Seismic imaging of crust-mantle interaction

控制地球表面和其内部深处演化的大规模过程是根本不同的：地壳经历板块构造，而地幔通过热对流翻转。我提出的研究计划将研究这两个过程是如何耦合的，特别是在厚大陆板块的情况下。大陆岩石圈，一个。250公里厚的地幔物质层，参与板块构造运动，但也受到深部地幔热柱的侵蚀。我建议检查岩石圈下的加拿大地盾地壳和地幔的影响，使用被动地震成像技术。这些技术包括在研究区域部署的地震仪网络上记录地震产生的地震波，然后在数学上重建波传播所通过的材料的特性。我计划的实地实验将集中在马尼托巴省，萨斯喀彻温省和安大略省西部，并将目标对准古代上级大陆的边缘，萨斯喀彻温省下方的前跨哈德逊山脉带，以及上级湖下方的十亿年前的裂谷带。对于所有这些结构，我打算研究地壳地质在岩石圈内的反映程度。我还将协助开发利用地震波制作地球结构图像的新方法：特别是在结构成像中使用地震噪音记录，以及使用沿地球表面沿着的散射波和偏转波。这项工作将有助于更好地了解作用在大陆板块上的力，沿着这些板块的变形历史。因此，我希望帮助建立一个框架，以了解保存或变形古代大陆地壳的大规模过程，以及加拿大地盾的具体历史和动态。由于古地盾区域下方的岩石圈是钻石的来源区域，因此加拿大地盾下方岩石圈的更好图像也将有助于未来的钻石勘探。

The large-scale processes governing the evolution of the Earth's surface and its deep interior are fundamentally different: the crust undergoes plate tectonics, while the mantle overturns through thermal convection. My proposed research program will examine how these two processes are coupled, particularly in the case of thick continental plates. The continental lithosphere, a ca. 250 km thick layer of mantle material, participates in plate-tectonic motions, but is also eroded by thermal plumes arising from the deep mantle. I propose to examine the lithosphere beneath the Canadian Shield for both crustal and mantle influences, using passive seismic imaging techniques. These techniques involve recording seismic waves produced by earthquakes at networks of seismometers deployed over the study area, and then mathematically reconstructing the properties of the material through which the waves were transmitted. My planned field experiments will be focused on Manitoba, Saskatchewan, and western Ontario, and will target the edge of the ancient Superior continent, the former Trans-Hudson mountain belt lying beneath Saskatchewan, and a billion-year-old rift zone underlying Lake Superior. For all of these structures, I intend to examine the extent to which the geology of the crust is reflected within the lithosphere below. I will also contribute to the development of new methods for producing images of Earth structure from seismic waves: in particular, the use of seismic noise recordings in structural imaging, and the use of scattered and deflected waves travelling along the Earth's surface. This work will contribute to a better understanding of the forces acting on continental plates, along with the deformation history of these plates. I thereby expect to help establish a framework for understanding the large-scale processes that have preserved or deformed ancient continental crust, and the specific history and dynamics of the Canadian Shield. As the lithosphere beneath ancient shield regions is known to be a source region for diamonds, better images of the lithosphere beneath the Canadian Shield will also assist in future diamond exploration.