气候变化领域集成服务门户(CCPortal): Sharp contrasts in observed and modeled crevasse patterns at Greenland’s marine terminating glaciers

CCPortal

DOI	10.5194/tc-14-4121-2020
	Sharp contrasts in observed and modeled crevasse patterns at Greenland’s marine terminating glaciers
	Enderlin E.M.; Bartholomaus T.C.
发表日期	2020
ISSN	19940416
起始页码	4121
结束页码	4133
卷号	14 期号:11
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
英文关键词	advection; crevasse; glacier mass balance; iceberg calving; lidar; meltwater; remote sensing; Arctic; Greenland
语种	英语
来源期刊	Cryosphere
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/202073
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
推荐引用方式 GB/T 7714	Enderlin E.M.,Bartholomaus T.C.. Sharp contrasts in observed and modeled crevasse patterns at Greenland’s marine terminating glaciers[J],2020,14(11).
APA	Enderlin E.M.,&Bartholomaus T.C..(2020).Sharp contrasts in observed and modeled crevasse patterns at Greenland’s marine terminating glaciers.Cryosphere,14(11).
MLA	Enderlin E.M.,et al."Sharp contrasts in observed and modeled crevasse patterns at Greenland’s marine terminating glaciers".Cryosphere 14.11(2020).