Active volcanoes are associated with microearthquake (MEQ) hypocenters that form plane-oriented cluster distributions. These are faults delineating a magma injection system of dykes and sills. The Frac-Digger program was used to track fracking faults in the Kamchatka active volcanic belt and fore-arc region of Russia. In the case of magma laterally injected from volcanoes into adjacent structures, high-temperature hydrothermal systems arise, for example at Mutnovsky and Koryaksky volcanoes. Thermal features adjacent to these active volcanoes respond to magma injection events by degassing CO₂ and by transient temperature changes. Geysers created by CO₂-gaslift activity in silicic volcanism areas also flag magma and CO₂ recharge and redistributions, for example at the Uzon-Geyserny, Kamchatka, Russia and Yellowstone, USA magma hydrothermal systems. Seismogenic faults in the Kamchatka fore-arc region are indicators of geofluid fracking; those faults can be traced down to 250 km depth, which is within the subduction slab below primary magma sources.

It is shown that the productive reservoir received considerable quantities of meteoric water during the operation of the Pauzhetka geothermal field (1960–2007), which amounted to 30% of the total...

A laboratory installation has been developed together with a technique for determining thermo-physical properties (thermal conductivity and specific heat) in cylindrical rock specimens. The technique is based on iTOUGH2-EOS3 inversion modeling using temperature measurements inside specimens as a result of their short-term heating and subsequent return to the initial temperature. We estimated the thermal conductivity and specific heat for a collection of volcanogenic petrotypes that reflect the rocks that compose the Rogozhnikovskii volcanogenic oil reservoir (29 specimens). The average thermal conductivity of the dry rocks is 1.47 W/m °C and the average specific heat is 754 kJ/kg °C; the reproducibility of this estimation is 2.2% for thermal conductivity and 0.7% for specific heat.

Geofluid systems are unique geomechanical sensors, as they can generate earthquakes themselves and also respond to changes in Earth activity. The MW = 8.8 earthquake of July 29, 2025 in Kamchatka was accompanied by numerous geofluid anomalous phenomena: (1) regional seismogenic faults activity; (2) significant post-seismic decreases in water levels (the first meters) and rates in wells of low temperature geothermal fields (Vilyuchinsky, Paratunsky and Ketkinsky); (3) omissions of eruptions of the Bolshoy geyser (Valley of Geysers) and the emergence of a new geyser-well (Kumroch); (4) the beginning of volcanic eruptions (Krasheninnikov volcano for the first time in ∼600 years, Klyuchevskoy volcano) and volcanoes activity increase (Karymsky, Mutnovsky, Kambalny). In this study, the ability of geofluid systems to track seismic events was used to identify the activity of regional seismogenic faults and volcanic magmatic systems (the Frac-Digger method). This provides an explanation for the observed phenomena in terms of the geomechanical regional stretching of Kamchatka, which was associated with an MW = 8.8 earthquake followed by a decrease in geofluid pressure. In magma systems of volcanoes, this triggered boiling and gas-lift of magma with subsequent eruptions. In the fractured-type reservoirs of low-temperature hydrothermal systems, this led to a significant drop in water levels and a cessation of discharge. In the high-temperature and gas-rich Valley of the Geysers Field, this led to the disintegration of the caprock and the infiltration of water, resulting in the subsequent eruptions of the Grotto and the Great Geyser being skipped, while the Kumroch CO2 reached the hydrothermal reservoir, boiled, and began cycling eruptions. These phenomena are consistent with the models of the MW = 8.8 earthquake’s focal mechanism and satellite geodetic data from GNSS and InSAR.

The thermal, hydrogeological, and chemical processes affecting Kamchatka geothermal reservoirs were studied by using isotope and geochemistry data: (1) The Geysers Valley hydrothermal reservoirs; (2) The Paratunsky low temperature reservoirs; (3) The North-Koryaksky hydrothermal system; (4) The Mutnovsky high temperature geothermal reservoir; (5) The Pauzhetsky geothermal reservoir. In most cases water isotope in combination with Cl^- transient data are found to be useful tool to estimate reservoirs natural and disturbed by exploitation recharge conditions, isotopes of carbon-13 (in CO₂) data are pointed either active magmatic recharge took place, while SiO₂ and Na-K geothermometers shows opposite time transient trends (Paratunsky, Geysers Valley) suggest that it is necessary to use more complicated geochemical systems of water/mineral equilibria.