气候变化领域集成服务门户(CCPortal): Buoyant forces promote tidewater glacier iceberg calving through large basal stress concentrations

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DOI	10.5194/tc-13-1877-2019
	Buoyant forces promote tidewater glacier iceberg calving through large basal stress concentrations
	Trevers M.; Payne A.J.; Cornford S.L.; Moon T.
发表日期	2019
ISSN	19940416
EISSN	13
起始页码	1877
结束页码	1887
卷号	13 期号:7
英文摘要	Iceberg calving parameterisations currently implemented in ice sheet models do not reproduce the full observed range of calving behaviours. For example, though buoyant forces at the ice front are known to trigger fulldepth calving events on major Greenland outlet glaciers, a multi-stage iceberg calving event at Jakobshavn Isbræ is unexplained by existing models. To explain this and similar events, we propose a notch-triggered rotation mechanism, whereby a relatively small subaerial calving event triggers a larger full-depth calving event due to the abrupt increase in buoyant load and the associated stresses generated at the ice-bed interface. We investigate the notch-triggered rotation mechanism by applying a geometric perturbation to the subaerial section of the calving front in a diagnostic flow-line model of an idealised glacier snout, using the full-Stokes, finite element method code Elmer/Ice. Different sliding laws and water pressure boundary conditions are applied at the ice-bed interface. Water pressure has a big influence on the likelihood of calving, and stress concentrations large enough to open crevasses were generated in basal ice. Significantly, the location of stress concentrations produced calving events of approximately the size observed, providing support for future application of the notch-triggered rotation mechanism in ice-sheet models. © Author(s) 2019.
学科领域	basal melting; buoyancy forcing; concentration (composition); crevasse; ice sheet; iceberg calving; parameterization; tidewater glacier; Arctic; Greenland; Jakobshavn Glacier
语种	英语
scopus关键词	basal melting; buoyancy forcing; concentration (composition); crevasse; ice sheet; iceberg calving; parameterization; tidewater glacier; Arctic; Greenland; Jakobshavn Glacier
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/118862
作者单位	Centre for Polar Observation and Modelling, School of Geographical Sciences, University of Bristol, Bristol, BS8 1SS, United Kingdom; Department of Geography, Swansea University, Swansea, SA2 8PP, United Kingdom; National Snow and Ice Data Center, University of Colorado, Boulder, CO 80309-0449, United States
推荐引用方式 GB/T 7714	Trevers M.,Payne A.J.,Cornford S.L.,et al. Buoyant forces promote tidewater glacier iceberg calving through large basal stress concentrations[J],2019,13(7).
APA	Trevers M.,Payne A.J.,Cornford S.L.,&Moon T..(2019).Buoyant forces promote tidewater glacier iceberg calving through large basal stress concentrations.The Cryosphere,13(7).
MLA	Trevers M.,et al."Buoyant forces promote tidewater glacier iceberg calving through large basal stress concentrations".The Cryosphere 13.7(2019).