DOI: 10.5194/tc-11-1283-2017
Scopus记录号: 2-s2.0-85020000309
论文题名: Iceberg calving of Thwaites Glacier, West Antarctica: Full-Stokes modeling combined with linear elastic fracture mechanics
作者: Yu H ; , Rignot E ; , Morlighem M ; , Seroussi H
刊名: Cryosphere
ISSN: 19940416
出版年: 2017
卷: 11, 期: 3 起始页码: 1283
结束页码: 1296
语种: 英语
英文关键词: crevasse
; feedback mechanism
; fracture mechanics
; ice mechanics
; ice shelf
; iceberg calving
; laser method
; stress field
; timescale
; two-dimensional modeling
; viscous flow
; Antarctica
; Thwaites Glacier
; West Antarctica
英文摘要: Thwaites Glacier (TG), West Antarctica, has been losing mass and retreating rapidly in the past few decades. Here, we present a study of its calving dynamics combining a two-dimensional flow-band full-Stokes (FS) model of its viscous flow with linear elastic fracture mechanics (LEFM) theory to model crevasse propagation and ice fracturing. We compare the results with those obtained with the higher-order (HO) and the shallow-shelf approximation (SSA) models coupled with LEFM. We find that FS/LEFM produces surface and bottom crevasses that are consistent with the distribution of depth and width of surface and bottom crevasses observed by NASA's Operation IceBridge radar depth sounder and laser altimeter, whereas HO/LEFM and SSA/LEFM do not generate crevasses that are consistent with observations. We attribute the difference to the nonhydrostatic condition of ice near the grounding line, which facilitates crevasse formation and is accounted for by the FS model but not by the HO or SSA models. We find that calving is enhanced when pre-existing surface crevasses are present, when the ice shelf is shortened or when the ice shelf front is undercut. The role of undercutting depends on the timescale of calving events. It is more prominent for glaciers with rapid calving rates than for glaciers with slow calving rates. Glaciers extending into a shorter ice shelf are more vulnerable to calving than glaciers developing a long ice shelf, especially as the ice front retreats close to the grounding line region, which leads to a positive feedback to calving events. We conclude that the FS/LEFM combination yields substantial improvements in capturing the stress field near the grounding line of a glacier for constraining crevasse formation and iceberg calving. © Author(s) 2017. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/75550
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: Department of Earth System Science, University of California, Irvine, CA, United States; Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, United States
Recommended Citation:
Yu H,, Rignot E,, Morlighem M,et al. Iceberg calving of Thwaites Glacier, West Antarctica: Full-Stokes modeling combined with linear elastic fracture mechanics[J]. Cryosphere,2017-01-01,11(3)