| DOI: | 10.1016/j.gloplacha.2014.07.015
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| 论文题名: | New constraints on the timing of West Antarctic Ice Sheet retreat in the eastern Amundsen Sea since the Last Glacial Maximum |
| 作者: | Smith J.A.; Hillenbrand C.-D.; Kuhn G.; Klages J.P.; Graham A.G.C.; Larter R.D.; Ehrmann W.; Moreton S.G.; Wiers S.; Frederichs T.
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| ISSN: | 0921-8435
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| 出版年: | 2014
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| 卷: | 122 | | 起始页码: | 224
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| 结束页码: | 237
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| 语种: | 英语
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| 英文关键词: | 14C dating
; Grounding zone wedge
; Ice sheet modelling
; Ice shelf
; Pine Island Glacier
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| Scopus关键词: | <sup>14</sup>C dating
; Grounding-zone wedges
; Ice sheet modelling
; Ice shelves
; Pine island glaciers
; data set
; fractionation
; geomorphology
; ice shelf
; Last Glacial Maximum
; radiocarbon dating
; Amundsen Sea
; Antarctica
; Pine Island Glacier
; Southern Ocean
; West Antarctica
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| 英文摘要: | Glaciers flowing into the Amundsen Sea Embayment (ASE) account for >35% of the total discharge of the West Antarctic Ice Sheet (WAIS) and have thinned and retreated dramatically over the past two decades. Here we present detailed marine geological data and an extensive new radiocarbon dataset from the eastern ASE in order to constrain the retreat of the WAIS since the Last Glacial Maximum (LGM) and assess the significance of these recent changes. Our dating approach, relying mainly on the acid insoluble organic (AIO) fraction, utilises multi-proxy analyses of the sediments to characterise their lithofacies and determine the horizon in each core that would yield the most reliable age for deglaciation. In total, we dated 69 samples and show that deglaciation of the outer shelf was underway before 20,600 calibrated years before present (calyrBP), reaching the mid-shelf by 13,575calyrBP and the inner shelf to within ca. 150km of the present grounding line by 10,615calyrBP. The timing of retreat is broadly consistent with previously published radiocarbon dates on biogenic carbonate from the eastern ASE as well as AIO 14C ages from the western ASE and provides new constraints for ice sheet models. The overall retreat trajectory - slow on the outer shelf, more rapid from the middle to inner shelf - clearly highlights the importance of reverse bedslopes in controlling phases of accelerated groundling line retreat. Despite revealing these broad scale trends, the current dataset does not capture detailed changes in ice flow, such as stillstands during grounding line retreat (i.e., deposition of grounding zone wedges) and possible readvances as depicted in the geomorphological record. © 2014 Elsevier B.V. |
| URL: | https://www.scopus.com/inward/record.uri?eid=2-s2.0-84907480981&doi=10.1016%2fj.gloplacha.2014.07.015&partnerID=40&md5=d9dc91b3a8fd35249e926e0e38c591e1
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| Citation statistics: |
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| 资源类型: | 期刊论文
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| 标识符: | http://119.78.100.158/handle/2HF3EXSE/11341
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| Appears in Collections: | 全球变化的国际研究计划
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作者单位: | British Antarctic Survey, High Cross, Madingley Road, Cambridge, United Kingdom
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| Recommended Citation: | |
Smith J.A.,Hillenbrand C.-D.,Kuhn G.,et al. New constraints on the timing of West Antarctic Ice Sheet retreat in the eastern Amundsen Sea since the Last Glacial Maximum[J],2014-01-01,122.
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