Response to “Comments on ‘Pore fluid viscosity and the wave properties of saturated granular materials including marine sediments [J. Acoust. Soc. Am. 127, 2095–2098 (2010)]’ ”

Abstract

Chotiros and Isakson [J. Acoust. Soc. Am. 127, 2095–2098 (2010)] raised three main issues concerning the grain-shearing and viscous-grain-shearing (VGS) theories of wave propagation in saturated marine sediments. (1) They introduced the R-ratio as a test of the two theories, (2) they then used the R-ratio to compare the theories with published measurements of compressional and shear wave properties of laboratory sediments under high confinement pressures, and (3) they pointed out that the VGS theory overestimates the shear attenuation measured during the Sediment Acoustics Experiment 1999 (SAX99) by about an order of magnitude. With regard to the R-ratio, it provides an incomplete test of the theories and, moreover, it returns ambiguous results. As for the tests against measurements made under high confinement pressures, they are invalid because the theories are not applicable under such conditions. The third point is correct, but a minor modification to the VGS theory resolves the difficulty.