Related Experiment Video
Updated: Aug 1, 2026

Studying Cavitation Enhanced Therapy
Published on: April 9, 2021
Nonlinear scattering of acoustic waves by natural and artificially generated subsurface bubble layers in sea
Lev A Ostrovsky1, Alexander M Sutin, Irina A Soustova
1Zel Technologies/NOAA Environmental Technology Laboratory, Boulder, Colorado 80303, USA.
Abstract:
The paper describes nonlinear effects due to a biharmonic acoustic signal scattering from air bubbles in the sea. The results of field experiments in a shallow sea are presented. Two waves radiated at frequencies 30 and 31-37 kHz generated backscattered signals at sum and difference frequencies in a bubble layer. A motorboat propeller was used to generate bubbles with different concentrations at different times, up to the return to the natural subsurface layer. Theoretical consideration is given for these effects. The experimental data are in a reasonably good agreement with theoretical predictions.
More Related Videos
Related Concept Videos
Sound Waves
Sound waves are longitudinal in most fluids because fluids cannot sustain any lateral pressure. In solids, however, shear forces help in propagating the disturbance in the lateral direction as well. Hence,...
Sound Waves: Resonance
Shock Waves
When the source's speed approaches the speed of sound, constructive interference between successive wavefronts emitted by the source occurs immediately behind it. Initially, scientists believed that this constructive interference would result in such high pressures...
Sound as Pressure Waves
The pressure fluctuation depends on the difference in displacements between the successive points in the...
Echo
Imagine the sound is reflected back to the ears. Assuming that the source is very close to the human, the difference between hearing the two sounds—the emitted sound and the reflected sound—may be more than the minimum time for perceiving distinct sounds. If this is the case, then the...
Partial Differential Equations

