New constraints on the timing of West Antarctic Ice Sheet retreat in the eastern Amundsen Sea since the Last Glacial Maximum
New constraints on the timing of West Antarctic Ice Sheet retreat in the eastern Amundsen Sea since the Last Glacial Maximum
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自末次盛冰期以来，阿蒙森海东部西南极冰盖退缩时间的新限制
DOI：
10.1016/j.gloplacha.2014.07.015
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发表时间：
2014
影响因子：
3.9
通讯作者：
Smith J
中科院分区：
文献类型：
--
作者：
Smith J
流入阿蒙森海湾（ASE）的冰川占西南极冰盖（WAIS）总流量的35%以上，并且在过去20年中急剧变薄和退缩。在这里，我们提出了详细的海洋地质数据和一个广泛的新的放射性碳数据集从东部ASE，以限制WAIS的撤退，因为末次盛冰期（LGM）和评估这些最近的变化的意义。我们的测年方法，主要依赖于酸不溶性有机（AIO）部分，利用多代理分析的沉积物，以确定其岩相，并确定在每个核心的地平线，将产生最可靠的年龄为冰川消退。总的来说，我们对69个样本进行了测年，结果表明，在距今20,600校准年（cal yr BP）之前，外大陆架的冰消作用正在进行中，在13,575 cal yr BP之前到达中大陆架，内大陆架在大约2500 cal yr BP之间。10，615 cal yr BP的现有接地线的150 km。撤退的时间大致与以前公布的放射性碳年代的生物碳酸盐从东部ASE以及AIO 14 C年龄从西部ASE和冰盖模型提供了新的限制。整体撤退轨迹-缓慢的外架，更迅速的从中间到内架-清楚地突出了反向bedslope在控制阶段的加速地面线撤退的重要性。尽管揭示了这些大规模的趋势，但目前的数据集并没有捕捉到冰流的详细变化，例如接地线撤退期间的静止（即，接地带楔的沉积）和可能的再流动，如地貌记录所示。
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 (cal yr BP), reaching the mid-shelf by 13,575 cal yr BP and the inner shelf to within ca. 150 km of the present grounding line by 10,615 cal yr BP. The timing of retreat is broadly consistent with previously published radiocarbon dates on biogenic carbonate from the eastern ASE as well as AIO14C 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.
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晚第四纪西南极冰盖动力学：阿蒙森海架古冰盖床的遥感和底质研究
DOI：
--
发表时间：
2014
期刊：
影响因子：
--
作者：
J. Klages
通讯作者：
J. Klages
2006 年极星号科考船 ANTARKTIS-XXIII/4 号探险队
影响因子：
2.8
作者：
K. Gohl
通讯作者：
K. Gohl
影响因子：
4
作者：
Lowe, AL;Anderson, JB
通讯作者：
Anderson, JB
影响因子：
30.7
作者：
Favier, L.;Durand, G.;Le Brocq, A. M.
通讯作者：
Le Brocq, A. M.
影响因子：
18.3
作者：
Rignot, Eric;Bamber, Jonathan L.;Van Meijgaard, Erik
通讯作者：
Van Meijgaard, Erik