DOI: 10.5194/tc-14-4121-2020
论文题名: Sharp contrasts in observed and modeled crevasse patterns at Greenland’s marine terminating glaciers
作者: Enderlin E.M. ; Bartholomaus T.C.
刊名: Cryosphere
ISSN: 19940416
出版年: 2020
卷: 14, 期: 11 起始页码: 4121
结束页码: 4133
语种: 英语
英文关键词: advection
; crevasse
; glacier mass balance
; iceberg calving
; lidar
; meltwater
; remote sensing
; Arctic
; Greenland
英文摘要: Crevasses are affected by and affect both the stresses and the surface mass balance of glaciers. These effects are brought on through potentially important controls on meltwater routing, glacier viscosity, and iceberg calving, yet there are few direct observations of crevasse sizes and locations to inform our understanding of these interactions. Here we extract depth estimates for the visible portion of crevasses from high-resolution surface elevation observations for 52 644 crevasses from 19 Greenland glaciers. We then compare our observed depths with those calculated using two popular models that assume crevasse depths are functions of local stresses: the Nye and linear elastic fracture mechanics (LEFM) formulations. When informed by the observed crevasse depths, the LEFM formulation produces kilometer-scale variations in crevasse depth, in decent agreement with observations. However, neither formulation accurately captures smaller-scale variations in the observed crevasse depths. Critically, we find that along-flow patterns in crevasse depths are unrelated to along-flow patterns in strain rates (and therefore stresses). Cumulative strain rate is moderately more predictive of crevasse depths at the majority of glaciers. Our reliance on lidar limits the inference we can make regarding fracture depths. However, given the discordant patterns in observed and modeled crevasses, we recommend additional in situ and remote sensing analyses before Nye and LEFM models are considered predictive. Such analyses should span extensional and compressive regions to better understand the influence of advection on crevasse geometry. Ultimately, such additional study will enable more reliable projection of terminus position change and supraglacial meltwater routing that relies on accurate modeling of crevasse occurrence. © Author(s) 2020. This work is distributed under Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/164451
Appears in Collections: 气候变化与战略
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作者单位: Department of Geosciences, Boise State University, Boise, ID 83725, United States; Department of Geological Sciences, University of Idaho, Moscow, ID 83844, United States
Recommended Citation:
Enderlin E.M.,Bartholomaus T.C.. Sharp contrasts in observed and modeled crevasse patterns at Greenland’s marine terminating glaciers[J]. Cryosphere,2020-01-01,14(11)