Compressional and shear wave properties of marine sediments: comparisons between theory and data.
Compressional and shear wave properties of marine sediments: comparisons between theory and data.
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DOI：
10.1121/1.1810231
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发表时间：
2005-01
期刊：
影响因子：
--
通讯作者：
M. Buckingham
中科院分区：
文献类型：
--
作者：
M. Buckingham
根据最近发展的海洋沉积物中的波传播理论，压缩波和剪切波的相速度和衰减的色散关系仅取决于三个宏观物理变量：沉积物中的孔隙度、颗粒尺寸和深度。色散关系还涉及三个（实际）参数，分配固定值，代表颗粒接触处发生的微观过程。将色散关系与取自文献的大量数据集进行比较，涵盖作为所有三个物理变量的函数的四种波属性。由于没有可用的可调参数，该理论准确地匹配了所有数据集的趋势。这种一致性延伸到压缩和剪切衰减，因为该理论准确地追踪了广泛分布的测量衰减的下限：该理论预测了由于波能不可逆地转化为热量而产生的固有衰减，而测量返回了有效衰减，其中包括固有衰减加上额外的损失源，例如来自贝壳碎片的散射和其他不均匀性。 中等的。如果已知一种波或物理特性，例如压缩速度或孔隙率，则可以根据理论可靠地估计所有剩余的沉积物特性。
According to a recently developed theory of wave propagation in marine sediments, the dispersion relationships for the phase speed and attenuation of the compressional and the shear wave depend on only three macroscopic physical variables: porosity, grain size, and depth in the sediment. The dispersion relations also involve three (real) parameters, assigned fixed values, representing microscopic processes occurring at grain contacts. The dispersion relationships are compared with extensive data sets, taken from the literature, covering the four wave properties as functions of all three physical variables. With no adjustable parameters available, the theory matches accurately the trends of all the data sets. This agreement extends to the compressional and shear attenuations, in that the theory accurately traces out the lower bound to the widely distributed measured attenuations: the theory predicts the intrinsic attenuation, arising from the irreversible conversion of wave energy into heat, whereas the measurements return the effective attenuation, which includes the intrinsic attenuation plus additional sources of loss such as scattering from shell fragments and other inhomogeneities in the medium. Provided one wave or physical property is known, say the compressional speed or the porosity, all the remaining sediment properties may be reliably estimated from the theory.