A Demonstration

Abstract

A set of parameter values was constructed to represent each of the sediment types in the Wentworth scale using the CREB model. It is shown that the wave speeds and attenuations and reflection coefficients of each sediment type compared favorably with known measurements in the open literature. The coarsest grains need to be measured at frequencies below 1 kHz to avoid multiple scattering effects. Sands and silts exhibit the typical sound speed dispersion and frequency dependence of absorption predicted by the Biot theory. The clays exhibit wave speeds that are very nearly independent of frequency, absorption that is nearly constant-Q, and creep with a long relaxation time constant. The reflection loss is consistent with known measurements, across all sediment types. These results suggest that the CREB model contains the physical processes underlying the acoustic properties of the full range of sediment types. By simply adjusting 5 input parameter values, it is possible to transition from one sediment type to another.