Collabortive Research: Elasticity Grand Challenge of the COMPRES Initiative

矿物的弹性测量是观测到的地球地震速度结构与地球深部性质（如化学成分和温度）之间的桥梁。 矿物物理学界准备进行新一代实验，这将使我们能够准确地确定在新的压力和温度（P-T）条件下深地物质的性质。 我们将开展协调一致的多机构努力，开发先进的实验和理论技术，以确定地球材料的声速和弹性模量。 我们将建立在目前的技术，利用光散射和超声方法，并充分利用同步辐射设施的同时表征。 我们将寻求利用非弹性X射线散射或千兆赫超声波的新方法来扩展当前的能力。 我们将把理论方法与实验方法紧密结合起来。 使用多种技术，包括理论计算，我们将集中精力确定橄榄石及其高压多晶型物在高P-T条件下的弹性性质，以及用于高P-T校准的标准材料（例如，Pt、Au、MgO、NACI）。 样品将在一个中心社区设施进行合成。 通过实验室间的交叉检查和与理论的比较，将提高每种技术的准确性。 这种协作方法将大大推进高压地球物理学技术，并将社区努力集中在准确确定最重要的地幔相的弹性特性上。 这些结果将反过来被用来阐明我们对地幔成分和热结构的看法。

WentzcovitchEAR-0135533Elasticity measurements on minerals are the bridge between the observed seismic velocity structure of the Earth and properties of the Earth at depth, such as chemical composition and temperature. The mineral physics community is poised to undertake a new generation of experiments, which will allow us to accurately determine the properties of deep-Earth materials under a new regime of pressure and temperature (P-T) conditions. We will undertake a coordinated, multi-institutional effort to develop advanced experimental and theoretical techniques for determining sound velocities and elastic moduli on Earth materials. We will build on the current technology that utilizes light scattering and ultrasonic methods and exploit the full use of synchrotron radiation facilities for simultaneous characterization. We will pursue new methodologies utilizing inelastic x-ray scattering or gigahertz ultrasonics to expand the current capabilities. We will closely integrate theoretical approaches with the experimental to ground-truth both. Using multiple techniques, including theoretical calculations, we will focus our efforts on determining the elastic properties of olivine and its high-pressure polymorphs under high P-T conditions, and standard materials for high P-T calibrations (e.g., Pt, Au, MgO, NACI). Samples will be synthesized at a central community facility. The accuracy of each technique will be improved through inter-laboratory cross-checks and comparison with theory. This collaborative approach will greatly advance the technology of high pressure geophysics, and focus a community effort on accurate determination of the elastic properties of the most important mantle phases. These results will, in turn, be used to clarify our view of mantle composition and thermal structure.