Modelling environmental influences on calving at Helheim Glacier in eastern Greenland
-
Published:2014-05-06
Issue:3
Volume:8
Page:827-841
-
ISSN:1994-0424
-
Container-title:The Cryosphere
-
language:en
-
Short-container-title:The Cryosphere
Author:
Cook S., Rutt I. C., Murray T., Luckman A.ORCID, Zwinger T.ORCID, Selmes N.ORCID, Goldsack A., James T. D.
Abstract
Abstract. 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.
Publisher
Copernicus GmbH
Subject
Earth-Surface Processes,Water Science and Technology
Reference66 articles.
1. Abdalati, W., Krabill, W., Frederick, E., Manizade, S., Martin, C., Sonntag, J., Swift, R., Thomas, R., Wright, W., and Yungel, J.: Outlet glacier and margin elevation changes: Near-coastal thinning of the Greenland Ice Sheet, J. Geophys. Res., 106, 33729–33742, 2001. 2. Amundson, J. M. and Truffer, M.: A unifying framework for iceberg-calving models, J. Glaciol., 56, 822–30, 2010. 3. Amundson, J. M., Fahnestock, M., Truffer, M., Brown, J., Lüthi, M. P., and Motyka, R.: Ice mélange dynamics and implications for terminus stability, Jakobshavn Isbræ, Greenland, J. Geophys. Res., 115, F01005, https://doi.org/10.1029/2009JF001405, 2010. 4. Andersen, M. L., Larsen, T. B., Nettles, M., Elosegui, P., van As, D., Hamilton, G. S., Stearns, L. A., Davis, J. L., Ahlstrøm, A. P., de Juan, J., Ekström, G., Stenseng, L., Khan, S. A., Forsberg, R., and Dahl-Jensen, D.: Spatial and temporal melt variability at Helheim Glacier, East Greenland, and its effect on ice dynamics, J. Geophys. Res., 115, F04041, https://doi.org/10.1029/2010JF001760, 2010. 5. Åström, J. A., Riikilä, T. I., Tallinen, T., Zwinger, T., Benn, D., Moore, J. C., and Timonen, J.: A particle based simulation model for glacier dynamics, The Cryosphere, 7, 1591–1602, https://doi.org/10.5194/tc-7-1591-2013, 2013.
Cited by
70 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献
|
|