Investigating climate controls on weathering processes in modern and ancient river systems

研究现代和古代河流系统中风化过程的气候控制

• 批准号: RGPIN-2019-05709
• 负责人: Bataille, Clement
• 金额: $ 2.19万
• 依托单位: University of Ottawa
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2020
• 资助国家: 加拿大
• 起止时间: 2020-01-01 至 2021-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=715758
• 关键词: Investigating; climate; controls; weathering; processes

The overarching goal of this research program is to better understand and predict the controls of chemical weathering at different spatiotemporal scales. Chemical weathering reactions transfer elements from the continental crust to rivers and to the ocean. This process is key to explaining why the earth is habitable by regulating biogeochemical cycles. For example, when the climate warms, the rate of chemical weathering increases, thereby accelerating the rate of marine carbonate precipitation. Carbonate precipitation consumes atmospheric carbon dioxide (CO2) and cools the climate, ultimately lowering chemical weathering rates. This climate-weathering feedback has allowed the Earth to maintain an active water cycle by keeping temperature within a tight and favorable range. Chemical weathering is also an important process at human timescales. For example, chemical weathering influences soil proprieties (e.g., fertility) and the chemistry of rivers, thereby controlling the sustainability of ecosystems and human societies. Global warming is rapidly changing the background conditions for chemical weathering reactions. Novel studies are urgently needed to investigate the interactions of climate and weathering to better reconstruct the past and forecast the future conditions on the Earth's surface. However, studying weathering is challenging because many geo-environmental variables influence this process. In the next 5 years, my group will work towards my overarching goal by studying the response of weathering to warming at different spatiotemporal scales as defined by the three following short-term goals. Our first goal will investigate how changes in permafrost cover influence weathering across the Yukon River catchment. Our second goal will develop novel paleo-weathering proxies to assess how soils of Laramide floodplains responded to early Paleogene warming trends and events. Our third goal will refine the marine strontium isotope budget at present-day to investigate the changes in weathering between glacial and interglacial periods. The results from this work will have regional implications for policy makers, helping them to improve the sustainability of specific environments (e.g., Yukon River catchment). This program will also advance our knowledge on the role of weathering as a long-term driver of climate, ocean composition and biosphere evolution. This knowledge is crucial to develop more robust Earth system models to reconstruct the past and predict the future of Earth's biogeochemical evolution. This research program will use field and laboratory experience, team work and collaborative multi-disciplinary projects to train 7 BSc, 2 MSc and 3 PhD. Through this training, HQP will improve their soft skills while gaining strong technical knowledge in isotope geochemistry and numerical methods. This program will educate versatile environmental geoscientists capable of managing natural resources in Canada and beyond.

这项研究计划的总体目标是更好地了解和预测在不同的时空尺度的化学风化的控制。 化学风化反应将元素从大陆地壳转移到河流和海洋。这个过程是解释为什么地球是可居住的关键，通过调节地球化学循环。例如，当气候变暖时，化学风化的速度加快，从而加快了海洋碳酸盐沉淀的速度。碳酸盐沉淀消耗大气中的二氧化碳（CO2），冷却气候，最终降低化学风化率。这种气候-风化的反馈使地球能够通过将温度保持在一个紧凑和有利的范围内来保持活跃的水循环。化学风化也是人类时间尺度上的一个重要过程。例如，化学风化影响土壤特性（例如，生态系统的组成（包括土壤肥力）和河流的化学性质，从而控制着生态系统和人类社会的可持续性。全球变暖正在迅速改变化学风化反应的背景条件。迫切需要新的研究来调查气候和风化的相互作用，以更好地重建过去并预测地球表面的未来状况。然而，研究风化是具有挑战性的，因为许多地质环境变量影响这一过程。在接下来的5年里，我的团队将通过研究风化对不同时空尺度变暖的响应来实现我的总体目标，这些时空尺度由以下三个短期目标定义。我们的第一个目标是调查永久冻土覆盖层的变化如何影响育空地区河流域的风化。我们的第二个目标是开发新的古风化代理，以评估土壤Laramide洪泛平原早第三纪变暖趋势和事件的反应。我们的第三个目标是完善现今海洋锶同位素收支，以研究冰期和间冰期之间风化作用的变化。这项工作的结果将对决策者产生区域影响，帮助他们改善特定环境的可持续性（例如，育空地区河流域）。该计划还将推进我们对风化作用的认识，作为气候，海洋组成和生物圈演变的长期驱动力。这些知识对于开发更强大的地球系统模型以重建过去并预测地球生物地球化学演化的未来至关重要。该研究计划将利用现场和实验室经验，团队合作和多学科合作项目，培养7个理学士，2个硕士和3个博士。通过这次培训，HQP将提高他们的软技能，同时获得同位素地球化学和数值方法的强大技术知识。该计划将教育能够管理加拿大及其他地区自然资源的多功能环境地球科学家。