The upper mantle structure of southern Africa using full-waveform tomography from long-period ambient noise and earthquake data

Erica Emry博士在宾夕法尼亚州立大学和罗德岛大学期间获得了美国国家科学基金会地球科学博士后奖学金，以开展研究并扩大未被充分代表的少数民族在地球科学领域的参与。她将利用新的全波地震层析成像技术对环境噪声和地震数据进行研究，研究非洲下地幔的结构。她将通过创建整个南部非洲的上地幔剪切速度概览图来解决非洲地幔动力学及其对地表过程的影响的问题，重点是东非裂谷系统（EARS）和太古宙克拉通。特别是，她将重点对非洲地幔中三个未解决的区域进行成像，并回答以下问题，这将有助于阐明地幔流动、克拉通岩石圈和地表过程之间的关系：1)刚果克拉通的深度和横向范围是多少？2)东非和埃塞俄比亚的低速带是否在图尔卡纳坳陷相连？3)阿法尔热点的深度和横向范围是多少？与位于埃塞俄比亚主裂谷（MER）或阿法尔坳陷下方的阿法尔热点相关的最慢的上地幔异常是什么？这个项目的结果将有助于更大范围的非洲地质和构造学界，以及当前的研究项目，如美国国家科学基金会地质研究所的裂谷形成和演化（RIE）项目。南部非洲地下上地幔结构的最终结果将在网上免费提供，供其他地球物理和地球科学研究使用（http://www.iris.edu/dms/products/emc/）。作为该提案的一部分，Emry博士将扩展非洲阵列多样性计划，担任2014年和2015年夏季地球物理实地课程的主要讲师。这门由宾夕法尼亚州立大学和威特沃特斯兰德大学合办的课程将来自少数民族院校的本科生带到宾夕法尼亚州立大学和南非学习地球物理野外技术和南非地质学。除了实地课程，她还将继续在每月的在线网络研讨会上指导来自非洲阵列多样性项目的学生，向他们介绍新的研究，并讨论地球科学领域的职业。此外，在每个学年，她将为来自非洲阵列多样性项目的学生提供建议，这些学生有兴趣完成一篇关于非洲构造或地震学的高级论文。

Dr. Erica Emry has been awarded an NSF Earth Sciences Postdoctoral Fellowship to carry out research and to broaden participation of underrepresented minorities in the Earth Sciences while at The Pennsylvania State University and The University of Rhode Island. She will investigate the structure of the upper mantle beneath Africa using new full-wave seismic tomography techniques on ambient noise and earthquake data. She will address questions of African mantle dynamics and their impact on surface processes by creating a synoptic map of the upper mantle shear velocities throughout southern Africa, focusing on the East African Rift system (EARS) and the Archean cratons. In particular, she will focus on imaging three unresolved regions in the African mantle and answering the following questions that will help to elucidate the relationships between mantle flow, cratonic lithosphere and surface processes: 1) What is the depth and lateral extent of the Congo craton? 2) Are the East African and Ethiopian low velocity zones connected at the Turkana Depression? 3) What is the depth and lateral extent of the Afar hotspot, and are the slowest upper mantle anomalies associated with the Afar hotspot located beneath the Main Ethiopian Rift (MER) or the Afar Depression? Results from this project will contribute to the larger African geology and tectonics community and current research initiatives such as the NSF GeoPRISMs Rift Initiation and Evolution (RIE) program. The finalized results of upper mantle structure beneath southern Africa will be made freely available online for use in other geophysics and earth science research (http://www.iris.edu/dms/products/emc/). As part of this proposal, Dr. Emry will expand upon the Africa Array diversity program, acting as primary instructor for the summer geophysics field course in 2014 and 2015. This course run by Penn State and the University of Witwatersrand brings undergraduate students from minority-serving institutions to Penn State and South Africa to learn geophysical field techniques and South African geology. In addition to the field course, she will continue to mentor students from the Africa Array diversity program on a monthly basis during online webinars, by introducing them to new research, and by discussing careers in the geosciences. Furthermore, during each school year, she will advise students from the Africa Array diversity program who are interested in completing a senior thesis focused on African tectonics or seismology.