Onshore-offshore broadband seismic studies of Earth structure and tectonic processes

我的研究计划集中在两个主要的科学目标上：限制地质结构和过程对活动的海洋-大陆板块边界动力学的作用，以及阐明地球物理数据所揭示的大型科迪拉克的生长和命运。针对这些目标，我利用从陆地和近海宽带地震仪器的大型网络获得的数据，建立了大陆和海洋板块系统及其地震活动的地震速度模型。特别是，我使用和开发植根于现代统计理论的地震分析工具，从这些数据中提取最大的信息。我的研究重点是加拿大西部的构造，那里形成了大型自然实验室来研究这些科学目标。在加拿大西部海岸线上，太平洋和胡安德富卡大洋板块沿着两个板块边界与北美大陆并列：南面是卡斯卡迪亚俯冲带，北面是夏洛特-费尔韦瑟女王断层。每种边界类型都包含长时间被摩擦锁定的大断层，并在大地震(有时是巨型地震)中滑动，因此对沿海人口构成重大地震危险。这些地震和断层本身大多位于近海；因此，他们的研究需要陆上-近海地震数据。除了对沿海地区构成威胁外，俯冲带还通过形成火山弧和大的背弧在大陆边缘留下印记，这些弧会演化成珊瑚山脉--这些山脉地带很热，很容易在长时间尺度上变形(~Myr)。加拿大科迪勒拉自中生代以来一直活跃，蕴藏着重要的矿物和地热能资源。它目前的地震活动也反映了不均匀的应力分布，这在一定程度上受其构造和地质构成的控制。在这份提案中，我计划使用涵盖加拿大西部的所有可用的宽带地震数据来源来研究这些大型构造系统；重要的是，我的长期愿景是致力于在太平洋东北部和加拿大北极西部建立新的宽带海底地震仪部署，并利用大型US阵列可移动阵列部署和加拿大科迪勒拉阵列计划创造的机会来研究这些系统和实现科学目标。

My research program focuses on two main scientific objectives: constraining the role of geological structure and processes on the dynamics of active ocean-continent plate boundaries and elucidating the growth and fate of large Cordilleras, as revealed by geophysical data. I address these objectives by developing seismic velocity models of continental and oceanic plate systems and their seismic activity using data obtained from large networks of broadband seismic instruments, both on land and offshore. In particular, I use and develop seismic analysis tools rooted in modern statistical theory to extract maximum information from these data. My research focuses on the tectonics of western Canada, which form large natural laboratories to study these scientific objectives. On the western Canadian coastline, the Pacific and Juan de Fuca oceanic plates are juxtaposed against the North American continent along two plate boundaries: the Cascadia subduction zone to the south and the Queen Charlotte-Fairweather Fault to the north. Each boundary type contains large faults that are frictionally locked for long periods of time, and slip in large (and sometimes giant) earthquakes, and therefore represent significant seismic hazard to coastal populations. The majority of these earthquakes and the faults themselves are located offshore; their study therefore requires onshore-offshore seismic data. In addition to the threat they pose to coastal areas, subduction zones leave their imprint on the continental margin by forming volcanic arcs and large back arcs that evolve into cordilleras – mountain belts that are hot and easy to deform over long time scales (~Myr). The Canadian Cordillera has been active since the Mezosoic and contains important mineral and geothermal energy resources. Its current seismic activity also reflects heterogeneous stress distribution that is partly controlled by its structural and geological makeup. In this proposal I plan to use all available sources of broadband seismic data encompassing western Canada to study these large tectonic systems; importantly, my long-term vision is to work toward new broadband ocean-bottom seismograph deployments in the northeast Pacific and western Canadian Arctic and capitalize on the presence of the large USArray Transportable Array deployment and on the opportunities created by the prospective Canadian Cordillera Array initiative to study these systems and address the scientific objectives.