Group by:  
Jump to:
Records: 2741
Gorbach N.V., Philosofova T.M, Portnyagin M.V. Amphibole record of 1964 plinian and following dome-forming eruptions of Shiveluch volcano, Kamchatka // Journal of Volcanology and Geothermal Research. 2020. Vol. 407. № 107108. doi: 10.1016/j.jvolgeores.2020.107108.
Shiveluch is one of the most active explosive volcanoes worldwide. During the last рlinian eruption in 1964 and the following (1980-current time) dome-forming eruptions Shiveluch has produced andesites and dacites (SiO2~60-64 wt.%) containing variably zoned, compositionally and texturally diverse amphibole phenocrysts. In this work, we attempt to decode the complex zoning of the amphibole crystals in the 55-year series of pumice, dome rocks and mafic enclaves in order to reconstruct the most recent evolution of the volcano plumbing system.
The amphibole zoning in Shiveluch andesites reveals correlation with the style and date of eruption. High-Al cores mantled by low-Al rims in amphiboles from the 1964 plinian eruption record a drastic decrease of pressure and rapid magma ascent from the lower crust to the shallow magma chamber. Typically unzoned and often opacitized low-Al crystals from the early dome-building episodes in 1980-1981 and 1993-1995 reflect magma crystallization in the shallow magma chamber. Complexly zoned amphiboles from andesites erupted in 2000s indicate replenishment of the shallow magma chamber with mafic magma and syn-eruptive mixing processes. Amphibole-based barometric calculations obtained by different approaches indicate that the Shiveluch plumbing system is complex and comprises two, mafic and silicic magma storage zones at ~15-20 km and ~5-6 km depths. We suggest that both episodes of the plinian eruption in 1964 and the extensive dome growth in 2001-2016 were driven by influx of mafic magma in the shallow storage zone beneath Shiveluch. The mafic replenishment likely preceded the 1964 plinian eruption and repeatedly occurred during the period of extensive dome growth in 2001-2016. The variable styles of the recent Shiveluch eruptions may be controlled by the relative volume of the mafic recharges and their thermal and viscosity effects on the efficiency of magma mixing.
Gorbach N.V., Plechova A.A. The lava field in the center of Dzendzur-Zhupanovsky volcanic group, Eastern Kamchatka // Abstract volume of the 8th International Maar Conference, Petropavlovsk-Kamchatsky, Russia, August 24-30, 2020. Petropavlovsk-Kamchatsky: IVS FEB RAS. 2020. P. 58-59.
Khubaeva Olga, Bergal-Kuvikas Olga, Sidorov M.D. Identification of Ruptures and their Interaction with Hydrothermal–Magmatic Systems on Northern Paramushir Isl. (Kuril Islands, Russia): 3D Modeling of Tectonic Fragmentation // Geotecton. 2020. № 54. P. 785-796. doi: 10.1134/S0016852120060072.
Kopylova G.N., Boldina S.V. Groundwater Pressure Changes Due to Magmatic Activation: Case Study of The E-1 Well, Kamchatka Peninsula, Russia // Geothermal Volcanology Workshop 2020. September 03-09, 2020, Petropavlovsk-Kamchatsky, Institute of Volcanology and Seismology. 2020.
Korolev S.P., Urmanov I.P., Kamaev A., Girina O.A. Parametric Methods and Algorithms of Volcano Image Processing / Software Engineering Perspectives in Intelligent Systems. Advances in Intelligent Systems and Computing. Cham: Springer. 2020. Vol. 1295. P. 253-263.
A key problem of any video volcano surveillance network is an inconsistent quality and information value of the images obtained. To timely analyze the incoming data, they should be pre-filtered. Additionally, due to the continuous network operation and low shooting intervals, an operative visual analysis of the shots stream is quite difficult and requires the application of various computer algorithms. The article considers the parametric algorithms of image analysis developed by the authors for processing the shots of the volcanoes of Kamchatka. They allow automatically filtering the image flow generated by the surveillance network, highlighting those significant shots that will be further analyzed by volcanologists. A retrospective processing of the full image archive with the methods suggested helps to get a data set, labeled with different classes, for future neural network training.
Marchenko A. G., Volfson A. A., Morozov M. V., Khrol N. S., Steinberg G. S., Steinberg M. G. Geochemical Characteristics of Volcanogenic Deposits and Exhalation Mineralization in the Crater Part of the Active Kudryavy Volcano (Iturup Island of the Kuril Arc) // Geology of Ore Deposits. 2020. Vol. 62. № 2. P. 122-137. doi:10.1134/S1075701520020038.
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.
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 Communications. 2020. Vol. 11. № 3918. doi: 10.1038/s41467-020-17759-4.
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.
Ozerov A.Yu., Girina O.A., Zharinov N.A., Belousov A.B., Demyanchuk Yu.V. Eruptions in the Northern Group of Volcanoes, in Kamchatka, during the Early 21st Century // Journal of Volcanology and Seismology. 2020. Vol. 14. P. 1-17.
The early 21st century saw increased eruption activity of major volcanoes in the Northern Group of Kamchatka, namely, Sheveluch, Klyuchevskoy, Bezymianny, and the Tolbachik Fissure Zone. The growth of an extrusive dome on Sheveluch andesitic volcano has occurred, with the dome reaching a height of 600 m after 38 years of nearly uninterrupted eruption activity. An 8-year period of relative quiet was followed by ten summit eruptions and two lateral vent openings on the Klyuchevskoy basaltic volcano. Explosive–effusive eruptions were observed nearly every year on the Bezymianny andesitic volcano. A 36-year quiet period gave way to a new eruption in the Tolbachik regional fissure zone.
Walter Thomas, Belousov Alexander, Belousova Marina, Kotenko Tatiana, Auer Andreas The 2019 Eruption Dynamics and Morphology at Ebeko Volcano Monitored by Unoccupied Aircraft Systems (UAS) and Field Stations // Remote Sensing. 2020. Vol. 12. № 12(1961). doi: 10.3390/rs12121961.
Арсанова Г.И. Вулкан как глубинная геологическая структура (механизмы возникновения и стока магм) // The Scientific Heritage. 2020. Т. 1. № 50. С. 16-24.
For the first time the causes of the birth of volcanoes in the depths of the planet and the mechanism of magma ejection to the surface are explained. The final conclusion was obtained as a result of the integration of knowledge of several sciences. Their synthesis allowed to define VOLCANO as a self-organizing space-time vortex dissipative structure, the form of which is created and carried in the form of waves, and through the thread (core) of the structure is the drain of magma. Such structures are itself born in a suitable chaotic environment; appropriate environment arises as a consequence of high pressure, which breaks down the structures of molecules and this creates a lot of different moving particles. The pressure necessary for this, apparently, is reached at the asthenosphere level, where the "roots" of volcanoes are localized.