A numerical study of hydrologically driven glacier dynamics and subglacial flooding

被引:101
作者
Pimentel, Sam [1 ]
Flowers, Gwenn E. [1 ]
机构
[1] Simon Fraser Univ, Dept Earth Sci, Burnaby, BC V5A 1S6, Canada
来源
PROCEEDINGS OF THE ROYAL SOCIETY A-MATHEMATICAL PHYSICAL AND ENGINEERING SCIENCES | 2011年 / 467卷 / 2126期
基金
加拿大自然科学与工程研究理事会;
关键词
ice sheets; subglacial hydrology; glacier sliding; glaciology; GREENLAND ICE-SHEET; OUTLET GLACIER; VISCOUS APPROXIMATION; SEASONAL EVOLUTION; DRAINAGE SYSTEM; WEST GREENLAND; WATER-PRESSURE; BASAL MOTION; HIGHER-ORDER; VELOCITY;
D O I
10.1098/rspa.2010.0211
中图分类号
O [数理科学和化学]; P [天文学、地球科学]; Q [生物科学]; N [自然科学总论];
学科分类号
07 ; 0710 ; 09 ;
摘要
A hydrologically coupled flowband model of 'higher order' ice dynamics is used to explore perturbations in response to supraglacial water drainage and subglacial flooding. The subglacial drainage system includes interacting 'fast' and 'slow' drainage elements. The fast drainage system is assumed to be composed of ice-walled conduits and the slow system of a macroporous water sheet. Under high subglacial water pressures, flexure of the overlying ice is modelled using elastic beam theory. A regularized Coulomb friction law describes basal boundary conditions that enable hydrologically driven acceleration. We demonstrate the modelled interactions between hydrology and ice dynamics by means of three observationally inspired examples: (i) simulations of meltwater drainage at an Alpine-type glacier produce seasonal and diurnal variability, and exhibit drainage evolution characteristic of the so-called 'spring transition'; (ii) horizontal and vertical diurnal accelerations are modelled in response to summer meltwater input at a Greenland-type outlet glacier; and (iii) short-lived perturbations to basal water pressure and ice-flow speed are modelled in response to the prescribed drainage of a supraglacial lake. Our model supports the suggestion that a channelized drainage system can form beneath the margins of the Greenland ice sheet, and may contribute to reducing the dynamic impact of floods derived from supraglacial lakes.
引用
收藏
页码:537 / 558
页数:22
相关论文
共 76 条
[1]   Access of surface meltwater to beds of sub-freezing glaciers: preliminary insights [J].
Alley, RB ;
Dupont, TK ;
Parizek, BR ;
Anandakrishnan, S .
ANNALS OF GLACIOLOGY, VOL 40, 2005, 2005, 40 :8-14
[2]   Strong feedbacks between hydrology and sliding of a small alpine glacier [J].
Anderson, RS ;
Anderson, SP ;
MacGregor, KR ;
Waddington, ED ;
O'Neel, S ;
Riihimaki, CA ;
Loso, MG .
JOURNAL OF GEOPHYSICAL RESEARCH-EARTH SURFACE, 2004, 109 (F3)
[3]  
[Anonymous], 1974, Ice Physics
[4]  
[Anonymous], 1994, The Physics of Glaciers
[5]   Flow variability in the Scandinavian ice sheet: modelling the coupling between ice sheet flow and hydrology [J].
Arnold, N ;
Sharp, M .
QUATERNARY SCIENCE REVIEWS, 2002, 21 (4-6) :485-502
[6]   Response of glacier basal motion to transient water storage [J].
Bartholomaus, Timothy C. ;
Anderson, Robert S. ;
Anderson, Suzanne P. .
NATURE GEOSCIENCE, 2008, 1 (01) :33-37
[7]   Seasonal evolution of subglacial drainage and acceleration in a Greenland outlet glacier [J].
Bartholomew, Ian ;
Nienow, Peter ;
Mair, Douglas ;
Hubbard, Alun ;
King, Matt A. ;
Sole, Andrew .
NATURE GEOSCIENCE, 2010, 3 (06) :408-411
[8]   The role of subglacial water in ice-sheet mass balance [J].
Bell, Robin E. .
NATURE GEOSCIENCE, 2008, 1 (05) :297-304
[10]   The role of hydrologically-driven ice fracture in drainage system evolution on an Arctic glacier [J].
Boon, S ;
Sharp, M .
GEOPHYSICAL RESEARCH LETTERS, 2003, 30 (18) :CRY1-1