DOI: 10.5194/tc-15-3059-2021
论文题名: Thaw-driven mass wasting couples slopes with downstream systems, and effects propagate through Arctic drainage networks
作者: Kokelj S.V. ; Kokoszka J. ; Van Der Sluijs J. ; Rudy A.C.A. ; Tunnicliffe J. ; Shakil S. ; Tank S.E. ; Zolkos S.
刊名: Cryosphere
ISSN: 19940416
出版年: 2021
卷: 15, 期: 7 起始页码: 3059
结束页码: 3081
语种: 英语
英文关键词: drainage
; geomorphology
; landscape evolution
; marine environment
; mass wasting
; permafrost
; Postglacial
; Arctic
; Arctic Ocean
; Banks Island
; Beaufort Sea
; Canada
; Mackenzie River [Northwest Territories]
; Northwest Territories
; Peel [Ontario]
; Victoria Island [Canada]
英文摘要: The intensification of thaw-driven mass wasting is transforming glacially conditioned permafrost terrain, coupling slopes with aquatic systems, and triggering a cascade of downstream effects. Within the context of recent, rapidly evolving climate controls on the geomorphology of permafrost terrain, we (A) quantify three-dimensional retrogressive thaw slump enlargement and describe the processes and thresholds coupling slopes to downstream systems, (B) investigate catchment-scale patterns of slope thermokarst impacts and the geomorphic implications, and (C) map the propagation of effects through hydrological networks draining permafrost terrain of northwestern Canada. Power-law relationships between retrogressive thaw slump area and volume (R2Combining double low line0.90), as well as the thickness of permafrost thawed (R2Combining double low line0.63), combined with the multi-decadal (1986-2018) increase in the areal extent of thaw slump disturbance, show a 2 order of magnitude increase in catchment-scale geomorphic activity and the coupling of slope and hydrological systems. Predominant effects are to first- and second-order streams where sediment delivery, often indicated by formation of recent debris tongue deposits, commonly exceeds the transport capacity of headwater streams by orders of magnitude, signaling centennial- to millennial-scale perturbation of downstream systems. Assessment of hydrological networks indicates that thaw-driven mass wasting directly affects over 5538ĝ€¯km of stream segments, 889ĝ€¯km of coastline, and 1379 lakes in the 994ĝ€¯860ĝ€¯km2 study area. Downstream propagation of slope thermokarst indicates a potential increase in the number of affected lakes by at least a factor of 4 (n>5692) and impacted stream length by a factor of 8 (>44343ĝ€¯km), and it defines several major impact zones on lakes, deltas, and coastal areas. Prince of Wales Strait is the receiving marine environment for greatly increased sediment and geochemical fluxes from numerous slump-impacted hydrological networks draining Banks Island and Victoria Island. The Peel and Mackenzie rivers are globally significant conveyors of the slope thermokarst cascade, delivering effects to North America's largest Arctic delta and the Beaufort Sea. Climate-driven erosion of ice-rich slopes in permafrost-preserved glaciated terrain has triggered a time-transient cascade of downstream effects that signal the rejuvenation of post-glacial landscape evolution. Glacial legacy, ground-ice conditions, and continental drainage patterns dictate that terrestrial, freshwater, coastal, and marine environments of western Arctic Canada will be an interconnected hotspot of thaw-driven change through the coming millennia. © Author(s) 2021. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/164729
Appears in Collections: 气候变化与战略
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作者单位: Northwest Territories Geological Survey, Yellowknife, NT X1A 2L9, Canada; Wilfrid Laurier University, Yellowknife, NT X1A 2P8, Canada; Northwest Territories Centre for Geomatics, Yellowknife, NT X1A 2L9, Canada; School of Environment, University of Auckland, Auckland, New Zealand; Department of Biological Sciences, University of Alberta, Edmonton, AB T6G 2E3, Canada; Woodwell Climate Research Center, Falmouth, MA 02540, United States
Recommended Citation:
Kokelj S.V.,Kokoszka J.,Van Der Sluijs J.,et al. Thaw-driven mass wasting couples slopes with downstream systems, and effects propagate through Arctic drainage networks[J]. Cryosphere,2021-01-01,15(7)