BRITICE

英国

基本信息

批准号：
NE/J008095/1
负责人：
Richard Hindmarsh
金额：
$ 8.81万
依托单位：
British Antarctic 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%2FJ008095%2F1
关键词：
BRITICE

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.

最近对地球极性冰盖的卫星测量突出了冰块和厚度的变化的发生率远高于预期。研究人员面临的挑战是将这些观察结果置于长期的环境中，并产生计算机模型（“冰盖预测”），这些模型可靠地预测本世纪及以后的冰盖的命运。尽管远离居住，但极地冰盖影响了全球海平面。通过增加融化和冰山产犊的撤退会产生更高的海平面，并担心海平面可能会增加数百万人及其生计，从其沿海房屋上升。在这个时间点，由于它们仍在不断发展并经历大规模变化，因此无法研究目前南极或格陵兰冰盖的全部生命周期。取而代之的是，我们将使用现在完全退缩的冰盖。在上一个冰河时代，覆盖了英国，爱尔兰和北海大部分地区的冰盖。最后一个英里期的冰盖大约在25,000年前覆盖了100万km2，按全球标准覆盖了相对较小的。但是，它的特征，环境和行为与现代西南极和格陵兰冰盖都具有惊人的相似之处。像今天的南极洲一样，英美冰盖的大部分地区受到海洋影响。就像今天的格陵兰冰盖一样，许多快速流动的冰流都带有大部分质量。在气候敏感的区域中，这三个均具有高度动态性，海洋部门，海洋末端边缘和陆基冰川。所有这些共同的因素使英国 - 爱尔兰冰盖成为理解一系列时间尺度上的冰盖动态的强大类似物，该财团成员的工作揭示了冰盖静修的模式，曾经覆盖了不列颠群岛的模式，该模式由End Moraines和其他Glacial Landforms记录。该财团成员的其他工作使用了复杂的计算机模型来模拟冰盖在最后一个冰河时代结束时对气候变化的反应。但是，这些模型只能与它们所基于的地质数据一样好，并且该模式在时间上受到限制。我们需要更多地了解冰期衰变的风格，速率和时机，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，从而可以做出更好的预测。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沉积的沉积物和岩石，并将其与有机残留物一起使用（例如，通过放射性碳分析）的冰盖边缘的撤退。该项目将使用200多个精心选择的站点，约会约800个样本以实现这一目标。在近海，将使用从研究船向海床降低的加油装置，并通过手动采样和使用小型钻机来提取样品。一旦将样品日期添加并添加到地面提供的图案信息中，就会生成收缩冰盖的地图。这些将提供有关整个冰盖的时间和变化率的关键信息。英国爱尔兰冰盖将成为世界上任何地方受到的最佳约束，并成为将来对冰盖模型进行改进和测试的基准。了解不列颠群岛周围的海底沉积物的特征和时代，也可用于许多工业，考古和遗产应用。因此，该项目与有兴趣的合作伙伴密切相关，例如，在近海风电场，英国和爱尔兰之间的电缆以及旨在保存离岸考古遗迹的遗产机构。