INFLUENCE OF GLACIER HYDROLOGY ON THE DYNAMICS OF A LARGE QUATERNARY ICE-SHEET

被引:39
作者
ARNOLD, N
SHARP, M
机构
[1] Department of Geography, University of Cambridge, Cambridge, CB2 3EN, Downing Place
关键词
GLACIER HYDROLOGY; QUATERNARY; SCANDINAVIA; ICE SHEET DYNAMICS;
D O I
10.1002/jqs.3390070204
中图分类号
P9 [自然地理学];
学科分类号
0705 ; 070501 ;
摘要
The influence of glacier hydrology on the time-dependent morphology and flow behaviour of the late Weichselian Scandinavian ice sheet is explored using a simple one-dimensional ice sheet model. The model is driven by orbitally induced radiation variations, ice-albedo feedback and eustatic sea-level change. The influence of hydrology is most marked during deglaciation and on the southern side of the ice sheet, where a marginal zone of rapid sliding, thin ice and low surface slopes develops. Such a zone is absent when hydrology is omitted from the model, and its formation results in earlier and more rapid deglaciation than occurs in the no-hydrology model. The final advance to the glacial maximum position results from an increase in the rate of basal sliding as climate warms after 23000 yr BP. Channelised subglacial drainage develops only episodically, and is associated with relatively low meltwater discharges and high hydraulic gradients. The predominance of iceberg calving as an ablation mechanism on the northern side of the ice sheet restricts the occurrence of surface melting. Lack of meltwater penetration to the glacier bed in this area means that ice flow is predominantly by internal deformation and the ice sheet adopts a classical parabolic surface profile.
引用
收藏
页码:109 / 124
页数:16
相关论文
共 49 条
[1]  
Allen J.R.L., A theoretical and experimental study of climbing‐ripple cross‐lamination, with a field application to the Uppsala esker, Geografiska Annaler. Series A, Physical Geography, 53 A, pp. 157-187, (1971)
[2]  
Alley R.B., Multiple steady states in ice‐water‐till systems, Annals of Glaciology, 14, pp. 1-5, (1990)
[3]  
Banerjee I., McDonald B.C., Nature of esker sedimentation, Glaciofluvial and Glaciolacustrine Sedimentation, pp. 132-154, (1975)
[4]  
Beget J.E., Modeling the influence of till rheology on the flow and profile of the lake Michigan Lobe, southern Laurentide Ice Sheet, USA, Journal of Glaciology, 32, pp. 235-241, (1986)
[5]  
Boulton G.S., Hindmarsh R.C.A., Sediment deformation beneath glaciers: rheology and geological consequences, Journal of Geophysical Research, 92, 9 B, pp. 9059-9082, (1987)
[6]  
Boulton G.S., Jones A.S., Stability of temperate ice caps and ice sheets resting on beds of deformable sediment, Journal of Glaciology, 24, pp. 29-43, (1979)
[7]  
Boulton G.S., Smith G.D., Jones A.S., Newsome J., Glacial geology and glaciology of the last mid‐latitude ice sheets, Journal of the Geological Society of London, 142, pp. 447-474, (1985)
[8]  
Brown C.S., Meier M.F., Post A., Calving speed of Alaska tidewater glaciers, with application to Columbia Glacier, US Geological Survey Professional Paper, 1258, 100, (1982)
[9]  
Budd W.F., Smith I.N., The growth and retreat of ice sheets in response to orbital radiation changes, Sea Level, Ice and Climatic Change, pp. 369-409, (1981)
[10]  
Budd W.F., Smith I.N., Large scale numerical modelling of the Antarctic Ice Sheet, Annals of Glaciology, 3, pp. 42-49, (1982)