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Modelled fracture and calving on the Totten Ice Shelf

Citation

Cook, S and Astrom, J and Zwinger, T and Galton-Fenzi, BK and Greenbaum, JS and Coleman, R, Modelled fracture and calving on the Totten Ice Shelf, The Cryosphere, 12 pp. 2401-2411. ISSN 1994-0416 (2018) [Refereed Article]


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Copyright Statement

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

DOI: doi:10.5194/tc-12-2401-2018

Abstract

The Totten Ice Shelf (IS) has a large drainage basin, much of which is grounded below sea level, leaving the glacier vulnerable to retreat through the marine ice sheet instability mechanism. The ice shelf has also been shown to be sensitive to changes in calving rate, as a very small retreat of the calving front from its current position is predicted to cause a change in flow at the grounding line. Therefore understanding the processes behind calving on the Totten IS is key to predicting its future sea level rise contribution. Here we use the Helsinki Discrete Element Model (HiDEM) to show that not all of the fractures visible at the front of the Totten IS are produced locally, but that the across-flow basal crevasses, which are part of the distinctive cross-cutting fracture pattern, are advected into the calving front area from upstream. A separate simulation of the grounding line shows that re-grounding points may be key areas of basal crevasse production, and can produce basal crevasses in both an along- and across-flow orientation. The along-flow basal crevasses at the grounding line may be a possible precursor to basal channels, while we suggest the across-flow grounding-line fractures are the source of the across-flow features observed at the calving front. We use two additional models to simulate the evolution of basal fractures as they advect downstream, demonstrating that both strain and ocean melt have the potential to deform narrow fractures into the broad basal features observed near the calving front. The wide range of factors which influence fracture patterns and calving on this glacier will be a challenge for predicting its future mass loss.

Item Details

Item Type:Refereed Article
Keywords:glaciology, calving, Antarctica
Research Division:Earth Sciences
Research Group:Physical Geography and Environmental Geoscience
Research Field:Glaciology
Objective Division:Expanding Knowledge
Objective Group:Expanding Knowledge
Objective Field:Expanding Knowledge in the Earth Sciences
UTAS Author:Cook, S (Dr Sue Cook)
UTAS Author:Galton-Fenzi, BK (Dr Ben Galton-Fenzi)
UTAS Author:Coleman, R (Professor Richard Coleman)
ID Code:127374
Year Published:2018
Web of Science® Times Cited:1
Deposited By:CRC-Antarctic Climate & Ecosystems
Deposited On:2018-07-25
Last Modified:2019-03-14
Downloads:115 View Download Statistics

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