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

本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。研究成果将通过研究生用于幼儿园的激励和教育。为此目的开发的工具将依次用于研究人员探索研究产品并创建学生研究项目。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，是由粘度的空间变化指导的。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。从水中获得的含有少量氢的矿物，黏性也明显低于纯地幔矿物。这两个参数可以通过地球物理，特别是地震学观测的组合来估计。地震记录提供了支持或反对地震s波速度降低和相关刚度、异常泊松比以及北美地下偏移和蚀变的地幔不连续的证据。这些观测值受到这两个参数的不同影响，将同时用于估计地幔温度和氢含量。这项工作将通过观测重力、推断衰减、捕虏体分析和测量热流来辅助。拟议的研究是与美国长期的国家地球科学设施Earthscope协同作用的。教学组件围绕着一个亭子，亭子将有三个互动组件，在广泛的教育水平和环境中有用。互动将围绕上述总结的研究成果展开。拟议的教学利用了研究产品的强大视觉方面，并与拟议的研究相结合，因为1)研究产品用于向K-12儿童展示动手和开阔视野的地球科学，2)研究助理将促进K-12学生和本科生的教学和公共沟通，4)与亭内多层次观众的互动可以帮助引导研究。5)为教育外展亭开发的互动工具将用于探索和解释研究成果。研究成果是北美地幔温度和氢含量的三维地震模型和衍生模型。

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.