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Thwaites Glacier grounding-line retreat: influence of width and buttressing parameterizations

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Docquier, David [UCL] Pollard, David [FUNDP] Pattyn, Frank

Major ice loss has recently been observed along coastal outlet glaciers of the West Antarctic ice sheet, mainly due to increased melting below the ice shelves. However, the behavior of this marine ice sheet is poorly understood, leading to significant shortcomings in ice-sheet models attempting to predict future sea-level rise. The stability of a marine ice sheet is controlled by the dynamics at the grounding line, the boundary between the grounded ice stream and the floating ice shelf. One of the largest contributors to current sea-level rise is the fast-flowing Thwaites Glacier, which flows into the Amundsen Sea. Here we use an ice-stream/ice-shelf model and perform a number of experiments along a central flowline to analyze the sensitivity of its grounding line on centennial timescales. In the absence of width and buttressing effects, we find that the grounding line retreats by ∼300 km in 200 years from the present day (rate of 1.5 km a–1). With variable glacier width implemented in the model, flow convergence slows the retreat of Thwaites grounding line at 0.3–1.2 km a–1. The parameterization of ice-shelf buttressing according to different observed scenarios further reduces the glacier retreat and can even lead to a slight advance in the most buttressed case.

Document type Article de périodique (Journal article) – Article de recherche
Access type Accès libre
Publication date 2014
Language Anglais
Journal information "Journal of Glaciology" - Vol. 60, no.220, p. 305-313 (2014)
Peer reviewed yes
Publisher International Glaciological Society
issn 0022-1430
e-issn 1727-5652
Publication status Publié
Affiliations Université Libre de Bruxelles - Laboratoire de Glaciologie
Pennsylvania State University - Earth and Environmental Systems Institute
UCL - SST/ELI/ELIC - Earth & Climate
Keywords glacier flow ; ice dynamics ; ice-sheet modeling
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Bibliographic reference Docquier, David ; Pollard, David ; Pattyn, Frank. Thwaites Glacier grounding-line retreat: influence of width and buttressing parameterizations. In: Journal of Glaciology, Vol. 60, no.220, p. 305-313 (2014)
Permanent URL http://hdl.handle.net/2078/167215