GLOBAL GEOPHYSICAL EFFECTS CAUSED BY THE HUNGA-TONGA- HUNGA-HAAPAI VULCAN ERUPTION 15 JANUARY 2022 (REVIEW)

Abstract

The eruption of the Hunga-Tonga-Hunga-Hapai volcano on January 15, 2022, and associated explosive events recorded by seismic and acoustic instruments across the planet caused significant and prolonged effects in the atmosphere and ionosphere. Measurement data obtained using a record number of ground observation sites and space-based systems provided an unprecedented amount of geophysical information. Analysis of seismic and atmospheric-ionospheric disturbances allowed to determine the value of the volcanic activity index for the Hunga-Tonga-Hunga-Hapai eruption VEI = 6, which places it among the largest volcanic eruptions ever recorded. Unique or rarely observed events are the height of volcanic cloud rise to the mesosphere boundaries, record thunderstorm activity, the scale, amplitude and duration of atmospheric, stratospheric and ionospheric disturbances registered over the entire planet, the strongest infrasound signals observed in the world for the last 30 years. The synchronous registration of low- frequency variations of the geomagnetic field and the amplitude of the Shuman resonance signals made it possible to determine the propagation velocities of Lamb waves, acoustic-gravity and infrasound waves, to determine the phases of eruptions responsible for the generation of various types of atmospheric and ionospheric perturbations and the propagation velocity of the corresponding perturbing agents. At the same time, a comprehensive analysis of the dynamics and mechanisms of global geophysical perturbations caused by the eruption is impeded by the absence of a complete model of a multiphase high-energy underwater eruption, the difficulty of joint analysis of the entire set of revealed geophysical effects of the eruption with the use of existing models of the atmosphere and ionosphere. It is obvious that understanding of the whole complex of global geophysical disturbances on the planet caused by the eruption provides unique material for studying the processes of geospheres interaction, which is a combination of interdependent and actively interacting physical phenomena.