Possible Subsurface Source of an Acoustic Tsunami Precursor

Abstract

A hypothetical model is introduced to show that focused caustics can be the source of a boom which may be an acoustic precursor of a big tsunami. This model helps us have a more reasonable understanding about what was written in the old historical descriptions about booms followed by big tsunamis after the significant earthquake events. In this model, the fault line that includes the epicenter of an earthquake at the sea bed was assumed to be a source of sound. Some of the acoustic rays radiated from the source form an acoustic caustic between the sea surface and the axis of the sound channel. This caustics can be subsurface audible source of an acoustic tsunami precursor.