A seismic synthesis model for the Eastern North American Continent and its integration with the Western Atlantic upper mantle

北美大陆东部地震综合模型及其与西大西洋上地幔的整合

• 批准号: 1736046
• 负责人: Frederik Simons
• 金额: $ 44.42万
• 依托单位: Princeton University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-09-01 至 2022-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1736046&HistoricalAwards=false
• 关键词: seismic; synthesis; model; Eastern; North

We synthesize over a decade of EarthScope research by investigating the seismic structure of the eastern North American continent to arrive at an understanding of the processes at work in a geodynamic context. We complete the analysis of EarthScope seismic data most recently recorded on the eastern seaboard. In this area of the United States, where a continental passive margin meets oceanic crust, the upper-mantle structure remains complex and in need of robust seismic imaging in order to integrate our understanding of it within a tectonic, structural, geochemical and geodynamic framework. We pair up the structure of the edge of the continent with the mantle regime that underlies the Atlantic, which is host to active mantle dynamics, where the mantle moves down as well as up, and which shows a hint of an as yet incompletely imaged mantle plume. Tightly linked with our effort to image and interpret the seismic structure of the Eastern North American continent, we develop an education plan that brings a taste of EarthScope to Princeton University. Undergraduates will conduct research on the science-quality data continuously acquired by a new campus observatory composed of two seismometers, a weather station and a permanent geodetic beacon. Project "GuyotPhysics"provides educational input, real-world excitement and hands-on experience to a variety of undergraduate and graduate classes, beginning with first-year college students.We exploit the quality of the completed EarthScope seismic data set to maximize our ability to extract mantle discontinuity structure from receiver functions, interrogate these results in the interpretative light of new findings from mineral physics, and combine those with the latest developments in lithospheric tomographic imaging to characterize the eastern portion of the North American continent in terms of seismic wavespeed. We integrate our results with existing models by quantitatively comparing a variety of lithosphere and mantle models to one another, by determining a suitable wavespeed model to serve as the reference within which we embed our receiver-function images, and from which we carry out a last round of tomographic inversions. We develop double-difference data products from EarthScope as a basis for the closure of our tomographic inversion. Inversions carried out in the form of three-dimensional full-waveform elastic adjoint-state tomographic imaging experiments show how our double-difference technique will be able to unearth a meaningful quantity of new structural information from previously imaged regions, while being able to determine the as yet unknown structure in the previously understudied eastern section, starting from the barest and most featureless initial models. Our final synthesis will capture the North American upper mantle without terminating abruptly at the coast. The images will harmonize with models for the oceanic mantle below the western Atlantic.

我们通过调查北美大陆东部的地震结构，综合了十多年来对EarthScope的研究，以达到对地球动力学背景下工作过程的理解。我们完成了对东海岸最近记录的EarthScope地震数据的分析。在美国这个大陆被动边缘与洋壳相遇的地区，上地幔结构仍然复杂，需要强有力的地震成像，以便将我们对它的理解整合到构造、构造、地球化学和地球动力学框架中。我们将大陆边缘的结构与大西洋下面的地幔制度配对，大西洋是活跃的地幔动力学的宿主，地幔在那里既向上移动也向下移动，这表明了一种尚未完全成像的地幔热柱的迹象。与我们成像和解释北美大陆东部地震结构的努力紧密联系在一起，我们制定了一项教育计划，将地球望远镜的味道带到普林斯顿大学。本科生将对由两个地震仪、一个气象站和一个永久大地测量信标组成的新校园天文台连续获得的科学质量数据进行研究。我们利用完整的EarthScope地震数据集的质量，最大限度地利用我们从接收器函数提取地幔不连续结构的能力，根据矿物物理的新发现来解释这些结果，并将这些结果与岩石圈层析成像的最新发展相结合，以从地震波速度的角度描述北美大陆东部的特征。我们通过定量比较各种岩石圈和地幔模型，确定一个合适的波速模型作为参考，将我们的接收函数图像嵌入其中，并从该模型进行最后一轮层析反演，从而将我们的结果与现有模型相结合。我们开发了来自EarthScope的双差数据产品，作为结束我们的层析反演的基础。以三维全波形弹性伴随状态层析成像实验的形式进行的反演表明，我们的双差分技术将如何能够从先前成像的区域中挖掘出有意义的新的构造信息，同时能够从最简单和最没有特征的初始模型开始确定先前未被研究的东部部分中的未知结构。我们的最终合成将捕获北美上地幔，而不会突然终止于海岸。这些图像将与西大西洋下方的海洋地幔模型相一致。

项目成果

Instrument Response Removal and the 2020 MLg 3.1 Marlboro, New Jersey, Earthquake

仪器响应消除和 2020 年 MLg 3.1 万宝路，新泽西州，地震

• DOI: 10.1785/0220210118
• 发表时间: 2021
• 期刊: Seismological Research Letters
• 影响因子: 3.3
• 作者: Burky, Alexander L.;Irving, Jessica C.;Simons, Frederik J.
• 通讯作者: Simons, Frederik J.

Inferring Earth’s discontinuous chemical layering from the 660-kilometer boundary topography

• DOI: 10.1126/science.aav0822
• 发表时间: 2019-02
• 期刊: Science
• 影响因子: 56.9
• 作者: Wenbo Wu;S. Ni;J. Irving

Mantle Transition Zone Receiver Functions for Bermuda: Automation, Quality Control, and Interpretation

• DOI: 10.1029/2020jb020177
• 发表时间: 2021-03-01
• 期刊: JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
• 影响因子: 3.9
• 作者: Burky, Alexander L.;Irving, Jessica C. E.;Simons, Frederik J.
• 通讯作者: Simons, Frederik J.