Timing and pathways of East Antarctic Ice Sheet retreat
Timing and pathways of East Antarctic Ice Sheet retreat
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南极东部冰盖消退的时间和路径
DOI：
10.1016/j.quascirev.2020.106166
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发表时间：
2020
影响因子：
4
通讯作者：
Ohkouchi Naohiko
中科院分区：
文献类型：
--
作者：
Prothro Lindsay O.;Majewski Wojciech;Yokoyama Yusuke;Simkins Lauren M.;Anderson John B.;Yamane Masako;Miyairi Yosuke;Ohkouchi Naohiko
缺乏可靠的年代学往往使南极冰盖的重建不完整。尽管是南极大陆架研究最多的地区，但罗斯海海洋冰盖动态的末次冰期最大期（LGM）后记录在很大程度上仍然难以捉摸，并且与边缘冰盖衰减的陆地记录不一致。放射性碳测年的问题主要来自于保存不好的碳酸盐，冰川循环碳的污染，以及对冰川地貌背景和沉积相的考虑不足。我们在一致的沉积相和地貌框架的背景下评估了近70个新获得的放射性碳年龄和200多个已发表的放射性碳年龄，以解释当地冰川最大值和随后罗斯海东南极冰盖（EAIS）退缩的时间以及潜在的原因退缩。化合物特定的放射性碳年龄有助于提供良好的约束，开放的海洋发病，我们证明，适当的校正和考虑，酸不溶性有机（AIO）放射性碳年龄可以是可靠的开放的海洋沉积物和碳酸盐年龄可以是可靠的接地区近端沉积物。我们发现，冰流经彭内尔和JOIDES槽保持在最大程度约10,000年，然后撤退在15.1和13 cal ka BP，分别。冰架覆盖着外大陆架，直到199.5 cal ka BP，之后它在Joides海槽坍塌，形成深冰山沟。通过彭内尔海槽撤退是更插曲，标志着接地区楔后退上游和侧银行创造冰川消退紧急冰上升。随着冰从2009年至2004年cal ka BP的退缩，排水系统发生了相当大的重组，至少有一次通过南部JOIDES海槽的再进，在2007年cal ka BP罗斯岛附近的陆地冰开始下降。冰架似乎已经撤退到近目前的配置2 cal ka BP。然而，由于在日历年龄的不一致，接地线的位置必须推断出相对年代学的基础上冰川地貌，这表明接地冰退缩近德里加尔斯基冰舌和徘徊在克拉里银行，它是由冰从大卫冰川。我们的重建进一步表明，在罗斯海西部的EAIS是不是一个明显的贡献者融水脉冲1A，但可能有助于海平面上升以及通过中期甚至晚全新世。
A lack of reliable chronology often leaves Antarctic ice sheet reconstructions incomplete. Despite being the most heavily investigated region of the Antarctic continental shelf, the post-Last Glacial Maximum (LGM) record of marine-based ice sheet dynamics in the Ross Sea has remained largely elusive and at odds with fringing terrestrial records of ice sheet decay. Issues with radiocarbon dating stem primarily from poorly preserved carbonate, contamination by glacially-recycled carbon, and insufficient consideration for glacial geomorphic context and sedimentary facies. We assess nearly 70 newly acquired and more than 200 published radiocarbon ages in the context of a consistent sedimentary facies and geomorphic framework to interpret the timing of the local glacial maximum and subsequent retreat of the East Antarctic Ice Sheet (EAIS) in the Ross Sea and potential causes of retreat. Compound-specific radiocarbon ages help to provide good constraints on open marine onset, and we demonstrate that, with proper corrections and considerations, acid insoluble organic (AIO) radiocarbon ages can be reliable in open marine sediments and carbonate ages can be reliable in grounding-zone proximal sediments. We find that the ice flowing through Pennell and JOIDES troughs remained at maximum extent for approximately 10,000 years before retreating at 15.1 and 13 cal ka BP, respectively. An ice shelf covered the outer continental shelf until ∼9.5 cal ka BP, after which it collapsed in JOIDES Trough, creating deep iceberg furrows. Retreat through Pennell Trough was more episodic, marked by grounding-zone wedges that backstep upstream and onto lateral banks creating deglacial emergent ice rises. As ice retreated from ∼9 to ∼4 cal ka BP, there was considerable reorganization of drainage and at least one episode of readvance through southern JOIDES Trough that began drawdown of terrestrial ice near Ross Island at ∼7.8 cal ka BP. The ice shelf appears to have retreated to a near-present configuration by 2 cal ka BP. However, due to inconsistencies in calendar ages, grounding line position must be inferred from relative chronology based on glacial landforms, which suggests grounded ice retreated nearly to Drygalski Ice Tongue and lingered atop Crary Bank where it was maintained by ice from David Glacier. Our reconstruction further suggests that the EAIS in the western Ross Sea was not a discernible contributor to Meltwater Pulse 1A, but likely contributed to eustatic sea level rise well through the middle—perhaps even late—Holocene.
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DOI：
--
发表时间：
2006
期刊：
影响因子：
--
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DOI：
10.1016/0031-0182(88)90122-8
发表时间：
1988
期刊：
Palaeogeography, Palaeoclimatology, Palaeoecology
影响因子：
--
作者：
T. B. Kellogg;D. Kellogg
通讯作者：
D. Kellogg
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影响因子：
5.3
作者：
E. Brook;M. Kurz;R. P. Ackert;G. Raisbeck;F. Yiou
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DOI：
--
发表时间：
1986
期刊：
影响因子：
--
作者：
D. Kellogg;T. B. Kellogg
通讯作者：
T. B. Kellogg