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Titel |
Modelling environmental influences on calving at Helheim Glacier in eastern Greenland |
VerfasserIn |
S. Cook, I. C. Rutt, T. Murray, A. Luckman, T. Zwinger, N. Selmes, A. Goldsack, T. D. James |
Medientyp |
Artikel
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Sprache |
Englisch
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ISSN |
1994-0416
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Digitales Dokument |
URL |
Erschienen |
In: The Cryosphere ; 8, no. 3 ; Nr. 8, no. 3 (2014-05-06), S.827-841 |
Datensatznummer |
250116149
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Publikation (Nr.) |
copernicus.org/tc-8-827-2014.pdf |
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Zusammenfassung |
Calving is an important mass-loss process for many glaciers worldwide, and
has been assumed to respond to a variety of environmental influences. We
present a grounded, flowline tidewater glacier model using a physically-based
calving mechanism, applied to Helheim Glacier, eastern
Greenland. By qualitatively examining both modelled size and frequency of
calving events, and the subsequent dynamic response, the model is found to
realistically reproduce key aspects of observed calving behaviour. Experiments explore four
environmental variables which have been suggested to affect calving rates:
water depth in crevasses, basal water pressure, undercutting of the calving
face by submarine melt and backstress from ice mélange. Of the four
variables, only crevasse water depth and basal water pressure were found to
have a significant effect on terminus behaviour when applied at a realistic
magnitude. These results are in contrast to previous modelling studies, which
have suggested that ocean temperatures could strongly influence the calving
front. The results raise the possibility that Greenland outlet glaciers could
respond to the recent trend of
increased surface melt observed in Greenland more strongly than previously thought, as surface ablation can
strongly affect water depth in crevasses and water pressure at the glacier
bed. |
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