Antarctic palaeo-ice streams
Antarctic palaeo-ice streams
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DOI：
10.1016/j.earscirev.2011.10.003
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发表时间：
2012-02-01
影响因子：
12.1
通讯作者：
Jamieson, Stewart S. R.
中科院分区：
文献类型：
--
作者：
Livingstone, Stephen J.;Cofaigh, Colm O.;Jamieson, Stewart S. R.
我们回顾了南极大陆架古冰流的地貌、沉积和年代学证据，并利用这些信息来研究基础条件和过程，并确定控制接地线退缩的因素。本文还提供了已知的环南极古冰流的综合清单、它们的基本特征和它们在末次盛冰期（LGM）后退缩的最小年龄。南极古冰流是由一组诊断地貌确定的，然而，由于基材、流速和冰下过程的影响，这些地貌表现出相当大的空间变异性。在LGM期间，古冰流通过等深槽延伸到南极半岛和西南极洲的大陆架边缘，并典型地延伸到东南极洲的中外大陆架。自LGM以来，南极冰盖的退缩历史具有相当大的不同步性，个别冰流表现出不同的退缩历史。这种变异性使得南极古冰流可以被划分为离散的退缩类型，并对接地线退缩的控制进行了研究。这种分析强调了内部因素对冰流动力学的重要影响，如河床特征和坡度，以及流域大小。虽然接地线的退缩可能被外部（大气和海洋）强迫触发，并在某种程度上被加速，但每条冰流的个别特征将随着时间的推移调节退缩的精确时间和速度。(C) 2011 Elsevier B.V.版权所有
We review the geomorphological, sedimentological and chronological evidence for palaeo-ice streams on the continental shelf of Antarctica and use this information to investigate basal conditions and processes, and to identify factors controlling grounding-line retreat. A comprehensive circum-Antarctic inventory of known palaeo-ice streams, their basal characteristics and minimum ages for their retreat following the Last Glacial Maximum (LGM) is also provided. Antarctic palaeo-ice streams are identified by a set of diagnostic landforms that, nonetheless, display considerable spatial variability due to the influence of substrate, flow velocity and subglacial processes. During the LGM, palaeo-ice streams extended, via bathymetric troughs, to the shelf edge of the Antarctic Peninsula and West Antarctica, and typically, to the mid-outer shelf of East Antarctica. The retreat history of the Antarctic Ice Sheet since the LGM is characterised by considerable asynchroneity, with individual ice streams exhibiting different retreat histories. This variability allows Antarctic palaeo-ice streams to be classified into discrete retreat styles and the controls on grounding-line retreat to be investigated. Such analysis highlights the important impact of internal factors on ice stream dynamics, such as bed characteristics and slope, and drainage basin size. Whilst grounding-line retreat may be triggered, and to some extent paced, by external (atmospheric and oceanic) forcing, the individual characteristics of each ice stream will modulate the precise timing and rate of retreat through time. (C) 2011 Elsevier B.V. All rights reserved.