CCPortal
DOI10.5194/tc-13-2475-2019
A simple stress-based cliff-calving law
Schlemm T.; Levermann A.
发表日期2019
ISSN19940416
EISSN13
起始页码2475
结束页码2488
卷号13期号:9
英文摘要Over large coastal regions in Greenland and Antarctica the ice sheet calves directly into the ocean. In contrast to ice-shelf calving, an increase in calving from grounded glaciers contributes directly to sea-level rise. Ice cliffs with a glacier freeboard larger than ≈100 m are currently not observed, but it has been shown that such ice cliffs are increasingly unstable with increasing ice thickness. This cliff calving can constitute a self-amplifying ice loss mechanism that may significantly alter sea-level projections both of Greenland and Antarctica. Here we seek to derive a minimalist stress-based parametrization for cliff calving from grounded glaciers whose freeboards exceed the 100 m stability limit derived in previous studies. This will be an extension of existing calving laws for tidewater glaciers to higher ice cliffs.

To this end we compute the stress field for a glacier with a simplified two-dimensional geometry from the two-dimensional Stokes equation. First we assume a constant yield stress to derive the failure region at the glacier front from the stress field within the glacier. Secondly, we assume a constant response time of ice failure due to exceedance of the yield stress. With this strongly constraining but very simple set of assumptions we propose a cliff-calving law where the calving rate follows a power-law dependence on the freeboard of the ice with exponents between 2 and 3, depending on the relative water depth at the calving front. The critical freeboard below which the ice front is stable decreases with increasing relative water depth of the calving front. For a dry water front it is, for example, 75 m. The purpose of this study is not to provide a comprehensive calving law but to derive a particularly simple equation with a transparent and minimalist set of assumptions. © Author(s) 2019. This work is distributed under the Creative Commons Attribution 4.0 License.

学科领域cliff; geometry; glacier dynamics; ice sheet; ice shelf; ice thickness; iceberg calving; sea level change; stress field; water depth; Antarctica; Arctic; Greenland
语种英语
scopus关键词cliff; geometry; glacier dynamics; ice sheet; ice shelf; ice thickness; iceberg calving; sea level change; stress field; water depth; Antarctica; Arctic; Greenland
来源期刊The Cryosphere
文献类型期刊论文
条目标识符http://gcip.llas.ac.cn/handle/2XKMVOVA/118834
作者单位Potsdam Institute for Climate Impact Research, Potsdam, Germany; Institute of Physics and Astronomy, University of Potsdam, Potsdam, Germany; Lamont-Doherty Earth Observatory, Columbia UniversityNY, United States
推荐引用方式
GB/T 7714
Schlemm T.,Levermann A.. A simple stress-based cliff-calving law[J],2019,13(9).
APA Schlemm T.,&Levermann A..(2019).A simple stress-based cliff-calving law.The Cryosphere,13(9).
MLA Schlemm T.,et al."A simple stress-based cliff-calving law".The Cryosphere 13.9(2019).
条目包含的文件
条目无相关文件。
个性服务
推荐该条目
保存到收藏夹
导出为Endnote文件
谷歌学术
谷歌学术中相似的文章
[Schlemm T.]的文章
[Levermann A.]的文章
百度学术
百度学术中相似的文章
[Schlemm T.]的文章
[Levermann A.]的文章
必应学术
必应学术中相似的文章
[Schlemm T.]的文章
[Levermann A.]的文章
相关权益政策
暂无数据
收藏/分享

除非特别说明,本系统中所有内容都受版权保护,并保留所有权利。