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P. Borejko, F. Ziegler:
"Response of a Fluid-Solid Interface to an Impulsive Point-Source";
Talk: The 40th Annual Technical Meeting of the Society of Engineering Science, University of Michigan, Ann Arbor, Michigan, USA (invited); 2003-10-12 - 2003-10-15.

A new time domain analytical solution is presented for the acoustic pressure-field from an impulsive point-source in a liquid medium with a solid bottom. This theoretical point-source solution is in the form of a sum of two partial wave-motions, where the first is radiated from the source (the direct wave) and the second is excited in the fluid by the interaction of the former with the bottom, the latter including the contributions from the critically refracted longitudinal and shear waves (the head or conical waves), the pseudo-Rayleigh and Stoneley interface waves, and the totally reflected wave.
Opposite to an approximate point-source solution for the problem under consideration, obtained by means of the asymptotic expansion method and thus applicable to large source-receiver separations, the present point-source solution is accurate for any separation. In particular, it is also accurate for small separations where the asymptotic solution is apparently invalid and the normal mode solution (for the case of a point-source in a liquid layer with a solid bottom) becomes impracticable due to poor convergence.
Exact and complete time records of the pressure are obtained for two fluid-solid systems: one where the shear wave speed in the solid is lower than the sound speed in the fluid and the other where the shear wave speed is higher. For the case of a low shear wave speed bottom, there are four distinct wave-form arrivals: (1) the critically refracted longitudinal wave, (2) the direct wave, (3) the totally reflected wave, and (4) the Stoneley wave. Both the critically refracted longitudinal wave and the Stoneley wave appear to be the most prominent wave-forms (large in amplitude and wide in time) on the response curve. For the case of a high shear wave speed bottom, besides the four arrivals occurring in the former case, there are two additional arrivals: the critically refracted shear wave and the pseudo-Rayleigh wave, and the most significant of these six arrivals are the Stoneley and pseudo-Rayleigh waves.
The arrival times of the pseudo-Rayleigh and Stoneley waves can possibly be used to solve the inverse problem of in situ determination of the bottom rigidity in fluid-covered areas.