CAREER: Seismic Imaging of Large-Scale Structure in the Lithosphere and the Core-Mantle Boundary Region

职业：岩石圈和核幔边界区域大尺度结构的地震成像

• 批准号: 1352214
• 负责人: Vedran Lekic
• 金额: $ 64.7万
• 依托单位: University of Maryland, College Park
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-07-01 至 2020-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1352214&HistoricalAwards=false
• 关键词: CAREER; Seismic; Imaging; Large; Scale

I propose to obtain new constraints on the structure of the continental lithosphere and the core-mantle boundary region, with the goal of improving our understanding of the formation, evolution, and preservation of large-scale structures within the mantle. Accomplishing this goal will require improving on existing and developing new methods for modeling and analyzing seismic waveforms, and will have implications for the understanding of the dynamics of the Earth's deep interior and its relationship to the surface. The scientific questions to be addressed are: 1. What is the nature of the mid-lithospheric discontinuity and what does it tell us about the architecture, origin, and evolution of stable continental lithosphere? 2. What processes control the development of rifts in general, and strain localization throughout the lithosphere? 3. What are the morphology, and elastic characteristics of mesoscale structures in the lowermost mantle? The improved seismic imaging methods will be built around flexible and parsimonious parameterizations that can also reproduce the various ways in which seismic waves interact with geological structures. The proposed work also includes developing automated computational algorithms for analyzing and modeling seismic data, determining optimal weighting of different datasets, and identifying new seismic observables. Alongside this research project, I propose to undertake a comprehensive educational project called SeismoABCs (Seismology Across and Beyond Classrooms), whose purpose is to improve undergraduate education and learning outcomes through the incorporation of seismological instrument deployment, data collection and analysis across the undergraduate curriculum at the Department of Geology of the University of Maryland, College Park.The proposed work will develop and apply new methods for imaging the Earth's interior using multiple seismic datasets. It will focus on providing new images of and constraining structures in two distinct settings: the continental lithosphere, which makes up the tectonic plates and controls the internal deformation in continents, and the core-mantle boundary region, which contains exotic features fundamentally related to the dynamics and thermo-chemical evolution of the Earth. The new methods developed as part of the proposed work will be broadly applicable to any discipline confronted with the problem of combining different pieces of information in order to constrain characteristics of a system or object. The SeismoABCs educational component of the proposed work will have substantial broader impacts for undergraduate education at the University of Maryland. SeismoABCs is a plan to (A) incorporate the conceptualization, design, execution, and analysis of seismological experiments across classrooms in geophysics and related sciences, and (B) to enable research experiences in seismology beyond classrooms by scaling up undergraduate participation in seismological research. The desired learning outcomes of SeismoABCs include improving student's ability to formulate clear and testable research questions / hypotheses, identify relevant seismological observations, design a geophysical network to collect calibrated observations, process and analyze data in a statistically rigorous way in order to accept or reject their research hypothesis, and engage in long term research projects. The SeismoABCs program will also furnish graduate students and postdoctoral fellows with experience in mentoring students and designing and implementing a research plan. Finally, the undergraduate seismological laboratory research experiences implemented as part of this program will be targeted toward first and second year undergraduate students, and will help improve their academic achievement across STEM disciplines by providing them with real-world applications of the quantitative methods taught in the classroom setting.

我建议获得对大陆岩石圈和核幔边界区域结构的新约束，目的是提高我们对地幔内大型结构的形成、演化和保存的认识。实现这一目标需要改进现有的和开发新的地震波形建模和分析方法，并将对理解地球深处的动力学及其与地表的关系产生影响。需要解决的科学问题是： 1. 岩石圈中部不连续面的本质是什么？它告诉我们关于稳定大陆岩石圈的结构、起源和演化的什么信息？ 2. 一般而言，什么过程控制裂谷的发展以及整个岩石圈的应变局部化？ 3. 下地幔中尺度结构的形态和弹性特征是什么？改进的地震成像方法将围绕灵活且简约的参数化构建，这些参数化还可以重现地震波与地质结构相互作用的各种方式。拟议的工作还包括开发用于分析和建模地震数据的自动化计算算法，确定不同数据集的最佳权重，以及识别新的地震可观测值。除了这个研究项目之外，我还建议开展一个名为 SeismoABCs（课堂之外的地震学）的综合教育项目，其目的是通过将地震仪器部署、数据收集和分析纳入本科课程，提高本科教育和学习成果。马里兰大学帕克分校地质系。拟议的工作将开发和应用使用多个地震数据集对地球内部进行成像的新方法。它将侧重于在两个不同的背景下提供新的图像和约束结构：大陆岩石圈，它构成构造板块并控制大陆的内部变形，以及核-地幔边界区域，它包含与地壳基本相关的奇异特征。地球动力学和热化学演化。作为拟议工作的一部分开发的新方法将广泛适用于面临组合不同信息以限制系统或对象特征的问题的任何学科。拟议工作中的 SeismoABC 教育部分将对马里兰大学的本科教育产生更广泛的影响。 SeismoABCs 是一项计划，旨在 (A) 将地震实验的概念化、设计、执行和分析纳入地球物理学和相关科学的课堂中，(B) 通过扩大本科生对地震研究的参与，在课堂之外提供地震学研究经验。 SeismoABC 的预期学习成果包括提高学生提出清晰且可测试的研究问题/假设的能力，识别相关的地震观测结果，设计地球物理网络来收集校准观测结果，以统计上严格的方式处理和分析数据，以便接受或拒绝他们的研究结果。研究假设，并从事长期研究项目。 SeismoABCs 项目还将为研究生和博士后提供指导学生以及设计和实施研究计划的经验。最后，作为该计划的一部分实施的本科生地震实验室研究经验将针对一年级和二年级本科生，并将通过为他们提供课程中教授的定量方法的实际应用来帮助提高他们在 STEM 学科的学术成就。课堂设置。