This paper reconstructs, for the first time, the motion dynamics of an eruptive cloud formed during the catastrophic eruption of the Sheveluch volcano in November 1964 (Volcanic Explosivity Index 4+). This became possible due to the public availability of atmospheric reanalysis data from the ERA-40 archive of the European Center for Medium-Range Weather Forecasts (ECMWF) and the development of numerical modeling of volcanic ash cloud propagation. The simulation of the eruptive cloud motion process, which was carried out using the FALL3D and PUFF models, made it possible to clarify the sequence of events of this eruption (destruction of extrusive domes in the crater and the formation of an eruptive column and pyroclastic flows), which lasted only 1 h 12 min. During the eruption, the ash cloud consisted of two parts: the main eruptive cloud that rose up to 15,000 m above sea level (a.s.l.), and the co-ignimbrite cloud that formed above the moving pyroclastic flows. The ashfall in Ust-Kamchatsk (Kamchatka) first occurred out of the eruptive cloud moving at a higher speed, then out of the co-ignimbrite cloud. In Nikolskoye (Bering Island, Commander Islands), ash fell only out of the co-ignimbrite cloud. Under the turbulent diffusion, the forefront of the main eruptive cloud rose slowly in the atmosphere and reached 16,500 m a.s.l. by 04:07 UTC on November 12. Three days after the eruption began, the eruptive cloud stretched for 3000 km over the territories of the countries of Russia, Canada, the USA, Mexico, and over both the Bering Sea and the Pacific Ocean. It is assumed that the well-known long-term decrease in the solar radiation intensity in the northern latitudes from 1963–1966, which was established according to the world remote sensing data, was associated with the spread of aerosol clouds formed not only by the Agung volcano, but those formed during the 1964 Sheveluch volcano catastrophic eruption

A conceptual model of the thermal and water recharge of the Ketkinsky geothermal field as a product of magma and water injection from the Koryaksky volcano located 24 km apart was proposed. A digital hydrogeological model of the Ketkinsky geothermal field was developed in the volume of 7 km x 5 km x 2.5 km (from the topographic surface), it includes the space drilled by exploration and production wells. The model is based on an analysis of 3D distributions of temperature, pressure, salinity and CH4 content, geometrization of productive faults and well productivity characteristics. The geofiltration space was zoned in the model with separation of
deep and shallow productive geothermal reservoirs, the area of deep thermal fluid upflow in the SSE part of the model base and the area of hidden thermal water discharge at the ground surface.
A natural state inversion iTOUGH2-EWASG simulation was performed to estimate the deep thermal water upflow and permeability of productive geothermal reservoirs. The deep thermal water upflow is estimated to be about 10 kg/s, the permeability is estimated to be 190 mD (shallow productive reservoir) and 35 mD (deep productive reservoir). Inverse iTOUGH2-EWASG modeling of the hydrodynamic operating history of 1989–2020 was used to estimate the compressibility of the productive geothermal reservoirs: the compressibility of the deep reservoir is estimated at 7.16E-10 Pa???? 1, the shallow reservoir at 4.14E-07 Pa???? 1. Direct iTOUGH2-EWASG modeling with the above parameters reproduces the history of salinity and temperature changes in production wells.
Forecast modeling of existing producing wells #23, K6, K01, K5 operation for 25 years with application of submersible pumps at immersion depth of 70 m confirms the possibility of their sustainable operation with total flow rate not less than 14.2 kg/s, adding four producing wells may yield to 54.3 kg/s with retaining of produced water quality (temperature, gas content of CH4, salinity).
The use of submersible pumps and reinjection can significantly increase the reserves of Ketkinsky field to 165–175 kg/s of 70–80 ◦C and 60–70 g/s of CH4. Additional increase in reserves may be obtained by drilling the already known thermal anomaly in the SSE sector of the field and in the SWW foothills of Koryaksky volcano.

Mutnovsky geothermal area in Kamchatka, Russia where 62 MWe GeoPP installed - is a source of geothermal electricity supply, as well as a hazard volcanic area. We used local seismicity micro-earthquakes (MEQ’s) data from 2009 to 2021 to define seismogenic faults beneath and adjacent to Mutnovsky volcano, which interpreted as magma injections in form of dykes and sills. Magma fracking beneath Mutnovsky volcano pointed on shear mode low angle dykes in northeast sector and opening mode geomechanical conditions at -3000 m, where sills in area of 62 km2 are suggested to be formed. Low angle dykes injections were reproduced by hydromechanical simulation using CFRAC, modeling results matches with MEQ’s statistics observed.
Mutnovsky GeoPP steam collection system shows sensitivity to non-condensable gasses (NCG) content (partial gas pressure) variations (2019—2020), that is used as indicator of magmatic gasses recharge via magma fracking volcano system to production geothermal reservoir. Partial gas pressure measured at GeoPP condenser unit. Magma injections associated with NCG (CO2) release in production reservoirs seems to be synchronize with partial NCG pressure excursions at GeoPP condenser. Some signs of magma fracking events were also revealed using discreet observations (2016–2021) on a blowing wells on a foothills of Mutnovsky volcano. Magma fracking beneath Mutnovsky volcano is associate with small and medium hydrothermal explosions and landslide (2009–2021). Magma fracking distributions pointed on a new potentially production geothermal reservoir beneath northeast foothills of Mutnovsky volcano (depth range from -4000 to -2000 m, accessible area of 30 km2).

The geochemical variations of magmas across and along supra-subduction zones (SSZ) have been commonly attributed to profound changes in the phase and chemical compositions of the mantle source and subduction-derived melt and fluid fluxes, as well as the physical parameters (e.g. depth, temperature, oxygen fugacity etc) of slab dehydration, mineral breakdown and melting. Here we test the variability of the Late Quaternary primitive magmas in the southern and northern parts of the meridionally oriented Eastern Volcanic Belt (EVB) of Kamchatka, with a slab depth varying from 60 to 160 km. Eight high-Mg (Mg# > 60 mol%) basalts were characterized for major, trace and platinum-group element (PGE) abundances, as well as the compositions of olivine phenocrysts and olivine-hosted spinel inclusions. The basalts in our study are geochemically typical of SSZ magmas and contain similar liquidus assemblages of forsteritic olivine (Mg# 78–92 mol%), low-Ti Cr-spinel and clinopyroxene. Although the absolute abundances of major and trace elements, and their ratios, in the basalts fluctuate to some extent, the observed variability cannot be correlated with any of considered parameters in the geometry of the Kamchatka SSZ and conditions of melting. This unexpected result led to the evaluation of the platinum-group element (PGE) systematics against the lithophile and chalcophile trace element geochemistry and the compositions of phenocrysts. Total whole-rock PGE content varies from 2.3 to 11.7 ppb, whereas the normalized PGE concentration patterns are typical for supra-subduction zones magmas and broadly similar in all studied samples. They are enriched in Rh, Pd and Pt relative to mid-ocean ridge basalts (MORB) and have nearly identical concentrations of Ir-group PGE. The only parameter that correlates well with PGE contents is the average Mg# of olivine phenocrysts from 84 to 90.3 mol%. This is interpreted to result from minor cryptic fractionation of sulfide melt, together with primitive olivine, in low-to-mid crustal conditions. Negative Ru anomalies on chondrite-normalized diagrams correspond to the Fe2+/Fe3+ ratios in spinel (a proxy for magma redox conditions), which reflects a replacement of monosulfide solid solution by laurite in the mantle wedge during oxidation.