Deglacial environments in eastern Prydz Bay, East Antarctica
Deglacial environments in eastern Prydz Bay, East Antarctica
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DOI：
10.1016/j.quascirev.2010.06.027
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发表时间：
2010-09-01
影响因子：
4
通讯作者：
Ther, Olivier
中科院分区：
文献类型：
--
作者：
Barbara, Laic;Crosta, Xavier;Ther, Olivier
沉积岩芯 NBP0101-JPC24 中硅藻普查计数和硅藻特异性生物标志物的高分辨率连续记录允许在十年时间尺度上评估冰消期（11100-9000cal yr BP）期间普里兹湾东部的海洋和环境条件。我们的研究改进了之前基于树脂嵌入薄片的快照研究，并提出了一种补充硅藻普查计数的新代理。我们的研究结果表明，冰盖在核心位置上的退缩时间大约为距今 11100 年，从而引发了局部冰川消融和随后的开放海洋条件。普里兹湾的冰川退缩是由于18cal ka BP开始的全球变暖和普里兹湾气旋环流的区域发展造成的。我们的研究结果进一步表明，普里兹湾东部的冰消作用可以分为四个阶段：第一个阶段是在距今11100到10900年之间，当时冰架最近，海冰几乎是常年存在的；第二阶段和第三阶段分别在10 900-10 400 Cal BP和10 400-9900 Cal BP之间，此时冰架后退，季节性海冰循环随之发展，促使温暖的海水泵入环流内的海湾，进而迫使冰架后退和年度海冰循环建立；第四次是在距今 9900 到 9000 年之间，当时全新世的条件是周期性的季节性海冰循环和完善的普里兹湾环流。 (c) 2010 Elsevier Ltd. 保留所有权利。
A high-resolution continuous record of diatom census counts and diatom specific biomarkers in sediment core NBP0101-JPC24 allows assessment of oceanographic and environmental conditions in eastern Prydz Bay during the deglaciation (11 100-9000 cal yr BP) at decadal timescale. Our study improves previous snapshots investigations based on resin-embedded thin sections and presents a new proxy that compliments the diatom census counts. Our results suggest that the ice sheet retreat over the core site is dated at similar to 11 100 cal yr BP, setting the onset of local deglaciation and subsequent open marine conditions. The glacial retreat in Prydz Bay is due to global warming initiated at 18 cal ka BP and the regional development of the Prydz Bay cyclonic gyre. Our results further demonstrate that the deglaciation in eastern Prydz Bay can be separated in four phases: the first between 11 100 and 10 900 cal yr BP when the ice shelf was proximal and sea ice was almost perennial; the second and the third phases between 10 900-10 400 cal yr BP and 10 400-9900 cal yr BP, respectively, when the ice shelf retreated and seasonal sea ice cycle consequently developed promoting warmer water to pump into the bay within the gyre, which in turn forced the ice shelf recession and the yearly sea ice cycle establishment; and the fourth between 9900 and 9000 cal yr BP when Holocene condition were set with a recurrent seasonal sea ice cycle and a well established Prydz Bay gyre. (c) 2010 Elsevier Ltd. All rights reserved.