CAREER: Mantle Seismic Structure Beneath North America and Evolving Seismcity in the Raton Basin

职业生涯：北美地幔地震结构和拉顿盆地不断变化的地震活动性这个项目将支持两条研究路线。第一个项目利用了最近和正在进行的由社区驱动的宽带地震数据收集，这些数据系统地覆盖了北美一半以上的地区。第二个重点是拉顿盆地的地震活动，该盆地位于新墨西哥州和科罗拉多州的边界，是天然气生产和废水注入的地区。这两条研究线包括为本科生和研究生提供教育机会，以及开展外联活动，以提高地球科学，特别是地球物理学在阿尔伯克基周围中学的代表性。第一线的研究目标将实现地震调查地幔结构及其影响下的热量和化学对流过程北美，特别是考虑到潜在的证据或反对大量的地球化学水库的水在一个不寻常的层约400？700公里深的地幔过渡带。这一层的性质可以提供新的见解限制地球表面水的演变？的历史和发生的部分熔融作为一个持续的对流的结果。研究的第二条线将涉及在该项目期间在拉顿盆地收集和分析地震数据，以测试地震的空间和时间模式和机制如何对不同的废水注入率、增加的累积注入量和小的自然瞬态应力作出反应。的两个主要研究目标是：1）测试的假设，即地幔过渡带在北美是一个主要的地球化学水库和2）限制的时间依赖于响应的拉顿盆地地震活动的废水注入。这两条研究路线都与增加新墨西哥州学生在中学到研究生院的不同层次参与地球科学研究的教育目标相结合。研究的第一线将使用一套相互依赖的分析EarthScope地震数据，包括映射连续和横向零星的接口，映射接口的锐度和振幅的变化，并限制界面成像的三维速度结构的影响。将通过与矿物物理学家和地球动力学家的合作，对水合转变假说进行定量评估。第二条研究线涉及对拉顿盆地地震活动性的扩展观察和分析，该盆地的地震活动性随着废水注入量的增加而增加。这一组成部分将能够对孕震变形和废水注入之间的反馈进行更高分辨率和更长期的观测。年度类研究项目和本科生实习生将主要进行数据收集和分析，以限制活动断层分布，震源机制，震级分布和对外部触发敏感性的时间变化。在中学一级，许多学生第一次接触到地球科学，基于地点的教育工作将利用Raton Basin和EarthScope数据，提高对地球科学研究的了解，并提高代表性不足的人口对地球科学职业机会的认识。

CAREER: Mantle seismic structure beneath North America and evolving seismicity in the Raton BasinThis project will support two lines of research. The first takes advantage of recent and ongoing community-driven collection of broadband seismic data systematically covering more than half of North America. The second focuses on earthquake activity in the Raton Basin, which is on the New Mexico-Colorado border and an area of natural gas production and wastewater injection. Both lines of research include educational opportunities for undergraduate and graduate students as well as outreach activities to improve the representation of Earth science and particularly geophysics in middle schools around Albuquerque. The goals of the first line of research will be achieved by seismic investigation of mantle structure and its implications for thermal and chemical convection processes beneath North America, with particular consideration of potential evidence for or against a substantial geochemical reservoir of water in an unusual layer about 400?700 km deep referred to as the mantle transition zone. The properties of this layer could provide new insights into limits on the evolution of surface water over Earth?s history and occurrence of partial melting as a result of ongoing convection. The second line of research will involve collection and analysis of seismic data in the Raton Basin over the duration of this project in order to test how spatial and temporal patterns and mechanisms of earthquakes respond to varying wastewater injection rates, increasing cumulative injected volume, and small natural transient stresses.This project?s two main research goals are: 1) to test the hypothesis that the mantle transition zone beneath North America is a major geochemical reservoir of water and 2) constrain the time dependent response of Raton Basin seismicity to wastewater injection. Both lines of research are integrated with the educational goal of increasing participation in geoscience research among the diverse population of New Mexico students at levels ranging from middle school to graduate school. The first line of research will use a suite of interdependent analyses of EarthScope seismic data including mapping of continuous and laterally sporadic interfaces, mapping variations in the sharpness and amplitude of interfaces, and constraining the influence of 3-D velocity structure on interface imaging. Quantitative assessment of the hydrated transition hypothesis will be conducted through collaborations with mineral physicists and geodynamicists. The second line of research involves extended observation and analysis of seismicity in the Raton Basin, which has hosted an increase in seismicity correlated with increased wastewater injection. This component will enable higher resolution and longer-term observations of feedbacks between seismogenic deformation and wastewater injection. Annual class research projects and undergraduate interns will primarily conduct data collection and analysis to constrain temporal variations in the distribution of active faults, source mechanisms, magnitude distribution, and susceptibility to external triggering. Place-based education efforts at the middle school level, where many students first encounter the geosciences, will use Raton Basin and EarthScope data to enhance exposure to geoscience research and awareness of geoscience career opportunities among underrepresented populations.