DOI: 10.5194/tc-8-587-2014
Scopus记录号: 2-s2.0-84897975011
论文题名: Fracture-induced softening for large-scale ice dynamics
作者: Albrecht T ; , Levermann A
刊名: Cryosphere
ISSN: 19940416
出版年: 2014
卷: 8, 期: 2 起始页码: 587
结束页码: 605
语种: 英语
英文关键词: fracture
; ice flow
; ice sheet
; ice shelf
; ice stream
; viscous flow
; Antarctica
英文摘要: Floating ice shelves can exert a retentive and hence stabilizing force onto the inland ice sheet of Antarctica. However, this effect has been observed to diminish by the dynamic effects of fracture processes within the protective ice shelves, leading to accelerated ice flow and hence to a sea-level contribution. In order to account for the macroscopic effect of fracture processes on large-scale viscous ice dynamics (i.e., ice-shelf scale) we apply a continuum representation of fractures and related fracture growth into the prognostic Parallel Ice Sheet Model (PISM) and compare the results to observations. To this end we introduce a higher order accuracy advection scheme for the transport of the two-dimensional fracture density across the regular computational grid. Dynamic coupling of fractures and ice flow is attained by a reduction of effective ice viscosity proportional to the inferred fracture density. This formulation implies the possibility of non-linear threshold behavior due to self-amplified fracturing in shear regions triggered by small variations in the fracture-initiation threshold. As a result of prognostic flow simulations, sharp across-flow velocity gradients appear in fracture-weakened regions. These modeled gradients compare well in magnitude and location with those in observed flow patterns. This model framework is in principle expandable to grounded ice streams and provides simple means of investigating climate-induced effects on fracturing (e.g., hydro fracturing) and hence on the ice flow. It further constitutes a physically sound basis for an enhanced fracture-based calving parameterization. © 2014 Author(s). Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/74867
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: Earth System Analysis, Potsdam Institute for Climate Impact Research, Potsdam, Germany; Institute of Physics and Astronomy, University of Potsdam, Potsdam, Germany
Recommended Citation:
Albrecht T,, Levermann A. Fracture-induced softening for large-scale ice dynamics[J]. Cryosphere,2014-01-01,8(2)