DOI: 10.1002/2016GL069558
论文题名: Subglacial bed form morphology controlled by ice speed and sediment thickness
作者: Barchyn T.E. ; Dowling T.P.F. ; Stokes C.R. ; Hugenholtz C.H.
刊名: Geophysical Research Letters
ISSN: 0094-8890
EISSN: 1944-8621
出版年: 2016
卷: 43, 期: 14 起始页码: 7572
结束页码: 7580
语种: 英语
英文关键词: drumlins
; instability
; megascale glacial lineations
; paleolandscapes
; ribbed moraines
; rogen moraines
Scopus关键词: Dynamics
; Glacial geology
; Parallel flow
; Plasma stability
; Sediments
; Drumlins
; Glacial lineation
; Paleolandscapes
; Ribbed moraines
; Rogen moraines
; Ice
; bedform
; boundary condition
; eolian process
; hill
; ice flow
; ice sheet
; instability
; landscape evolution
; moraine
; paleoenvironment
; sediment thickness
; subglacial deposit
英文摘要: Subglacial bed forms (drumlins, ribbed moraines, and megascale glacial lineations) are enigmatic repetitive flow-parallel and flow-transverse landforms common in glaciated landscapes. Their evolution and morphology are a potentially powerful constraint for ice sheet modeling, but there is little consensus on bed form dynamics or formative mechanisms. Here we explore shallow sediment bed form dynamics via a simple model that iterates (i) down-flow till flux, (ii) pressure gradient-driven till flux, and (iii) entrainment and deposition of sediment. Under various boundary conditions, replicas of subglacial bed forms readily emerge. Bed form dynamics mirror those in subaqueous and aeolian domains. Transitions between ribbed moraines and elongate flow-parallel bed forms are associated with increasing ice speeds and declining sediment thickness. These simulations provide quantitative flux estimates and suggest that widely observed transitions in shallow sediment subglacial bed forms (e.g., ribbed moraines to drumlinoids to megascale glacial lineations) are manifestations of subtle variations in ice velocity and sediment thickness. ©2016. American Geophysical Union. All Rights Reserved. URL: https://www.scopus.com/inward/record.uri?eid=2-s2.0-84979782482&doi=10.1002%2f2016GL069558&partnerID=40&md5=2a228843d25dec65794c0db84c35130d
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资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/9853
Appears in Collections: 科学计划与规划 气候变化与战略
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作者单位: Department of Geography, University of Calgary, Calgary, AB, Canada
Recommended Citation:
Barchyn T.E.,Dowling T.P.F.,Stokes C.R.,et al. Subglacial bed form morphology controlled by ice speed and sediment thickness[J]. Geophysical Research Letters,2016-01-01,43(14).