DOI: 10.1016/j.quascirev.2013.09.007
Scopus记录号: 2-s2.0-84900402077
论文题名: Late Quaternary ice flow in a West Greenland fjord and cross-shelf trough system: Submarine landforms from Rink Isbrae to Uummannaq shelf and slope
作者: Dowdeswell J.A. ; Hogan K.A. ; Ó Cofaigh C. ; Fugelli E.M.G. ; Evans J. ; Noormets R.
刊名: Quaternary Science Reviews
ISSN: 2773791
出版年: 2014
卷: 92 起始页码: 292
结束页码: 309
语种: 英语
英文关键词: Arctic
; Ice flow
; Ice stream
; Late Quaternary
; Submarine landforms
; Trough-mouth fan
; West Greenland
Scopus关键词: Floors
; Geomorphology
; Landforms
; Sea ice
; Stratigraphy
; Arctic
; Ice flow
; Ice streams
; Late quaternary
; Submarine landforms
; West Greenland
; Glacial geology
; coastal morphology
; debris flow
; fjord
; geomorphological mapping
; glacier retreat
; glaciomarine deposit
; GRIP
; grounding line
; ice flow
; ice sheet
; ice stream
; iceberg
; Last Glacial Maximum
; moraine
; reworking
; shelf break
; trough
; Arctic
; Greenland
; Greenland Ice Sheet
; Rink Glacier
; Uummannaq
英文摘要: Sea-floor landforms and acoustic-stratigraphic records allow interpretation of the past form and flow of a westward-draining ice stream of the Greenland Ice Sheet, Rink Isbrae. The Late Pliocene-Pleistocene glacial package is several hundred metres thick and down-laps onto an upper Miocene horizon. Several acoustic facies are mapped from sub-bottom profiler records of the 400km-long Uummannaq fjord-shelf-slope system. An acoustically stratified facies covers much of the fjord and trough floor, interpreted as glacimarine sediment from rain-out of fine-grained debris in turbid meltwater. Beneath this facies is a semi-transparent deformation-till unit, which includes buried streamlined landforms. Landform distribution in the Uummannaq system is used to reconstruct past ice extent and flow directions. The presence of streamlined landforms (mega-scale glacial lineations, drumlins, crag-and-tails) shows that an ice stream advanced through the fjord system to fill Uummannaq Trough, reaching the shelf edge at the Last Glacial Maximum. Beyond the trough there is a major fan built mainly of glacigenic debris flows. Turbidity-current channels were not observed on Uummannaq Fan, contrasting with well-developed channels on Disko Fan, 300km to the south. Ice retreat had begun by 14.8cal.ka ago. Grounding-zone wedges (GZW) in Uummannaq Trough imply that retreat was episodic, punctuated by several still-stands. Ice retreat between GZWs may have been relatively rapid. There is little sedimentary evidence for still-stands in the inner fjords, except for a major moraine ridge marking a Little Ice Age maximum position. On the shallow banks either side of Uummannaq Trough, iceberg ploughing has reworked any morphological evidence of earlier ice-sheet activity. © 2013 The Authors. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/60293
Appears in Collections: 过去全球变化的重建
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作者单位: Scott Polar Research Institute, University of Cambridge, Cambridge CB2 1ER, United Kingdom; Department of Geography, Durham University, Durham DH1 3LE, United Kingdom; BP Norway, Godesetdalen 8, Postboks 197, 4065 Stavanger, Norway; Department of Geography, Loughborough University, Loughborough LE11 3TU, United Kingdom; The University Centre in Svalbard (UNIS), Postboks 156, 9171 Longyearbyen, Norway
Recommended Citation:
Dowdeswell J.A.,Hogan K.A.,Ó Cofaigh C.,et al. Late Quaternary ice flow in a West Greenland fjord and cross-shelf trough system: Submarine landforms from Rink Isbrae to Uummannaq shelf and slope[J]. Quaternary Science Reviews,2014-01-01,92