Terrestrial and submarine evidence for the extent and timing of the Last Glacial Maximum and the onset of deglaciation on the maritime-Antarctic and sub-Antarctic islands
Terrestrial and submarine evidence for the extent and timing of the Last Glacial Maximum and the onset of deglaciation on the maritime-Antarctic and sub-Antarctic islands
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DOI：
10.1016/j.quascirev.2013.12.001
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发表时间：
2014-09-15
影响因子：
4
通讯作者：
Smith, James A.
中科院分区：
文献类型：
--
作者：
Hodgson, Dominic A.;Graham, Alastair G. C.;Smith, James A.
本文是海洋和亚南极地区对南极研究科学委员会（SCAR）过去南极冰盖动力学（PAIS）社区南极冰盖重建的贡献。南极洲所有部门的首要目标是重建末次冰期最大冰盖的范围和厚度，并绘制一系列5000年时间切片中随后的冰川消退。然而，我们对文献的回顾发现，令人惊讶的是，在海洋和亚南极地区，在这些时间尺度上，对冰川范围变化的高质量时间顺序限制很少。因此，在本文中，我们专注于评估的陆地和近海证据的末次冰期冰的范围，建立最低年龄的冰川消退的开始，并分离证据的末次冰期的限制与晚全新世冰川波动。证据包括冰川景观的地貌描述，放射性碳定年的基底泥炭和湖泊沉积物，冰川特征的宇宙成因同位素年龄和分子生物学数据。根据这些收集的证据，我们提出了对海洋和亚南极岛屿冰川历史的分类。其中包括：（I）没有或几乎没有积累LGM冰的岛屿;（II）LGM冰范围有限但有广泛早期大陆架冰川证据的岛屿;（第三类）海山和火山不太可能积累大量末次大冰期冰盖;（第四类）浅架上的岛屿，有陆地和海底末次大冰期的证据（和/或更早）冰扩张;（V型）南极极锋以北的岛屿，有LGM冰扩张的陆地证据;（VI型）没有数据的岛屿。最后，我们审查的气候和地貌环境，分离的冰川历史的岛屿在这个分类方案。(C)2014作者由爱思唯尔有限公司出版。保留所有权利。
This paper is the maritime and sub Antarctic contribution to the Scientific Committee for Antarctic Research (SCAR) Past Antarctic Ice Sheet Dynamics (PAIS) community Antarctic Ice Sheet reconstruction. The overarching aim for all sectors of Antarctica was to reconstruct the Last Glacial Maximum (LGM) ice sheet extent and thickness, and map the subsequent deglaciation in a series of 5000 year time slices. However, our review of the literature found surprisingly few high quality chronological constraints on changing glacier extents on these timescales in the maritime and sub Antarctic sector. Therefore, in this paper we focus on an assessment of the terrestrial and offshore evidence for the LGM ice extent, establishing minimum ages for the onset of deglaciation, and separating evidence of deglaciation from LGM limits from those associated with later Holocene glacier fluctuations. Evidence included geomorphological descriptions of glacial landscapes, radiocarbon dated basal peat and lake sediment deposits, cosmogenic isotope ages of glacial features and molecular biological data. We propose a classification of the glacial history of the maritime and sub Antarctic islands based on this assembled evidence. These include: (Type I) islands which accumulated little or no LGM ice; (Type II) islands with a limited LGM ice extent but evidence of extensive earlier continental shelf glaciations; (Type III) seamounts and volcanoes unlikely to have accumulated significant LGM ice cover; (Type IV) islands on shallow shelves with both terrestrial and submarine evidence of LGM (and/or earlier) ice expansion; (Type V) Islands north of the Antarctic Polar Front with terrestrial evidence of LGM ice expansion; and (Type VI) islands with no data. Finally, we review the climatological and geomorphological settings that separate the glaciological history of the islands within this classification scheme. (C) 2014 The Authors. Published by Elsevier Ltd. All rights reserved.