A Calcium-in-Olivine Geohygrometer and its Application to Subduction Zone Magmatism (2016)
Gavrilenko M., Herzberg C., Vidito C., Carr M., Tenner T., Ozerov A. A Calcium-in-Olivine Geohygrometer and its Application to Subduction Zone Magmatism // Journal of Petrology. 2016. V. 57. № 9. P. 1811-1832. doi:10.1093/petrology/egw062.
High-precision electron microprobe analyses were obtained on olivine grains from Klyuchevskoy, Shiveluch and Gorely volcanoes in the Kamchatka Arc; Irazu, Platanar and Barva volcanoes of the Central American Arc; and mid-ocean ridge basalt (MORB) from the Siqueiros Transform. Calcium contents of these subduction zone olivines are lower than those for olivines from modern MORB, Archean komatiite and Hawaii. A role for magmatic H2O is likely for subduction zone olivines, and we have explored the suggestion of earlier workers that it has affected the partitioning of CaO between olivine and silicate melt. We provide a provisional calibration of DCaO Ol/L as a function of magmatic MgO and H2O, based on nominally anhydrous experiments and minimally degassed H2O contents of olivine-hosted melt inclusions. Application of our geohygrometer typically yields 3–4 wt % magmatic H2O at the Kamchatka and Central American arcs for olivines having 1000 ppm Ca, which agrees with H2O maxima from melt inclusion studies; Cerro Negro and Shiveluch volcanoes are exceptions, with about 6% H2O. High-precision electron microprobe analyses with 10–20 lm spatial resolution on some olivine grains from Klyuchevskoy and Shiveluch show a decrease in Ca content from the core centers to the rim contacts, and a sharp increase in Ca in olivine rims. We suggest that the zoning of Ca in olivine from subduction zone lavas may provide the first petrological record of temporal changes that occur during hydration of the mantle wedge and dehydration during ascent, and we predict olivine H2O contents that can be tested by secondary ionization mass spectrometry analysis.
A Model for Klyuchevskoy Volcano Activity from Geodelical and Seismological Data (1988)
Zharinov N.A., Fedotov S.A., Gorelchik V.I. A Model for Klyuchevskoy Volcano Activity from Geodelical and Seismological Data // Kagoshima International Conference on Volcanoes: Proceedings of the International Conference on Volcanoes, Japan, Kagoshima, 19-23 July 1988. Kagoshima: Kagoshima Prefectural Government. 1988. P. 71-74.
A New Cluster Regime Of Gas-Liquid Flow In Vertical Columns (Physical Modeling) (2009)
Ozerov A.Yu. A New Cluster Regime Of Gas-Liquid Flow In Vertical Columns (Physical Modeling) // Сборник тезисов Международной конференции «Потоки и Структуры в Жидкостях: Физика Геосфер». М.: ИПМех РАН. 2009. V. 1. P. 178-181.
A New Estimate of Gas Emissions from Ebeko Volcano, Kurile Islands (2016)
Melnikov Dmitry, Malik N., Kotenko T., Inguaggiato Salvatore, Zelenski M. A New Estimate of Gas Emissions from Ebeko Volcano, Kurile Islands // Goldschmidt Conference. 26 June - 1 July, Yokohama, Japan. 2016. P. 2047
Concentrations and emission rates of major gas species were measured in August 2015 at Ebeko volcano, a quiescently degassing andesitic volcano on Paramushir Island, Northern Kuriles. Using mobile and scanning DOAS measurements we estimated SO 2 emission from the active crater of the volcano at 100 +36/-15 t/d. Based on the comparison of plume areas of individual fumaroles, ca. 90% of the total gas emission from Ebeko in 2015 was provided by a single powerful vent (" Active Funnel " fumarole) and the rest was shared among low-temperature fumaroles. At the time of measurements, gases from the main fumarole had temperature from 420 to 490 °C and composition close to the average arc gas , as shown in Table. Gas species CO2 SO2 H2S HCl H2O T, °C mmol/mol Main fumarole 27.9 23.5 6.1 5.6 936 420 Low-temp. jets 92.2 2.62 0.68 1.6 902 <120 Low-temperature fumaroles (<120 °C) emitted gas enriched in CO 2 (up to 28 mol%, 9.2 mol% on average). Such CO 2 enrichment together with depletion in HCl and sulfur species can be explained by scrubbing of soluble gas species by a well-developed hydrothermal system which discharges ultra-acid SO 4-Cl waters . A weighted-average estimate of the total gas+vapor emission from the Ebeko summit provided 1470 t/d, which includes ~ 101 t/d SO2, ~ 110 t/d CO2, ~ 14 t/d H2S and HCl, and 1230 t/d of water vapour with > 50% of the magmatic component. The gas fluxes measured in August 2015 using DOAS fall into the range of previous measurements made from 1960 to 2012 that used direct methods  and correspond to the moderate degassing rate of the volcano.
A Physicochemical Model for Deep Degassing of Water-Rich Magma (2008)
Maksimov A.P. A Physicochemical Model for Deep Degassing of Water-Rich Magma // Journal of Volcanology and Seismology. 2008. V. 2. № 5. P. 356-363. doi: 10.1134/S0742046308050059.
Two powerful eruptions of Quizapu vent on Cerro Azul Volcano, Chile are used as examples to discuss
the problem of effusive eruptions of magmas having high preeruptive volatile concentrations. A physicochemical
mechanism is proposed for magma degassing, with the volatiles being lost before coming to the surface.
The model is based on the interaction of magmas residing in chambers at different depths and on the difference
between the solubility of water in the melt and the water equilibrium concentration in a magma body
having a considerable vertical extent. The shallower chamber can accumulate the volatiles released from the
magma that is supplied from the deeper chamber. An explanation is provided of the dramatic differences in the
character of the 1846–1847 and 1932 eruptions, which had identical chemical–petrographic magma compositions.
На примере двух мощных извержений конуса Квицапу вулкана Сьерро-Ассуль (Чили) рассматривается проблема эффузивных извержений магм с высокими предэруптивными содержаниями летучих. Предложен физико-химический механизм дегазации магм с потерей ими летучих до появления на поверхности. Модель основана на взаимодействии магм, находившихся в разных по глубине очагах, и различии между растворимостью воды в расплаве и ее равновесной концентрацией в протяженном по вертикали магматическом теле. При этом малоглубинный очаг может аккумулировать летучие, выделяющиеся из магмы, поступающей в него из глубинного очага. Дается объяснение резких различий в характере извержений 1846–1847 и 1932 г. при идентичном химико-петрографическом составе магм.
A Proposal to Monitor Volcanic Activity in the Kurile Islands (2002)
Girina O.A., Rybin A.V., Kirianov V.Yu. A Proposal to Monitor Volcanic Activity in the Kurile Islands // Abstracts. 3rd Biennial Workshop on Subduction Processes emphasizing the Kurile-Kamchatka-Aleutian Arcs (JKASP-3). Fairbanks. June 2002. 2002. P. 120
A chronology of the Holocene eruptions from the northern Kamchatka volcanoes based on linking major C14-dated tephra sequences with the help of EMPA glass data (2012)
Ponomareva Vera A chronology of the Holocene eruptions from the northern Kamchatka volcanoes based on linking major C14-dated tephra sequences with the help of EMPA glass data // Quaternary International. 2012. V. 279–28. P. 383 doi: 10.1016/j.quaint.2012.08.1191.
Volcanic eruptions from Kamchatka have deposited many unique tephra layers over a large region within the North Pacific, providing important isochrons between key sites such as marine ODP core 883 (Pacific Ocean, Detroit Seamount) and Elgygytgyn Lake (Chukotka, eastern Siberia). Here we present a compilation of C14 dates on major Holocene tephras from the volcanically highly active region, based on decades of detailed stratigraphical fieldwork on Shiveluch, Kliuchevskoy, and other volcanoes.The 12-m thick tephra sequence at the Kliuchevskoy slope has been continuously accumulating during the last ∼11 ka. It contains over 200 visible individual tephra layers and no datable organic material. The section is dominated by dark-gray mafic cinders related to Kliuchevskoy activity. In addition, it contains 30 light-colored thin layers of silicic tephra from distant volcanoes including 11 layers from Shiveluch volcano located only 65 km to the north. We have used EMPA glass analysis to correlate most of the marker tephra layers to their source eruptions dated earlier by C14 (Braitseva et al., 1997; Ponomareva et al., 2007), and in this way linked Kliuchevskoy tephra sequence to sequences at other volcanoes including Shiveluch. The C14 dates and tephras from the northern Kamchatka are then combined into a single Bayesian framework taking into account stratigraphical ordering within and between the sites. This approach has allowed us to enhance the reliability and precision of the estimated ages for the eruptions. Age-depth models are constructed to analyse changes in deposition rates and volcanic activity throughout the Holocene. This detailed chronology of the eruptions serves as a basis for understanding temporal patterns in the eruption sequence and geochemical variations of magmas. This research could prove important for the long-term forecast of eruptions and volcanic hazards.
A dangling slab, amplified arc volcanism, mantle flow, and seismic anisotropy in the Kamchatka plate corner (2002)
Park J., Levin V., Brandon M., Lees J., Peyton V., Gordeev E., Ozerov A. A dangling slab, amplified arc volcanism, mantle flow, and seismic anisotropy in the Kamchatka plate corner // AGU Geodynamics Series. // Plate Boundary Zones. 2002. V. 30. P. 295-324.
A full holocene tephrochronology for the Kamchatsky Peninsula region: Applications from Kamchatka to North America (2017)
Ponomareva Vera, Portnyagin Maxim, Pendea I. Florin, Zelenin Egor, Bourgeois Joanne, Pinegina Tatiana, Kozhurin Andrey A full holocene tephrochronology for the Kamchatsky Peninsula region: Applications from Kamchatka to North America // Quaternary Science Reviews. 2017. V. 168. P. 101-122. doi:10.1016/j.quascirev.2017.04.031.
Geochemically fingerprinted widespread tephra layers serve as excellent marker horizons which can directly link and synchronize disparate sedimentary archives and be used for dating various deposits related to climate shifts, faulting events, tsunami, and human occupation. In addition, tephras represent records of explosive volcanic activity and permit assessment of regional ashfall hazard. In this paper we report a detailed Holocene tephrochronological model developed for the Kamchatsky Peninsula region of eastern Kamchatka (NW Pacific) based on ∼2800 new electron microprobe analyses of single glass shards from tephra samples collected in the area as well as on previously published data. Tephra ages are modeled based on a compilation of 223 14C dates, including published dates for Shiveluch proximal tephra sequence and regional marker tephras; new AMS 14C dates; and modeled calibrated ages from the Krutoberegovo key site. The main source volcanoes for tephra in the region are Shiveluch and Kliuchevskoi located 60–100 km to the west. In addition, local tephra sequences contain two tephras from the Plosky volcanic massif and three regional marker tephras from Ksudach and Avachinsky volcanoes located in the Eastern volcanic front of Kamchatka. This tephrochronological framework contributes to the combined history of environmental change, tectonic events, and volcanic impact in the study area and farther afield. This study is another step in the construction of the Kamchatka-wide Holocene tephrochronological framework under the same methodological umbrella. Our dataset provides a research reference for tephra and cryptotephra studies in the northwest Pacific, the Bering Sea, and North America.
A geochemical model for fumaroles of the Mutnovsky volcano, Kamchatka, USSR (1992)
Taran Yu.A., Pilipenko V.P., Rozhkov A.M., Vakin E.A. A geochemical model for fumaroles of the Mutnovsky volcano, Kamchatka, USSR // Journal of Volcanology and Geothermal Research. 1992. V. 49. № 3–4. P. 269 - 283. doi: 10.1016/0377-0273(92)90018-9.
On the basis of the chemical, isotopic and thermodynamic characteristics of fluids sampled between 1964 and 1989 a genetic model description is given for fumaroles of the Mutnovsky volcano. There are three individual groups of fumaroles in the Mutnovsky crater which show stable activity for a long period of time: “the Active Funnel” (temperatures exceed 600°C), the “Upper Field” (up to 320°C) and the “Bottom Field” (from 100 to 150°C). The three principal zones of emission have different gas composition, water isotopic composition, radioactivity and 3He/4He ratios. The abundance of magmatic components in the high-temperature fumaroles of the “Active Funnel” is much higher than those in gases from the other groups. Emission rate of SO2 from the “Active Funnel” is about 200 t/d, which requires complete degassing as a minimum of 1 km3 of magma every 20 years. Fluids of the “Upper Field” contain up to 80% of steam from the Mutnovsky geothermal system. Temperature variations of the “Bottom Field” fumaroles (from 97°C before 1982 to 151°C in 1989) result from changes in hydrological conditions in the crater. Evaporation of high-saline acid brine which is formed in the interior of the volcano is responsible for the composition of the “Bottom Field” gas-steam discharges.