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Kalacheva Elena, Taran Yuri, Kotenko Tatiana Geochemistry and solute fluxes of volcano-hydrothermal systems of Shiashkotan, Kuril Islands // Journal of Volcanology and Geothermal Research. 2015. V. 296. P. 40-54. doi:10.1016/j.jvolgeores.2015.03.010.    Аннотация
Shiashkotan Island belongs to the Northern Kuril island arc and consists of two joined volcanoes, Sinarka and
Kuntomintar, with about 18 km of distance between the summits. Both volcanoes are active, with historic
eruptions, and both emit fumarolic gases. Sinarka volcano is degassing through the extrusive domewith inaccessible
strong and hot (N400 °C) fumaroles. A large fumarolic field of the Kuntomintar volcano situated in a wide
eroded caldera-like crater hosts many fumarolic vents with temperatures from boiling point to 480 °C. Both
volcanoes are characterized by intense hydrothermal activity discharging acid SO4-Cl waters, which are drained
to the Sea of Okhotsk by streams. At least 4 groups of near-neutral Na-Mg-Ca-Cl-SO4 springs with temperatures in
the range of 50–80 °C are located at the sea level,within tide zones and discharge slightly altered diluted seawater.
Volcanic gas of Kuntomintar as well as all types of hydrothermal manifestations of both volcanoes were collected
and analyzed for major and trace elements and water isotopes. Volcanic gases are typical for arc volcanoes
with 3He/4He corrected for air contamination up to 6.4 Ra (Ra=1.4 ×10−6, the air ratio) and δ13C (CO2) within
−10‰to−8‰VPDB. Using a saturation indices approach it is shown that acid volcanic waters are formed at a
shallow level, whereas waters of the coastal springs are partially equilibrated with rocks at ~180 °C. Trace
element distribution and concentrations and the total REE depend on the water type, acidity and Al+Fe concentration.
The REE pattern for acidic waters is unusual but similar to that found in some acidic crater lake waters.
The total hydrothermal discharge of Cl and S from the island associated with volcanic activity is estimated at
ca. 20 t/d and 40 t/d, respectively, based on the measurements of flow rates of the draining streams and
their chemistry. The chemical erosion of the island by surface and thermal waters is estimated at 27 and 140
ton/km2/year, respectively, which is 2–3 times lower than chemical erosion of tropical volcanic islands.
Kalacheva Elena, Taran Yuri, Kotenko Tatiana, Hattori Keiko, Kotenko Leonid, Solis-Pichardo Gabriela Volcano–hydrothermal system of Ebeko volcano, Paramushir, Kuril Islands: Geochemistry and solute fluxes of magmatic chlorine and sulfur // Journal of Volcanology and Geothermal Research. 2016. V. 310. P. 118-131. doi:10.1016/j.jvolgeores.2015.11.006.    Аннотация
Ebeko volcano at the northern part of Paramushir Island in the Kuril island arc produces frequent phreatic eruptions and relatively strong fumarolic activity at the summit area ~ 1000 m above sea level (asl). The fumaroles are characterized by low-temperature, HCl- and S-rich gas and numerous hyper-acid pools (pH < 1) without drains. At ~ 550 m asl, in the Yurieva stream canyon, many hot (up to 87 °C) springs discharge ultra-acidic (pH 1–2) SO4–Cl water into the stream and finally into the Sea of Okhotsk. During quiescent stages of degassing, these fumaroles emit 1000–2000 t/d of water vapor, < 20 t/d of SO2 and < 5 t/d of HCl. The measurement of acidic hot Yurieva springs shows that the flux of Cl and S, 60–80 t/d each, is independent on the volcanic activity in the last two decades. Such high flux of Cl is among the highest ever measured in a volcano–hydrothermal system. Oxygen and hydrogen isotopic composition of water and Cl concentration for Yurieva springs show an excellent positive correlation, indicating a mixing between meteoric water and magmatic vapor. In contrast, volcanic gas condensates of Ebeko fumaroles do not show a simple mixing trend but rather a complicated data suggesting evaporation of the acidic brine. Temperatures calculated from gas compositions and isotope data are similar, ranging from 150 to 250 °C, which is consistent with the presence of a liquid aquifer below the Ebeko fumarolic fields. Saturation indices of non-silicate minerals suggest temperatures ranging from 150 to 200 °C for Yurieva springs. Trace elements (including REE) and Sr isotope composition suggest congruent dissolution of the Ebeko volcanic rocks by acidic waters. Waters of Yurieva springs and waters of the summit thermal fields (including volcanic gas condensates) are different in Cl/SO4 ratios and isotopic compositions, suggesting complicated boiling–condensation–mixing processes.
Kersting Annie B., Arculus Richard J. Pb isotope composition of Klyuchevskoy volcano, Kamchatka and North Pacific sediments: Implications for magma genesis and crustal recycling in the Kamchatkan arc // Earth and Planetary Science Letters. 1995. V. 136. № 3–4. P. 133 - 148. doi: 10.1016/0012-821X(95)00196-J.    Аннотация
Pb isotope data are used to constrain the chemical contribution of the subducted components in the recycling beneath Klyuchevskoy volcano, the most active volcano in the Kamchatkan arc. The Pb isotope ratios of Klyuchevskoy basalts (206Pb/204Pb= 18.26–18.30, 207/Pb204Pb= 15.45–15.48, 208/Pb204Pb= 37.83–37.91) define a narrow range that falls within the Pacific mid-ocean ridge basalt (MORB) field and are among the least radiogenic island arc basalts measured to date. These data are similar to data from three other Quaternary Kamchatkan volcanoes: Tolbachik, Kumroch-Shish, and Maly Semiachik. In contrast, North Pacific sediments (primarily siliceous oozes) collected parallel to the Kamchatkan trench during Ocean Drilling Program Leg 145, have Pb isotope ratios (206Pb/204Pb= 18.51–18.78, 207Pb/204Pb= 15.56–15.64, 208Pb/204Pb= 38.49–38.75) that are more radiogenic than either the Klyuchevskoy basalts or Pacific MORB. Incorporation of even a small amount of sediment in the source of the Klyuchevskoy magmas would shift the Pb isotope ratios of the erupted basalts from the MORB field to more radiogenic values. The absence of 10Be and elevated Pb isotope ratios in the Kamchatkan volcanic lavas, despite the presence of distinctively radiogenic Pb in the North Pacific sediments makes it unlikely that sediments or sediment-derived fluids are involved in the source magmas beneath Kamchatka. The Kamchatkan arc thus represents an “end-member” whereby little or no sediment is involved in terms of elemental recycling and arc magma genesis. The major and trace elements, Pb, Sr and Nd isotope data of the Kamchatkan basalts are most consistently explained if derived from a fluid-fluxed, peridotitic mantle wedge source, wherein the fluid composition is dominantly controlled by dehydration of altered oceanic crust, imparting a radiogenic 87Sr/86Sr, and MORB-like Pb isotope signature to the mantle source. The erupted Klyuchevskoy lavas preserve a slab signature derived from incompatible elements that are strongly partitioned into the fluid. The 30 km of arc crust through which the Klyuchevskoy magmas traverse prior to eruption is not composed of older crust, but must be juvenile, similar in isotopic composition to MORB.
Khubunaya S.A., Eremina T.S., Sobolev A.V. The classification of potassium basaltic trachyandesites that were discharged by the 2012–2013 parasitic eruption on Ploskii Tolbachik Volcano, Kamchatka using geochemical criteria // Journal of Volcanology and Seismology. 2016. V. 10. № 1. P. 33-49. doi: 10.1134/S0742046316010024.    Аннотация
Abstract—This study is concerned with the petrographic, mineralogic, and geochemical features in the K-high basaltic trachyandesites that were discharged by the 2012–2013 parasitic eruption on Ploskii Tolbachik Volcano. These K-high basaltic trachyandesites exhibit some obvious characteristics that testify to their suprasubduction origin. They are deeply differentiated rocks with strongly fractionated plagioclase.A study of the Sr, Nd, and Pb radiogenic isotope ratios in the K-high basaltic trachyandesites provided evidence of their mantle origin and of the fact that the crust has exerted no influence on their compositions. We performed a comparative analysis of the ratios of the concentrations for some incoherent elements in the K-high basaltic trachyandesites, as well as in intraplate, riftogenic, and island-arc moderate potassium basalts and basaltic andesites in relation to the concentrations of these elements in the primitive mantle. The geochemical features of these K-high basaltic trachyandesites classify them as belonging to the suprasubduction subalkaline formation of the potassium series.

Изучены петрографические, минералогические и геохимические особенности К-трахиандезибазальтов побочного извержения 2012–2013 гг. вулкана Плоский Толбачик. К-трахиандезибазальты имеют явные признаки надсубдукционного происхождения. Это глубоко дифференцированные породы, характеризующиеся значительным фракционированием плагиоклаза. Изучение радиогенных изотопных отношений Sr, Nd и Pb в К-трахиандезибазальтах свидетельствует об их мантийном происхождении и отсутствии влияния земной коры на их составы. Проведен сравнительный анализ отношений содержаний некогерентых элементов в К-трахиандезибазальтов,внутриплитных,рифтогенных и островодужных умереннокалиевых базальтах и андезибазальтах к содержанию этих элементов в примитивной мантии. Геохимические особенности К-трахиандезибазальтов позволяют отнести их к надсубдукционной субщелочной формации калиевого ряда.
http://repo.kscnet.ru/2626/ [связанный ресурс]
Khubunaya S.A., Gontovaya L.I., Sobolev A.V., Nizkous I.V. Magma Chambers beneath the Klyuchevskoy Volcanic Group // Journal of Volcanology and Seismology. 2007. V. 1. № 2. P. 98-118. doi: 0.1134/S0742046307020029.    Аннотация
A 3D velocity model of the Earth's crust beneath the Klyuchevskoy volcanic group has been constructed using the seismic tomography method. Anomalies of the velocity parameters related to the zones of magma supply to active volcanoes have been distinguished. Petrological data on the composition, temperature, and pressure of generation and crystallization of primary melts of Klyuchevskoy volcano magnesian basalts have been obtained. The primary melt corresponds to picrite (MgO = 13-14 wt %) with an ultimate saturation of SiO2 (49-50 wt %), a high H2O content (2.2-2.9%), and incompatible elements (Sr, Rb, Ba, Hf). This melt is formed at pressures of 15-20 kbar and temperatures of 1280--1320С . Its further crystallization proceeds in intermediate magma chambers at two discrete pressure levels (i.e., greater than 6, and 1-2 kbar). The results of the petrological studies are in good agreement with the seismotomographic model.

Поступила в редакцию 1. 11. 2006 г.
Методом сейсмической томографии построена объемная скоростная модель земной коры под Ключевской группой вулканов. Выделены аномалии скоростных параметров связанных с зонами магматического питания активных вулканов. Получены петрологические данные о составе, температуре и давлении генерации и кристаллизации родоначальных расплавов магнезиальных базальтов Ключевского вулкана. Родоначальный расплав отвечает пикриту (MgO=13-14%,мас) с предельным насыщением SiO2 (49-50%, мас.), высоким содержанием H2O (2,2-2.9%) и несовместимыми элементами (Sr, Rb, Ba, Hf). Он образуется при давлениях 15-20 кбар и температурах 1280-13200С. Его дальнейшая кристаллизация проходит в промежуточных магматических камерах при двух дискретных уровнях давлений (более 6 и 1-2 кбар). Результаты петрологических исследований находятся в хорошем соответствии с сейсмотомографической моделью.
http://repo.kscnet.ru/2129/ [связанный ресурс]
Kirianov V.Yu., Melekestsev I.V., Andreev V.N., Ovsyannikov A.A. Reconstruction of the eruptive activity of Momotombo volcano (Nicaragua) to assess volcanic hazards // Kagoshima International Conference on Volcanoes: Proceedings of the International Conference on Volcanoes, Japan, Kagoshima, 19-23 July 1988. Kagoshima: Kagoshima Prefectural Government. 1988. P. 495-498.
Kochegura V.V., Zubov A.G. Paleomagnetic chronostratigraphy of young eruptive series // Abstracts: generation of major basalt types. August 15-22, 1982. Reykjavik, Island: IAVCEI-IAGC Scientific Assembly. 1982. V. 81.
Kochegura V.V., Zubov A.G., Braytseva O.A. Magnetostratigraphy of Kamchatkan Holocene formations of soil and pyroclastics // Journal of Volcanology and Seismology. 1990. V. 8. № 6. P. 825-849.    Аннотация
An account is given of magnetostratigraphic studies of Kamchatkan Holocene formations: the cover of soil and pyroclastics and the rocks of the cinder cones from the flank eruptions of Klyuchevskoi Volcano. А study was made of seven sections of the soil and pyroclastics and of samples from 17 cinder cones. А detailed account is given of the data processing procedure. Consideration is given to the reasons for the established incompleteness of the paleomagnetic record in the sections and it is demonstrated that adequately detailed reconstruction of the history of the geomagnetic 1ield is possible only provided that а study is made of а series of рагаllеl sections. The trajесtory of the geomagnetic field vector over the last 4000 years is determined on the basis of the material on radiocarbon datings. Seven cycles of paleosecular variations are distinguished in the age range investigated; each of these cycles has individual features by which they can be recognised and used for stratigraphic correlation. The, features taken were the direction of rotation of the vector, the shape and size of its loops, and the length of the cycles. Correlation of the sections based on paleomagnetic data was found to be in good agreement with the tephrostratigraphic correlation and enabled corrections to be made to the age of some horizons, including the archeological layers of the primitive settlement at Zhupanovo and the cinder cones. The metachronous magnetization present in some tephra layers was found to be an obstacle to any improvement in the accuracy and detail of magnetochronological reconstructions.
http://repo.kscnet.ru/290/ [связанный ресурс]
Koloskov A.V., Flerov G.B., Perepelov A.B., Melekestsev I.V., Puzankov M.Yu., Filosofova T.M. Evolution Stages and Petrology of the Kekuknai Volcanic Massif as Reflecting the Magmatismin Backarc Zone of Kuril-Kamchatka Island Arc System. Part 1. Geological Position and Geochemistry of Volcanic Rocks // Journal of Volcanology and Seismology. 2011. V. 5. № 5. P. 312-334. doi: 10.1134/S074204631104004X.    Аннотация
The evolution of the Quaternary Kekuknai volcanic massif (the western flank of the Sredinnyi Range in Kamchatka) has been subdivided into five stages: (I) the pre-caldera trachybasalt- basaltic andes- ite, (2) the extrusive trachyandesite-trachydacite, (3) the early trachybasalt, (4) the middle hawaiite- mugearite (with occasional occurrences of basaltic andesites), and (5) the late trachybasalt-hawaiite- mugearite (with occasional andesites) of areal volcanism. On the basis of petrologic data we identified the island arc and the intraplate geochemical types of rocks in the massif. The leading part in petrogenesis was played by dynamics of the fluid phase with a subordinated role of fractional crystallization and hybridism. Successive saturation of rocks with the fluid phase in the course of melt evolution stopped at the time of caldera generation when most fluid mobile elements and silica had been extracted. The geological and petrologic data attest to the formation of the massif in the environment of a backarc volcanic basin during the beginning of rifting with active participation of mantle plume components.

Выделено пять стадий эволюции четвертичного Кекукнайского вулканического массива (западный фланг Срединного хребта Камчатки): 1) докальдерная трахибазальтовая-андезибазальтовая, 2) экструзивная трахиандезит-трахидацитовая, 3) ранняя трахибазальтовая, 4) средняя гавайит-муджиеритовая (с единичными проявлениями андезибазальтов) и 5) поздняя трахибазальт-гавайит-муджиеритовая (с единичными проявлениями андезитов) - ареального вулканизма. По петрологическим данным среди пород массива выделены островодужный и внутриплитный геохимические типы. Ведущую роль в пет-рогенезисе играла динамика флюидной фазы при подчиненной роли процессов фракционной кристаллизации и гибридизма. Последовательное насыщение пород флюидной фазой в ходе эволюции расплавов было прервано в период кальдерообразования, когда осуществилась экстракция большей части флюидомобильных элементов и кремнезема. Геологические и петрологические материалы свидетельствуют о том, что формирование массива произошло в обстановке задугового вулканического бассейна в условиях начавшегося рифтогенеза, при активном участии компонентов мантийного плюма.
http://repo.kscnet.ru/883/ [связанный ресурс]
Koloskov A.V., Flerov G.B., Perepelov A.B., Melekestsev I.V., Puzankov M.Yu., Filosofova T.M. The Evolutionary Stages and Petrology of the Kekuknai Volcanic Massif Reflecting the Magmatism in the Backarc Zone of the Kuril-Kamchatka Island Arc System. Part II. Petrologic and Mineralogical Features, Petrogenesis Model // Journal of Volcanology and Seismology. 2013. V. 7. № 2. P. 145-169. doi: 10.1134/S0742046313020048.    Аннотация
The Kekuknai massif was formed in the course of tectono-magmatic activity that involved the origin of a shield volcano and a caldera depression with associated emplacement of extrusions that terminated in intense post-caldera areal volcanism. The mineralogical compositions of the massifs rocks have been considered in detail. The use of previously known and newly developed indicator properties of rock-forming minerals allowed the reconstruction of the general picture of the magmatic melt evolution and conditions of rock crystallization (various fluid and water saturation levels, as well as the oxidation state of the system). Essentially island-arc or intraplate characteristics of the massif s rock compositions are found at different stages of development of a single fluid-magmatic system. Decompression evolution of the parent deep-seated basanitic magma occurred via occurrence in intermediate magma chambers of daughter magmas of trachybasalt (pre-caldera stage) or hawaiite (areal volcanism) composition. Subsequent emanate-magmatic differentiation of these melts, combined with crystallization differentiation under changing P-T-f0l conditions, resulted in the formation of the entire diversity of the Kekuknai rocks.

Кекукнайский массив сформировался в результате тектоно-магматической деятельности, выразившейся образованием щитообразного вулкана, кальдерной депрессии с сопутствующим внедрением экструзий, и завершившейся интенсивным посткальдерным ареальным вулканизмом. Проведено детальное рассмотрение особенностей минералогического состава пород массива. Использование уже имеющихся и дополнительно выявленных индикаторных возможностей породообразующих минералов позволило восстановить общую картину эволюции магматических расплавов и условия кристаллизации пород (различная флюидонасыщенность-обводненность и окисленность системы). Существенно островодужные или внутриплитные характеристики в составе пород массива проявлены на разных стадиях развития единой флюидно-магматической системы. Декомпрессионная эволюция материнской глубинной базанитовой магмы была реализована появлением в промежуточных очагах дочерних магм трахибазальтового (докальдерный этап развития системы) или гавайитового (ареальный вулканизм) состава. Дальнейшая эманационно-магматическая дифференциация этих расплавов в сочетании с кристаллизационной дифференциации в условиях меняющейся P-T-f02 обстановки и привела к образованию всего многообразия пород Кекукнайского массива.
http://repo.kscnet.ru/885/ [связанный ресурс]
Kontorovich A.E., Bortnikova S.B., Karpov G.A., Kashirtsev V.A., Kostyreva E.A., Fomin A.N. Uzon volcano caldera (Kamchatka): A unique natural laboratory of the present-day naphthide genesis // Russian Geology and Geophysics. 2011. V. 52. № 8. P. 768 - 772. doi: 10.1016/j.rgg.2011.07.002.    Аннотация
Oil shows from the thermal springs of the Uzon volcano caldera have been studied by gas chromatography–mass spectrometry methods. Based on the composition and distribution of biomarker molecules, their genetic identity with the organic matter of Pliocene–Quaternary deposits has been established. It has been shown that the Uzon caldera is a unique natural laboratory of the present-day oil formation from the organic matter of Pliocene–Quaternary sediments. It has been stated that attempts to consider the compounds forming these oil shows as a product of hydrothermal abiogenic synthesis are absolutely unfounded.
Kopylova G.N., Boldina S.V. On the Relationships of Water-Level Variations in the E-1 Well, Kamchatka to the 2008–2009 Resumption of Activity on Koryakskii Volcano and to Large (M ≥ 5) Earthquakes // Journal of Volcanology and Seismology. 2012. V. 6. № 5. P. 312-328. doi: 10.1134/S074204631205003X.    Аннотация
Abstract—We discuss the water!level variations in the E!1 well for the time period between May 2006 and
2010, inclusive. A trend towards an increasing level at an abnormally high rate occurred from mid!2006 to
December 2009. This increase is regarded as the response of the aquifer of gas!saturated ground water that
exists in the volcanogenic–sedimentary deposits of the Avacha volcano!tectonic depression to volumetric
strain changes during the precursory period and the occurrence of a swarm of small earthquakes ( = 8.3)
in the area of Koryakskii Volcano and to its phreatic eruption. We estimated the volumetric compression as
Δε = –(4.1 × 10–6–1.5 × 10–5) from the amplitude of water!level rise using the elastic parameters of the wa!
ter!saturated rocks. While the strain source was active, we observed a decreasing sensitivity of the hydrologic
regime in the well to the precursory processes before large (M ≥ 5.0) tectonic earthquakes.
Koulakov Ivan, Gordeev Evgeniy I., Dobretsov Nikolay L., Vernikovsky Valery A., Senyukov Sergey, Jakovlev Andrey, Jaxybulatov Kayrly Rapid changes in magma storage beneath the Klyuchevskoy group of volcanoes inferred from time-dependent seismic tomography // Journal of Volcanology and Geothermal Research. 2013. V. 263. P. 75 - 91. doi: 10.1016/j.jvolgeores.2012.10.014.    Аннотация
We present the results of time-dependent local earthquake tomography for the Kluchevskoy group of volcanoes in Kamchatka, Russia. We consider the time period from 1999 to 2009, which covers several stages of activity of Kluchevskoy and Bezymianny volcanoes. The results are supported by synthetic tests that recover a common 3D model based on data corresponding to different time windows. Throughout the period, we observe a robust feature below 25 km depth with anomalously high Vp/Vs values (up to 2.2). We interpret this feature as a channel bringing deep mantle materials with high fluid and melt content to the bottom of the crust. This mantle channel directly or indirectly determines the activity of all volcanoes of the Kluchevskoy group. In the crust, we model complex structure that varies over time. During the pre-eruptive period, we detected two levels of potential magma storage: one in the middle crust at 10–12 km depth and one close to the surface just below Kluchevskoy volcano. In 2005, a year of powerful eruptions of Kluchevskoy and Besymiyanny volcanoes, we observe a general increase in Vp/Vs throughout the crust. In the relaxation period following the eruption, the Vp/Vs values are generally low, and no strong anomalous zones in the crust are observed. We propose that very rapid variations in Vp/Vs are most likely due to abrupt changes in the stress and deformation states, which cause fracturing and the active transport of fluids. These fluids drive more fracturing in a positive feedback system that ultimately leads to eruption. We envision the magma reservoirs beneath the Kluchevskoy group as sponge-structured volumes that may quickly change the content of the molten phases as fluids pulse rapidly through the system.
Koulakov Ivan, Jaxybulatov Kayrly, Shapiro Nikolay M., Abkadyrov Ilyas, Deev Evgeny, Jakovlev Andrey, Kuznetsov Pavel, Gordeev Evgeny, Chebrov Viktor Asymmetric caldera-related structures in the area of the Avacha group of volcanoes in Kamchatka as revealed by ambient noise tomography and deep seismic sounding // Journal of Volcanology and Geothermal Research. 2014. V. 285. P. 36 - 46. doi: 10.1016/j.jvolgeores.2014.08.012.    Аннотация
Avacha group includes two active and potentially dangerous volcanoes, Avachinsky and Koryaksky, located close to Petropavlovsk-Kamchatsky, the main city of Kamchatka. We present the results of two independent seismic studies of shallow crustal structures beneath the Avacha group based on passive and active source observations. The first study is based on the analysis of continuous recording by 11 seismic stations installed over the Avacha group in 2012 and 7 permanent stations in the same region. We present a series of 2D Rayleigh-wave group velocity maps based on correlation of ambient noise, that were then converted into 3D distribution of shear wave velocity. The second work was based on the reprocessing of an active source deep seismic sounding profile across the Avachinsky volcano that was shot in 1982–1984. We made the analysis of travel times of refracted waves using a 2D tomography inversion. The resulting seismic models appear to be consistent with each other and show clear low-velocity zone to the SW of the Avachinsky volcano and high velocity structures to NE. These observations also agree with the existing gravity and magnetotelluric measurements. Based on the obtained seismic models we identify two large buried calderas and large lava flows that are thought to be related to a series of large eruption episodes of Avachinsky occurred within the last 30,000 years.
Kugaenko Yulia, Titkov Nikolay, Saltykov Vadim Constraints on unrest in the Tolbachik volcanic zone in Kamchatka prior the 2012–13 flank fissure eruption of Plosky Tolbachik volcano from local seismicity and GPS data // Journal of Volcanology and Geothermal Research. 2015. V. 307. P. 38 - 46. doi: 10.1016/j.jvolgeores.2015.05.020.    Аннотация
Abstract A new fissure eruption began on 27 November 2012 on the southern slope of Plosky Tolbachik volcano, which is located in central Kamchatka, Russia, and is part of the Klyuchevskoy volcano group. We analyzed the displacement of the earth surface and the seismicity during several months before the eruption onset. According to seismic and GPS data the eruption was preceded by about 4–5 months (July–November 2012) of synchronous crustal deformation and seismicity. The seismic anomaly comprises low energy level seismicity (mainly M = 1.2–2.3) under Plosky Tolbachik volcano at a depth of less than 5 km. In the 2–3 weeks immediately preceding the eruption the rate of seismicity and the amount of radiated seismic energy exceeded the long-term average values (2000–2011) by more than 40 times. The deformation anomaly was recorded by displacement of the GPS points at distances from 20 to 60 km to the north of Tolbachik. The principal axis of the compressive strain was approximately directed towards the Tolbachik eruption site. The permanent GPS network detected radial compression and tangential stretching. The compressive strain reached about 10− 7 prior to eruption onset. The comparable duration of seismic and deformation anomalies (~ 4–5 months before the eruption) is consistent with a common origin, connected to magma rising from depth, and is interpreted as indicating that they were medium-term precursors to the eruption. Data recorded during this unrest episode of the Tolbachik volcanic zone will contribute to understanding of the reawakening of volcanic activity in this region and others worldwide with similar characteristics.
Kuno H. Petrology of Alaid volcano, north Kurile // Japanese journal of geology and geography. 1935. V. 12. P. 153-162.
Kuznetsova E., Muravyev Y.D., Motenko R. The physical and chemical properties of volcanic ashes of different ages (Kamchatka) // Вулканизм и геодинамика. Мат-лы IY ВС по Вулканологии и палеовулканологии. сентябрь 2011 г., Петропавловск-Камчатский. 2011.    Аннотация
Большая часть Камчатки покрыта почвенно-пирокластическим чехлом, который представляет собой непрерывно накапливающийся "слоёный пирог", состоящий из горизонтов тефры и погребенных почв. Пеплы крупнейших извержений образуют чёткие маркирующие прослои во вмещающих отложениях, которые прослеживаются на огромных территориях. Толща между маркирующими прослоями пеплов имеет также пирокластическую природу и включает как продукты менее мощных или дальних извержений, так и вторично переотложенные пеплы [2]. В данной работе представлены результаты исследования физико-химических свойств вулканических пеплов, представленных как пеплами-маркерами, так и неопознанной тефрой.
В работе использовались следующие экспериментальные методы исследования:
- гранулометрический состав определялся пипеточным методом (ГОСТ…).
- теплопроводные характеристики вулканических пеплов определяли методом регулярного режима I рода [7].
- фазовый состав влаги и температура начала замерзания определялись криоскопическим и контактным методами [7].
- минеральный анализ определен на ИК-спектрометре ФСМ-1201 (Россия) в интервале 400-4000 cм-1 при комнатной температуре. Спектральное разрешение составляло 2,0 cм-1, абсолютная калибровочная ошибка волнового числа - не больше ±0,1 cм-1 [6]. Состав стекол этих пеплов был проанализирован на микрозонде "Jeol JSM-6480LV", энергодисперсионным спектрометром "INCA-Energy 350" (окно ATW-2) в Лаборатории локальных методов исследования вещества МГУ.
Были исследованы образцы вулканического пепла, отобранные в районе Ключевской группы вулканов и в долине р. Камчатка, в диапазоне высот 129-1650 м. Почти все пеплы относятся к голоценовым, за исключением образца, отобранного из отложений озерных диатомовых глин яра Половинка в долине р. Камчатки, возраст которых относится ко второй половине раннего плейстоцена (Q21). Образец представляет собой белый рыхлый витрокластический пепел кислого состава.
Согласно ГОСТ 25100-95 по гранулометрическому составу вулканические пеплы относятся к пескам пылеватым. По содержанию SiO2 вулканическое стекло исследуемых пеплов относится к трем типам: риолитовый, андезитовый и базальтовый. Согласно данным ИК-спектроскопии в камчатских пеплах с андезитовым и базальтовым стеклом был найден аллофан, с риолитовым стеклом - опал (аллофан - аморфный слоистый алюмосиликат, опал - минерал подкласса гидроксидов, не является глинистым минералом).
Получены следующие результаты исследования физ.-хим. свойств рассматриваемых пеплов.
Фазовый состав влаги. Впервые в наших исследованиях был получен фазовый состав влаги (т.е. содержание льда, незамерзшей воды и пара) в мерзлых вулканических пеплах Камчатки (ссылки на наши работы). Наиболее важная характеристика фазового состава влаги в мёрзлой породе - зависимость содержания незамерзшей воды Ww от температуры t. Экспериментально установлены зависимости содержания незамерзшей воды от температуры для мёрзлых вулканических пеплов в диапазоне температур от 0 до -15 оС, содержание Ww при температуре ниже -3 оС изменяется незначительно. Установлено, что, например, при температуре определения теплофизических характеристик -10оС в исследуемых образцах содержание незамерзшей воды изменяется от 0 до 11%. Это связано с преобразованием вулканического стекла и появлением глинистых минералов (аллофанов). Последние характеризуются большой удельной поверхностью, что и определяет появление разного количества незамерзшей воды.
Теплопроводные свойства. Получены экспериментальные данные по изучению теплопроводности вулканических пеплов для талого и мерзлого состояния в широком диапазоне влажности и плотности (ссылки на наши работы). При изменении влажности от 0 до 78% и плотности скелета ?d от 0,7 до 1,7 г/см3 коэффициент теплопроводности ? закономерно увеличивается от 0,13 до 1,0 Вт/(м·К) в талом и от 0,14 до 1,27 Вт/(м·К) в мерзлом состоянии. При этом не смотря на то, что вулканические пеплы по гранулометрическому составу относятся к пескам пылеватым, они очень сильно отличаются от последних. Так, сравнение данных по теплопроводности для вулканогенно-обломочных и осадочных дисперсных пород показало, что вулканические дисперсные породы имеют очень низкую теплопроводность как в талом, так и в мерзлом состоянии, что объясняется многими причинами, например, разностью теплопроводностей скелета пород (теплопроводности кварца и вулканического стекла отличаются в 3-4 раза), так и формой самих частиц.
Засоленность. Анализ засоленности пеплов показал, что по ГОСТ 25100-95 все исследованные пеплы, за исключением образца, отобранного из яра Половинка, относятся к незасоленным, суммарное содержание легкорастворимых солей в них около 0,02-0,03%; пепел из яра относится к сильно засоленным. По результатам химического анализа водной вытяжки этого пепла сумма солей составляет 1,815% от массы вещества, а по химическому составу представлена преимущественно сульфатами (содержание SO42- составляет 1,242% от массы вещества). Также отмечено очень низкое pH=3,4.
Kyle Philip R., Ponomareva Vera V., Rourke Schluep Rachelle Geochemical characterization of marker tephra layers from major Holocene eruptions, Kamchatka Peninsula, Russia // International Geology Review. 2011. V. 53. № 9. P. 1059-1097. doi:10.1080/00206810903442162.    Аннотация
Kamchatka Peninsula is one of the most active volcanic regions in the world. Many Holocene explosive eruptions have resulted in widespread dispersal of tephra-fall
deposits. The largest layers have been mapped and dated by the 14C method. The tephra provide valuable stratigraphic markers that constrain the age of many geological
events (e.g. volcanic eruptions, palaeotsunamis, faulting, and so on). This is the first systematic attempt to use electron microprobe (EMP) analyses of glass to characterize
individual tephra deposits in Kamchatka. Eighty-nine glass samples erupted from 11 volcanoes, representing 27 well-identified Holocene key-marker tephra layers, were analysed. The glass is rhyolitic in 21 tephra, dacitic in two, and multimodal in three.
Two tephra are mixed with glass compositions ranging from andesite/dacite to rhyolite. Tephra from the 11 eruptive centres are distinguished by their glass K2O,
CaO, and FeO contents. In some cases, individual tephra from volcanoes with multiple eruptions cannot be differentiated. Trace element compositions of 64 representative
bulk tephra samples erupted from 10 volcanoes were analysed by instrumental neutron activation analysis (INAA) as a pilot study to further refine the geochemical haracteristics; tephra from these volcanoes can be characterized using Cr and Th contents and La/Yb ratios.
Unidentified tephra collected at the islands of Karaginsky (3), Bering (11), and Attu (5) as well as Uka Bay (1) were correlated to known eruptions. Glass compositions and
trace element data from bulk tephra samples show that the Karaginsky Island and Uka Bay tephra were all erupted from the Shiveluch volcano. The 11 Bering Island tephra
are correlated to Kamchatka eruptions. Five tephra from Attu Island in the Aleutians are tentatively correlated with eruptions from the Avachinsky and Shiveluch volcanoes.
Ladygin V.М., Girina O.A., Frolova Yu.V. Petrophysical features of lava flows from Bezymyannyi volcano, Kamchatka // Journal of Volcanology and Seismology. 2012. V. 6. № 6. P. 341-351. doi: 10.1134/S074204631206005X.    Аннотация
This paper presents results from a study of lava flows that were discharged by Bezymyannyi Volcano at different times, from old (about 3500 years ago) to recent ones (1985–1989). We provide detailed descriptions of the composition, structure, and petrophysical properties for the main types of constituent rocks, which are andesites and basaltic andesites. It was found that porosity is the leading factor that controls rock properties, while the effects of structural and mineralogical features are less prominent. We demonstrate the variation in the properties of rocks that compose the lava flows in relation to their ages: the older a rock is, the higher its density and strength and the lower its porosity is.
Ladygin V.М., Girina O.A., Frolova Yu.V., Kondrashov I.A. The lava flows of Bezymianny volcano, Kamchatka // 4rd International Biennial Workshop on Subduction Processes emphasizing the Japan-Kurile-Kamchatka-Aleutian Arcs, Petropavlovsk-Kamchatsky, August 21-27, 2004. Petropavlovsk-Kamchatsky: IVS FED RAS. 2004. P. 63-64.





 

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