Massive ground ice in the western Canadian Arctic: distribution, origin, age and role in past, present and future landscape change

在过去的几十年里，由于20世纪的气候变化，整个北极地区的永久冻土温度有所上升。富冰的冰缘环境，其中永久冻土带的上部可能是70-90%的体积水，本质上是不稳定的，并且随着景观对气候变化的适应，可能会发生实质性的地貌改变。在这些地区，融化滑坡的发展是富冰永久冻土退化的最显著表现之一。融冰的减少已经对陆地和水生生态系统造成了影响，并成为当地北极社区的一个主要问题。预计融化滑坡的数量和规模的增加将对水文地貌产生重大影响。这一建议分为一系列相互关联的项目：1)调查融化滑坡的分布、增长和稳定速率；2)通过发展新的和扩展现有的冰中闭塞气体测量技术，确定富冰永久冻土的起源、年龄和可居住性；3)量化解冻滑坡对水文地貌的影响——出现“退化的大块地冰河系”。总的来说，这项研究计划将包括培训11名高素质的跨学科冰周研究人员。拟议的研究计划的结果将大大增加我们对加拿大北极西部大量地面冰的分布、特征和年龄的了解。这些信息对于确定富冰永久冻土、区域更新世冰川边界和地表地质之间的关系至关重要；2)评估富冰永久冻土对上一次北极比当前条件更温暖的反应；3)了解热岩溶过程的潜在驱动因素，特别是与融化滑坡的增长和稳定有关；4)评估融雪滑坡对景观水文地貌的影响；5)预测富冰冻土景观对未来气候变化的区域水文地貌响应。

Over the last few decades, permafrost temperatures have increased across the Arctic in response to the 20th century climate change. Ice-rich periglacial environments, where the upper part of permafrost may be 70-90% water by volume, are inherently unstable and may undergo substantial geomorphic modification as landscapes adjust to changing climate. In these regions, the development of thaw slumps is one of the most dramatic manifestations of degradation of ice-rich permafrost. The thaw slumps are already causing impacts on terrestrial and aquatic ecosystems and are becoming a major concern for local Arctic communities. It is expected that the increasing number and size of thaw slumps will have major hydrogeomorphic consequences. This proposal is divided into a series of interrelated projects: 1) Investigating the distribution, growth and stabilization rates of thaw slumps; 2) Determining origin, age and habitability of ice-rich permafrost by developing new and expanding current techniques for occluded gases measurements in ice; 3) Quantify the impacts of thaw slumps on hydrogeomorphology - the emergence of the "degrading massive ground ice fluvial regime. Overall, this research program will involve the training of 11 highly qualified personnel in field-based multi-disciplinary periglacial studies. The results of the proposed research program will greatly increase our knowledge about the distribution, characteristics and age of massive ground ice in western Arctic Canada. This information is essential for: 1) determining the relation between ice-rich permafrost, regional Pleistocene glacial limits and surface geology; 2) assessing the response of ice-rich permafrost to the last time that the Arctic was warmer than current conditions; 3) understanding the potential drivers of thermokarst processes, in particular in relation to growth and stabilization of thaw slumps; 4) assessing the hydrogeomorphic impacts of thaw slumps in the landscape; and 5) predicting regional hydrogeomorphic responses of ice-rich permafrost landscape to future climate change.