Measurements of Thermal Conductivity of Deep Earth Minerals

地球深部矿物热导率的测量

• 批准号: 0510914
• 负责人: Abby Kavner
• 金额: $ 21.58万
• 依托单位: University of California-Los Angeles
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-07-01 至 2009-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0510914&HistoricalAwards=false
• 关键词: Measurements; Thermal; Conductivity; Deep; Earth

The heat transport across the core/mantle boundary places the largest constraint on the whole-Earth heat budget, with ramifications for behavior extending well beyond the physical boundary itself-including generation and power of the dynamo-generated magnetic field, timing of inner-core formation, the driving force and style of whole-mantle convection including the surface manifestation of plate tectonics. This experimental study will take advantage of new precision in temperature measurements in the laser heated diamond cell laboratory at UCLA to measure the pressure and temperature dependence of thermal conductivity of important Earth materials (including iron and alloys, silicates and oxides) at temperatures and pressures mirroring the conditions of Earth's deep interior. In the first approach, temperature gradients will be measured for a series samples at high pressures, and best-fit thermal conductivity models will be chosen from diamond cell heat flow models. A second, more "frontiers" approach, will provide a measurement of temperature gradient in two dimensions, which will be used to measure anisotropic thermal diffusivity in natural and engineered laminar composites. Intellectual Merit: The results will be used to help address key scientific questions regarding heat transport in the Earth's deep interior, including (1) What is the heat flow through the core/mantle boundary? (2) Does the Earth's core require an internal source of heating? and (3) Can chemical heterogeneities in the Earth's lowermost mantle contribute to the style of convection through differences in heat flow mechanisms? Broader Impacts: This experimental system is the focal point of a laboratory-based state of the art research and research-training program in mineral physics at UCLA. The measurements performed by this study are a necessary first step required to calibrate and test the PI's laser heating system's ability to accurately and reproducibly measure temperature and associated gradients. The PI is an active member of the NSF-sponsored COnsortium for Mineral Physics Research at High Pressure (COMPRES) community, and innovations in temperature measurement at UCLA will be presented and exported to community facilities where feasible. In addition, the PI is actively involved in formal and informal science education spanning the pre-school through postdoctoral levels.

横跨核心/地幔边界的热传输对整个地球预算构成了最大的约束，行为的影响远远超出了物理边界本身本身，包括发电机生成的磁场的产生和力量，内部核心形成的时机，驱动力和全效方对对流的驱动力和样式，包括平板构造的表面表现。这项实验研究将利用UCLA激光加热的钻石细胞实验室中温度测量的新精度，以测量重要的地球材料（包括铁和合金，硅酸盐，硅酸盐和氧化物）在温度和压力下的压力和温度依赖性，反映了地球深内部的条件。在第一种方法中，将在高压下的串联样品中测量温度梯度，并将从钻石细胞热流模型中选择最合适的热导率模型。 第二种“边界”方法将在二维中提供温度梯度的测量，该温度梯度将用于测量自然和工程层状复合材料中各向异性热扩散率。智力优点：结果将用于帮助解决有关地球深内部热传输的关键科学问题，包括（1）通过核心/地幔边界的热流量是多少？ （2）地球核心是否需要内部加热来源？ （3）地球最低地幔中的化学异质性是否可以通过热流机制的差异来促进对流的风格？更广泛的影响：该实验系统是UCLA矿物质物理学的基于实验室的最先进研究和研究训练计划的焦点。这项研究执行的测量是校准和测试PI激光加热系统准确和可重复测量温度和相关梯度所需的必要第一步。 PI是NSF赞助的高压（Compres）矿产物理研究财团的活跃成员，UCLA温度测量的创新将被介绍并出口到可行的社区设施。此外，PI积极参与正规和非正式的科学教育，这些教育跨越学前班，通过博士后水平。