DOI: 10.1016/j.gloplacha.2015.02.008
论文题名: Increased precipitation drives mega slump development and destabilization of ice-rich permafrost terrain, northwestern Canada
作者: Kokelj S.V. ; Tunnicliffe J. ; Lacelle D. ; Lantz T.C. ; Chin K.S. ; Fraser R.
刊名: Global and Planetary Change
ISSN: 0921-8181
出版年: 2015
卷: 129 起始页码: 56
结束页码: 68
语种: 英语
英文关键词: Climate change
; Ground ice
; Landscape change
; Mass wasting
; Permafrost
; Rainfall intensity
; Thaw slump
; Thermokarst
Scopus关键词: Climate change
; Debris
; Deposits
; Digital storage
; Geomorphology
; Landforms
; Permafrost
; Rain
; Remote sensing
; Sediments
; Slope stability
; Surficial sediments
; Thawing
; Time series analysis
; Ground ice
; Landscape changes
; Mass wasting
; Rainfall intensity
; Thaw slump
; Thermokarst
; Ice
; climate effect
; geomorphology
; glacial debris
; glacial deposit
; ice core
; ice flow
; permafrost
; precipitation (climatology)
; slumping
; thawing
; Canada
英文摘要: It is anticipated that an increase in rainfall will have significant impacts on the geomorphology of permafrost landscapes. Field observations, remote sensing and historical climate data were used to investigate the drivers, processes and feedbacks that perpetuate the growth of large retrogressive thaw slumps. These "mega slumps" (5-40ha) are now common in formerly glaciated, fluvially incised, ice-cored terrain of the Peel Plateau, NW Canada. Individual thaw slumps can persist for decades and their enlargement due to ground ice thaw can displace up to 106m3 of materials from slopes to valley bottoms reconfiguring slope morphology and drainage networks. Analysis of Landsat images (1985-2011) indicate that the number and size of active slumps and debris tongue deposits has increased significantly with the recent intensification of rainfall. The analyses of high resolution climatic and photographic time-series for summers 2010 and 2012 shows strong linkages amongst temperature, precipitation and the downslope sediment flux from active slumps. Ground ice thaw supplies meltwater and sediments to the slump scar zone and drives diurnal pulses of surficial flow. Coherence in the timing of down valley debris tongue deposition and fine-scaled observations of sediment flux indicate that heavy rainfall stimulates major mass flow events. Evacuation of sediments from the slump scar zone can help to maintain a headwall of exposed ground ice, perpetuating slump growth and leading to larger disturbances. The development of debris tongue deposits divert streams and increase thermoerosion to initiate adjacent slumps. We conclude that higher rainfall can intensify thaw slump activity and rapidly alter the slope-sediment cascade in regions of ice-cored glaciogenic deposits. © 2015. URL: https://www.scopus.com/inward/record.uri?eid=2-s2.0-84926432063&doi=10.1016%2fj.gloplacha.2015.02.008&partnerID=40&md5=cf19b87f6c989bbdc67e49a7453219a0
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资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/11530
Appears in Collections: 全球变化的国际研究计划 气候变化与战略
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作者单位: Northwest Territories Geological Survey, Industry, Tourism and Investment, Government of the Northwest Territories, Yellowknife, NT, Canada
Recommended Citation:
Kokelj S.V.,Tunnicliffe J.,Lacelle D.,et al. Increased precipitation drives mega slump development and destabilization of ice-rich permafrost terrain, northwestern Canada[J]. Global and Planetary Change,2015-01-01,129.