CSEDI: Experimental Constraints on Dynamic Processes in Earth's Core

CSEDI：地核动态过程的实验约束

• 批准号: 0215624
• 负责人: James Van Orman
• 金额: $ 16.25万
• 依托单位: Carnegie Institution of Washington
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-09-01 至 2003-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0215624&HistoricalAwards=false
• 关键词: CSEDI; Experimental; Constraints; Dynamic; Processes

The transport properties of iron alloys are central to the understanding ofdynamic processes in the Earth's core, including convective motions in theouter core (which drive the geodynamo) and solid-state deformation in theinner core, which may be responsible for the observed seismic anisotropy.To better understand these processes the PIs propose to conductexperimental studies of diffusional transport in iron at high pressure (upto 27 GPa). Rates of diffusion of several chemical species (Fe, S, O, andOs) will be measured in both liquid iron and in high-pressure solid phases(fcc and hcp). The experiments will extend to significantly higherpressures than have been examined previously and will provide a more securebasis for extrapolating diffusion rates and diffusion-related properties tothe conditions of the core. The results will lead to a betterunderstanding of inner core rheology and mechanisms for producinganisotropic textures; the viscosity and role of compositional convection inthe outer core; and the spatial distribution of osmium isotopes and otherchemical species within the core.

铁合金的输运特性是理解地核动力学过程的核心，包括外核的对流运动（驱动地球发电机）和内核的固态变形，这可能是观测到的地震各向异性的原因。为了更好地理解这些过程，pi建议在高压（高达27 GPa）下对铁中的扩散输运进行实验研究。几种化学物质（Fe， S， O和do）在液态铁和高压固相（fcc和hcp）中的扩散速率将被测量。实验将扩展到比以前所研究的压力高得多的压力，并将为外推扩散速率和扩散相关特性到核心条件提供更安全的基础。这些结果将有助于更好地理解内核流变学和各向异性织构的产生机制；外核成分对流的黏度及作用；以及核内锇同位素和其他化学物质的空间分布。