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来综合十多年的EarthScope研究，以了解地球动力学背景下的工作过程。我们完成了对东海岸最近记录的EarthScope地震数据的分析。在美国的这一地区，大陆被动边缘与大洋地壳相遇，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纳入构造、结构、地球化学和地球动力学框架。我们将大陆边缘的结构与大西洋下的地幔体系配对，大西洋是活跃的地幔动力学的宿主，地幔在那里向下移动和向上移动，并显示出一个尚未完全成像的地幔柱的暗示。与我们的努力，以图像和解释北美大陆东部的地震结构紧密相连，我们开发了一个教育计划，带来了地球镜普林斯顿大学的味道。本科生将对由两个地震仪、一个气象站和一个永久性大地信标组成的新校园观测站连续获得的科学质量数据进行研究。“GuyotPhysics“项目为各种本科生和研究生班提供教育投入、真实世界的兴奋和实践经验，从大学一年级学生开始。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器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，联合收割机与岩石圈层析成像的最新发展相结合，以地震波速度表征北美大陆东部。我们将我们的结果与现有的模型定量比较各种岩石圈和地幔模型，通过确定一个合适的波速模型作为参考，我们嵌入我们的接收器功能的图像，并从我们进行了最后一轮的层析反演。我们开发的双差数据产品从EarthScope的基础上关闭我们的层析反演。反演进行的三维全波形弹性伴随态层析成像实验的形式表明，我们的双差技术将能够从先前成像的区域中挖掘出有意义的新结构信息量，同时能够从最裸露和最无特征的初始模型开始，确定在先前未充分研究的东段中的未知结构。我们最后的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.