DOI: 10.1016/j.quascirev.2013.08.011
Scopus记录号: 2-s2.0-84889235269
论文题名: Glaciology and geological signature of the Last Glacial Maximum Antarctic ice sheet
作者: Golledge N.R. ; Levy R.H. ; McKay R.M. ; Fogwill C.J. ; White D.A. ; Graham A.G.C. ; Smith J.A. ; Hillenbrand C.-D. ; Licht K.J. ; Denton G.H. ; Ackert R.P. ; Maas S.M. ; Hall B.L.
刊名: Quaternary Science Reviews
ISSN: 2773791
出版年: 2013
卷: 78 起始页码: 225
结束页码: 247
语种: 英语
英文关键词: Glacial geology
; Ice-sheet modelling
; Plio-Pleistocene
; Subglacial erosion
Scopus关键词: Antarctic ice sheets
; Continental scale
; Continental shelves
; Erosion and sediment transports
; Last Glacial Maximum
; Ocean temperature
; Plio-pleistocene
; Robust mechanisms
; Erosion
; Glacial geology
; Ice
; Sea level
; Sediment transport
; Glaciers
; deglaciation
; evolution
; flow modeling
; glacial hydrology
; glaciology
; ice sheet
; Last Glacial Maximum
; sea level
; simulation
; Southern Ocean
英文摘要: Dynamical changes in contemporary ice sheets account for significant proportions of their current rates of mass loss, but assessing whether or not these processes are a natural part of ice-sheet evolution requires inference from palaeo-glaciological records. However, a robust mechanism for translating sparse geological data into meaningful interpretations of past glacier dynamics at the continental scale is lacking, since geological archives can be ambiguous, and often their chronology is only poorly constrained. To address this, we combine the interpretation of high-resolution Antarctic ice sheet model results with continent-wide geological evidence pertinent to the dynamical configuration of the ice sheet during the last, and possibly preceding, glacial maxima. We first focus on the thermal regime of the ice sheet, its pattern and velocity of flow, variability in likely subglacial erosion and sediment transport, and how these characteristics evolve during glacial transitions. We show that rapid basal sliding was restricted to discrete outlets that eroded and advected sediment toward and across the continental shelf primarily during the early stages of advance and retreat of the ice sheet, highlighting the need to consider time-transgressive behaviour in the interpretation of geological archives. Secondly, we present new modelling that attempts to improve the fit of our numerical model to geologically-based reconstructions in the Ross Sea. By accounting for locally-enhanced ablation in McMurdo Sound, our new simulation achieves a much closer fit to empirically-derived flow patterns than previously. Growth of the modelled Last Glacial Maximum ice sheet takes place primarily by marine ice accretion in the major embayments, as a consequence of cooler ocean temperatures and reduced sub-ice-shelf melting, and at its maximal extent represents a grounded ice volume excess above present of approximately 8.3m sea-level equivalent. This figure thus provides an upper bound on the possible Antarctic contribution to deglacial meltwater pulses. © 2013 Elsevier Ltd.
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资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/60505
Appears in Collections: 过去全球变化的重建
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作者单位: Antarctic Research Centre, Victoria University of Wellington, Wellington 6140, New Zealand; GNS Science, Avalon, Lower Hutt 5011, New Zealand; Climate Change Research Centre, University of New South Wales, Sydney, NSW 2052, Australia; Institute for Applied Ecology, University of Canberra, ACT 2601, Australia; British Antarctic Survey, High Cross, Madingley Road, Cambridge CB3 0ET, United Kingdom; Indiana University-Purdue University Indianapolis, Dept. of Earth Sciences, Indianapolis, IN 46202, United States; School of Earth and Climate Sciences and The Climate Change Institute, Bryand Global Sciences Center, University of Maine, Orono, ME 04469, United States; Department of Earth and Planetary Science, Harvard University, Cambridge, MA 02138, United States
Recommended Citation:
Golledge N.R.,Levy R.H.,McKay R.M.,et al. Glaciology and geological signature of the Last Glacial Maximum Antarctic ice sheet[J]. Quaternary Science Reviews,2013-01-01,78