Izbekov Pavel E., Eichelberger John C., Patino Lina C., Vogel Thomas A., Ivanov Boris V. Calcic cores of plagioclase phenocrysts in andesite from Karymsky volcano: Evidence for rapid introduction by basaltic replenishment // Geology. 2002. Vol. 30. № 9. P. 799-802.
Calcic cores in plagioclase of Karymsky andesite of the 1996–2000 eruptive cycle texturally and compositionally (both trace and major elements) mimic the plagioclase phenocrysts of basalt erupted 6 km away at the onset of the cycle. These observations support the view that simultaneous eruption of andesite and basalt at Karymsky in the beginning of the cycle represents an example of replenishment and eruption triggering of an andesitic reservoir. Homogeneity of andesitic output occurred within two months. This suggests to us that blending of injected basalt into reservoir magma was thorough and rapid.
Kirianov V.Yu., Neal C.A., Gordeev E.I., Miller T.P. The Kamchatkan Volcanic Eruption Response Team (KVERT) // USGS Fact Sheet. 2002. Vol. 064-02.
Korzhinsky Mikhail A., Botcharnikov Roman E., Tkachenko Sergey I., Steinberg Genrikh S. Decade-long study of degassing at Kudriavy volcano, Iturup, Kurile Islands (1990–1999): Gas temperature and composition variations, and occurrence of 1999 phreatic eruption // Earth, Planets and Space. 2002. Vol. 54. № 3. P. 337-347. doi:10.1186/BF03353032.
A high-temperature (up to 940°C) fumarolic activity at Kudriavy volcano had been studied during 1990–1999. The maximum gas temperatures of the fumaroles were measured in 1992 as 940°C, then gradually decreased with time and reached to 907°C in 1999. Gas composition of the high-temperature fumarole became enriched in H2O and depleted in other gas components, in particular in CO2. Hydrogen isotopic compositions of the high-temperature fumarolic gases were gradually depleted in deuterium. The gradual and continuous decrease in temperature and changes in gas composition observed during the last 10-year suggest that a magmatic melt have been degassing in a relatively steady-state manner from a single magma chamber. The detail investigations in 1998 and 1999 revealed short-term changes in gas composition characterized by sporadic increases in H2, CO2, and Stotal after intense precipitations. Small-scale eruptions occurred on October 7, 1999 at the summit. The ratios of major gas components (C/S, C/Cl, S/Cl, C/F, S/F, and Cl/F) significantly increased just prior to the eruption. The eruption at the Kudriavy volcano in 1999 was likely a phreatic eruption as a result of the intense precipitations after unusually long dry period. Meteoric water penetrated into the hot zone of volcano edifice and rapidly boiled causing the eruption.
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.
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.
Muravyev Y.D., Shiraiwa T. 400 years of climatic change in Kamchatka Peninsula, Russia: paleoglaciologic, tree-ring and ice-core evidance // Proceedings International Workshop. Matsuyama, Japan, 2002. 2002. P. 76-91.
Nakagawa Mitsuhiro, Ishizuka Yoshihiro, Kudo Takashi, Yoshimoto Mitsuhiro, Hirose Wataru, Ishizaki Yoshio, Gouchi Nobuo, Katsui Yoshio, Solovyow Alexander W., Steinberg Genrikh S., Abdurakhmanov Arslan I. Tyatya Volcano, southwestern Kuril arc: Recent eruptive activity inferred from widespread tephra // The Island Arc. 2002. Vol. 11. № 4. P. 236-254. doi:10.1046/j.1440-1738.2002.00368.x.
Tyatya Volcano, situated in Kunashir Island at the southwestern end of Kuril Islands, is a large composite stratovolcano and one of the most active volcanoes in the Kuril arc. The volcanic edifice can be divided into the old and the young ones, which are composed of rocks of distinct magma types, low‐ and medium‐K series, respectively. The young volcano has a summit caldera with a central cone. Recent eruptions have occurred at the central cone and at the flank vents of the young volcano. We found several distal ash layers at the volcano and identified their ages and sources, that is, tephras of ad 1856, ad 1739, ad 1694 and ca 1 Ka derived from three volcanoes of Hokkaido, Japan, and caad 969 from Baitoushan Volcano of China/North Korea. These could provide good time markers to reveal the eruptive history of the central cone, which had continued intermittently with Strombolian eruptions and lava flow effusions since before 1 Ka. Relatively explosive eruptions have occurred three times at the cone during the past 1000 years. We revealed that, topographically, the youngest lava flows from the cone are covered not by the tephra of ad 1739 but by that of ad 1856. This evidence, together with a report of dense smoke rising from the summit in ad 1812, suggests that the latest major eruption with lava effusion from the central cone occurred in this year. In 1973, after a long period of dormancy, short‐lived phreatomagmatic eruptions began to occur from fissure vents at the northern flank of the young volcano. This was followed by large eruptions of Strombolian to sub‐Plinian types occurring from several craters at the southern flank. The 1973 activity is evaluated as Volcanic Explosivity Index = 4 (approximately 0.2 km3), the largest eruption during the 20th century in the southwestern Kuril arc. The rocks of the central cone are strongly porphyritic basalt and basaltic andesite, whereas the 1973 scoria is aphyric basalt, suggesting that magma feeding systems are definitely different between the summit and flank eruptions.
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 / Plate Boundary Zones. AGU Geodynamics Series. 2002. Vol. 30. P. 295-324.
Voight B., Komorowski J-C., Norton G. E., Belousov A. B., Belousova M., Boudon G., Francis P. W., Franz W., Heinrich P., Sparks R. S. J., Young S. R. The 26 December (Boxing Day) 1997 sector collapse and debris avalanche at Soufriere Hills Volcano, Montserrat // Geological Society, London, Memoirs. 2002. Vol. 21. № 1. P. 363-407. doi:10.1144/GSL.MEM.2002.021.01.17.
Альмеев Р.Р., Арискин A.A., Озеров А.Ю., Кононкова Н.Н. Проблемы стехиометрии и термобарометрии магматических амфиболов (на примере роговых обманок из андезитов вулкана Безымянный, Восточная Камчатка) // Геохимия. 2002. № 8. С. 803-819.
Апрелков С.Е., Богдан П.С., Попруженко С.В. Палеовулканоструктуры Уннэйваямского вулканического поля в Корякском нагорье и связь с ними оруденения (по геолого-геофизическим данным) // Тихоокеанская геология. 2002. Т. 21. № 5. С. 51-61.
Basing on the analysis of the data of detailed geophysical investigations in the Unneivayam Paleogene volcanic field, Koryak Upland, linear systems (zones) of volcanic domal and caldera structures are distinguished and characterized. Their relationship with ore fields and structures is analyzed, and new ore targets are predicted.