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.

There are 30 active volcanoes in the Kamchatka, and several of them are continuously active. In 2014-2015, four of the Kamchatkan volcanoes (Sheveluch, Klyuchevskoy, Karymsky and Zhupanovsky) had strong and moderate explosive eruptions.
Strong explosive eruption of volcanoes is the most dangerous for aircraft because in a few hours or days in the atmosphere and the stratosphere can produce about several cubic kilometers of volcanic ash and aerosols. Ash plumes and the clouds, depending on the power of the eruption, the strength and wind speed, can travel thousands of kilometers from the volcano for several days, remaining hazardous to aircraft, as the melting temperature of small particles of ash below the operating temperature of jet engines.
Annual Kamchatkan strong explosive eruptions with ash emissions by 8-15 km above sea level represent a real threat to modern jet aviation. To reduce the risk of aircraft encounters with volcanic ash clouds in the North Pacific region, since 2002, KVERT IVS FEB RAS conduct a daily satellite monitoring of 30 Kamchatkan volcanoes and visual and video monitoring of Klyuchevskoy, Sheveluch, Bezymianny, Koryaksky, Avachinsky, Mutnovsky and Gorely volcanoes. KVERT analyses seismic data for 9 volcanoes (Klyuchevskoy, Sheveluch, Bezymianny, Tolbachik, Kizimen, Karymsky, Koryaksky, Avachinsky and Gorely) from the Kamchatkan Branch of Geophysical Survey RAS.
KVERT send Volcano Observatory Notice for Aviation (VONA) by email to Airport Meteorological Center (AMC) at Yelizovo Airport; and the Tokyo Volcanic Ash Advisory Centers (VAAC), the Anchorage VAAC, the Washington VAAC, the Montreal VAAC, and the Darwin VAAC; aviation services, and scientists located throughout the North Pacific region. VONA/KVERT Releases are posted on the web site: http://www.kscnet.ru/ivs/kvert/
Since 2011, experts from IVS FEB RAS, Space Research Institute RAS, Computing Center FEB RAS and the Far Eastern Planeta Research Center have operated the information system “Monitoring of Volcanoes Activity in Kamchatka and the Kuriles” (VolSatView; http://volcanoes.smislab.ru) that uses all available satellite data (operative and long-term archive data), weather and on-ground observations, the results of computational modeling of ash clouds and plumes trajectories to ensure continues monitoring and study of volcanic activity in Kamchatka and the Kuriles.

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

Sheveluch is one of the most active volcanoes in Kamchatka. Its modern edifice includes three main elements: Old Sheveluch, an ancient caldera and Young Sheveluch. On the southeastern slope of Old Sheveluch, there is a group of ancient extrusive domes (from south to north): Sherokhovataya, Krasnaya, Karan, and Sopochka na sklone. Only in the area of the Karan dome are there heated areas with mofets temperature of 70–96°C. After the powerful explosive eruption of the Sheveluch volcano in April 2023, the gas–steam activity of the Karan dome intensified, and a thermal anomaly began to be noted in satellite images of the area of this dome. On April 26, 2024, in a JPSS-1 satellite image at 15:07 UTC, Kamchatkan Volcanic Eruption Response Team scientists discovered a bright thermal anomaly in the area of the Karan dome; that is, they recorded a unique phenomenon on this day: the birth of a new volcanogenic formation – the new lava dome. It was given the name 300 years of the Russian Academy of Sciences. As of June 7, 2024, the size of the new dome was 800 × 500 m and the area of the dome crown was 0.19 km2. The eruption of the new lava dome 300 Years of the Russian Academy of Sciences is continuing.

The powerful explosive eruptions with large volumes of volcanic ash pose a great danger to the population and jet aircraft. Global experience in monitoring volcanoes and observing changes in the parameters of their thermal anomalies is successfully used to analyze the activity of volcanoes and predict their danger to the population. The Kamchatka Peninsula in Russia, with its 30 active volcanoes, is one of the most volcanically active regions in the world. The article considers the thermal activity in 2015–2022 of the Klyuchevskoy, Sheveluch, Bezymianny, and Karymsky volcanoes, whose rock composition varies from basaltic andesite to dacite. This study is based on the analysis of the Value of Temperature Difference between the thermal Anomaly and the Background (the VTDAB), obtained by manual processing of the AVHRR, MODIS, VIIRS, and MSU-MR satellite data in the VolSatView information system. Based on the VTDAB data, the following “background activity of the volcanoes” was determined: 20 °C for Sheveluch and Bezymianny, 12 °C for Klyuchevskoy, and 13–15 °C for Karymsky. This study showed that the highest temperature of the thermal anomaly corresponds to the juvenile magmatic material that arrived on the earth’s surface. The highest VTDAB is different for each volcano; it depends on the composition of the eruptive products produced by the volcano and on the character of an eruption. A joint analysis of the dynamics of the eruption of each volcano and changes in its thermal activity made it possible to determine the range of the VTDAB for different phases of a volcanic eruption.

In 2005, six major eruptions of four Kamchatka volcanoes (Bezymyannyi, Klyuchevskoy, Shiveluch, and Karymskii) occurred and the Avachinskii, Mutnovskii, and Gorelyi Kamchatka volcanoes and the Ebeko and Chikurachki volcanoes in northern Kurils were in a state of increased activity. Owing to a close collaboration between the KVERT project, Elizovo airport meteorological center, and volcanic ash advisory centers in Tokyo, Anchorage, and Washington (Tokyo, Anchorage, and Washington VAACs), all necessary measures for safe airplane flights near Kamchatka were taken and fatal accidents related to volcanic activity did not occur.

Large explosive eruptions of volcanoes pose the highest hazard to modern jet f lights, because such eruptions can eject as much as several cubic kilometers of volcanic ash and aerosol into the atmosphere during a few hours or days. The year 2016 saw eruptions on 5 of the 30 active Kamchatka volcanoes (Sheveluch, Klyuchevskoy, Bezymianny, Karymsky, and Zhupanovsky) and on 3 of the 6 active volcanoes that exist on the North Kuril Islands (Alaid, Ebeko, and Chikurachki). Effusive activity was observed on Sheveluch, Klyuchevskoy, Bezymianny, and Alaid. All volcanoes showed explosive activity. The large explosive events mostly occurred from September through December (Sheveluch), a moderate ash emission accompanied the entire Klyuchevskoy eruption in March–November, and explosive activity of Karymsky, Zhupanovsky, Alaid, and Chikurachki was mostly observed in the earlie r half of the year. The ash ejected in 2016 covered a total area of 600 000 km2, with 460 000 km2 of this being due to Kamchatka volcanoes and 140 000 km2 to the eruptions of the North Kuril volcanoes. The activity of Sheveluch, Klyuchevskoy, and Zhupanovsky was dangerous to international and local f lights, because the explosions sent ash to heights of 10–12 km above sea level, while the eruptions of Bezymianny, Karymsky, Alaid, Ebeko, and Chikurachki were dangerous for local flights, since the ash did not rise higher than 5 km above sea level.