Microbarom:
In acoustics, microbaroms, also known as the “voice of the sea“, are a class of atmospheric infrasonic waves generated in marine storms by a non-linear interaction of ocean surface waves with the atmosphere. They typically have narrow-band, nearly sinusoidal waveforms with amplitudes up to a few microbars, and wave periods near 5 seconds (0.2 hertz). Due to low atmospheric absorption at these low frequencies, microbaroms can propagate thousands of kilometers in the atmosphere, and can be readily detected by widely separated instruments on the Earth’s surface. [Wikipedia]
Noted in “The Sounds of the Earth are all around us.” Dana Milbank and Hailey Haymond, WaPo:
The infrasound coming from the ocean is called a “microbarom.” The interaction of wind and surface waves create something reminiscent of a background heartbeat. Sometimes it sounds like ripples of thunder or the echoes of an explosion.
