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 2015
Girina O.A., Romanova I.M. Activity of Kamchatkan and Northern Kuriles volcanoes database of Kamchatkan volcanic eruption response team // 26th IUGG General Assembly. June 22-July 02, 2015. Abstracts. Prague: IUGG/IAVCEI. 2015. P. VS10p-456.
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. Vol. 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.
Kardanova O. F., Dubrovskaya I. K., Murav’ev Ya. D. Thermal anomalies on Savich Cone, Kikhpinych Volcano, Kamchatka: IR surveys and land-based observations for 30 years (1982 through 2012) // Journal of Volcanology and Seismology. 2015. Vol. 9. № 6. P. 368-377. doi:10.1134/S0742046315060032.
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. Vol. 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.
Lundgren Paul, Kiryukhin Alexey, Milillo Pietro, Samsonov Sergey Dike model for the 2012–2013 Tolbachik eruption constrained by satellite radar interferometry observations // Journal of Volcanology and Geothermal Research. 2015. Vol. 307. P. 79 - 88. doi: 10.1016/j.jvolgeores.2015.05.011.
   Аннотация
Abstract A large dike intrusion and fissure eruption lasting 9 months began on November 27, 2013, beneath the south flank of Tolbachik Volcano, Kamchatka, Russia. The eruption was the most recent at Tolbachik since the Great Tolbachik Eruption from 1975 to 1976. The 2012 eruption was preceded by more than 6 months of seismicity that clustered beneath the east flank of the volcano along a NW–SE trend. Seismicity increased dramatically before the eruption, with propagation of the seismicity from the central volcano conduit in the final hours. We use interferometric synthetic aperture radar (InSAR) to compute relative displacement images (interferograms) for {SAR} data pairs spanning the eruption. We use satellite {SAR} data from the Canadian Space Agency's RADARSAT-2 and from the Italian Space Agency's COSMO-SkyMed missions. Data are modeled first through a Markov Chain Monte Carlo solution for a single tensile dislocation (dike). We then use a boundary element method that includes topography to model a distributed dike-opening model. We find the best-fitting dike dips 80° to the {WNW} with maximum opening of 6–8 m, localized in the near surface and more broadly distributed in distinct regions up to 3 km beneath the surface, which varies from 1 to 2 km elevation for the eruptive fissures. The distribution of dike opening and its correspondence with co-diking seismicity suggests that the dike propagated radially from Tolbachik's central conduit.
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.
   Аннотация
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.
National Report for the International Association of Volcanology and Chemistry of the Earth’s Interior of the International Union of Geodesy and Geophysics 2011–2014. Presented to the XXVI General Assembly of the IUGG Geoinf. Res. Papers, 3, BS3011. / Ed. Churikova T.G., Gordeychik B.N., Fedotov S.A. Moscow: GCRAS Publ. 2015. 185 p. doi: 10.2205/2015IUGG-RU-IAVCEI.
   Аннотация
In the present National Report, major results are given of research conducted by Russian scientists in 2011–2014 on the topics of the International Association of Volcanology and Chemistry of the Earth’s Interior (IAVCEI) of the International Union of Geodesy and Geophysics. Kamchatka Peninsula with its famous Klyuchevskaya Group of volcanoes is the most volcanically active area in Russia and one of the most active in the world. Majority of researches and scientific results on Volcanology and Geochemistry of the Earth’s Interior during 2011–2014 were achieved in this region including recent data on new Tolbachik fissure eruption in 2012–2013. Besides it, the scientific results on the magmatism outside Russia, which were achieved by Russian scientists, are also included in this review. Major achievements in the chemistry of the Earth, geothermy, geodynamics, geochronology and deep mantle structure are featured. The studies as for the single volcanoes as well the regional observations are outlined. The theoretical and applied efforts connected to the volcanological processes are considered. The main conclusions are illustrated by summarized figures. All the required references are given.
Plechov Pavel, Blundy Jon, Nekrylov Nikolay, Melekhova Elena, Shcherbakov Vasily, Tikhonova Margarita S. Petrology and volatile content of magmas erupted from Tolbachik Volcano, Kamchatka, 2012–13 // Journal of Volcanology and Geothermal Research. 2015. Vol. 307. P. 182 - 199. doi: 10.1016/j.jvolgeores.2015.08.011.
   Аннотация
Abstract We report petrography, and bulk rock, mineral and glass analyses of eruptive products of the 2012–13 eruption of Tolbachik volcano, Central Kamchatka Depression, Russia. Magmas are shoshonitic in composition, with phenocrysts of olivine and plagioclase; clinopyroxene phenocrysts are scarce. Samples collected as bombs from the active vent, from liquid lava at the active lava front, and as naturally solidified “toothpaste” lava allow us to quantify changes in porosity and crystallinity that took place during 5.25 km of lava flow and during solidification. Olivine-hosted melt inclusions from rapidly-cooled, mm-size tephra have near-constant {H2O} contents (1.19 ± 0.1 wt) over a wide range of {CO2} contents (< 900 ppm), consistent with degassing. The groundmass glasses from tephras lie at the shallow end of this degassing trend with 0.3 wt {H2O} and 50 ppm CO2. The presence of small saturation, rather than shrinkage, bubbles testifies to volatile saturation at the time of entrapment. Calculated saturation pressures are 0.3 to 1.7 kbar, in agreement with the depths of earthquake swarms during November 2012 (0.6 to 7.5 km below the volcano). Melt inclusions from slowly-cooled and hot-collected lavas have {H2O} contents that are lower by an order of magnitude than tephras, despite comparable {CO2} contents. We ascribe this to diffusive {H2O} loss through olivine host crystals during cooling. The absence of shrinkage bubbles in the inclusions accounts for the lack of reduction in dissolved {CO2} (and S and Cl). Melt inclusions from tephras experienced < 3 wt post-entrapment crystallisation. Melt inclusion entrapment temperatures are around 1080 °C. Compared to magmas erupted elsewhere in the Kluchevskoy Group, the 2012–13 Tolbachik magmas appear to derive from an unusually H2O-poor and K2O-rich basaltic parent.
Ponomareva Vera, Portnyagin Maxim, Davies Siwan M. Tephra without Borders: Far-Reaching Clues into Past Explosive Eruptions // Frontiers in Earth Science. 2015. Vol. 3. № 83. doi:10.3389/feart.2015.00083.
   Аннотация
This review is intended to highlight recent exciting advances in the study of distal (>100 km from the source) tephra and cryptotephra deposits and their potential application for volcanology. Geochemical correlations of tephra between proximal and distal locations have extended the geographical distribution of tephra over tens of millions square kilometers. Such correlations embark on the potential to reappraise volume and magnitude estimates of known eruptions. Cryptotephra investigations in marine, lake, and ice-core records also give rise to continuous chronicles of large explosive eruptions many of which were hitherto unknown. Tephra preservation within distal ice sheets and varved lake sediments permit precise dating of parent eruptions and provide new insight into the frequency of eruptions. Recent advances in analytical methods permit an examination of magmatic processes and the evolution of the whole volcanic belts at distances of hundreds and thousands of kilometers from source. Distal tephrochronology has much to offer volcanology and has the potential to significantly contribute to our understanding of sizes, recurrence intervals and geochemical make-up of the large explosive eruptions.
Ponomareva Vera, Portnyagin Maxim, Pevzner Maria, Blaauw Maarten, Kyle Philip, Derkachev Alexander Tephra from andesitic Shiveluch volcano, Kamchatka, NW Pacific: chronology of explosive eruptions and geochemical fingerprinting of volcanic glass // International Journal of Earth Sciences. 2015. Vol. 104. № 5. P. 1459-1482. doi:10.1007/s00531-015-1156-4.
   Аннотация
The ~16-ka-long record of explosive eruptions from Shiveluch volcano (Kamchatka, NW Pacific) is refined using geochemical fingerprinting of tephra and radiocarbon ages. Volcanic glass from 77 prominent Holocene tephras and four Late Glacial tephra packages was analyzed by electron microprobe. Eruption ages were estimated using 113 radiocarbon dates for proximal tephra sequence. These radiocarbon dates were combined with 76 dates for regional Kamchatka marker tephra layers into a single Bayesian framework taking into account the stratigraphic ordering within and between the sites. As a result, we report ~1,700 high-quality glass analyses from Late Glacial–Holocene Shiveluch eruptions of known ages. These define the magmatic evolution of the volcano and provide a reference for correlations with distal fall deposits. Shiveluch tephras represent two major types of magmas, which have been feeding the volcano during the Late Glacial–Holocene time: Baidarny basaltic andesites and Young Shiveluch andesites. Baidarny tephras erupted mostly during the Late Glacial time (~16–12.8 ka BP) but persisted into the Holocene as subordinate admixture to the prevailing Young Shiveluch andesitic tephras (~12.7 ka BP–present). Baidarny basaltic andesite tephras have trachyandesite and trachydacite (SiO2 < 71.5 wt%) glasses. The Young Shiveluch andesite tephras have rhyolitic glasses (SiO2 > 71.5 wt%). Strongly calc-alkaline medium-K characteristics of Shiveluch volcanic glasses along with moderate Cl, CaO and low P2O5 contents permit reliable discrimination of Shiveluch tephras from the majority of other large Holocene tephras of Kamchatka. The Young Shiveluch glasses exhibit wave-like variations in SiO2 contents through time that may reflect alternating periods of high and low frequency/volume of magma supply to deep magma reservoirs beneath the volcano. The compositional variability of Shiveluch glass allows geochemical fingerprinting of individual Shiveluch tephra layers which along with age estimates facilitates their use as a dating tool in paleovolcanological, paleoseismological, paleoenvironmental and archeological studies. Electronic tables accompanying this work offer a tool for statistical correlation of unknown tephras with proximal Shiveluch units taking into account sectors of actual tephra dispersal, eruption size and expected age. Several examples illustrate the effectiveness of the new database. The data are used to assign a few previously enigmatic wide-spread tephras to particular Shiveluch eruptions. Our finding of Shiveluch tephras in sediment cores in the Bering Sea at a distance of ~600 km from the source permits re-assessment of the maximum dispersal distances for Shiveluch tephras and provides links between terrestrial and marine paleoenvironmental records.