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.

该研究遵循两个互补的轨道，为有关地球系统科学问题的国际倡议做出贡献：i）气候和海洋的动态，ii）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的未来，重点关注 i）海冰的命运及其对沉积体系的影响，ii）大陆冰的腐烂和径流，iii）它们对大西洋经向翻转环流和全球海平面的影响。过去“温暖”间隔期间的条件、过去和现在间冰期阶段的上新世和热最佳值以及向此类气候最佳值的过渡间隔将被重建并用于识别边界条件的变化并用于测试当前气候模型重现此类过去概要的能力。对地质档案、特别是深海沉积物的稳定、放射性和放射性同位素分析构成了计划研究的主要工具。它们提供了地质时间和大量古环境参数的获取，从而提供了地球系统“人工修改前”的状态，时间尺度从数百万年到现在。利用上述一些同位素示踪剂监测现代环境的补充努力构成了第二个研究轨道，通过国际原子能机构的一个项目，即“用于评估人为对大型河流系统水量和水质影响的同位素工具”的项目，目前处于规划阶段。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，既用于示踪剂校准目的，又用于记录正在进行的人为驱动过程与自然驱动过程对土壤侵蚀、径流、沉积物和从陆地到海洋的化学通量的影响。因此，该计划具有基础知识和社会相关目标，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重要的领域培训最多 20 名研究生或博士后科学家。