DOI: 10.1016/j.quascirev.2014.02.017
Scopus记录号: 2-s2.0-84897060438
论文题名: Retreat of the West Antarctic Ice Sheet from the western Amundsen Sea shelf at a pre- or early LGM stage
作者: Klages J.P. ; Kuhn G. ; Hillenbrand C.-D. ; Graham A.G.C. ; Smith J.A. ; Larter R.D. ; Gohl K. ; Wacker L.
刊名: Quaternary Science Reviews
ISSN: 2773791
出版年: 2014
卷: 91 起始页码: 1
结束页码: 15
语种: 英语
英文关键词: Amundsen Sea
; Deglaciation
; Getz ice shelf
; Glacial retreat
; Grounding-zone wedge
; Last glacial maximum
; LGM extent
; Sea-level rise
; West antarctic ice sheet
Scopus关键词: Glacial geology
; Glaciers
; Saline water
; Sea level
; Amundsen Sea
; Deglaciations
; Glacial retreat
; Grounding-zone wedges
; Ice shelves
; Last Glacial Maximum
; LGM extent
; Sea level rise
; West antarctic ice sheets
; Ice
; continental shelf
; deglaciation
; glacial history
; glacier retreat
; ice retreat
; ice sheet
; ice stream
; infill
; Last Glacial Maximum
; meltwater
; microfossil
; paleoceanography
; reconstruction
; sea level change
; Amundsen Sea
; Antarctic Ice Sheet
; Antarctica
; Getz Ice Shelf
; Ross Sea
; Southern Ocean
; West Antarctic Ice Sheet
; West Antarctica
英文摘要: Recent palaeoglaciological studies on the West Antarctic shelf have mainly focused on the wide embayments of the Ross and Amundsen seas in order to reconstruct the extent and subsequent retreat of the West Antarctic Ice Sheet (WAIS) since the Last Glacial Maximum (LGM). However, the narrower shelf sectors between these two major embayments have remained largely unstudied in previous geological investigations despite them covering extensive areas of the West Antarctic shelf. Here, we present the first systematic marine geological and geophysical survey of a shelf sector offshore from the Hobbs Coast. It is dominated by a large grounding zone wedge (GZW), which fills the base of a palaeo-ice stream trough on the inner shelf and marks a phase of stabilization of the grounding line during general WAIS retreat following the last maximum ice-sheet extent in this particular area (referred to as the Local Last Glacial Maximum, 'LLGM'). Reliable age determination on calcareous microfossils from the infill of a subglacial meltwater channel eroded into the GZW reveals that grounded ice had retreated landward of the GZW before ~20.88cal.kaBP, with deglaciation of the innermost shelf occurring prior to ~12.97cal.kaBP. Geophysical sub-bottom information from the inner-, mid- and outer shelf indicates grounded ice extended to the shelf edge prior to the formation of the GZW. Assuming the wedge was deposited during deglaciation, we infer the timing of maximum grounded ice extent occurred before ~20.88cal.kaBP. This could suggest that the WAIS retreat from the outer shelf was already underway during or even prior to the global LGM (~23-19cal.kaBP). Our new findings give insights into the regional deglacial behaviour of this understudied part of the West Antarctic shelf and at the same time support early deglaciation ages recently presented for adjacent drainage sectors of the WAIS. If correct, these findings contrast with the hypothesis that initial deglaciation of Antarctic Ice Sheets occurred synchronously at ~19cal.kaBP. © 2014 Elsevier Ltd. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/60309
Appears in Collections: 过去全球变化的重建
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作者单位: Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar-und Meeresforschung, Am Alten Hafen 26, 27568 Bremerhaven, Germany; British Antarctic Survey, High Cross, Madingley Road, Cambridge CB3 0ET, United Kingdom; College of Life and Environmental Sciences, University of Exeter, Amory Building, Rennes Drive, Exeter EX4 4RJ, United Kingdom; ETH Zürich, Laboratory of Ion Beam Physics, Schafmattstrasse 20, CH-8093 Zürich, Switzerland
Recommended Citation:
Klages J.P.,Kuhn G.,Hillenbrand C.-D.,et al. Retreat of the West Antarctic Ice Sheet from the western Amundsen Sea shelf at a pre- or early LGM stage[J]. Quaternary Science Reviews,2014-01-01,91