CAREER: Environmental Seismology and Geomechanics

除了地震之外，还有许多地球过程会引起地面运动。特别是，湍急的河流运动和由这些运动输送的沉积物、海冰-海浪相互作用、冰下水流和热液活动都会引起地面运动，这些都可以用灵敏的地震仪器观测到。该项目利用这种独特的地震观测从数量上更好地了解这些地球过程，其中许多过程极其复杂，很少被观测到，但在地球物理和社会方面都具有重要意义。这些过程还共享涉及流体与固体相互作用的相似基本力学，该项目将导致对流体和固体力学如何在自然界中结合产生所描述的各种现象的新见解。这项跨学科的工作有助于改进洪水预警、海冰预测、海平面上升预测以及对诱发地震的理解。该项目的主要目标是提高我们利用地震以外的环境来源的地震观测的能力。在复杂环境中应用波传播工具的改进，以及管理这些震源如何在地震中耦合的跨学科机制的改进，是实现这一目标的主要途径。这里重点介绍的新力学涉及对流体-固体相互作用以及这些相互作用如何结合在一起产生地震可观测的地面运动的更好的综合理解。这在一定程度上是通过解析近似来实现的，即将来自湍流涡流的力与附近的固体相耦合。进一步的半解析近似被用来研究复杂介质中的波传播。随着主要目标的实现，新的观察将有助于限制这些复杂系统的力学方面，这些方面已经很难用其他技术观察到。预计这将导致关于这些系统的新的概念概念，而这些概念反过来又有望导致对所观察到的现象背后的地球物理过程的新的定量理解。

There are many Earth processes besides earthquakes that cause ground movement. In particular, turbulent river motions, and sediment transported by these motions, sea ice-ocean wave interactions, subglacial water flow, and hydrothermal activity all cause ground motion that can be observed with sensitive seismic instrumentation. This project makes use of such unique seismic observations to quantitatively better understand these Earth processes, many of which are extremely complex and poorly observed yet important both geophysically and societally. These processes also share similar basic mechanics involving the interactions of fluids with solids, and this project will result in new insights into how fluid and solid mechanics combine in nature to produce the diverse phenomena described. This interdisciplinary work helps improve flood warnings, sea ice predictions, sea level rise predictions, and an understanding of induced earthquakes.The primary goal of the project is to improve our ability to make use of seismic observations of environmental sources other than earthquakes. Improvements in applying wave propagation tools in complex environments and improvements in the interdisciplinary mechanics that governs how these sources couple seismically are the main avenues by which this goal will be attained. The new mechanics focused on here involves a better-integrated understanding of fluid-solid interactions and how these interactions combine to produce seismically observable ground motions. This is accomplished partly by analytic approximations to couple forces from turbulent eddies with nearby solids. Further semi-analytic approximations are used for wave propagation in complex media. With the primary goals accomplished, the new observations will help constrain aspects of the mechanics of these complex systems that have been difficult to observe with other techniques. This is anticipated to lead to new conceptual ideas about these systems that in turn are expected to lead to new quantitative understanding of the geophysical processes underlying the observed phenomena.