The Kamchatka Peninsula is rightfully considered a zone of present-day volcanic activity. There are approximately 1,000 volcanoes (one-tenth of all the volcanoes on the planet), 29 of which are active. The volcanoes have different types of eruptions: some expel lava, others force out clouds of volcanic ash, and some eject blocks of viscous magma.
The history of Kamchatka is inextricably linked to volcanic eruptions. Indigenous peoples of the area long blamed the eruptions on the evil spirits that inhabited "yurts of fire".
Currently, Kamchatka residents most frequently experience the eruptions of the Klyuchevskoy group of 14 volcanoes. The latter includes Klyuchevskoy, the highest volcano in Eurasia, and the neighbouring Bezymyanny, which erupts exactly twice a year, making it the most predictable volcano in Kamchatka. These volcanoes are a unique natural attraction and draw in scientists, tourists and mountain climbers from all over the world because of their giant proportions, pronounced and varied activity and their dense clustering in a relatively small area.
The regular fall of volcanic ash in the area around the Klyuchevskoy, Bezymyanny, and Shiveluch volcanoes, is rich in chemical elements and so serves as a generous fertiliser to the soil and provides for good vegetable harvests.
The most active volcano on the peninsula is the constantly erupting Karymsky volcano. And the most unusual one is the Maly Semyachik volcano, which has an acid lake in one of its craters. The water temperature in this opaque lake ranges from 27°C to 42°C, and the mineral level is the same as in a solution of sulfuric and hydrochloric acids of medium concentration. The lake is peculiar not only for its deep-blue colour, but also for its size. It is approximately 500 metres wide and up to 140 metres deep. The most mysterious volcano is the flat Tolbachik volcano, the slopes of which look like alien landscapes. The first Soviet lunar rovers were tested there at one point.
The crater of a giant volcano was discovered on the peninsula several years ago. Its open caldera extends from the headwaters of the Paratunka River to the Banny springs. This volcano erupted around 1.5 million years ago.
The Klyuchevskoy, Koryaksky, and Kronotsky volcanoes are considered the most beautiful among the remarkable volcanoes of Kamchatka. Located 30 kilometres from the region's capital, the so-called home volcanoes, the Avachinsky, the Koryaksky, and the Kozelsky, are considered symbols of Petropavlovsk-Kamchatsky and the Yelizovo District. They can be seen from virtually anywhere in the city.
Following an eruption, many volcanoes remain inactive for many years, entering a stage of fumarole activity. Fumarole is an emission of volcanic gases with temperatures ranging from 300° to 800° C. In addition to water vapour, fumaroles also contain hydrogen sulfide, and sulfur and carbon dioxide. They actively transform the nearby terrain: acid rivers enriched with iron and aluminium flow along the land, sulfur crystallises on the rocks near the fumaroles, and in some areas deposits of zinc, lead, arsenic, and mercury are formed.