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

我们通过调查北美大陆东部的地震结构，综合了十多年来EarthScope的研究，以了解在地球动力学背景下工作的过程。我们完成了对最近在东海岸记录的地球范围地震数据的分析。在美国这个大陆被动边缘与海洋地壳交汇的地区，上地幔结构仍然很复杂，需要强大的地震成像，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结构配对，大西洋是活跃的地幔动力学的主体，在那里地幔向下和向上移动，这显示了一个尚未完全成像的地幔柱的暗示。与我们努力成像和解释北美东部大陆的地震结构紧密相连，我们制定了一项教育计划，将地球范围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不断获得的科学质量数据进行研究。“GuyotPhysics”项目从大学一年级学生开始，为各种本科生和研究生班级提供教育投入、现实世界的兴奋和实践经验。我们利用已完成的EarthScope地震数据集的质量，最大限度地提高我们从接收函数中提取地幔不连续结构的能力，根据矿物物理学的新发现对这些结果进行解释，并将这些结果与岩石圈层析成像的最新发展相结合，以地震波速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，确定合适的波速模型作为参考，将我们的结果与现有模型相结合，在此基础上嵌入接收器函数图像，并进行最后一轮层析反演。我们开发了EarthScope的双差数据产品，作为完成层析反演的基础。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，我们的双差技术将如何能够从先前成像的区域中挖掘出大量有意义的新结构信息，同时能够从最原始和最无特征的初始模型开始，确定先前未充分研究的东部剖面中未知的结构。我们最后的合成将捕捉到北美的上地幔而不会突然终止于海岸。这些图像将与西大西洋以下的海洋地幔模型相协调。

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.