What are infrasonic waves?

- Hint: Sound waves are longitudinal propagation of energy through a medium. Infrasonic waves are low frequency(less than audible sounds) sound waves and their propagation requires a medium. It’s frequency normally below 20Hz.

Complete step-by-step solution -
Infrasonic waves are sound waves in the frequency range 0.1 Hz to 20 Hz typically. Human hearing is confined in the sound wave frequency range of 20 Hz to 20,000 Hz. In the infrasonic range, humans can perceive sound waves through various parts of the body.
Infrasonic waves can be generated from natural sources like volcanoes, earthquakes, and meteor showers.
Some animals (e.g. hippopotamuses, elephants, whales) use infrasonic sound for communication within the respective species.
Infrasonic waves are often used in the study of earthquakes and rock formations.

Note: The sensation of high intensity infrasonic waves through different body parts can result in a sense of fear, nausea, and anxiety.