Библиография
Вулкан:
Группировать:  
Записей: 2737
Статьи
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. Vol. 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. Vol. 6. № 6. P. 341-351. https://doi.org/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. The Petrophysical Properties and Strength of Extrusive Rocks Discharged by Bezymianny Volcano, Kamchatka // Journal of Volcanology and Seismology. 2023. Vol. 17. № 3. P. 159-174. https://doi.org/10.1134/S0742046323700197.
   Аннотация
This is the first petrophysical study of extrusive rocks (dacites to andesites) discharged by Bezymianny Volcano. We provide a comparative description of properties for extrusive rocks in accordance with identified age groups. We show the dynamics in the variation of extrusive rock properties in relation to their ages, with the result that the older a rock the higher are its density, strength, and elastic parameters. Rocks petrophysical features are compared between extrusive domes and lava flows. We argue for petrophysical properties to be applicable for deriving more accurate results for the genesis of rocks having similar petrophysical properties, in particular, rocks of extrusive and effusive origin.
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.
Lees J.M., Johnson J., Gordeev E.I., Batereau K., Ozerov A.Yu. Volcanic Explosions at Karymsky: A Broadband Experiment Around the cone // AGU Spring Meeting 1997 Abstracts. Baltimore, Maryland: AGU. 1997. P. S11C-06.
Lees J.M., Johnson J.B., Gordeev E.I., Ozerov A.Yu. Degassing explosion at Karymsky volcano, Kamchatka // Abstracts of international seismic volcanic workshop on Kamchatkan and Alaska-Aleutian island arcs, Petropavlovsk-Kamchatsky, July 1-9, 1998. 1998. P. 23
Lees J.M., Ozerov A.Yu., Gordeev E.I. Quasi-Periodic Eruptions on Karymsky Volcano, Kamchatka, 1996 // AGU Spring Meeting 1997 Abstracts. Baltimore, Maryland: AGU. 1997. P. V22A-05.
Levin V., Park J., Brandon M., Lees J., Peyton V., Gordeev E., Ozerov A. Crust and upper mantle of Kamchatka from teleseismic receiver functions // Tectonophysics. 2002. № 358. P. 233-256.
   Аннотация
Teleseismic receiver functions (RFs) from a yearlong broadband seismological experiment in Kamchatka reveal regional variations in the Moho, anisotropy in the supra-slab mantle wedge, and, along the eastern coast, Ps converted phases from the steeply dipping slab. We analyze both radial- and transverse-component RFs in bin-averaged epicentral and backazimuthal sweeps, in order to detect Ps moveout and polarity variations diagnostic of interface depth, interface dip, and anisotropic fabric within the shallow mantle and crust. At some stations, the radial RF is overprinted by near-surface resonances, but anisotropic structure can be inferred from the transverse RF. Using forward modeling to match the observed RFs, we find Moho depth to range between 30 and 40 km across the peninsula, with a gradational crust –mantle transition beneath some stations along the eastern coast. Anisotropy beneath the Moho is required to fit the transverse RFs at most stations. Anisotropy in the lower crust is required at a minority of stations. Modeling the amplitude and backazimuthal variation of the Ps waveform suggests that an inclined axis of symmetry and 5 – 10% anisotropy are typical for the crust and the shallow mantle. The apparent symmetry axes of the anisotropic layers are typically trench-normal, but trench-parallel symmetry axes are found for stations APA and ESS, both at the fringes of the central Kamchatka depression. Transverse RFs from east-coast stations KRO, TUM, ZUP and PET are fit well by two anisotropic mantle layers with trench-normal symmetry axes and opposing tilts. Strong anisotropy in the supraslab mantle wedge suggests that the mantle ‘‘lithosphere’’ beneath the Kamchatka volcanic arc is actively deforming, strained either by wedge corner flow at depth or by trenchward suction of crust as the Pacific slab retreats.
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.
Maksimov A.P. A Physicochemical Model for Deep Degassing of Water-Rich Magma // Journal of Volcanology and Seismology. 2008. Vol. 2. № 5. P. 356-363. doi: 10.1134/S0742046308050059.
   Аннотация
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.