Reconstructing millennial-scale ice sheet change in the western AmundsSea Embaymenten , Antarctica, using high-precision exposure dating.

如果各国政府要在全球变暖的情况下成功地规划未来，准确预测未来海平面可能上升的时间和幅度，具有重要的社会和经济意义。西南极冰盖(WAIS)，特别是它的阿蒙森海部分，是这种预测的关键，因为它有可能非常迅速地退缩，可能只需要几个世纪的时间。我们迫切需要改进预测它未来稳定性的模型，因为锁在它里面的水有可能对全球海平面上升做出重大贡献(高达1.2米)。这将对世界各地的低洼城市造成广泛的破坏，包括欧洲的主要沿海和经济中心，如伦敦。有关过去冰盖大小和形状的信息对于测试和改进预测模型是必不可少的。然而，尽管它对了解未来海平面上升很重要，但目前在南极洲阿蒙森海湾(ASE)的模拟工作由于缺乏关于WAIS历史的数据而受到阻碍，特别是在ASE西部(我们知道ASE东部的总体退缩和变薄模式，尽管一些细节尚不清楚)。拟议中的项目将从鲜为人知的西部ASE产生一个独特的高分辨率冰盖变薄记录，记录过去2万年来的情况。我们将使用表面暴露测年技术中令人兴奋的创新来确定冰盖厚度的微小波动，比以前在南极洲实现的更高的精度。自那时以来，随着冰盖的消退和变薄，关于过去20,000年来WAIS的形状和大小的信息包含在南极洲表面的岩石中。地表暴露测年涉及收集这类岩石，并测量集中在其上表面的同位素10Be的丰度，这种同位素充当自岩石最后一次被冰覆盖以来的时间长度的化学信号。因为我们计划从海冰西部冰面上方的一系列高度收集这一信息，我们将能够知道WAIS这一部分变薄的速度有多快，以及变薄开始和停止的时间。除了建立WAIS这一部分的历史之外，这种方法还将使我们深入了解过去十年来记录和广泛宣传的冰盖变化的重要性。例如，它们仅仅是长期变薄趋势的延续，还是相对最近才开始发生，如果是的话，原因是什么？通过比较ASE西部和东部的冰川消退历史，我们还将了解ASE的不同部分可能如何应对未来的环境变化。我们建议的一个重要部分将是进一步发展我们与使用地质数据来测试和调整他们的冰盖模型的模型师的现有合作。我们的数据将使这些模型得到显著改进，最终有助于更准确地预测未来全球海平面上升。

Accurate prediction of when and how much sea level rise is likely to take place in the future is of great societal and economic importance if governments are to successfully plan for the future in a warming world. The West Antarctic Ice Sheet (WAIS), and particularly its Amundsen Sea sector, is key to such predictions because it has the potential to retreat very rapidly, perhaps over just a few centuries. We urgently need improvements to models that predict its future stability because the water locked inside it has the potential to make a major contribution (up to 1.2 metres) to global sea level rise. This would result in widespread damage to low-lying cities around the world, including major coastal and economic hubs in Europe, such as London. Information about the past size and shape of ice sheets is essential for testing and refining predictive models. However, despite its importance for understanding future sea level rise, modelling efforts in the Amundsen Sea Embayment (ASE) of Antarctica are currently hindered by a lack of data on the history of the WAIS, particularly in the western ASE (we know the general pattern of retreat and thinning in the eastern ASE, although some of the details are not yet clear). The proposed project will produce a unique high-resolution record of ice sheet thinning over the past 20,000 years from the poorly-known western ASE. We will use exciting innovations in the technique of surface exposure dating to determine small fluctuations in ice sheet thickness with greater precision than has previously been achieved in Antarctica. Information on the shape and size of the WAIS over the past 20,000 years is contained within rocks deposited on the surface of Antarctica as the ice sheet has retreated and thinned since that time. Surface exposure dating involves collecting such rocks and measuring the abundance of an isotope, 10Be, concentrated within their upper surfaces, which acts as a chemical signal for the length of time since the rock was last covered by ice. Because we plan to collect this information from a range of heights above today's ice surface in the western ASE, we will be able to tell how rapidly that part of WAIS has thinned, and when the thinning started and stopped. As well as establishing the history of this part of the WAIS, this approach will also give us insight into the significance of ice sheet changes recorded and widely publicised over the past decade. For example, are they simply the continuation of a long-term trend of thinning, or have they only started happening relatively recently and, if so, why? By comparing the retreat history of glaciers in the western and eastern parts of the ASE, we will also learn how different parts of the ASE are likely to respond to future environmental change.An important part of our proposal will be to further develop our existing collaborations with modellers who use geological data to test and tune their ice sheet models. Our data will permit significant improvements in these models, ultimately contributing to more accurate prediction of future global sea level rise.