Annually, from 3 to 6 Kamchatkan volcanoes produce eruptions, during which the explosions eject ash to 10-15 km a.s.l., and ash clouds spread thousands of kilometers from volcanoes. Ash clouds pose a serious threat to the modern jet aviation. Scientists of KVERT have conduct daily monitoring of Kamchatka volcanoes since 1993, to mitigate volcanic hazards to airline operations and population. Since 2014, satellite monitoring of volcanoes they carried out with the VolSatView (Remote monitoring of active volcanoes of Kamchatka and the Kuril Islands) (http://volcanoes.smislab.ru) IS. The system utilize all the available satellite data, weather and video observations to ensure continues monitoring and study of volcanic activity in Kamchatka. The VolSatView work with distributed information resources and computation systems. This work was supported by the Russian Science Foundation, project No. 16-17-00042.

The Sheveluch volcano is the most active volcano in Kamchatka. The paroxysmal explosive eruption of the volcano that destroyed the lava dome in the volcanic crater continued on April 10–13, 2023. According to various satellite data, the height of the separate eruptive clouds probably exceeded 15 km above sea level. A powerful cyclone, which dominated the entire Kamchatka Peninsula, pulled the eruptive cloud to the west, turned it to the south, stretched it to the north, and directed it to the east from the volcano. The dynamics of the development of ash and aerosol clouds of this eruption is reflected in the animations made from a series of Himawari-9 satellite images in the VolSatView IS from 08:00 UTC on April 10 to 07:00 UTC on April 14 (http://d33.infospace.ru/jr_d33/materials/2023v20n2/283-291/1683110898.webm) and of the Arctica-M1 satellite from 16:00 to 21:30 UTC on April 10 (http://d33.infospace.ru/jr_d33/materials/2023v20n2/283-291/1683821166.webm). It was noted that the eruptive column was not vertical: for example, at the initial moment of the eruption on April 10 at 13:20 UTC, it deviated to the north–northeast; on April 11, at 12:00 UTC to the northwest; and, on April 12, at 7:00 UTC to the southwest. During the paroxysmal eruption, sulfur dioxide continuously entered the atmosphere, the maximum amount of which was released on April 10–11, as a result of the explosive destruction of the lava dome of the Sheveluch volcano. Ash clouds along with aerosol clouds on April 10–13 were stretched into a strip more than 3500 km long from west to northeast. On April 21–22, the Sheveluch aerosol cloud was observed in the region of the Scandinavian Peninsula. The total area of the territory of Kamchatka and the Pacific Ocean where ash and aerosol plumes and clouds were observed during the April 10–13 eruption was about 3280000 km2. The paroxysmal eruption of Sheveluch volcano belongs to the sub-Plinian type because it is characterized by a large height of the eruptive cloud and a long event duration. For this eruption, the Volcanic Explosivity Index is estimated to be 3–4. A detailed description of the paroxysmal explosive eruption of the Sheveluch volcano and the spread of the eruptive cloud was performed based on data from various satellite systems (Himawari-9, NOAA-18/19, GOES-18, Terra, Aqua, JPSS-1, Suomi NPP, Arctica-M1, etc.) in the information system “Remote Monitoring of Kamchatka and Kuril Islands Volcanic Activity” (VolSatView, http://kamchatka.volcanoes.smislab.ru).

There are 30 active volcanoes in the Kamchatka, and several of them are continuously active. In the XX-XXI centuries 17 volcanoes of Kamchatka erupted. During this time, 183 volcanic eruptions occurred, including three catastrophic eruptions (Ksudach, 1907; Bezymianny, 1956; Sheveluch, 1964). Strong explosive eruptions of volcanoes were the most dangerous for human society because they produce in a few hours or days to the atmosphere till 2-3 cubic kilometers of volcanic products. Ash plumes and the clouds, depending on the power of the eruptions, the strength and wind speed, to traveled thousands of kilometers from the volcanoes for several days. Any territory of the Kamchatka Peninsula has repeatedly been exposed to ash falls, the thickness of ash in settlements was from less than 1 mm to 4-5 cm. Strong explosive eruptions of volcanoes Sheveluch, Klyuchevskoy, Bezymianny, Kizimen, Karymsky, Zhupanovsky, Avachinsky, Kambalny were the most dangerous for air travel not only over Kamchatka, but also hundreds of kilometers away from the peninsula.
The strong explosive and effusive eruptions of Sheveluch, Klyuchevskoy, Bezymianny, Kizimen and the other were often accompanied by the formation of hot mud flows (lahars), which sometimes disrupted transport communications (roads, bridges) of nearby settlements.
Scientists of KVERT monitor Kamchatkan volcanoes since 1993. Thanks to satellite monitoring of volcanoes carried out by KVERT, several explosive eruptions were predicted in the XXI century, and early warnings were made to the population about possible ashfalls in settlements and about hazard to aviation.

The active andesitic Zhupanovsky Volcano consists of four coalesced stratovolcano cones. The historical explosive eruptions of 1940, 1957, and 2014‒2016 discharged material from the Priemysh Cone. The recent Zhupanovsky eruptions were studied using satellite data supplied by the Monitoring of Active Volcanoes in Kamchatka and on the Kuril Islands information system (VolSatView), as well as based on video and visual observations of the volcano. The first eruption started on October 22 and lasted until October 24, 2013. Fumaroles situated on the Priemysh western slope were the centers that discharged gas plumes charged with some amount of ash. The next eruption started on June 6, 2014 and lasted until November 20, 2016. The explosive activity of Zhupanovsky was not uniform in 2014–2016, with the ash plumes being detected on satellite images for an approximate total duration of 112 days spread over 17 months. The most vigorous activity was observed between June and October, and in November 2014, with a bright thermal anomaly being nearly constantly seen on satellite images around Priemysh between January and April 2015 and in January–February 2016. The 2014–2016 eruption culminated in explosive events and collapse of parts of the Priemysh Cone on July 12 and 14, November 30, 2015, and on February 12 and November 20, 2016.

The work is devoted to the activity analysis of Kamchatka and the Kuril Islands volcanoes in 2019-2020.The activity of the volcanoes was estimated based on the processing of data from daily satellite monitoring carried out using the information system “Remote monitoring of Kamchatkan and the Kuriles volcanoes activity (VolSatView)”. The activity of the Kamchatka and the Kuril Islands volcanoes considered based on the analysis of their thermal anomalies. Analysis of the characteristics of thermal anomalies over volcanoes was carried out in KVERT IS. Analysis of the temperature of thermal anomalies of volcanoes in the Kuril - Kamchatka region in 2019-2020 shows a significantly higher activity of the Kamchatka volcanoes in comparison with the Kuril volcanoes.