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BRITICE-CHRONO

基本信息

批准号：
NE/J007846/1
负责人：
Tom Bradwell
金额：
$ 24.16万
依托单位：
British Geological Survey
依托单位国家：
英国
项目类别：
Research Grant
财政年份：
2012
资助国家：
英国
起止时间：
2012 至无数据
项目状态：
已结题

来源：
https://gtr.ukri.org/projects?ref=NE%2FJ007846%2F1
关键词：
BRITICE CHRONO

项目摘要

Recent satellite measurements of the Earth's polar ice sheets highlight that changes in ice extent and thickness are occurring at rates far higher than expected. The challenge for researchers is to place these observations into a longer-term context and produce computer models ('ice sheet forecasts') that reliably predict the fate of ice sheets over this century and beyond. Although remote from habitation, the polar ice sheets influence global sea level. Retreat by increased melting and iceberg calving produces higher sea levels and concerns exist that sea level may rise by metres displacing many millions of people, and their livelihoods, from their coastal homes. At this point in time, it is not possible to study the full life cycle of the present Antarctic or Greenland ice sheets as they are still evolving and undergoing large-scale changes. Instead, we will use an ice sheet that has now fully retreated; the ice sheet that covered most of Britain, Ireland and the North Sea during the last ice age. The last British-Irish ice sheet covered up to 1,000,000 km2 at its maximum size, around 25,000 yrs ago, and was relatively small by global standards. However, its character, setting and behaviour have striking parallels with both the modern West Antarctic and Greenland Ice Sheets. Large parts of the British-Irish Ice Sheet were marine-influenced just like in west Antarctica today; and numerous fast-flowing ice streams carried much of its mass, just like in the Greenland Ice Sheet today. All three are or were highly dynamic, in climatically sensitive regions, with marine sectors, ocean-terminating margins and land-based glaciers. All these common factors make the British-Irish Ice Sheet a powerful analogue for understanding ice sheet dynamics on a range of timescales, operating now and in the future.Recent work by members of this consortium has revealed the pattern of ice sheet retreat that once covered the British Isles, as recorded by end moraines and other glacial landforms. Other work by members of this consortium has used sophisticated computer models to simulate the ice sheet's response to climate change at the end of the last Ice Age. However, these models can only be as good as the geological data on which they are based, and the pattern is poorly constrained in time. We need to know more about the style, rate and timing of ice sheet decay in response to past climate change. Such knowledge allows us to further refine computer modelling so that better predictions can be made. The main focus of the project therefore, is to collect sediments and rocks deposited by the last ice sheet that covered the British Isles, and use these, along with organic remains, to date (e.g. by radiocarbon analyses) the retreat of the ice sheet margins. The project will use over 200 carefully chosen sites, dating some 800 samples in order to achieve this. Offshore, samples will be extracted using coring devices lowered from a research ship to the seabed, and onshore by manual sampling and by use of small drilling rigs. Once the samples are dated and added to the pattern information provided by the landforms, maps of the shrinking ice sheet will be produced. These will provide crucial information on the timing and rates of change across the whole ice sheet. The British-Irish Ice Sheet will become the best constrained anywhere in the world and be the benchmark against which ice sheet models are improved and tested in the future.Knowledge on the character and age of the seafloor sediments surrounding the British Isles is also useful for many industrial, archaeological and heritage applications. Accordingly, the project is closely linked to partners interested, for example, in locating offshore windfarms, electricity cables between Britain and Ireland, and heritage bodies aiming to preserve offshore archaeological remains.

最近对地球极地冰盖的卫星测量突出表明，冰的范围和厚度的变化速度远远高于预期。研究人员面临的挑战是将这些观测结果置于长期背景下，并制作计算机模型（“冰盖预测”），可靠地预测本世纪及以后冰盖的命运。虽然远离人类居住地，但极地冰盖影响着全球海平面。由于冰川融化和崩解而导致的后退造成海平面上升，人们担心海平面可能上升数米，使数百万人及其生计离开沿海家园。目前还不可能研究目前南极或格陵兰冰盖的整个生命周期，因为它们仍在演变和经历大规模变化。相反，我们将使用一个现在已经完全消退的冰盖;在上一个冰河时代覆盖大部分英国、爱尔兰和北海的冰盖。最后一个英国-爱尔兰冰盖在大约25，000年前的最大规模时覆盖了1，000，000平方公里，按照全球标准相对较小。然而，它的特征、环境和行为与现代南极西部和格陵兰冰盖有着惊人的相似之处。英国-爱尔兰冰盖的大部分地区都受到海洋的影响，就像今天的南极洲西部一样;许多快速流动的冰流携带了它的大部分质量，就像今天的格陵兰冰盖一样。所有这三个区域都是或曾经是高度动态的，位于气候敏感区域，有海洋部分、海洋终止边缘和陆地冰川。所有这些共同的因素使英国-爱尔兰冰盖的一个强大的模拟理解冰盖动态的时间尺度范围内，现在和未来的操作，这个财团的成员最近的工作已经揭示了冰盖退缩的模式，一旦覆盖不列颠群岛，记录的结束冰碛和其他冰川地貌。该联盟成员的其他工作使用复杂的计算机模型来模拟冰盖对上一个冰河时代结束时气候变化的反应。然而，这些模型只能与它们所基于的地质数据一样好，并且模式在时间上的约束很差。我们需要更多地了解冰盖衰退的方式、速度和时间，以应对过去的气候变化。这些知识使我们能够进一步完善计算机建模，以便做出更好的预测。因此，该项目的主要重点是收集覆盖不列颠群岛的最后一个冰盖所沉积的沉积物和岩石，并利用这些沉积物和岩石，沿着有机残留物，确定冰盖边缘退缩的日期（例如通过放射性碳分析）。该项目将使用200多个精心挑选的地点，测定约800个样本的年代，以实现这一目标。在近海，将使用从研究船下放到海底的取芯装置提取样本，在陆上则采用人工取样和使用小型钻机。一旦样本被确定日期并添加到地形提供的模式信息中，冰盖萎缩的地图将被制作出来。这些将提供关于整个冰盖变化的时间和速度的关键信息。英国-爱尔兰冰盖将成为世界上最受约束的冰盖，并成为未来改进和测试冰盖模型的基准。关于不列颠群岛周围海底沉积物的特征和年龄的知识也有助于许多工业，考古和遗产应用。因此，该项目与感兴趣的合作伙伴有着密切的联系，例如，确定海上风电场、英国和爱尔兰之间的电缆以及旨在保护海上考古遗迹的遗产机构。

项目成果

期刊论文数量（8）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

Asymmetric ice-sheet retreat pattern around northern Scotland revealed by marine geophysical surveys

DOI：
10.1017/s1755691015000109
发表时间：
2014-12
期刊：
Earth and Environmental Science Transactions of the Royal Society of Edinburgh
影响因子：
1.2
作者：
T. Bradwell;M. Stoker
通讯作者：
T. Bradwell;M. Stoker

Geophysical Research Abstracts