气候变化领域集成服务门户(CCPortal): Quantifying irreversible movement in steep, fractured bedrock permafrost on Matterhorn (CH)

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DOI	10.5194/tc-11-567-2017
	Quantifying irreversible movement in steep, fractured bedrock permafrost on Matterhorn (CH)
	Weber S.; Beutel J.; Faillettaz J.; Hasler A.; Krautblatter M.; Vieli A.
发表日期	2017
ISSN	19940416
卷号	11 期号:1
英文摘要	Understanding rock slope kinematics in steep, fractured bedrock permafrost is a challenging task. Recent laboratory studies have provided enhanced understanding of rock fatigue and fracturing in cold environments but were not successfully confirmed by field studies. This study presents a unique time series of fracture kinematics, rock temperatures and environmental conditions at 3500 mg a. s. l. on the steep, strongly fractured Hörnligrat of the Matterhorn (Swiss Alps). Thanks to 8 years of continuous data, the longer-term evolution of fracture kinematics in permafrost can be analyzed with an unprecedented level of detail. Evidence for common trends in spatiotemporal pattern of fracture kinematics could be found: a partly reversible seasonal movement can be observed at all locations, with variable amplitudes. In the wider context of rock slope stability assessment, we propose separating reversible (elastic) components of fracture kinematics, caused by thermoelastic strains, from the irreversible (plastic) component due to other processes. A regression analysis between temperature and fracture displacement shows that all instrumented fractures exhibit reversible displacements that dominate fracture kinematics in winter. Furthermore, removing this reversible component from the observed displacement enables us to quantify the irreversible component. From this, a new metric-termed index of irreversibility-is proposed to quantify relative irreversibility of fracture kinematics. This new index can identify periods when fracture displacements are dominated by irreversible processes. For many sensors, irreversible enhanced fracture displacement is observed in summer and its initiation coincides with the onset of positive rock temperatures. This likely indicates thawing-related processes, such as meltwater percolation into fractures, as a forcing mechanism for irreversible displacements. For a few instrumented fractures, irreversible displacements were found at the onset of the freezing period, suggesting that cryogenic processes act as a driving factor through increasing ice pressure. The proposed analysis provides a tool for investigating and better understanding processes related to irreversible kinematics. © 2017 Author(s).
学科领域	bedrock; displacement; environmental conditions; fracture mechanics; kinematics; mass movement; meltwater; percolation; permafrost; quantitative analysis; regression analysis; slope stability; Alps; Central Alps; Matterhorn; Pennine Alps; Switzerland
语种	英语
scopus关键词	bedrock; displacement; environmental conditions; fracture mechanics; kinematics; mass movement; meltwater; percolation; permafrost; quantitative analysis; regression analysis; slope stability; Alps; Central Alps; Matterhorn; Pennine Alps; Switzerland
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/119434
作者单位	Department of Geography, University of Zurich, Zurich, Switzerland; Computer Engineering and Networks Laboratory, ETH Zurich, Zurich, Switzerland; Department of Geosciences, University of Fribourg, Fribourg, Switzerland; Landslide Research, Technical University of Munich, Munich, Germany
推荐引用方式 GB/T 7714	Weber S.,Beutel J.,Faillettaz J.,et al. Quantifying irreversible movement in steep, fractured bedrock permafrost on Matterhorn (CH)[J],2017,11(1).
APA	Weber S.,Beutel J.,Faillettaz J.,Hasler A.,Krautblatter M.,&Vieli A..(2017).Quantifying irreversible movement in steep, fractured bedrock permafrost on Matterhorn (CH).Cryosphere,11(1).
MLA	Weber S.,et al."Quantifying irreversible movement in steep, fractured bedrock permafrost on Matterhorn (CH)".Cryosphere 11.1(2017).