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

• Published in: Journal of Glaciology
• Main Authors: GILLESPIE, METTE K., LAWSON, WENDY, RACK, WOLFGANG, ANDERSON, BRIAN, BLANKENSHIP, DONALD D., YOUNG, DUNCAN A., HOLT, JOHN W.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Cambridge University Press (CUP) 2017
• Subjects: Earth-Surface Processes; Antarctic; East Antarctic Ice Sheet; Ross Ice Shelf; Transantarctic Mountains; Polar Plateau; Darwin Glacier; Hatherton Glacier; Antarc*; Ice Sheet; Ice Shelf; Journal of Glaciology
• Online Access: http://dx.doi.org/10.1017/jog.2017.60; https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143017000600

ABSTRACT 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 km 3 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.