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Rifting processes and ice-flow modulation observed on Mertz Glacier, East Antarctica

Citation

Lescarmontier, L and Legresy, B and Young, NW and Coleman, R and Testut, L and Mayet, C and Lacroix, P, Rifting processes and ice-flow modulation observed on Mertz Glacier, East Antarctica, Journal of Glaciology, 61, (230) pp. 1183-1193. ISSN 0022-1430 (2015) [Refereed Article]


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Copyright unknown. Licensed under Creative Commons Attribution 4.0 International (CC BY 4.0) http://creativecommons.org/licenses/by/4.0/

DOI: doi:10.3189/2015JoG15J028

Abstract

We investigated the evolution of two major rifts cutting across Mertz Glacier Tongue, East Antarctica, using a combination of satellite images and 60 day sets of GPS data from two stations deployed either side of the western rift in 2007. The eastern rift began to open in the early 1990s, and the western rift initiated in 2002 in conjunction with the collision of a large iceberg with the tongue. Velocity time series derived from the 2007 GPS data exhibited strong variations at tidal periods modulated by sea-surface height and sea-surface slope and reproduced here with a conceptually simple model. We found that opening of the western rift in 2002 leads to a dramatic change in behavior of the tongue as the large range in velocity (700–2400 m a–1) observed in 2000 was largely reduced (1075–1225 m a–1) in 2007. Opening of the western rift decoupled the glacier from the transverse loading on the tongue driven by east–west tidal circulation. This loading previously induced time-varying lateral drag, which caused the large velocity range. Our results suggest changes in the mechanical behavior of an ice tongue impact the dynamics of the outlet glacier system and should be considered in longer-term mass-balance evaluations.

Item Details

Item Type:Refereed Article
Keywords:Antarctic glaciology, calving, crevasses, glacier flow, glacier mechanics
Research Division:Earth Sciences
Research Group:Physical Geography and Environmental Geoscience
Research Field:Glaciology
Objective Division:Environment
Objective Group:Other Environment
Objective Field:Antarctic and Sub-Antarctic Oceanography
Author:Legresy, B (Dr Benoit Legresy)
Author:Young, NW (Mr Neal Young)
Author:Coleman, R (Professor Richard Coleman)
ID Code:106028
Year Published:2015
Deposited By:IMAS Research and Education Centre
Deposited On:2016-01-25
Last Modified:2016-04-21
Downloads:76 View Download Statistics

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