EAGER: Quantification of Ocean Water Column Contributions to Bottom Pressure offshore Cascadia using Current and Pressure Recording Inverted Echo Sounders

大地震发生在俯冲带，在那里一个构造板块俯冲到另一个板块之下。其中一些地震会引发大海啸。由于缺乏有关海底如何向近海移动的信息，我们了解哪些地震会引发海啸的能力受到限制。为了解决这个问题，在俄勒冈州海岸外的俯冲带上部署了连续记录的海底压力记录器，以估计长期的垂直形变。海底压力测量结合了海底运动和上覆海洋水柱的贡献。目前正在努力利用区域海洋学模型估计水柱对测量的贡献。然而，这个模型很难估计海底附近的涡流和洋流带来的压力变化，这可能是很重要的。在工程期间，将在海底压力记录仪附近放置特殊仪器。这些仪器将能够测量来自上覆水柱的不断变化的压力，从而能够更准确地测量近海发生的构造变形。该项目支持一名来自代表性不足群体的早期职业教师。该项目将利用现场观测来量化水柱对海底压力记录器信号的贡献。具体地说，将在俄勒冈州近海部署四台电流和压力记录反向回声测深仪(CPIES)，接近现有的海底压力记录仪基准。CPIES是独一无二的，因为它们同时测量海底压力、海流和从海底到海面和回来的往返声波旅行时间。通过组合这些测量，可以从测量的海底压力信号中分离出水信号。这些测量补充了现有的测量，并提供了关键信息，以区分长期和瞬时信号的水柱信号和构造信号。将采用从以前的物理海洋过程研究中发展出来的方法，这一努力将展示其在地球物理研究中的应用。

Large earthquakes occur at subduction zones where one tectonic plate plunges underneath another. Some of these earthquakes generate large tsunamis. Our ability to understand which earthquakes produce tsunamis is limited by the lack of information about how the seafloor is moving offshore. To address this, continuously recording bottom pressure recorders have been deployed over the subduction zone off the coast of Oregon to estimate long-term vertical deformation. Seafloor pressure measurements combine both seafloor movement and a contribution from the overlying ocean water column. Present efforts to estimate water-column contributions to the measurement use a regional oceanographic model. This model, however, has difficulty estimating pressure variations from eddies and currents near the seafloor, which may be significant. During the project, special instruments will be placed near to the ocean bottom pressure recorders. These instruments will be able to measure the changing pressures from the overlying water column, allowing for a more accurate measure of the tectonic deformation that is occurring offshore. The project supports an early career faculty member from an under-represented group.This project will quantify the water-column contributions to the signal from ocean bottom pressure recorders using in situ observations. Specifically, four Current and Pressure Recording Inverted Echo Sounder (CPIES) will be deployed offshore Oregon near existing ocean bottom pressure recorder benchmarks. CPIES are unique because they simultaneously measure bottom pressure, current, and round-trip acoustic travel time from the sea floor to the sea surface and back. By combining these measurements, the water signal can be separated from the measured bottom pressure signal. These measurements complement existing measurements and provide critical information to distinguish water column signal from tectonic signal for both long-term and transient signals. Methodology developed from previous physical oceanographic process studies will be applied and this effort will demonstrate the application for geophysical studies.