Data showing the activity of the volcanoes in the Kurilе Island Arc in the XXI century are given. The volcanic eruptions at the volcanoes Chikurachki, Chirinkotan, Ebeko, Sarychev Peak, Ekarma, Ivan Grozny, Alaid and Snow were considered. Increase of steam-gas activity was observed at the volcanoes Sinarka (Shiashkotan Isl.), Berg (Urup Isl.), Severgin Peak (Kharimkotan Isl.) and Kudryavy (Iturup Isl.). It is shown that the brief (from a few hours to several days) explosive eruptions of weak and moderate intensity (VEI = 0–3) prevailed. The most active were volcanoes Chikurachki (8 events) and Ebeko (4 events) (Paramushir Isl.). The strongest eruption during the reporting period was explosiveeffusive eruption of Sarychev Peak volcano in 2009; the longest were effusive eruptions of Snow Volcano (Chirpoi Isl.) in 2012–2016. The total volume of erupted material for the years 2000–2016 does not exceed 0.3–0.4 km3.

The information system "Remote monitoring of Kamchatka and Kuril Islands volcanic activity" (VolSatView IS) was created in 2011. The system provides specialists with access to a variety of information, including long-term archives of remote sensing data needed for remote monitoring of volcanic activity, requiring only a web browser to use the system. Since the launch of the system, the list of available data, as well as tools for their analysis, has been continuously expanding. By now, there is a lot of experience in daily use of the system by the specialists in volcanology. This article describes the current state of the system, including recent developments, such as determination of the height of ash plumes, improvement of the time series analysis tools, implementation of specialized data processing products.

Owing to modern development of information technologies and computer simulation systems, and datasets derived from open historical meteorological data archives, it appeared possible to perform retrospective analysis of large explosive volcanic eruptions. This work analyzes the results of simulation of the events associated with the eruptive cloud propagation during the catastrophic eruption of the November, 1964 Sheveluch volcano. The obtained additional eruptive cloud parameters enabled us to reproduce the dynamics of the explosive eruption and to validate its magmatic genesis.

An analysis of local seismicity within the Klyuchevskoi Volcanic Cluster and Shiveluch Volcano for the period 2000–2017 revealed a sequence of plane-oriented earthquake clusters that are interpreted here as the emplacement of dikes and sills (magmatic fracking). The geometry of magma bodies reflects the geomechanical conditions in volcanic plumbing systems and at the bases of the volcanoes. Magmatic fracking within active magmatic plumbing systems results in the formation of permeable reservoirs whose vertical extent can reach 35 km (Klyuchevskoi) and can be as wide as 15 km across (Shiveluch), depending on the geomechanical condition of the host rocks. These reservoirs will be the arena of subsequent hydrothermal circulation, producing geothermal and ore fields, as well as hydrocarbon fields. TOUGH2-EOS1sc simulation tools were used to estimate the conditions for the formation of hydrothermal reservoirs at temperatures below 1200°С and pressures below 1000 bars.

An analysis of local seismicity within the Avacha–Koryakskii Volcanic Cluster during the 2000–2016 period revealed a sequence of plane-oriented earthquake clusters that we interpret as a process of dike and sill emplacement. The highest magmatic activity occurred in timing with the 2008–2009 steam–gas eruption of Koryakskii Volcano, with magma injection moving afterwards into the cone of Avacha Volcano (2010–2016). The geometry of the magma bodies reflects the NF geomechanical conditions (tension and normal faults, Sv >SHmax >Shmin ) at the basement of Koryakskii Volcano dominated by vertical stresses Sv, with the maximum horizontal stress SHmax pointing north. A CFRAC simulation of magma injection into a fissure under conditions that are typical of those in the basement of Koryakskii Volcano (the angle of dip is 60о, the size is 2 × 2 km2, and the depth is –4 km abs.) showed that when the magma discharge is maintained at the level of 20000 kg/s during 24 hours the fissure separation increases to reach 0.3 m and the magma injection is accompanied by shear movements that occur at a rate as high as 2 × 10–3 m/s, thus corresponding to the conditions of local seismic events with Mw below 4.5. We are thus able to conclude that the use of planeoriented clusters of earthquakes for identification of magma emplacement events is a physically sound procedure. The August 2, 2011 seismicity increase in the area of the Izotovskii hot spring (7 km from the summit of Koryakskii Volcano), which is interpreted as the emplacement of a dike, has been confirmed by an increase in the spring temperature by 10–12°С during the period from October 2011 to July 2012.

Mechanism of Kamchatka geofluid systems functionality was studied based on the isotopic composition: Paratunsky geothermal area; Koryaksky-Avachinsky volcanogenic basin.