Isotopic tracers and chronometers of Earth surface processes (Arctic/subarctic realm)

地球表面过程的同位素示踪剂和计时器（北极/亚北极地区）

• 批准号: 444885-2013
• 负责人: HillaireMarcel, Claude
• 金额: $ 1.31万
• 依托单位: Université du Québec à Montréal
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Northern Research Supplement
• 财政年份: 2013
• 资助国家: 加拿大
• 起止时间: 2013-01-01 至 2014-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=535711
• 关键词: Isotopic; tracers; chronometers; Earth; surface

The research follows two complementary tracks contributing to international initiatives about Earth system science issues: i) the dynamics of climate and ocean, and ii) the impact of climatic changes on land erosion, geochemical cycles and sea-levels, with focus on high Northern Hemisphere latitudes. The first track aims at predicting the future of the Canadian Arctic under a warmer globe with attention paid to i) the fate of sea-ice and its impact on sedimentary regimes, ii) continental ice decay and runoff, iii) their impact on the Atlantic Meridional Overturning Circulation and on global sea-levels. Conditions during past "warm" intervals, the Pliocene and thermal optima of the past- and present interglacial stages, and transition intervals towards such climatic optima, will be reconstructed and used to identify changes in boundary conditions and for testing current climate model abilities to reproduce such past-synopses. Stable, radioactive and radiogenic isotope analysis of geological archives, in particular of deep-sea sediments, constitute primary tools for the planned studies. They provide access to geological time and a large array of paleo-environmental parameters, thus to "pre antropogenically-modified" states of the Earth system, at time scale varying from million years to the present. Complementary efforts towards using some of the above isotopic tracers for the monitoring of modern environments constitute the second research track, through a project of the International Atomic Energy Agency on "Isotopic tools to assess anthropogenic impacts on water quantity and quality on large river systems", at planning stage. Here, the focus will be on the Mackenzie, St. Lawrence, circum-Hudson Bay and Hudson Strait rivers, both for tracer-calibration purposes and the documenting of on-going anthropogenically- vs naturally-driven processes with impact on soil erosion, runoff, sediment and chemical fluxes from the land to the ocean. This program has thus basics and socially relevant objectives and will permit the training of up to 20 graduate or post-doctoral scientists in domains of importance for the development of the North and/or the assessment of soil and water resources under the present anthropogenic pressure.

这项研究遵循两个互补的方向，为有关地球系统科学问题的国际倡议作出贡献：1)气候和海洋的动态，以及2)气候变化对土地侵蚀、地球化学循环和海平面的影响，重点关注北半球高纬度地区。第一个轨道旨在预测全球变暖下加拿大北极地区的未来，重点关注1)海冰的命运及其对沉积制度的影响，2)大陆冰的衰变和径流，3)它们对大西洋经向翻转环流和全球海平面的影响。将重建过去“温暖”间冰期的条件、过去和现在间冰期的上新世和热最佳状态，以及向这种气候最佳状态过渡的间冰期，并用于确定边界条件的变化，并用于测试当前气候模式重现这种过去天气的能力。地质档案，特别是深海沉积物的稳定、放射性和放射性成因同位素分析是计划进行的研究的主要工具。它们提供了了解地质年代和大量古环境参数的途径，从而了解地球系统在从百万年到现在不等的时间尺度上的“前人类活动改变”状态。利用上述一些同位素示踪剂监测现代环境的补充努力是第二个研究方向，通过国际原子能机构在规划阶段的一个关于“同位素工具评估对大型河流系统水量和水质的人为影响”的项目。在这里，重点将放在麦肯齐河、圣劳伦斯河、环哈德逊湾河和哈德逊海峡河上，这既是为了示踪校准的目的，也是为了记录正在进行的人为与自然驱动的过程，这些过程对土壤侵蚀、径流、沉积物和从陆地到海洋的化学通量有影响。因此，该方案具有基本和与社会相关的目标，并将允许在对北方发展和/或在当前人为压力下评估土壤和水资源具有重要意义的领域培训多达20名研究生或博士后科学家。