CAREER: Estimating Temperature and Water Content of the North American Mantle from Geophysical Observations

这个项目研究地幔温度和氢含量在地球动力学和板块构造中的作用。研究产品将用于幼儿园到研究生的激励和教育。为此目的开发的工具将反过来用于研究人员探索研究产品，并创建学生的研究项目。地幔中的对流模式，以及它们如何与构造板块运动和变形耦合，由粘度的空间变化指导。地幔温度和氢含量是影响粘度的主要参数。高温会降低粘度。从水中获得的含氢百分比很小的矿物，也比纯地幔矿物的粘性要小得多。这两个参数可以通过地球物理观测，特别是地震观测的组合来估计。地震图提供了证据，或反对减少地震S波速度和相关的刚度，异常泊松比，偏移和改变地幔不连续性在北美。这些观测值受这两个参数的影响不同，将同时用于估计地幔温度和氢含量。这项工作将得到观测重力、推断衰减、捕虏体分析和测量热流的帮助。拟议的研究是协同与Earthscope -一个长期的国家地球科学设施在美国。教学组件是围绕一个亭，将有三个互动组件，在广泛的教育水平和环境有用。互动将以上述研究成果为中心。拟议的教学利用了研究产品强大的视觉方面，并与拟议的研究相结合，因为1）研究产品用于使K-12儿童接触地球科学，2）研究助理将促进K-12和本科生的信息亭，从而在教学和公共交流方面得到培训，（4）在资讯站与不同层次的观众互动，有助引导研究工作;及（5）为教育外展资讯站开发的互动工具&，将用于探讨和解释研究产品。研究产品是三维地震模型和北美洲地幔温度和氢含量的衍生模型。

This project examines the roles of mantle temperature and hydrogen content in geodynamics and plate tectonics. Research products will be used for stimulation and education of kindergarten through graduate students. Tools developed for this purpose will be used in turn to have researchers explore the research products and to create student research projects.Convection patterns in the Earth's mantle, and how they couple with tectonic plate motion and deformation, are directed by spatial variations in viscosity. Mantle temperature and hydrogen content are principal parameters affecting viscosity. High temperatures will lower viscosity. Minerals with small percentages of hydrogen, obtained from water, are also significantly less viscous than pure mantle minerals. These two parameters can be estimated from a combination of geophysical, in particular seismological observations. Seismograms provide evidence for or against reduced seismic S-wave velocity and associated rigidity, anomalous Poisson ratios, and offset and altered mantle discontinuities beneath North America. These observables are affected differently by the two parameters and will be used simultaneously to estimate mantle temperature and hydrogen content. This effort will be aided by observed gravity, inferred attenuation, xenolith analyses, and measured heat flow. The proposed research is synergistic with Earthscope - a long-term national Earth Sciences facility in the United States.Teaching components are centered around a kiosk that will have three interactive components, useful at a wide range of educational levels and environments. The interaction will be centered around the products of the research summarized above. The proposed teaching capitalizes on the strong visual facets of the research products and integrates with the proposed research because 1) the research products are used to expose K-12 children hands-on and eyes-open to Earth Science, 2) the research assistants that will facilitate the kiosk to K-12 and undergraduate students are thus trained in teaching and public communication, 4) the interactions with the multi-level audience at the kiosks could help steer research, and 5) the interactive tool developed for the education & outreach kiosk will be used to explore and interpret the research products. Research products are three-dimensional seismic models and derivative models for temperature and hydrogen content in the mantle under North America.