Marine Acoustics

Marine acoustics is the study of sound generation, propagation, and reception in seawater, the basis of all underwater remote sensing because sound, not light or radio, travels far in the ocean. Sound speed is about 1500 m/s and varies with temperature, salinity, and pressure, so the vertical sound-speed profile bends rays and creates ducts such as the SOFAR channel. The field covers sonar, ambient noise and soundscapes, acoustic tomography, bioacoustics, and anthropogenic-noise impact. Propagation is modeled with ray, normal-mode, and parabolic-equation methods, and measured quantities follow the sonar equation in transmission loss, target strength, and noise.