Investigation of the sources of microseism noise in the Indian Ocean caused by movements between the ocean and the atmosphere.

This study investigates microseism noise, a distinct sound occurring within 2 to 20 seconds, known as the loudest frequency in Earth's background noise. Focusing on the Indian Ocean, researchers analyzed the magnitude and direction of subtle movements using data from ten land-based stations across the region. Microseism characteristics were described using probability power spectral density, examining variations in vibration frequencies with Eigenvalue decomposition to understand three-dimensional vibration dispersion. Findings reveal that the Indian Ocean significantly contributes to global microseism, with certain stations displaying dual-frequency microseism periods of 2 to 5 seconds and 6 to 10 seconds. The study highlights that low-frequency seismic activity is largely influenced by the Southern Ocean. A comparative analysis showed a correlation between wave height and sound wave intensity across locations and time frames. Additionally, common wave types within the microseism band on Earth’s surface were reviewed, with a particular focus on Rayleigh waves over extended periods.