CAREER: Integrating Seismic Constraints on Continental Upper Mantle

本项目主要利用地震体和地表波对三个克拉通区域进行研究。研究区域包括卡普瓦尔克拉通、北美克拉通东部和怀俄明克拉通。这些地区的区域地震台网，如南部非洲的SASE阵列，加拿大东南部的POLARIS网络，以及怀俄明州和蒙大拿州的USArray网络，为研究提供了丰富的宽带地震数据。项目研究内容包括：(1)在非洲南部、北美东部和怀俄明克拉通进行Rayleigh和Love波反演，确定三维横波速度、方位各向异性和径向各向异性结构；(2)利用横波分裂和面波约束进行正演模拟，确定非洲南部地区端元各向异性模型。(3)建立体波和面波联合反演方法，并将其应用于SASE和POLARIS数据集。本项目构建的高分辨率地震模型将为克拉通岩石圈性质研究提供新的思路，为大陆克拉通动力学过程研究提供新的思路。该项目改进和发展的反演方法可以很容易地应用于USArray和其他区域地震阵列的地震数据。这个职业发展项目的另一个重要组成部分是教育。教育活动包括：(1)为休斯敦大学物理地质学课程的学生提供每学期的地震学研讨会，(2)开发新的研讨会课程和关于大陆克拉通的网站，(3)开发有关反演和表面波概念的网络模块，以及(4)在校园内安装地震仪。这些活动将向广大读者介绍地震地震学，帮助招收地球物理学学生，改善休斯敦大学地球物理学的教学环境，并为社区提供一个关于大陆克拉通的新网络资源。这些教育产品将在网上提供，以便在地球科学界广泛使用。

This project focuses on studying three cratonic regions using seismic body and surface waves. The study areas include the Kaapvaal craton, the eastern part of the North America craton, and the Wyoming craton. Regional seismic networks in these regions, such as the SASE array in southern Africa, the POLARIS network in southeastern Canada, and the USArray in Wyoming and Montana, provide abundant broadband seismic data for the studies. The research components of the project are (1) to perform Rayleigh and Love wave inversions to determine 3-D shear-wave velocity, azimuthal anisotropy, and radial anisotropy structure in southern Africa, eastern North America, and the Wyoming craton, (2) to conduct forward modeling to determine endmember anisotropic models beneath southern Africa using shear-wave splitting and surface wave constraints, (3) to develop a joint inversion method for body and surface waves and apply it to the SASE and the POLARIS data sets. High resolution seismic models constructed from this project will cast new light on properties of cratonic lithosphere and provide new insights into the dynamic process of continental cratons. The inversion methods that are modified and developed in this project can be easily applied to seismic data from the USArray and other regional seismic arrays.Another significant component of this CAREER development project is education. The education activities include (1) offering a seismology workshop for students in the Physical Geology class each semester at the University of Houston, (2) developing a new seminar course and a website about continental cratons, (3) developing web-based modules about inversion and surface wave concepts, and (4) installing a seismograph on campus. These activities will introduce earthquake seismology to a broad audience, help to recruit geophysics students, enhance the teaching and learning environment in geophysics at UH, and provide the community with a new web source about continental cratons. The educational products will be made available online so that they can be widely used in the earth science community.