Thermal conductivity of Deep Earth&#39;s materials studied by fast pulsed laser techniques

GSTDTAP

项目编号	1520648
	Thermal conductivity of Deep Earth's materials studied by fast pulsed laser techniques
	Alexander Goncharov
主持机构	Carnegie Institution of Washington
项目开始年	2015
	2015-07-01
项目结束日期	2018-06-30
资助机构	US-NSF
项目类别	Continuing grant
项目经费	120029(USD)
国家	美国
语种	英语
英文摘要	Knowledge of thermal conductivity and thermal diffusivity of the Earth's minerals under extreme conditions is important for understanding the physical and chemical processes and their evolution in the Earth. The rate of the heat transport through the mantle is crucial for the existence and stability of the Earth's magnetic field. The temperature distribution inside the Earth's mantle depends on the rate of heat transfer by convection, conduction, and radiation. An understanding of these processes requires knowledge of the thermal conductivity as a function of pressure and temperature. Thermal conductivity of materials in Earth and planetary interiors is one of the key parameters controlling the thermal history of the core and mantle and their dynamics. These are related to the processes of planetary accretion and differentiation, the time evolution of mantle and core temperatures, and the generation of the Earth's magnetic field. In this project, it is proposed to determine the thermal conductivity of the Earth's key minerals under high P-T conditions by using pump-probe pulsed laser techniques. To determine the lattice thermal conductivity, the heat fluxes across the sample and their time history using time- and spatially resolved spectroradiometry and/or time-domain thermoreflectance will be measured. These measurements will be applied to lower mantle minerals and also Fe and Fe-rich alloys. To infer the radiative thermal conductivity, the optical spectra of these mantle minerals in the ultraviolet-to-infrared spectral range at high P-T conditions (up to 150 GPa and 6000 K) will be studied. For in situ high-temperature measurements of the optical properties, broad band optical spectroscopy systems in visible and infrared spectral ranges will be employed which use supercontinuum and nonlinearly mixed pulsed laser sources in combination with time-resolved multichannel detectors (streak camera, intensified CCD, and array MCT detector). These techniques will be applied to study lower mantle minerals, silicate melts, and planetary ices. These experimental data will give a direct estimate of the radiative and conduction parts of the thermal conductivity of deep Earth materials at the relevant P-T conditions. Knowledge of the depth-dependent thermal conductivity of the Earth's mantle will complement recent advances in mantle convection modeling, where a range of possible dynamic structures are predicted depending on the assumed thermal conductivity. Thus, the PI's work will provide a crucial test of these models and our current understanding of the Earth's interior.
来源学科分类	Geosciences - Earth Sciences
文献类型	项目
条目标识符	http://119.78.100.173/C666/handle/2XK7JSWQ/68160
专题	环境与发展全球科技态势
推荐引用方式 GB/T 7714	Alexander Goncharov.Thermal conductivity of Deep Earth's materials studied by fast pulsed laser techniques.2015.