Evidence of dispersion in a water-saturated granular sediment

An experiment was conducted to measure the sound speed in a water-saturated granular sediment within a range of frequencies where dispersion is predicted by a number of existing models. Between 2-4 kHz, the sound speed was inferred from measurements of the resonance frequencies of a right-circular-cylindrical container filled with the material. From 20-300 kHz, the sound speed was obtained directly from time-of-flight measurements within the same sediment. Dispersion consistent with the Williams Effective Density Fluid Model was observed.