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部多年冻土景观的长期影响将是21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方面几乎没有取得进展，温暖气候的影响迅速超过了我们几乎所有的陆生类似物。对于北部的景观和社区，我们必须开发更好的工具，为将来的融化做准备。如今，西方北极地区最严重的影响与埋藏的冰川冰有关，这在过去的10，000年中一直被遗忘，但现在正在变暖，在区域尺度上易于解冻。地面冰的分布反映了冰川的动态和冰埋在第四纪以前的冰缘附近。同样，整个加拿大北部的地面冰属性反映了最近的地质历史及其与过去的植被和气候的相互作用。这些历史偶然性的相互作用定义了将定义未来响应模式的区域多年冻土景观单元或土地系统的相互作用。了解其他解冻的其他区域轨迹将取决于区域第四纪地质的类似遗产，这些遗产强烈影响地面冰的分布和特征。模型存在于大陆尺度上，以实现未来气候变化对永久冻土的影响，但是这些模型的真实性受到我们对地面冰的性质和分布的理解的限制，这在很大程度上将决定区域对融化的敏感性。这项研究的目标是三重的：（1）详细详细介绍麦肯齐山谷的景观历史，快速脱位的影响以及在更新世晚期期间产生的地形； （2）通过田间映射在区域上建立这些属性，为中部和南部麦肯齐山谷的未来融化景观提供模型； （3）使用新工具（例如CT扫描和伽马密度）开发和测试新方法，以实现多年冻土核心的非破坏性表征。这项工作需要在麦肯齐山谷的多个夏季。