Permafrost archives of northern environmental change and permafrost landsystems of the Mackenzie valley

北部环境变化的永久冻土档案和麦肯齐山谷的永久冻土土地系统

• 批准号: RGPIN-2019-06820
• 负责人: Froese, Duane
• 金额: $ 4.44万
• 依托单位: University of Alberta
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2022
• 资助国家: 加拿大
• 起止时间: 2022-01-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=750895
• 关键词: Permafrost; archives; northern; environmental; change

The longterm impact of climate change on the permafrost landscape of northern Canada will be a defining issue in the 21st century. We have made little progress in decreasing our collective greenhouse gas emissions to the atmosphere, and the impacts of a warming climate are quickly exceeding nearly all of our terrestrial Quaternary analogues. For northern landscapes and communities, we must develop better tools to prepare for future thaw. Today, the most severely affected areas of the western Arctic are associated with buried glacier ice that has been relict for the last 10,000 years, but is now warming and becoming thaw susceptible at regional scales. This distribution of ground ice reflects the dynamics of glaciation and the burial of ice near the former ice margin in the Quaternary. Similarly, ground ice properties throughout northern Canada are a reflection of the recent geologic history and its interaction with past vegetation and climate. The interactions of these historical contingencies define regional permafrost landscape units, or Landsystems, that will define patterns of future response. Understanding other regional trajectories of thaw will depend on similar legacies of regional Quaternary geology that have strongly influenced the distribution and character of ground ice. Models exist at continental scales for future climate change impacts on permafrost, but the veracity of these models is limited by our understanding of the nature and distribution of ground ice, which in large part, will determine the susceptibility of areas to thaw. The objectives of this research are threefold: (1) to detail the landscape history of the Mackenzie valley, the impact of rapid deglaciation and resulting landforms during the late Pleistocene; (2) to establish these properties, regionally, through field mapping to provide a model for future thaw landscapes of the central and southern Mackenzie valley; and (3) develop and test new approaches to permafrost characterization using new tools such as CT scanning and gamma density that allow the non-destructive characterization of permafrost cores. This work requires multiple summers of fieldwork in the Mackenzie valley.

气候变化对加拿大北方永久冻土景观的长期影响将是21世纪世纪的一个决定性问题。我们在减少集体温室气体排放到大气中方面几乎没有取得什么进展，气候变暖的影响正在迅速超过几乎所有的地球第四纪类似物。对于北方的景观和社区，我们必须开发更好的工具，为未来的解冻做准备。今天，北极西部受影响最严重的地区与埋藏的冰川冰有关，这些冰川冰在过去10，000年中一直残留，但现在正在变暖，并且在区域范围内变得容易融化。地面冰的分布反映了第四纪冰川作用的动力学和冰在前冰缘附近的埋藏。同样，加拿大北方各地的地面冰特性反映了最近的地质历史及其与过去植被和气候的相互作用。这些历史偶然事件的相互作用定义了区域永久冻土景观单元或土地系统，这将定义未来的响应模式。了解其他地区的融化轨迹将取决于类似的区域第四纪地质遗产，强烈影响了地面冰的分布和特征。在大陆尺度上存在未来气候变化对永久冻土影响的模型，但这些模型的准确性受到我们对地面冰的性质和分布的理解的限制，这在很大程度上决定了地区解冻的敏感性。本研究的目的有三：（1）详细描述麦肯齐河谷的景观历史、冰川快速消融的影响以及在晚更新世形成的地貌;（2）通过野外测绘，在区域上建立这些特征，为麦肯齐河谷中部和南部未来的解冻景观提供一个模型;以及（3）开发和测试使用新工具（如CT扫描和伽马密度）进行永久冻土表征的新方法，这些新工具可以对永久冻土芯进行非破坏性表征。这项工作需要在麦肯齐山谷进行多个夏天的实地考察。