It is a widely adopted method to use the Rayleigh-wave dispersion curves to constrain the shear-wave velocity structure under the ocean. Traditional methods generally utilize ambient noise cross correlations between stations and teleseismic surface wave records to extract the dispersion curves. In this study, we develop a method that uses the microseism noise recorded at a single station to derive the Rayleigh-wave dispersion curves. The fundamental idea is that the ocean-bottom pressure and vertical acceleration of microseism noise satisfy a theoretical equation which depends on the wave frequency and phase velocity. By applying the method to the Cascadia Initiative data, Rayleigh dispersion curves between $3-10$ s are derived, and they are found to be consistent with the results from the ambient noise cross-correlation method. The cross-correlation method generally extracts dispersion curves in longer periods due to large spacing between stations, thus the new method provides complementary results in short periods. The extracted dispersion curves are used to estimate the shear-wave velocity and thickness of the sediment in the Cascadia area. For stations in shallow water, the new method is not applicable, and we use the compliance noise to constrain the sediment properties, providing a complete sediment model in the Cascadia area.

中文翻译：

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从单个海底地震仪记录的微震噪声中提取瑞利波色散曲线


使用瑞利波色散曲线来约束海底剪切波速度结构是一种广泛采用的方法。传统方法通常利用台站之间的环境噪声互相关和远震表面波记录来提取色散曲线。在这项研究中，我们开发了一种方法，该方法使用在单个站点记录的微震噪声来推导出瑞利波色散曲线。基本思想是，海底压力和微震噪声的垂直加速度满足一个取决于波频率和相速度的理论方程。通过将该方法应用于 Cascadia Initiative 数据，可以得出 s 之间的 $3-10$ 瑞利色散曲线，并发现它们与环境噪声互相关方法的结果一致。由于站点之间的间距较大，互相关方法通常会在较长周期内提取色散曲线，因此新方法在短期内提供了互补的结果。提取的扩散曲线用于估计 Cascadia 地区沉积物的剪切波速度和厚度。对于浅水站，新方法不适用，我们使用顺应噪声来约束沉积物特性，从而在 Cascadia 地区提供完整的沉积物模型。