Arctic Acoustics Ultrasonic Modeling Studies

A unique collection of laboratory ultrasonic modeling results are presented revealing and characterizing hidden pulsed seismoacoustic wave phenomena from 3-D range dependent liquidsolid boundaries. The research succeeded in isolating and identifying low-frequency 10-500 Hz transmission loss mechanisms and provided physical insight into Arctic acoustic problems generally beyond the state-of-the-art of theoretical and numerical analysis. The ultrasonic modeling studies dealt with controversial issues and existing discrepancies on seismo-acoustic waves at waterice interface, sea-ice thickness determination, low-frequency transmission loss, and bottom leaky Rayleigh waves. The areas investigated include leaky Rayleigh waves at waterice interface, leaky flexural waves in floating ice plates, effects of drywet cracks in sea- ice on plate waves and near-grazing acoustic waves, edge waves in floating plates, low-frequency backscatter from ice keel-width resonances, conversion of underwater acoustic waves into plate waves by keels, nondispersive flexural wave along apex of small-angle solid wedge, Scholte and leaky Rayleigh waves along apex of immersed 90 ice wedge, backscatter from trailing edge of floes, floating plate resonances associated with near-grazing underwater acoustic waves, acoustic coupling between adjacent floes, and multiple bottom leaky Rayleigh wave components in water layer over solid bottom.