BRITICE-CHRONO: Constraining rates and style of marine influenced ice sheet decay

BRITICE-CHRONO：受海洋影响的冰盖衰变的约束速率和类型

基本信息

批准号：
NE/J007056/1
负责人：
Richard Chiverrell
金额：
$ 42.51万
依托单位：
University of Liverpool
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%2FJ007056%2F1
关键词：
BRITICE CHRONO Constraining rates style

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更长期的背景下，并生成能够可靠预测本世纪及以后冰盖命运的计算机模型（“冰盖预测”）。尽管远离人类居住地，极地冰盖却影响着全球海平面。由于融化和冰山崩解加剧而导致的退缩会导致海平面上升，人们担心海平面可能会上升数米，导致数百万人离开沿海家园，失去生计。目前，不可能研究目前南极或格陵兰冰盖的整个生命周期，因为它们仍在演化并经历大规模变化。相反，我们将使用现已完全消退的冰盖；上一个冰河时期覆盖了英国、爱尔兰和北海大部分地区的冰盖。大约 25,000 年前，最后一个英国-爱尔兰冰盖的最大面积覆盖了 1,000,000 平方公里，按照全球标准来看，该冰盖相对较小。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。无数快速流动的冰流承载了它的大部分质量，就像今天的格陵兰冰盖一样。这三个区域现在或曾经都处于高度动态的气候敏感地区，包括海洋部门、海洋终止边缘和陆基冰川。所有这些共同因素使英国-爱尔兰冰盖成为了解一系列时间尺度上现在和未来冰盖动态的有力类比。该联盟成员最近的工作揭示了曾经覆盖的冰盖退缩模式不列颠群岛，根据末碛和其他冰川地貌的记录。该联盟成员的其他工作使用复杂的计算机模型来模拟上一个冰河时代末期冰盖对气候变化的反应。然而，这些模型的好坏取决于它们所基于的地质数据，而且模式在时间上的约束很差。我们需要更多地了解冰盖因过去的气候变化而衰退的方式、速率和时间。这些知识使我们能够进一步完善计算机模型，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沉积的沉积物和岩石，并利用这些沉积物和岩石以及有机残留物，迄今为止（例如通过放射性碳分析）冰盖边缘的退缩。为了实现这一目标，该项目将使用 200 多个精心挑选的地点，对大约 800 个样本进行测年。在海上，将使用从研究船降低到海底的取芯装置提取样本，在陆上则通过手动采样和使用小型钻机提取样本。一旦样本被标明日期并添加到地貌提供的模式信息中，就会生成冰盖收缩的地图。这些将提供有关整个冰盖变化的时间和速率的重要信息。英国-爱尔兰冰盖将成为世界上任何地方受约束最好的冰盖，并成为未来改进和测试冰盖模型的基准。有关不列颠群岛周围海底沉积物的特征和年龄的知识也很有用许多工业、考古和遗产应用。因此，该项目与对海上风电场定位、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等感兴趣的合作伙伴密切相关。

项目成果

期刊论文数量（10）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

Exploring controls of the early and stepped deglaciation on the western margin of the British Irish Ice Sheet

DOI：
10.1002/jqs.3315
发表时间：
2021-06
期刊：
Journal of Quaternary Science
影响因子：
2.3
作者：
S. Benetti;R. Chiverrell;C. Ó. Cofaigh;M. Burke;A. Medialdea;D. Small;C. Ballantyne;M. Bateman;S. L. Callard;P. Wilson;D. Fabel;C. Clark;R. Arosio;S. Bradley;P. Dunlop;J. Ely;Jenny G. Gales;S. Livingstone;S. Moreton;Catriona Purcell;M. Saher;K. Schiele;K. V. van Landeghem;Kasper Weilbach
通讯作者：
S. Benetti;R. Chiverrell;C. Ó. Cofaigh;M. Burke;A. Medialdea;D. Small;C. Ballantyne;M. Bateman;S. L. Callard;P. Wilson;D. Fabel;C. Clark;R. Arosio;S. Bradley;P. Dunlop;J. Ely;Jenny G. Gales;S. Livingstone;S. Moreton;Catriona Purcell;M. Saher;K. Schiele;K. V. van Landeghem;Kasper Weilbach

Pattern, style and timing of British-Irish Ice Sheet advance and retreat over the last 45 000 years: evidence from NW Scotland and the adjacent continental shelf

过去 45 000 年来英国-爱尔兰冰盖进退的模式、风格和时间：来自苏格兰西北部和邻近大陆架的证据