Review and analysis of genesis conditions for adakites and magnesian andesites with adakite properties showed that there are various tectonic and geodynamic settings within subduction zones of the Pacific Ring. These settings provide additional heating sufficient for slab melting in subduction zones. As a rule, on the initial stage of subduction process a front part of a new slab suffered melting caused by heat from hot asthenosphere. In this case, their association with NEB type can be traced. A large number of adakite location depend on additional heating and slab melting in slab windows regardless geodynamic conditions. Moreover, formation of adakites may probably be caused by subduction of hot spreding centers. Oblique subduction and transform interactions between plates may generate additional heating sufficient for adakite volcanism.

Based on the study of the waveforms and spectral composition of earthquakes recorded during the activation of Avachinsky volcano in 2019, three generally accepted types of volcanic earthquakes (VE) were identified: volcano-tectonic, hybrid and long-period, as well as the fourth – a “special” type of VE, characterized by differ of waveforms. 15 plane-oriented clusters have been identified and the characteristics of seismogenic areas
have been determined. Analysis of the seismic events recorded in autumn 2019 in the Young Cone of Avachinsky Volcano suggested a connection between the activation of the 1991 eruption in the body of the cone and their interaction with atmospheric precipitation with magmatic bodies. The most likely cause of the light flashes over the crater on December 8 is the interaction of a hydrogen-rich volcanic gas in contact with atmospheric oxygen.