有限長正弦波による傾斜層を伝わる表面波の模型実験

抄録

Experiments were carried out with two dimensional models which had various slope angles. Period of wave groups were changed from 10μs to 40μs. Three wave groups were distinctly observed. However, propagations of these wave groups were so complicated that dispersion curves could not be decided from the records observed.
Using the theoretical dispersion curves for dispersive Rayleigh waves in case of parallel layers, group velocities at any distance from the vertex of the sloping layer were obtained. Then, theoretical travel times were calculated for each wave group. The travel time of the most distinct wave group observed corresponds well to the theoretical time-distance curve of M₁₁. The other wave group may correspond to PL₂₁ near the vertex and to M₂₁ far from the vertex. Another is only refracted S waves, being P waves scarcely observed.