Eight-year (1996-2003) multidisciplinary biohydrochemical research provided data for this brief description of abiotic processes varying in time in Lake Karymskii and of simultaneous successions of plankton and benthic algae-bacterial communities following the 1996 catastrophic underwater eruption. One notes the well-ex-. pressed allochtonic character of plankton flora, a mosaic and local formation of benthic coenoses, the dominating influence of the volcanic factor on the overall evolution of limnic biocoenosis.

The main effusives of the ancient and present cones of Tyatya Volcano differ in the content of CaO, Al2O3, Sr, K2O and most incoherent elements. Geochemical evidence and also results of numerical modeling suggest that basalts of the initial stage of formation of the volcano were the result of the relatively high degree of melting of mantle source and subsequent deep fractionation in its rise to the surface accompanied with plagioclase accumulation. Considering that the lavas of the ancient cone of Tyatya Volcano are in many respects petrologically close to basic volcanics of the Miocene stage of Kunashir Island formation, the results of the relevant investigations can have implications for understanding the features of the evolution of volcanism in the Kuril island arc on the whole.

It is shown in the present study, in contrast to what has been thought geretofore, that Sredyaya Mt in the Klyuchevskoi Volcanic Group, Kamchatka is not a volcanic formation of its own, but a giant (of volume about 1 km3) allochthon. The allochthon resulted from the collapse and displacement of an enormous monolithic block from the summit of Pra-blizhnyaya Sopka Volcano which came into being when a Hawai'ian type caldera formed there about 8600 14C B. P.

It is shown that the young andesite-basaltic cone of Avacha Volcano was more complex, of the "cone-in-cone" type, in the 18th and early 19th century than is now the case. The upper cone was then nested in a crater of diameter 350-400 m, its base being at absolute heights of 2720 m, while the summit crater had a diameter of 50-100 m at absolute heights of 2800-2850 m. Since the summit crater was small, S.P. Krasheninnikov was induced to call Avacha Volcano a "peaked" one in 1738. The major eruption of 27-29 June, 1827 nearly anni-hilated the nested upper cone, while Young Cone of Avacha Volcano acquired nearly the present-day outward shape.

The actual collective monograph presents the results of both theoretical and experimental studies of the multi-disciplinary problem on volcanic hazard assessment and development of techniques for prediction of catastophic eruptions. The volcanism of Kamchatka and other regions of Russia has been analyzed. On the basis of geological, volcanological and tephrachronological studies including radiocarbon dating, there have been defined certain groups of volcanoes on different stages of evolution. At the same time the problem of determination of the internal structure of volcanic dome using modem theoretical methods and technologies is well investigated. The new techniques of estimation of volcanic hazard were developed. Whenever ti is required, theoretical approaches are confirmed by results of in-field observations.

The book will satisfy the needs of Earth sciences specialists from a variety of backgrounds, volcanology, geo-mechanics, ecology, industrial constuction applications and hazard assessment.

The role of flowing peripheral and crustal magma chambers in the Mutnovskii-Gorelyi volcanic cluster, Kamchatka is demonstrated for the thermal supply of the Mutnovskii hydrothermal system. A numerical study of the growth and evolution in size for several upper crustal magma chambers of various ages has been carried out for the Mutnovskii-Gorelyi volcanic cluster, which has a common magma system as the source of supply. The influence of fluids for heat transfer to the host rocks has been incorporated in our models. The results from this modeling of magma chamber growth were used to deal with the nonstationary problem of estimating the temperature distribution around size-varying magma chambers. This enabled us to compute the temperature fields around the chambers and to assess the heat stored in the host rocks. In addition, we found how much of the heat flow in the Mutnovskii geothermal field can be used to produce consumable energy.