CAREER: Investigating composition and rheology of circum-Pacific mantle wedges with body-wave attenuation

地震观测帮助我们了解俯冲带的地质过程，在那里发生了大型逆冲地震，并形成了大多数火山。地震学家通常通过测量在岩石中传播的地震波来探测地球的温度、成分和其他性质。然而，俯冲过程的许多细节仍然未知，部分原因是解释这些速度测量有时是模棱两可的。地震衰减测量地震波在穿过地球时如何损失能量，这些测量可能有助于减少我们在观测和解释地震信号时的一些不确定性。特别是，通过结合速度和衰减测量，该项目有可能探测与火山和地震形成有关的岩浆、水和氧气。该项目将地震衰减研究与教育计划相结合，为密歇根州立大学（MSU）培养多样化的地球物理人才。这项工作有助于解决构造、地震和火山等具有重大挑战性的科学问题，这些问题在美国国家科学院、工程院和医学院的《地球时代》报告中得到了强调。主要研究目标是在区域和全球尺度上进行一系列衰减研究。该项目将对太平洋周围多个俯冲带的衰减结构进行成像，其中三个重点地点为汤加、阿拉斯加和南美俯冲带的Pampean平板段。这些系统的调查将促进我们对地震解释、上地幔动力学、俯冲过程和地球内部物质循环的理解。该项目的教育部分提高了STEM学生对地球物理学作为一个研究领域的认识。该项目将与密歇根州立大学科学剧院（一个本科生组织）合作，开发几个用于校园和当地小学的地球物理演示。其次，PI将开发初级模块课程，为地球科学学生提供急需的定量技能。第三，本项目还将为本科生和研究生提供研究机会。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Seismic observations help us understand the geological processes in subduction zones, where megathrust earthquakes occur and most volcanoes form. Seismologists usually measure seismic waves propagating in rocks to probe the temperature, composition, and other properties of the Earth. Yet many details of the subduction processes remain unknown partly because interpreting these velocity measurement are sometimes ambiguous. Seismic attenuation measures how a seismic wave loses energy as it moves through the Earth, and these measurements may help to reduce some of the uncertainties we have in observing and interpreting seismic signals. In particular, by combining velocity and attenuation measurements this project has the potential for detecting magma, water, and oxygen associated with the formation of volcanoes and earthquakes. This project will integrate research in seismic attenuation with an education plan that will develop a diverse geophysics workforce at Michigan State University (MSU). This work helps to address grand challenge science questions about tectonics, earthquakes and volcanoes highlighted in the Earth in Time report from the National Academies of Science, Engineering, and Medicine. The primary research goal is to conduct a series of attenuation studies on regional and global scales. The project will image the attenuation structure of multiple subduction zones surrounding the Pacific Ocean, with three focus sites of Tonga, Alaska, and the Pampean flat slab segment of the South American subduction zone. These systematic investigations will advance our understanding of seismic interpretation, upper-mantle dynamics, subduction processes, and material recycling in the Earth’s interior. The education component of this project raises awareness of geophysics as an area of study for students in STEM. This project will work with the MSU Science Theatre, an undergraduate student organization, develop several geophysics demonstrations for use on campus and at local elementary schools. Second, the PI will develop a junior-level modular course to prepare geoscience students with much-needed quantitative skills. Third, this project will also provide research opportunities for undergraduate and graduate students.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.