Infrasound radiation from volcanic jets emitted by Plinian eruptions – IRADIANT

Over a thousand volcanoes are classified as potentially active, with about fifty eruptions occurring annually. Volcanic activity poses significant risks to communities and infrastructure. While effusive eruptions involving flowing lava can devastate local areas, explosive eruptions release ash, gas, and debris, affecting aviation and, in some instances, causing global disruptions. Among explosive eruptions, Plinian eruptions are particularly dramatic, producing towering ash columns. The lower section of these columns resembles the turbulent jet of a flight engine and generates infrasonic waves -- sounds with frequencies below the human hearing range -- that can travel thousands of kilometers and reach the thermosphere.
Infrasound is an essential tool for monitoring volcanic activity, with ground-based recordings routinely complementing seismic data to detect and locate eruptions. Recent research in volcano infrasound seeks to extend its use to characterizing eruptions. Studies on volcanic jets focus on linking parameters such as jet diameter, velocity, gas composition, and mass flow rate with infrasonic pressure signals recorded at large distances. This correlation could aid in estimating column height and ash release. The success of these efforts clearly relies on advancing our understanding of the mechanisms behind infrasound emissions. In this context, the IRADIANT project seeks to investigate the infrasound radiation from sustained volcanic jets, like those produced by Plinian eruptions. The study will rely on three-dimensional large-eddy simulations of the unsteady, compressible Navier-Stokes equations for gas mixtures. This ambitious, multidisciplinary project spans fluid mechanics, acoustics, aeroacoustics, volcanology, and numerical analysis, and aims to contribute to the emerging field of volcano acoustics.