Water in the Earth's lower mantle

地球下地幔中的水

• 批准号: 2242946
• 负责人: Jie Deng
• 金额: $ 44.27万
• 依托单位: Princeton University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-05-01 至 2026-04-30
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2242946&HistoricalAwards=false
• 关键词: Water; Earth; lower; mantle

The most vital component of the Earth is water. It is not only the source of life, but also the key ingredient controlling a wide range of solid earth processes, such as the operation of plate tectonics, the formation of volcanoes, and the emergence of continents. Plate tectonics and volcanic eruptions lead to the active exchange of surface water and interior water, regulating the variation of ocean volumes and continent areas throughout the Earth’s history. Despite its importance, in present-day the Earth’s surface water accounts for only 0.02 percent of the planet’s total mass. Most of the Earth’s water is instead thought to be present in the Earth’s deep interior, but the exact amount of water stored in the Earth’s interior remains largely unknown. This proposal will rigorously study the water solubility in bridgmanite, the most abundant material of the deep mantle. This will be accomplished by using large-scale computer simulations of bridgmanite and fluid in coexistence, using the latest innovations in machine learning. The calculations will be referenced to results derived from high-precision calculations based in quantum mechanics. This work will support the training of graduate students in cutting-edge computational techniques using high-performance computing centers. Water solubility in the mantle is a fundamental material property that quantifies the maximum amount of water that can be hosted within the Earth. Large-scale two-phase simulations of bridgmanite and fluid coexistence driven by machine learning potentials of ab initio quality will be carried out to rigorously study the water solubility in bridgmanite. These simulations will reveal: 1) the solubility of water in bridgmanite and the effects of Fe and Al across the entire lower mantle; 2) the hydrogen incorporation mechanisms as a function of pressures, temperatures, and bulk chemistry; 3) the bridgmanite-water (pseudo)-binary phase diagrams; and 4) the evolutionary history of the water storage capacity of the lower mantle over the past 4.5 billion years. This project is co-funded by the Directorate for Geosciences to support AI/ML advancement in the geosciences.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

地球最重要的组成部分是水。它不仅是生命的源泉，而且是控制广泛的固体地球过程的关键成分，例如板块构造的运作，火山的形成和大陆的出现。板块构造和火山爆发导致地表水和内部水的活跃交换，调节了整个地球历史上海洋体积和大陆面积的变化。尽管它的重要性，在今天的地球表面水只占地球总质量的0.02%。地球上大部分的水被认为存在于地球的内部深处，但地球内部储存的确切水量仍然是未知的。这项提议将严格研究深地幔中最丰富的材料-硼镁石的水溶性。这将通过使用大规模计算机模拟bridgmanite和流体共存，使用机器学习的最新创新来实现。计算将参考基于量子力学的高精度计算得出的结果。这项工作将支持使用高性能计算中心对研究生进行尖端计算技术的培训。水在地幔中的溶解度是一个基本的物质属性，它量化了地球内部可以容纳的最大水量。将进行由从头算质量的机器学习潜力驱动的bridgmanite和流体共存的大规模两相模拟，以严格研究bridgmanite中的水溶性。这些模拟将揭示：1）水在硼镁石中的溶解度以及Fe和Al在整个下地幔中的作用; 2）作为压力、温度和体化学的函数的氢结合机制; 3）硼镁石-水（伪）-二元相图; 4）过去45亿年来下地幔水储存能力的演化历史。该项目由地球科学理事会共同资助，旨在支持AI/ML在地球科学领域的进步。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。