Scholte wave generation by vertically guided waves in steep topographic feature

Abstract

Interaction of underwater acoustic waves with the Arctic ice cover is least understood when the wavelength is comparable to ice thickness and topographic feature dimensions. Generation and detection of Scholte waves along a flat water/ice interface require proximity of both source and receiver to the ice. Laboratory ultrasonic experimental results are presented demonstrating the generation of pulsed broadband Scholte waves at ice/water interfaces from interaction of remote underwater source with a single steep ice topographic feature. Examples are given from different bonded ice ridges and unattached floating scatterers near the interface. The effects of ridge height, ridge width, and relative source position on the generation of Scholte waves are revealed. Each topographic feature acts as a vertical acoustic waveguide and locally excites the ice/water interface. Focusing of guided waves by ridge geometry enhances the generation of Scholte waves. The results also provide physical insight into the excitati...