The area of Central Kamchatka limited by latitudes of 52.5 and 54 degrees includes six active volcanoes (Avacha, Koryaksky, Zhupanovsky, Mutnovsky, Gorely and Opala), as well as a number of dormant and extinct stratovolcanoes, monogenic cones and large calderas. Furthermore, it contains the Malko-Petropavlovsk fracture zone (MPZ), which marks the boundary between two distinct subduction regimes to the south and to the north. We present a new seismic tomography model for this area, which was constructed based on the joint use of data of the Kamchatkan permanent seismic stations and a temporary network installed in the region in 2019–2020. A series of synthetic tests have demonstrated fair resolution of the derived seismic velocity structures in the crust and in the mantle wedge down to ~150 km. The distributions of the P and S wave velocities, and especially the Vp/Vs ratio, clearly highlight the connection between the volcanic centers in Central Kamchatka and the subducting slab. At depths below 40 km depth, we observe two large low-velocity anomalies centered below Zhupanovsky and Mutnovsky volcanoes and covering all other volcanoes in the area. In the vertical sections, the corresponding anomalies of high Vp/Vs ratio have mushroom shapes with the heads spreading along the bottom of the crust, which probably represent the underplating of magma material that feeds the volcanoes of the groups. The tomography results also reveal some important tectonic features, such as a V-shaped fault system in the Avacha Graben, which is the part of the MPZ.

Der Geologe Karl von Ditmar erkundete von 1851 bis 1855 im Auftrag der russischen Regierung die Bodenschätze Kamčatkas. Dabei erforschte er das Land und seine Bevölkerung aber weit über diesen Autrag hinaus, was seine eindrucksvollen Reisebeschreibungen zeigen. So verbrachte er im Sommer 1853 als erster Forscher längere Zeit bei den Korjaken auf der Halbinsel Tajgonos. Der 1890 erschienene erste Teil seines Werkes enthält den ausführlichen Bericht seiner Reise nach den Tagebüchern, ein getrennt erscheinender zweiter Teil die systematische Darstellung der Natur und der Geschichte Kamčatkas.

Der Geologe Karl von Ditmar erkundete von 1851 bis 1855 im Auftrag der russischen Regierung die Bodenschätze Kamčatkas. Dabei erforschte er das Land und seine Bevölkerung aber weit über diesen Autrag hinaus, was seine eindrucksvollen Reisebeschreibungen zeigen. So verbrachte er im Sommer 1853 als erster Forscher längere Zeit bei den Korjaken auf der Halbinsel Tajgonos. Der 1900 erschienene zweite Teil seines Werkes enthält die systematische Darstellung der Natur und der Geschichte Kamčatkas sowie ein geografisches Lexikon.

The Volcanoes of the World database is a catalog of Holocene and Pleistocene volcanoes, and eruptions from the past 12,000 years.

The Paratunsky and Verkhne-Paratunsky fields (Kamchatka, Russia) are examples of low-temperature nitrogen (LT N2) geothermal systems that are widespread throughout the world and are believed to have formed as a result of penetration of meteoric water into deep faults and heat mining from host rocks under background heat flow and temperature gradient conditions. However, no one has tested the geologically long-term thermal recharge capability of such systems to be recharged by heat and water under real 3D environmental conditions. A solution to this unsolved problem has been obtained here using specific examples. The two closely spaced reservoirs are 15 km apart, composed of volcanogenic rocks of Eocene-Quaternary age and characterized by shallow permeability reservoirs underlain by extinct volcanic conductive roots, where 60–90 ◦C thermal N2 SO4–Na waters circulate. The Paratunsky reservoir has a 60-year history of intensive exploitation (150–250 kg/s), while the Verkhne-Paratunsky reservoir is just being brought into development. Application of a simple radial-cylindrical (RZ) model to the Verkhne-Paratunsky geothermal system allowed us to show the principal possibility of formation of a circulating hydrothermal system in a structure with a radius of about 15 km and a circulation depth of -3 km within the first thousand years at a temperature of 60 ◦C and a flow rate of 60 kg/s.
Then a three-dimensional numerical (3D) model of the Verkhne- Paratunsky and Paratunsky low-temperature nitrogen geothermal system was constructed, assuming that the upper part of the pre-Cretaceous basement is a permeable conduit surface and the roots of extinct volcanoes provide vertical down-flow recharge and up-flow discharge of this natural heat and mass circulation system. This numerical model covers all significant thermal discharge features, recharge area of the adjacent highlands. Subsequent modeling confirms the possibility of increasing the temperature to 80 ◦C, diluting the initially brine-saturated NaCl permeable reservoirs and maintaining up-flow rate at observed values for thousands of years from the onset of hydrothermal circulation.

Late Pleistocene-Holocene volcanism in Kamchatka results from the subduction of the
Pacific Plate under the peninsula and forms three volcanic belts arranged in en echelon manner
from southeast to northwest. The cross-arc extent of recent volcanism exceeds 250 km and
is one of the widest worldwide. All the belts are dominated by mafic rocks. Eruptives with
SiO2>57% constitute ~25% of the most productive Central Kamchatka Depression belt and
~30% of the Eastern volcanic front, but <10% of the least productive Sredinny Range belt.
All the Kamchatka volcanic rocks exhibit typical arc-type signatures and are represented
by basalt-rhyolite series differing in alkalis. Typical Kamchatka arc basalts display a strong
increase in LILE, LREE and HFSE from the front to the back-arc. La/Yb and Nb/Zr increase
from the arc front to the back arc while B/Li and As, Sb, B, Cl and S concentrations decrease.
The initial mantle source below Kamchatka ranges from N-MORB-like in the volcanic front
and Central Kamchatka Depression to more enriched in the back arc. Rocks from the Central
Kamchatka Depression range in 87Sr/86Sr ratios from 0.70334 to 0.70366, but have almost
constant Nd isotopic ratios (143Nd/144Nd 0.51307–0.51312). This correlates with the highest
U/Th ratios in these rocks and suggest the highest fluid-flux in the source region.
Holocene large eruptions and eruptive histories of individual Holocene volcanoes have been
studied with the help of tephrochronology and 14C dating that permits analysis of time-space
patterns of volcanic activity, evolution of the erupted products, and volcanic hazards.

On Kamchatka, detailed geologic and geomorphologic mapping of young volcanic terrains and observations on historical eruptions reveal that landslides of various scales, from small (0.001 km3) to catastrophic (up to 20–30 km3), are widespread. Moreover, these processes are among the most effective and most rapid geomorphic agents. Of 30 recently active Kamchatka volcanoes, at least 18 have experienced sector collapses, some of them repetitively. The largest sector collapses identified so far on Kamchatka volcanoes, with volumes of 20–30 km3 of resulting debris-avalanche deposits, occurred at Shiveluch and Avachinsky volcanoes in the Late Pleistocene. During the last 10,000 yr the most voluminous sector collapses have occurred on extinct Kamen' (4–6 km3) and active Kambalny (5–10 km3) volcanoes. The largest number of repetitive debris avalanches (> 10 during just the Holocene) has occurred at Shiveluch volcano. Landslides from the volcanoes cut by ring-faults of the large collapse calderas were ubiquitous. Large failures have happened on both mafic and silicic volcanoes, mostly related to volcanic activity. Orientation of collapse craters is controlled by local tectonic stress fields rather than regional fault systems.

Specific features of some debris avalanche deposits are toreva blocks — huge almost intact fragments of volcanic edifices involved in the failure; some have been erroneously mapped as individual volcanoes. One of the largest toreva blocks is Mt. Monastyr' — a ∼ 2 km3 piece of Avachinsky Somma involved in a major sector collapse 30–40 ka BP.

Long-term forecast of sector collapses on Kliuchevskoi, Koriaksky, Young Cone of Avachinsky and some other volcanoes highlights the importance of closer studies of their structure and stability.