DOI: 10.5194/tc-9-631-2015
Scopus记录号: 2-s2.0-84926459586
论文题名: Interaction of marine ice-sheet instabilities in two drainage basins: Simple scaling of geometry and transition time
作者: Feldmann J ; , Levermann A
刊名: Cryosphere
ISSN: 19940416
出版年: 2015
卷: 9, 期: 2 起始页码: 631
结束页码: 645
语种: 英语
英文关键词: bedrock
; conceptual framework
; drainage basin
; elevation
; ice sheet
; ice shelf
; three-dimensional flow
; topography
; transition zone
英文摘要: The initiation of a marine ice-sheet instability (MISI) is generally discussed from the ocean side of the ice sheet. It has been shown that the reduction in ice-shelf buttressing and softening of the coastal ice can destabilize a marine ice sheet if the bedrock is sloping upward towards the ocean. Using a conceptional flow-line geometry, we investigate the possibility of whether a MISI can be triggered from the direction of the ice divide as opposed to coastal forcing and explore the interaction between connected basins. We find that the initiation of a MISI in one basin can induce a destabilization in the other. The underlying mechanism of basin interaction is based on dynamic thinning and a consecutive motion of the ice divide which induces a thinning in the adjacent basin and a successive initiation of the instability. Our simplified and symmetric topographic setup allows scaling both the geometry and the transition time between both instabilities. We find that the ice profile follows a universal shape that is scaled with the horizontal extent of the ice sheet and that the same exponent of 1/2 applies for the scaling relation between central surface elevation and horizontal extent as in the pure shallow ice approximation (Vialov profile). Altering the central bed elevation, we find that the extent of grounding-line retreat in one basin determines the degree of interaction with the other. Different scenarios of basin interaction are discussed based on our modeling results as well as on a conceptual flux-balance analysis. We conclude that for the three-dimensional case, the possibility of drainage basin interaction on timescales on the order of 1 kyr or larger cannot be excluded and hence needs further investigation. © 2015 Author(s). Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/75321
Appears in Collections: 影响、适应和脆弱性 气候变化与战略
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作者单位: Potsdam Institute for Climate Impact Research (PIK), Potsdam, Germany; Institute of Physics, University of Potsdam, Potsdam, Germany
Recommended Citation:
Feldmann J,, Levermann A. Interaction of marine ice-sheet instabilities in two drainage basins: Simple scaling of geometry and transition time[J]. Cryosphere,2015-01-01,9(2)