Acoustic-gravity waves generated by surface disturbances

Abstract

The sudden generation of wave disturbances in the ocean is associated with a change in the pressure field in the liquid layer. Consequently, compression-type of waves, known as acoustic-gravity waves, form and radiate at the speed of sound, carrying information on the event source, namely its magnitude and location. This information can be recorded by hydrophones hundreds of kilometres away from the event, and if analyzed at near-real time using an inverse model it could allow for an early warning system. The near-real time analysis requires an explicit form of the pressure field induced by the acoustic-gravity waves. In this work, we derive an explicit solution for the bottom pressure field using stationary phase approximation. Then, to demonstrate the effectiveness of the warning system, we apply an inverse model to calculate the generation time and location of the event.