Infrasound (Marine)

Marine infrasound is sound below about 20 Hz in the ocean and atmosphere, used to monitor large-scale geophysical events. In water, low frequencies suffer little absorption and travel basin-scale distances through the SOFAR channel, so hydroacoustic stations of the CTBTO International Monitoring System detect underwater explosions, large iceberg calving and grounding, and submarine earthquakes thousands of kilometers away. Atmospheric infrasound arrays track the same explosive and volcanic sources. Microbaroms near 0.2 Hz, generated by interacting ocean swell, form the dominant ambient infrasound background and themselves carry information on sea-state and storms.