Geometry and ice dynamics of the Darwin–Hatherton glacial system, Transantarctic Mountains

The Darwin–Hatherton Glacial system (DHGS) connects the East Antarctic Ice Sheet (EAIS) with the Ross Ice Shelf and is a key area for understanding past variations in ice thickness of surrounding ice masses. Here we present the first detailed measurements of ice thickness and grounding zone characte...

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Bibliographic Details
Published in:Journal of Glaciology
Main Authors: METTE K. GILLESPIE, WENDY LAWSON, WOLFGANG RACK, BRIAN ANDERSON, DONALD D. BLANKENSHIP, DUNCAN A. YOUNG, JOHN W. HOLT
Format: Article in Journal/Newspaper
Language:English
Published: Cambridge University Press 2017
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Online Access:https://doi.org/10.1017/jog.2017.60
https://doaj.org/article/1f4273c25492414b8a198923e3738504
Description
Summary:The Darwin–Hatherton Glacial system (DHGS) connects the East Antarctic Ice Sheet (EAIS) with the Ross Ice Shelf and is a key area for understanding past variations in ice thickness of surrounding ice masses. Here we present the first detailed measurements of ice thickness and grounding zone characteristics of the DHGS as well as new measurements of ice velocity. The results illustrate the changes that occur in glacier geometry and ice flux as ice flows from the polar plateau and into the Ross Ice Shelf. The ice discharge and the mean basal ice shelf melt for the first 8.5 km downstream of the grounding line amount to 0.24 ± 0.05 km3 a−1 and 0.3 ± 0.1 m a−1, respectively. As the ice begins to float, ice thickness decreases rapidly and basal terraces develop. Constructed maps of glacier geometry suggest that ice drainage from the EAIS into the Darwin Glacier occurs primarily through a deep subglacial canyon. By contrast, ice thins to <200 m at the head of the much slower flowing Hatherton Glacier. The glaciological field study establishes an improved basis for the interpretation of glacial drift sheets at the link between the EAIS and the Ross Ice Sheet.