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Records: 1741
Melekestsev Ivan V., Ponomareva Vera V., Volynets Oleg N. Kizimen volcano, Kamchatka — A future Mount St. Helens? // Journal of Volcanology and Geothermal Research. 1995. Vol. 65. № 3-4. P. 205-226.    Annotation
We studied the tectonic setting, morphology, geologic structure, history of eruptive activity and evolution of the composition of the erupted material of Kizimen volcano, Kamchatka, from the moment of its origination 11–12 thousand years ago to the present time. Four cycles, each 2–3.5 thousand years long, were distinguished that characterize the activity of the volcano. All of the largest eruptions were dated, and their parameters determined. We also estimated the volume and the mass of the erupted products, the volcanic intensity of eruption of material during periods of high activity, and the amount of material the volcano ejected at different stages of its formation. It has been shown that the evolution of the composition of the rocks erupted (from dacite to basaltic andesite) takes place as a result of mixing of dacitic and basaltic magma. It is suggested that future eruptions that may take place at Kizimen may be similar to those at Bandai (1888) and Mount St. Helens (1980) volcanoes.

Melnik O., Lyakhovsky V., Shapiro Nikolay M., Galina N., Bergal-Kuvikas Olga Deep long period volcanic earthquakes generated by degassing of volatile-rich basaltic magmas // Nature Communication. 2020. Vol. 11. № 3918. doi: 10.1038/s41467-020-17759-4.    Annotation
Deep long-period (DLP) earthquakes observed beneath active volcanoes are sometimes considered as precursors to eruptions. Their origin remains, however, unclear. Here, we present a possible DLP generating mechanism related to the rapid growth of gas bubbles in response to the slow decompression of over-saturated magma. For certain values of the gas and bubble content, the elastic deformation of surrounding rocks forced by the expanding bubbly magma can be fast enough to generate seismic waves. We show that amplitudes and frequencies of DLP earthquakes observed beneath the Klyuchevskoy volcano (Kamchatka, Russia) can be predicted by our model when considering pressure changes of ~107 Pa in a volume of ~103–104 m3 and realistic magma compositions. Our results show importance of the deep degassing in the generation of volcanic seismicity and suggest that the DLP swarms beneath active volcanoes might be related to the pulses of volatile-rich basaltic magmas rising from the mantle.
Melnikov D.V., Volynets Anna Spatial and morphometric analyses of Anaun monogenetic volcanic field (Sredinny Range, Kamchatka) // 7th International Maar Conference, Olot, Catalonia, Spain. 2018. P. 61    Annotation
Monogenetic volcanic fields are frequently located in the faulted area and in clusters which are associated with the particular geometry of the magmatic chambers and structures of the magma plumbing system in the crust. The method of cluster analyses of the spatial distribution and morphometric characteristics of the cinder cones was used in our research of the conditions of origin and evolution of one of the largest monogenetic fields in Kamchat-ka back-arc-the Anaunsky Dol, or Anaun MVF. Kamchat-ka subduction system is located at the northwestern part of the Pacific at the convergent boundary of the Okhotsk and Pacific plates. Today, Sredinny Range represents its back-arc part and is characterized by the wide distribution of the monogenetic volcanic fields: it has more than 1000 cinder cones, which deposits cover the area of about 8500 km2 (Laverov, 2005; Ogorodov et al., 1972) (Fig. 1). Sredinny Range has a complex structure with several volcanic provinces with different geological history and variable composition of products. Anaun monogenetic volcanic field occupies one of the lowest sections of the whole Sredinny Range. The youngest volcanism in this area (according to the geological map, it was formed in Quaternary times, although our geochemical research and isotopic dating shows its earlier age) is confined to the lowered block of basement rocks. Shield volcanoes, volcanic ridges, cinder and lava cones are located on a low-laying volcanic dale. We made an attempt to make a spatial analysis of distribution of the volcanic edifices and to quantitatively estimate the structural control of the magma plumbing channels. Based on a digital relief model (DEM SRTM, spatial resolution 30 m) we distinguished more than 100 morphometrically expressed cinder cones. For them, using semi-automatic mode, we estimated the morphometric characteristics: height, diameter of the basement, height/basement ratio, angle of the slope, volume of the edifice. With time, cinder cones change their shape due to the erosion processes. Therefore, finally the edifice height is decreased while the basement diameter increased. Determination of the morphometric parameters allowed us to compose a relative age scale for the cinder cones located in Anaun monogenetic volcanic field. Spatial analysis has shown that cones tend to form series of clusters, which are associated with the systems of lineaments. Statistically significant patterns in the cinder cones distribution were then compared with the strike of lineaments to estimate possible location of the magma feeding channels.
Melnikov Dmitry, Malik Nataliya, Chaplygin Ilya, Zelenski Mikhail First data on the volatile fluxes from passively degassing volcanoes of the Kuril Island arc // EGU General Assembly 2017. 2017. Vol. 19.
Melnikov Dmitry, Volynets Anna O. Remote sensing and petrological observations on the 2012–2013 fissure eruption at Tolbachik volcano, Kamchatka: Implications for reconstruction of the eruption chronology // Journal of Volcanology and Geothermal Research. 2015. Vol. 307. P. 89 - 97. doi: 10.1016/j.jvolgeores.2015.09.025.    Annotation
Abstract We present a reconstruction of the chronological sequence of events that took place during the first days of the 2012–2013 Tolbachik fissure eruption using petrological data and remote sensing methods. We were forced to use this approach because bad weather conditions did not allow direct observations during the first two days of the eruption. We interpreted infrared images from the scanning radiometer {VIIRS} Suomi {NPP} and correlated the output with the results of the geochemical study, including comparison of the ash, deposited at the period from 27 to 29 November, with the samples of lava and bombs erupted from the Menyailov and Naboko vents. We argue that the compositional change observed in the eruption products (the decrease of SiO2 concentration and K2O/MgO ratio, increase of MgO concentration and Mg#) started approximately 24 h after the eruption began. At this time the center of activity moved to the southern part of the fissure, where the Naboko group of vents was formed; therefore, this timeframe also characterizes the timing of the Naboko vent opening. The Naboko group of vents remained active until the end of eruption in September 2013.
Menyailov I.A., Nikitina L.P., Shapar V.N. Results of geochemical monitoring of the activity of Ebeko volcano (Kurile Islands) used for eruption prediction // Journal of Geodynamics. 1985. Vol. 3. № 3-4. P. 259 - 274. doi: 10.1016/0264-3707(85)90038-9.    Annotation
The monitoring of the state of active volcanoes, carried out using different parameters, including geochemical, is very important for studies of deep processes and geodynamics. All changes which occur within the crater before eruptions reflect the magma activation and depend on the deep structure of volcano. This paper gives the results of prolonged monitoring of Ebeko volcano, located in the contact zone between the oceanic and continental plates (the Kurile Island Arc). The geochemical method has been used as the basis for eruption prediction because the increase in the activity of the Ebeko in the period from 1963 to 1967 that ended in a phreatic eruption was not preceded by seismic preparation. Investigations carried out at Ebeko volcano give evidence that change of all the chosen geochemical parameters is a prognostic indicator of a forthcoming eruption. This change depends on the type of eruption, and the deep structure and hydrodynamic regime of the volcano.
Miller T.P., Kirianov V.Yu. Volcanic Ash Hazard along the North Pacific (NOPAC) Air Routs: Kurile Islands - Kamchatka - Alaska // Proc. of the 95 International workshop on Volcanoes Commemorating the 50-th Anniversary of the Mt. Shova-Shinzan: Short papers and Abstracts. 1995.
Mironov N.L., Portnyagin M.V. H2O and CO2 in parental magmas of Kliuchevskoi volcano inferred from study of melt and fluid inclusions in olivine // Russian Geology and Geophysics. 2011. Vol. 52. № 11. P. 1353 - 1367. doi: 10.1016/j.rgg.2011.10.007.    Annotation
This paper reports new FTIR data on the H2O and CO2 concentrations in glasses of 26 naturally quenched and experimentally partially homogenized melt inclusions in olivine (Fo85–91) phenocrysts from rocks of the Kliuchevskoi volcano. Measured H2O concentrations in the inclusions range from 0.02 to 4 wt.%. The wide variations in the H2O content of the inclusions, which do not correlate with the host olivine composition and contents of major elements in the melts, are explained by the H2O escape from inclusions via diffusion through the host olivine during the magma eruption and the following cooling. The largest H2O loss is characteristic of inclusions from lava samples which cooled slowly after eruption. The minimal H2O loss is observed for inclusions from rapidly quenched pyroclastic rocks. Parental magmas of the Kliuchevskoi volcano are estimated to contain 3.5 wt.% H2O. The new data imply a 40 °C lower mantle temperatures than that estimated earlier for the Kliuchevskoi primary melts. The concentrations of CO2 in glasses range from <0.01 to 0.13 wt.% and do not correlate with the type of studied inclusions and their composition. The calculated pressures of melt equilibria with H2O–CO2 fluid inside the inclusions are lower than 270 MPa. They are significantly lower than a pressure of 500 MPa calculated from the density (~0.8 g/cm3) of cogenetic fluid inclusions in high-Fo olivine. The significant pressure drop inside the melt inclusions after their trapping in olivine might be due to the H2O loss and redistribution of CO2 from melt to daughter fluid phase. Compared with melt inclusions, cogenetic fluid inclusions provide independent information about the crystallization pressures of olivine and initial CO2 content in the Kliuchevskoi magma, which were estimated to be at least 500 MPa and 0.35 wt.%, respectively. The maximum CO2 concentrations in the primary Kliuchevskoi melts are estimated at 0.8–0.9 wt.%. The decompression crystallization of the Kliuchevskoi magmas starts at depths of 30–40 km and proceeds with a continuous decrease in CO2 content and an increase (up to 6–7 wt.%) and then a decrease (at <300 MPa) in H2O content in melts, which explains the origin of the whole spectrum of rocks and melt inclusions of the Kliuchevskoi volcano.
Muravyev Y.D., Fedotov S.A., Budnikov V.A., Ozerov A.Yu., Maguskin M.A., Dvigalo V.N., Andreev V.I., Ivanov V.V., Kartasheva L.A., Markov I.A. Activity in the Karymsky Center in 1996: Summit Eruption at Karymsky and Phreatomagmatic Eruption in the Akademii Nauk Caldera // Volcanology and Seismology. 1998. Vol. 19. № 5. P. 567-604.    Annotation
Data are presented from studies of volcanoes in the Karymsky long-living volcanic center, Kamchatka in 1996. We examine the dynamics and rock composition for eruptions that started simultaneously on Karymsky Volcano and in the Akademia Nauk caldera. The effusive-explosive eruption of Karymsky Volcano was resumed after a 14-year repose period, producing about 30 million tons of andesite-dacite discharges through the summit vent. Long-continued eruptive activity of that volcano is supposed to go on during the near future. Simultaneously with this activity, typical of Karymsky Volcano, a subaquaceous explosive eruption was observed in the lake that occupies the Akademia Nauk caldera 6 km south of the volcano for the first time in Kamchatka during the historical period. An edifice arose in the northern part of Lake Karymsky during 18 hours of this eruption consisting of basaltic and basaltic andesite pyroclastic material surrounding a crater of diameter 650 m. The amount of erupted pyroclastic material is estimated as 0.04 km3, the total weight being over 70 million tons. A discussion is provided of the impact of these eruptions on the environment; we describe renewed hydrothermal activity and the formation of a new group of hot springs in the Akademia Nauk caldera, and estimate the possibility of breakthrough floods from Lake Karymsky etc.

Представлены материалы исследований деятельности вулканов Карымского долгоживущего вулканического центра на Камчатке в 1996 г. Рассмотрены особенности динамики и вещественный состав пород одновременно начавшихся извержений вулкана Карымский и в кальдере Академии Наук. Эффузивно-эксплозивное извержение Карымского вулкана возобновилось после 14-летнего периода покоя и в течение года поставило через вершинный кратер -30 млн.т вещества андезитодацитового состава. Предполагается длительная эруптивная активность этого вулкана в ближайшие годы. Одновременно с типичной для Карымского вулкана активностью в 6 км южнее впервые на Камчатке в историческое время наблюдалось субаквальное эксплозивное извержение в озере, занимающем кальдеру Академии Наук. За 18ч извержения в северной части Карымского озера выросла постройка из пирокластического материала базальтового, андезитобазальтового состава с кратером диаметром 650 м. Объем извергнутого пирокластического материала оценивается в 0.04 км3, общий вес >70 млн.т. Обсуждены последствия извержений для окружающей среды, описаны оживление гидротермальной деятельности и образование новой группы горячих источников в кальдере Академии Наук, сделаны оценки прорывных паводков из Карымского озера и т.п.
Muravyev Y.D., Salamatin A.N. Mass balance and thermal regime of a crater glacier at Ushkovskii volcano // Volcanology and Seismology. 1990. Vol. 11. № 3. P. 411-424.    Annotation
A thermal model has been constructed for a steady-state glacier of Ushkovskii Volcano. Analysis of ice mass balance components has revealed elevated heat flow (mean valce 10 W/m2) in the summit crater wich has remained nearly constant over the last 40 years. The measured accumulation rate and temperature distribution in the snow and firn body in the middle of the Gorshkov crater suggest the existence of a considerable uplift (a small embedded crater) overlain by the glaciers. The formulas proposed in this paper can be used to evaluate critical state parameters for unsteady ice masses on the slopes of Klyuchevskoi Volcano.

Построена теплофизическая модель стационарного состояния ледника в активном кратере Ушковского вулкана. Анализ составляющих баланса массы льда показал повышенный геотермический поток (среднее значение 10 Вт/м¤) в пределах вершинного конуса и слабую его изменчивость за последние 40 лет. По измеренной скорости аккумуляции и распределению температуры в снежнофирновой скорости аккумуляции и распределению температуры в снежно-фирновой толще в центре кратера Горшкова предполагается существование значительного поднятия (вложенного малого кратера), перекрытого ледником.
Полученные расчетные формулы помогут оценить параметры критических состояний нестационарных ледяных масс на склонах Ключевского вулкана.

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