Geophysics of Iron in the Earth's Core

地核铁的地球物理学

• 批准号: 1446969
• 负责人: Wendy Mao
• 金额: $ 33.01万
• 依托单位: Stanford University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-01-01 至 2019-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1446969&HistoricalAwards=false
• 关键词: Geophysics; Iron; Earth; Core

Located nearly 3000 km below the crust, the core represents the most remote region within our planet. Seismology and geodynamics have provided detailed descriptions of the core and its central role in the Earth's evolution and its dynamic processes. Determining the high pressure-temperature behavior of iron and iron-rich compounds and alloys is an important but challenging area of research which is integral for gaining insight into the Earth's core. The PI proposes to conduct laboratory experiments that simulate the high pressures and temperatures that exist in the Earth's deep interior and measure the properties of iron-rich materials which can be dramatically altered at extreme conditions. The primary goal of the present research is thus to understand the Earth's core, which plays a central role in the magnetism, dynamic processes, and thermal evolution of our planet. The anticipated, high pressure-temperature data on iron and iron-rich compounds will be valuable to a wide variety of researchers involved in deep Earth studies (e.g. theoretical mineral physicists for improving their calculations, seismologists for interpretation of their observations, and geodynamicists for constraining their models). In addition, the technical advances will be useful to other experimentalists in the geosciences as well as fundamental and applied sciences.The central theme of this renewal proposal is to continue to improve our understanding of the high pressure-temperature shear properties and strength of iron and iron-rich compounds and alloys through a two-pronged approach, specifically by conducting both static and dynamic compression experiments. The first direction will build on the team's progress with diamond anvil cell measurements coupled with multiple synchrotron x-ray techniques to investigate the aggregate sound velocities and strength of iron and iron-rich compounds and alloys at high pressures and temperatures. The second approach is focused on reaching core conditions via laser-driven shock experiments and developing diagnostics to study the shear properties and dynamic behavior of iron and iron-rich compounds and alloys. The combination of the static and dynamic results will provide important information for helping to understand and interpret the complex seismic signatures in the Earth's core. The static and dynamic experimental measurements on the shear properties of Fe and Fe-rich compounds and alloys represent a valuable data set for many other deep Earth researchers. They provide comparisons for interpreting seismic observations of sound velocities in the core. Geodynamicists can potentially use the results for testing hypotheses on the geodynamo and crystallization/melting processes. The team's experimental data will also provide a useful constraint and comparison for theoretical mineral physics.

地核位于地壳以下近3000公里处，是地球上最偏远的地区。地震学和地球动力学提供了关于地核及其在地球演化和动力过程中的中心作用的详细描述。确定铁和富铁化合物和合金的高压-温度行为是一个重要但具有挑战性的研究领域，对于深入了解地球核心是不可或缺的。 PI建议进行实验室实验，模拟地球内部深处存在的高压和高温，并测量在极端条件下可能发生巨大变化的富铁材料的性质。 因此，目前研究的主要目标是了解地球的核心，它在我们星球的磁性，动力学过程和热演化中起着核心作用。关于铁和富铁化合物的预期的高压-温度数据将对参与地球深部研究的各种研究人员有价值（例如，理论矿物物理学家用于改进他们的计算，地震学家用于解释他们的观察结果，地球动力学家用于限制他们的模型）。此外，这些技术进步将对地球科学、基础科学和应用科学的其他实验工作者有用。这一更新建议的中心主题是通过双管齐下的方法，特别是通过进行静态和动态压缩实验，继续提高我们对铁和富铁化合物和合金的高压-温度剪切特性和强度的认识。第一个方向将建立在该团队的进展与金刚石砧室测量加上多个同步加速器x射线技术，以调查在高压和高温下铁和富铁化合物和合金的总声速和强度。 第二种方法的重点是通过激光驱动冲击实验达到核心条件，并开发诊断方法，以研究铁和富铁化合物和合金的剪切特性和动态行为。静态和动态结果的结合将为帮助理解和解释地核中复杂的地震特征提供重要信息。铁和富铁化合物和合金的剪切性质的静态和动态实验测量为许多其他深地球研究人员提供了有价值的数据集。它们提供了解释地震观测的核心声速的比较。 地球动力学家可以潜在地使用这些结果来测试关于地球发电机和结晶/熔融过程的假设。该团队的实验数据也将为理论矿物物理学提供有用的约束和比较。