Seismoacoustic Waves in Water-Covered Sand

摘要

A collection of new findings are presented contributing to fundamental physical understanding of broadband (3-500 KHz) transient seismoacoustic wave phenomena in various sand conditions (water-saturated, naturally settled, disturbed, drained, liquefied, compacted, water-covered, air bubbles) important for acoustic modeling of seafloor and predicting the penetration and conversion of seismoacaoustic waves in sediments. The experimental results compare waveforms of different types of seismoacoustic waves. An explanation is given for the anomalous slow compressional wave observed in water-saturated sand by Boyle and Chotiros (1992). Other experimental results presented include (a) the effect of ripples on surface and interface waves dispersion, (b) the existence of high-frequency fast compressional waves (1650 rn/s) in drained sand, (c) the effect of puddles and water edges on converting interface waves into body shear waves, (d) the nonexistence of a second Rayleigh wave along with Scholte wave in soft sediments, and (e) the first experimental results on wedge waves along the edge of sand dollar skeletons.