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Seasonal dynamics of Totten Ice Shelf controlled by sea ice buttressing

Citation

Greene, CA and Young, DA and Gwyther, DE and Galton-Fenzi, BK and Blankenship, DD, Seasonal dynamics of Totten Ice Shelf controlled by sea ice buttressing, The Cryosphere, 12, (9) pp. 2869-2882. ISSN 1994-0416 (2018) [Refereed Article]


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Copyright Statement

Copyright 2018 the authors. Licensed under Creative Commons Attribution 4.0 International (CC BY 4.0) https://creativecommons.org/licenses/by/4.0/

DOI: doi:10.5194/tc-12-2869-2018

Abstract

Previous studies of Totten Ice Shelf have employed surface velocity measurements to estimate its mass balance and understand its sensitivities to interannual changes in climate forcing. However, displacement measurements acquired over timescales of days to weeks may not accurately characterize long-term flow rates wherein ice velocity fluctuates with the seasons. Quantifying annual mass budgets or analyzing interannual changes in ice velocity requires knowing when and where observations of glacier velocity could be aliased by subannual variability. Here, we analyze 16 years of velocity data for Totten Ice Shelf, which we generate at subannual resolution by applying feature-tracking algorithms to several hundred satellite image pairs. We identify a seasonal cycle characterized by a spring to autumn speedup of more than 100 m yr−1 close to the ice front. The amplitude of the seasonal cycle diminishes with distance from the open ocean, suggesting the presence of a resistive back stress at the ice front that is strongest in winter. Springtime acceleration precedes summer surface melt and is not attributable to thinning from basal melt. We attribute the onset of ice shelf acceleration each spring to the loss of buttressing from the breakup of seasonal landfast sea ice.

Item Details

Item Type:Refereed Article
Keywords:Antarctica, Totten Glacier, ice sheet, sea ice
Research Division:Earth Sciences
Research Group:Oceanography
Research Field:Physical oceanography
Objective Division:Environmental Management
Objective Group:Management of Antarctic and Southern Ocean environments
Objective Field:Antarctic and Southern Ocean oceanic processes
UTAS Author:Gwyther, DE (Dr David Gwyther)
UTAS Author:Galton-Fenzi, BK (Dr Ben Galton-Fenzi)
ID Code:128201
Year Published:2018
Web of Science® Times Cited:12
Deposited By:Oceans and Cryosphere
Deposited On:2018-09-07
Last Modified:2018-11-27
Downloads:104 View Download Statistics

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