权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

PREDICTING AND INVESTIGATING SUBGLACIAL LAKES OF THE FORMER BRITISH AND FENNOSCANDIAN ICE SHEETS

预测和研究前英国和芬诺斯坎迪亚冰盖的冰下湖泊

基本信息

批准号：
NE/H015256/1
负责人：
Stephen Livingstone
金额：
$ 33.31万
依托单位：
University of Sheffield
依托单位国家：
英国
项目类别：
Fellowship
财政年份：
2011
资助国家：
英国
起止时间：
2011 至无数据
项目状态：
已结题

来源：
https://gtr.ukri.org/projects?ref=NE%2FH015256%2F1
关键词：
PREDICTING INVESTIGATING SUBGLACIAL LAKES FORMER

项目摘要

The discovery that large lakes exist at the base of the Antarctic Ice Sheet and that these lakes can rapidly drain has major implications related to meltwater routing and supply and thus ice-sheet dynamics. Recent satellite observations show that subglacial lakes are very active, and can perturb the water system rapidly on annual or shorter time-scales, while at Byrd Glacier a direct link between water drainage and ice flow acceleration has been demonstrated. With over 250 lakes now known to exist under the Antarctic Ice Sheet there has also been rising interest in exploring these subglacial environments to look for evidence of life and to investigate their potential as long-term archives of climate change. This interest is demonstrated by three separate US-, Russian- and UK-led programs which aim to drill into these lakes. Despite the growing importance attached to studying subglacial lakes in Antarctica, the identification and study of palaeo subglacial lakes from former ice sheets has been neglible, with even fundamental questions related to their geological signatures remaining elusive. Yet investigations of palaeo subglacial lakes offers significant advantages because we have comprehensive information about the bed properties, they are logistically more accesable (i.e. on foot instead of 3 km long drills) and we can sample and examine the sediments with ease. If I can find palaeo subglacial lakes then I have the potential to make huge leaps in knowledge with regard to the topographic context and hydrological pathways that the phenomena form a part of; essentially I gain spatial and sedimentological information in relation to contemporary subglacial lake investigations and lose out on the short time dynamics. This proposal offers a pioneering study that aims to invigorate research on subglacial lakes by answering two major research questions: (1) can we successfully predict and identify subglacial lakes of the former British and Fennoscandian Ice Sheets during the last glaciation?; and (2) What impact did subglacial lakes have on meltwater routing and supply and thus ice sheet dynamics? The study will utilise GIS and numerical ice sheet modelling to predict where subglacial lakes may have ocurred in the former British and Fennoscandian Ice Sheets and then the identification and evaluation of some of these former subglacial lakes using sedimentological, stratigraphic and geomorphological techniques. The formulation of a diagnostic set of criteria for identying palaeo subglacial lakes is a major research objective for the project and will be first such attempted. Once identified further research will concentrate on the links between subglacial lakes and ice sheet dynamics, specifically related to meltwater routing and the relationship with ice streams. It is anticipate that findings arising from this work and the lakes I discover will stimulate many other researchers to exploit the record of palaeo subglacial lakes and set a new agenda for glaciological thinking of how basal water exerts a control on ice flux and routing.

在南极冰盖的底部存在大型湖泊，这些湖泊可以迅速排水，这一发现对融水的路线和供应以及冰盖动力学有重大影响。最近的卫星观测表明，冰下湖泊非常活跃，可以在一年或更短的时间尺度上迅速扰乱水系统，而在伯德冰川，已经证明了排水和冰流加速之间的直接联系。现在已知南极冰盖下存在250多个湖泊，人们对探索这些冰下环境的兴趣也越来越大，以寻找生命的证据，并调查它们作为气候变化长期档案的潜力。美国、俄罗斯和英国领导的三个独立项目表明了这种兴趣，这些项目旨在钻探这些湖泊。尽管对南极洲冰下湖泊的研究日益受到重视，但从前冰盖中识别和研究古冰下湖泊的工作一直被忽视，甚至与其地质特征有关的基本问题也仍然难以捉摸。然而，古冰下湖泊的调查提供了显着的优势，因为我们有关于床属性的全面信息，它们在后勤上更容易接近（即步行而不是3公里长的钻孔），我们可以轻松地采样和检查沉积物。如果我能找到古冰下湖泊，那么我就有可能在地形背景和水文路径方面取得巨大的知识飞跃，这些现象构成了其中的一部分;基本上，我获得了与当代冰下湖泊调查有关的空间和沉积学信息，并失去了短期动态。这一提议提供了一项开创性的研究，旨在通过回答两个主要的研究问题来振兴冰下湖泊的研究：（1）我们能否成功地预测和识别末次冰期期间前英国和芬诺斯堪的纳维亚冰盖的冰下湖泊？以及（2）冰下湖泊对融水路径和补给以及冰盖动态有什么影响？这项研究将利用地理信息系统和数值冰盖建模来预测在前英国和芬诺斯堪的纳维亚冰盖中可能出现的冰下湖泊，然后利用沉积学、地层学和地貌学技术来识别和评价其中一些前冰下湖泊。该项目的一个主要研究目标是制定一套用于确定古冰下湖泊的诊断标准，这将是第一次尝试。一旦确定，进一步的研究将集中在冰下湖泊和冰盖动态之间的联系，特别是有关融水的路由和与冰流的关系。预计这项工作和我发现的湖泊所产生的结果将刺激许多其他研究人员利用古冰下湖泊的记录，并为冰川学思考基底水如何控制冰通量和路由设定新的议程。