In a 2007 experiment conducted in the northern North Sea, observations of a low-frequency seismo-acoustic wave field with a linear horizontal array of vector sensors located on the seafloor revealed a strong, narrow peak around 38 Hz in the power spectra and a presence of multi-mode horizontally and vertically polarized interface waves with phase speeds between 45 and 350 m/s. Dispersion curves of the interface waves exhibit piece-wise linear dependences between the logarithm of phase speed and logarithm of frequency with distinct slopes at large and small phase speeds, which suggests a seabed with a power-law shear speed dependence in two distinct sediment layers. The power spectrum peak is interpreted as a manifestation of a seismo-acoustic resonance. A simple geoacoustic model with a few free parameters is derived that quantitatively reproduces the key features of the observations. This article's approach to the inverse problem is guided by a theoretical analysis of interface wave dispersion and resonance reflection of compressional waves in soft marine sediments containing two or more layers of different composition. Combining data from various channels of the vector sensors is critical for separating waves of different polarizations and helps to identify various arrivals, check consistency of inversions, and evaluate sediment density.

中文翻译：

---

使用矢量传感器的基于物理的软海底沉积物表征

在2007年在北海北部进行的一项实验中，利用位于海底的水平线性矢量传感器阵列对低频地震声波场的观测，发现功率谱中存在38 Hz左右的强而窄的峰，并且存在相位速度在45至350 m / s之间的多模水平和垂直极化界面波。界面波的频散曲线表现出相速度的对数和频率的对数之间的分段线性关系，在大，小相速度下具有明显的斜率，这表明在两个不同的沉积层中，海床具有幂律切变速度依赖性。功率谱峰值被解释为地震声共振的表现。推导了一个带有少量自由参数的简单地声模型，该模型定量地再现了观测的关键特征。本文针对反问题的方法是通过对界面波弥散和压缩波在包含两层或更多层不同成分的软海洋沉积物中的共振分析进行理论分析的。组合来自矢量传感器各个通道的数据对于分离不同极化的波非常关键，并且有助于识别各种到达波，检查反演的一致性以及评估沉积物密度。逆问题的解决方法是通过对包含两层或更多层不同成分的软性海洋沉积物中界面波弥散和压缩波的共振反射的理论分析来指导的。组合来自矢量传感器各个通道的数据对于分离不同极化的波非常关键，并且有助于识别各种到达波，检查反演的一致性以及评估沉积物密度。逆问题的解决方法是通过对包含两层或更多层不同成分的软性海洋沉积物中界面波弥散和压缩波的共振反射的理论分析来指导的。组合来自矢量传感器各个通道的数据对于分离不同极化的波非常关键，并且有助于识别各种到达波，检查反演的一致性以及评估沉积物密度。