The Sheveluch volcano is the northernmost active volcano in Kamchatka. In this work, we describe the activity of the new 300 Years of the RAS lava dome of volcano in 2024–2025. Explosive eruptions of the dome were observed on August 17–18, September 1–2, and November 7–10, 2024: eruptive columns rose up to 9, 8, and 11 km above sea level, respectively, and ash plumes were extended for 2400, 1100, and 3000 km to the east and northeast of the volcano. The results of detailed real-time monitoring of the volcanic eruption are presented using a video surveillance system and various satellite data from The Remote Monitoring of Volcanic Activity in Kamchatka and the Kurile Islands information system (VolSatView, http://kamchatka.volcanoes.smislab.ru).

Exhalation ore mineralization is developing in the crater part of the active Kudryavy volcano. Lithogeochemical sampling results have revealed that Re, Au, Ag, As, Bi, Cd, Cu, Ge, In, Mo, Pb, S, Sb, Se, Sn, Te, Tl, W, Zn, Rb, and Cs accumulate in solid fumarole formations. These elements are transported by high-temperature volcanic gases and are deposited in mineral phases in the near-surface horizons of fumarole fields under decreasing temperature conditions. The contents of rhenium and other metals in volcanic deposits of fumarole fields locally reach values characteristic of ore deposits. Zoning of lithogeochemical anomalies in ore element associations has been revealed, expressed by the series Re, Mo, W, Au, Cu, Ag, Zn, Cs, Ge → In → Bi, Cd, Pb, Sn, Tl → As, Sb, Se, Te, (Cu, Ag, Au) in the direction from the highest-temperature fumarole fields to less hot, reflecting their temperature zoning. It is demonstrated that lateral geochemical zoning is caused both by the ore element contents in fumarole gases, which depend on temperature, and by differences in the optimal temperature ranges in which various elements precipitate from gases. Signatures for similar exhalation mineral formation processes have been revealed that occurred in the recent geological past at the neighboring extinct Sredny volcano. This suggests the occurrence of similar processes within other volcanic systems of Iturup Island, which increases the prospects for detecting complex exhalation-related manifestations of rare, base, and noble metals.

The Sea of Okhotsk is the southernmost area in the Northern Hemisphere where seasonal sea ice is produced every year. The formation of sea ice drives thermohaline circulation in the Sea of Okhotsk, and this circulation supports the high productivity in the region. However, recent reports have indicated that sea-ice production in the Sea of Okhotsk is decreasing, raising concern that the decreased sea ice will affect not only circulation but also biological productivity in the sea. To reconstruct climatic changes in the Sea of Okhotsk region, we analyzed an ice core obtained from Ichinskaya Sopka (Mount Ichinsky), Kamchatka. We assumed that the remarkable negative peaks of δD in the ice core were caused by expansion of sea ice in the Sea of Okhotsk. Melt feature percentage (MFP), which indicates summer snowmelt, showed high values in the 1950–60s and the mid-1990s–2000s. The high MFP in the 1950–60s was assumed to be caused by an increase in cyclone activity reaching Kamchatka during a negative period of the Pacific Decadal Oscillation index, and that in the 1990–2000s may reflect the increase in solar irradiation during a positive period of the summer Arctic Oscillation index.