DOI: 10.1016/j.quascirev.2013.09.013
Scopus记录号: 2-s2.0-84900457830
论文题名: Controls upon the Last Glacial Maximum deglaciation of the northern Uummannaq Ice Stream System, West Greenland
作者: Lane T.P. ; Roberts D.H. ; Rea B.R. ; Cofaigh C. ; Vieli A. ; Rodés A.
刊名: Quaternary Science Reviews
ISSN: 2773791
出版年: 2014
卷: 92 起始页码: 324
结束页码: 344
语种: 英语
英文关键词: Deglaciation
; Greenland ice sheet
; Ice stream
; Topographic control
Scopus关键词: Bathymetry
; Glacial geology
; Sea level
; Deglaciations
; Geomorphological mapping
; Greenland Ice Sheet
; Holocene thermal maximums
; Ice streams
; Last Glacial Maximum
; Terrestrial cosmogenic nuclides
; Topographic control
; Ice
; climate forcing
; cosmogenic radionuclide
; deglaciation
; geomorphological mapping
; ice field
; ice margin
; ice retreat
; ice stream
; Last Glacial Maximum
; radiocarbon dating
; topographic effect
; Arctic
; Greenland
; Uummannaq
英文摘要: The Uummannaq Ice Stream System (UISS) was a convergent cross-shelf ice stream system that operated in West Greenland during the Last Glacial Maximum (LGM). This paper presents new evidence constraining the geometry and evolution of the northern sector of the UISS and considers the factors controlling its dynamic behaviour. Geomorphological mapping, 21 new terrestrial cosmogenic nuclide (TCN) exposure ages, and radiocarbon dating constrain LGM warm-based ice stream activity in the north of the system up to 1400ma.s.l. Intervening plateaux areas either remained ice free, or were covered by cold-based icefields. Beyond the inner fjords, topography and bathymetry forced ice flow southwards into the Uummannaq Trough, where it coalesced with ice from the south, and formed the trunk zone of the UISS.Deglaciation of the UISS began at 14.9cal.kaBP. Rapid retreat from the LGM limit was forced by an increase in air temperatures and rising sea level, enhanced by the bathymetric over-deepening of the Uummannaq and Igdlorssuit Sund troughs. Ice reached the inner fjord confines in the northern Uummannaq area by 11.6ka and experienced an ice marginal stabilisation in Rink-Karrat Fjord for up to 5ka. This was a function of topographic constriction and bathymetric shallowing, and occurred despite continued climatic forcing. In the neighbouring Ingia Fjord this did not occur. Following this period of stability, ice within Rink-Karrat Fjord retreated, reaching the present ice margin or beyond after 5ka. The presence of a major ice stream within a mid-fjord setting, during the mid-Holocene and the Holocene Thermal Maximum (~11-5ka) is in direct contrast to records of other ice streams throughout West Greenland, which suggest ice had retreated beyond its present margin by 9-7ka. This demonstrates the potential importance of topographic control on calving margin stability, and its ability to override climatic forcing. © 2013. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/60308
Appears in Collections: 过去全球变化的重建
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作者单位: Department of Geography, Durham University, Science Laboratories, Durham DH1 3LE, United Kingdom; School of Geosciences, University of Aberdeen, Elphinstone Road, Aberdeen AB24 3UF, Scotland, United Kingdom; Department of Geography, University of Zurich - Irchel, Winterthurerstr. 190, CH-8057 Zurich, Switzerland; NERC Cosmogenic Isotope Analysis Facility, Scottish Enterprise Technology Park, East Kilbride G75 0QF, United Kingdom
Recommended Citation:
Lane T.P.,Roberts D.H.,Rea B.R.,et al. Controls upon the Last Glacial Maximum deglaciation of the northern Uummannaq Ice Stream System, West Greenland[J]. Quaternary Science Reviews,2014-01-01,92