Sheveluch Volcano is one of the most productive volcanoes in Kamchatka, characterized during the Holocene by alternating periods of predominantly extrusive and explosive activity. New data on the volumetric parameters of fine ash emissions have been obtained, indicating that the mass of erupted material of dacitic composition during a single moderate-strength eruption can exceed 2 million tons. In those years when gas and ash cloud eruptions were particularly frequent (sometimes more than twenty per month), the total mass of fine dacitic ash can be comparable to the annual discharge of andesitic material (extrusive lavas and tephra), providing a new perspective on the genesis of andesites.

В работе описана активность вулкана Ключевской в 2025 г., в том числе его деятельность после окончания вершинного извержения.

В работе описана активность вулканов Камчатки и Курил в 2025 г. Эксплозивные извержения вулканов Шивелуч, Ключевской и Безымянный представляли опасность для международных и местных авиаперевозок, Карымский, Крашенинникова и Эбеко − для местных авиаперевозок.

В работе описана активность вулкана Крашенинникова в 2025-2026 гг. Первое историческое извержение вулкана началось 2 августа 2025 г. и продолжается до настоящего времени.

В работе описана активность вулкана Безымянный в 2025 г. и состав тефры извержений. Произошло два пароксизмальных эксплозивных извержения вулкана в апреле и ноябре, они представляли опасность для международных и местных авиаперевозок.

From August 14 to 26, 2024, a comprehensive expedition of the Institute of Volcanology and Seismology of the Far Eastern Branch of the Russian Academy of Sciences worked at the Karymsky Volcanic Center (KVC). Research was conducted to restore the hydrochemistry of Karymsky Lake after the catastrophic underwater eruption that occurred in the Academy of Sciences caldera in early January 1996, and a detailed geochemical survey was made of all thermal manifestations in the center. Seismic observations and assessment of the emission of volcanic gas SO2 were carried out, as carried out by the Karymsky volcano, the volume of above-ground CO2 degassing was measured at the thermal sites of the Karymskaya and Academy of Sciences calderas, and samples of spring water were taken to determine the chemical composition and analyze trace elements. Infrared survey and aerial photography of the southern sector of the KVC were carried out.
This publication presents the first results of seismic observations in conjunction with an assessment of the emission of the SO2 volcanic gas, information on the chemical and mineral composition of the springs of the Karymskaya caldera, and aerial photography data of the volcano.

Klyuchevskoy is one of the most powerful active basaltic volcanoes in the world. Information about its eruptions has been known since 1697. This paper describes the summit eruptions of the volcano from 1935 to 1999, and analyzes such eruptions from 1935 to 2024. Between 1935 and 2024 30 summit eruptions occurred: 11 explosive eruptions lasting from 6 to 1110 days and 19 explosive–effusive eruptions lasting from 26 to 1100 days. It was found that paroxysmal phases of eruptive events with ash ascent to the maximum height (15 km above sea level) are characteristic only of explosive–effusive eruptions of the volcano. It was noted that paroxysmal phases of eruptions were observed, as a rule, 6–15 days or 1–2.5 months (rarely 2 days or 7 months) before their end, i.e., an increase in the power of ash ascent from the volcanic crater in some cases led to the emptying of the magma reservoir (for example, the eruption of 1994) and in other cases to the rise of new portions of lava to the daylight surface (for example, the eruptions of 1944 and 1987–1990).

In 2024, explosive eruptions of the Sheveluch, Klyuchevskoy, Bezymianny, and Karymsky volcanoes occurred at Kamchatka, and the Ebeko volcano at the Northern Kurile Islands. On April 26, 2024, a new lava dome, named after the 300 years of the Russian Academy of Sciences began to grow in the area of the Karan old dome on the Stary Sheveluch volcano western slope. Powerful explosive eruptions that destroyed the new dome were observed on August 17–18, September 1–2, and November 7–10, 2024: eruptive columns rose up to 11 km above sea level, ash plumes extended for 2400 km mainly to the northeast and east of the volcano. The summit explosive eruption of the Klyuchevskoy volcano lasted from December 27, 2023 to January 2, 2024: explosions send ash up to 7 km above sea level and ash plumes extended for 230 km to the northwest of the volcano. The paroxysmal explosive eruption of Bezymianny volcano occurred on July 24, 2024: the eruptive cloud rose up to 12 km above sea level, the eruptive and coignimbrite clouds moved, respectively, to the northeast and northwest up to 2500 km from the volcano. The Bezymianny eruption forecast, which was published on the KVERT website, was realized 39 h 40 min later. Explosive activity of the Karymsky volcano was observed from June 20 to November 12, 2024: explosions raised ash up to 6 km above sea level and ash clouds moved for 665 km, mainly to the east and northeast of the volcano. In 2024, 287 explosive events occurred on the Ebeko volcano with ash removal up to 4.5 km above sea level. During the explosive eruptions, the Sheveluch and Bezymianny volcanoes were dangerous for international and local air travel and the Klyuchevskoy, Karymsky, and Ebeko volcanoes were dangerous for local air travel.

This paper describes the chemical composition of the thermal waters discharging on the northwestern slope of the active Ebeko Volcano in the Yuriev River valley. We are using continuous multiyear observations of the evolution of chemical and isotope compositions to estimate the response of volcanic events to the state of the hydrothermal system. It is shown that phreatomagmatic eruptions of the volcano were preceded by a change in the chemical and isotope compositions of thermal waters caused by increased inflow of magmatic volatiles into the system. The springs are observed to show increased concentrations of anion-generating components (chloride, sulfate, and fluorine ions) with concurrent increases in heavier isotopes of oxygen and hydrogen (deuterium) toward “andesitic” water. Recalling that the changes were detected a few months before the eruption, we infer that such geochemical effects can serve as predictive markers when monitoring the state of the volcano.