What is Infrasound?
Infrasound refers to sound waves that have frequencies below the lower limit of human audibility, which is typically 20 Hertz (Hz). These low-frequency waves can travel long distances and penetrate solid objects more effectively than audible sound, making them important for detecting distant or obscured phenomena.
Key Characteristics and How It Differs
Unlike the sound we hear, infrasound waves are characterized by their very long wavelengths and low energy per wave, allowing them to propagate over vast distances with minimal attenuation. This property makes them challenging for humans to perceive directly but valuable for scientific instrumentation designed to pick up these subtle vibrations.
Sources of Infrasound
Natural sources of infrasound include severe weather events like tornadoes and hurricanes, earthquakes, volcanic eruptions, avalanches, and even ocean waves. Animal communication, such as elephant calls, also uses infrasound. Human-made sources can include industrial machinery, explosions, and supersonic aircraft.
Applications and Importance
Scientists use infrasound for various purposes, including monitoring atmospheric phenomena, detecting nuclear tests, tracking severe weather, and studying seismic activity. By analyzing infrasound patterns, researchers can gain insights into Earth's processes and distant atmospheric disturbances, contributing to early warning systems and scientific research.