragnhild Glacier, the widest glacier in Dronning Maud Land, Antarctica. A new airborne radar survey points to substantially thicker ice (>2000 m) than previously thought. With a discharge estimate of 13–14 Gt yr−1, West Ragnhild Glacier thus becomes of the three major outlet glaciers in Dronning Maud Land. Its bed topography is distinct between the upstream and downstream section: in the downstream section (<65 km upstream of the grounding line), the glacier overlies a wide and flat basin well below the sea level, while the upstream region is more mountainous. Spectral analysis of the bed topography also reveals this clear contrast and suggests that the downstream area is sediment covered. Furthermore, bed-returned power varies by 30 dB within 20 km near the bed flatness transition, suggesting that the water content at bed/ice interface increases over a short distance downstream, hence pointing to water-rich sediment. Ice flow speed observed in the downstream part of the glacier (~250 m yr−1) can only be explained through very low basal friction, leading to a substantial amount of basal sliding in the downstream 65 km of the glacier. All the above lines of evidence (sediment bed, wetness and basal motion) and the relatively flat grounding zone give the potential for West Ragnhild Glacier to be more sensitive to external forcing compared to other major outlet glaciers in this region, which are more stable due to their bed geometry (e.g. Shirase Glacier).

Available from https://www.the-cryosphere.net/8/867/2014/
Author
CALLENS Denis
MATSUOKA Kenichi
PATTYN Frank
STEINHAGE Daniel
B. Smith, E. Witrant
Reference
Journal The Cryosphere
Volume 8
Pages 867-875
Year 2014
Times cited 7
Institute country Belgium
Type of science
  • Geophysics and Glaciology
Field of science
  • Polar regions
File details
Added Aug. 17, 2017, 14:27
Last update Aug. 17, 2017, 14:31
Size 1.7 MB
File name None
Visibility Public
Links with specific subjects

Go to the document list

Back to top
EUFAR
EU

This project has received funding from the European Union's Seventh Framework Programme for research, technological development and demonstration under grant agreement no. 312609

Copyright © 2018 EUFAR All rights reserved.