What is Infrasound?

About Infrasound:

• It refers to sound waves with very low frequencies, in contrast to the more ubiquitous ultrasound.
• It can be produced by a passing meteor, a storm, an aurora up north, volcanoes, earthquakes or even nuclear explosions.
• Infrasonic waves can cause minute changes in the atmospheric pressure, which can be measured by micro barometers.
• These noiseless sounds can travel very long distances without losing steam — a property that CTBTO finds useful for detecting distant nuclear explosions. 
• The CTBTO’s International Monitoring System (IMS) uses a range of technologies to detect nuclear explosions. Its Infrasound Network (that is being built) is the only global monitoring network of its kind, with plans to build a network of 60 array stations in 35 countries.
• Applications of Infrasound
  • It can be used to check the structural health of buildings, dams or bridges — because infrasonic waves can pass through dense materials and reveal internal stress, cracks or other defects.
  • In the field of aerospace, low-frequency sounds generated during a rocket’s lift-off can cue the stress and behaviour of a rocket, or detect aerodynamic instabilities of an aircraft.
  • In mining, infrasound can help check the integrity of mine shafts or determine whether a dynamite blast was successful.
  • This sound has also been used in wildlife tracking, such as monitoring the movement of whales.