US Geological Survey, Denver Federal Center, Box 25046, MS-939, Denver, Colorado 80225, USA.
J Acoust Soc Am. 2011 Apr;129(4):1707-20. doi: 10.1121/1.3552877.
Acoustic transmission measurements of compressional, P, and shear, S, wave velocities rely on correctly identifying the P- and S-body wave arrivals in the measured waveform. In cylindrical samples for which the sample is much longer than the acoustic wavelength, these body waves can be obscured by high-amplitude waveform features arriving just after the relatively small-amplitude P-body wave. In this study, a normal mode approach is used to analyze this type of waveform, observed in sediment containing gas hydrate or ice. This analysis extends an existing normal-mode waveform propagation theory by including the effects of the confining medium surrounding the sample, and provides guidelines for estimating S-wave velocities from waveforms containing multiple large-amplitude arrivals.
声传播测量的压缩波，P，和剪切波，S，波速依赖于正确识别在测量的波形中的 P 和 S 体波到达。在圆柱样品中，样品比声波波长长得多，这些体波可能会被在相对小振幅的 P 体波之后到达的高振幅波形成分所掩盖。在这项研究中，一种正常模式方法被用于分析在含有天然气水合物或冰的沉积物中观察到的这种类型的波形。这种分析通过包括围绕样品的约束介质的影响来扩展现有的正常模式波形传播理论，并提供了从含有多个大振幅到达的波形中估计 S 波速度的指南。
