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.

我建议获得关于大陆岩石圈和核幔边界区域结构的新约束，以提高我们对地幔内部大型结构的形成、演化和保存的理解。实现这一目标将需要改进现有的和开发新的地震波形建模和分析方法，并将对理解地球深层内部的动力学及其与地表的关系产生影响。要解决的科学问题有：1。岩石圈中部不连续性的本质是什么？它对稳定的大陆岩石圈的结构、起源和演化有什么启示？2. 一般来说，是什么过程控制着裂谷的发育，以及整个岩石圈的应变定位？3. 最底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和简洁的参数化建立，这些参数化也可以再现地震波与地质结构相互作用的各种方式。建议的工作还包括开发用于分析和建模地震数据的自动计算算法，确定不同数据集的最佳权重，以及识别新的地震观测值。除了这个研究项目，我还提议开展一个名为seismoabc（地震学跨教室和超越教室）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马里兰大学帕克分校地质系的本科课程，改善本科教育和学习成果。拟议的工作将开发和应用使用多个地震数据集成像地球内部的新方法。它将专注于在两个不同的环境中提供新的图像和约束结构：组成构造板块并控制大陆内部变形的大陆岩石圈，以及包含与地球动力学和热化学演化基本相关的外来特征的核心-地幔边界区域。作为提议工作的一部分开发的新方法将广泛适用于任何学科，这些学科面临着将不同的信息片段组合在一起以约束系统或对象的特征的问题。拟议工作的seismoabc教育部分将对马里兰大学的本科教育产生重大而广泛的影响。seismoabc计划(a)将地震实验的概念、设计、执行和分析整合到地球物理和相关科学的课堂中，以及(B)通过扩大大学生对地震研究的参与，使地震学的研究经验超越课堂。seismoabc课程期望的学习成果包括提高学生提出明确和可测试的研究问题/假设的能力，识别相关的地震观测，设计一个地球物理网络来收集校准观测，以统计严谨的方式处理和分析数据以接受或拒绝他们的研究假设，以及从事长期的研究项目。seismoabc项目还将为研究生和博士后提供指导学生、设计和实施研究计划的经验。最后，作为该项目一部分实施的本科生地震学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堂上教授的定量方法的实际应用，帮助他们提高STEM学科的学术成就。