Ishimaru Satoko, Arai Shoji Highly silicic glasses in peridotite xenoliths from Avacha volcano, Kamchatka arc; implications for melting and metasomatism within the sub-arc mantle // Lithos. 2009. Vol. 107. № 1–2. P. 93 - 106. doi: 10.1016/j.lithos.2008.07.005.
Silicate glasses in peridotite xenoliths from Avacha volcano have high SiO2 (up to 72 wt.) and highly SiO2-oversaturated characteristics; normative quartz content is up to 50 wt.. The glasses represent secondary melts solidified after interaction with mantle peridotite, i.e. crystallization of secondary orthopyroxene at the expense of olivine. We identified two kinds of silicate glasses in Avacha peridotites; one is higher in K2O and enriched in Rb, Ba, U, and Pb than the other. The glasses show basically similar chemical characteristics to the host basaltic andesite to andesite of the Avacha volcano. These chemical characteristics are inherited from slab-derived fluids/melts, which metasomatize the mantle wedge and induce partial melting. The differences of chemical features among the Avacha glasses are attributed to chemical difference of the slab-derived fluids/melts, possibly due to the difference of sediments/basalt ratio of the relevant slab. The low-degree partial melt of peridotite assisted by these fluids/melts, is primarily SiO2-oversaturated, and can conduct silicate metasomatism, evolving through interaction with surrounding mantle peridotite, i.e. formation of orthopyroxene at the expense of olivine. Highly silicic glasses, also reported from peridotite xenoliths from oceanic hotspots and continental rift zones, mostly result from assimilation of orthopyroxene by SiO2-undersaturated melts, which crystallize clinopyroxene and olivine. The glasses also show similar trace-element patterns to their host alkali basaltic magmas, as in the case of arc glasses/calc-alkali magmas. If the glasses in peridotite xenoliths are of silicate metasomatism origin, they are similar in chemistry to host magmas. Reaction between carbonatite melts and peridotites shows the same petrographical feature as that of SiO2-undersaturated silicate melts with peridotites. The glasses originated from carbonatite metasomatism, however, exhibit clearly different trace-element patterns from their host alkali basaltic magmas.
Ishimaru Satoko, Arai Shoji, Shukuno Hiroshi Metal-saturated peridotite in the mantle wedge inferred from metal-bearing peridotite xenoliths from Avacha volcano, Kamchatka // Earth and Planetary Science Letters. 2009. Vol. 284. № 3–4. P. 352 - 360. doi: 10.1016/j.epsl.2009.04.042.
Lithospheric mantle is inferred to be more oxidized than the asthenosphere, and mantle-wedge peridotites are characterized by high oxidation state relative to abyssal and continental peridotites due to addition of slab-derived fluids or melts. We found metals (native Ni, Fe silicides, native Fe and possible native Ti) from otherwise oxidized sub-arc mantle peridotite xenoliths from Avacha volcano, Kamchatka. This is contrary to the consensus and experimental results that the metals are stable only in deeper parts of the mantle (> 250 km). The metals from Avacha are different in chemistry and petrography from those in serpentinized peridotites. The Avacha metals are characteristically out of chemical equilibrium between individual grains as well as with surrounding peridotite minerals. This indicates their independent formation from different fluids. Some of the Avacha metals form inclusion trails with fluids and pyroxenes, leading to the inference that very local metal saturation resulted from rapid supply (‘flashing’) of reducing fluids from deeper levels. The fluids, possibly rich in H2, are formed by serpentinization at the cold base of the mantle wedge just above the slab, and they reduce overlying peridotites. We propose a metal-saturated peridotite layer, underlying the main oxidized portion, within the mantle wedge beneath the volcanic front to fore-arc region.
Jiang Guoming, Zhao Dapeng, Zhang Guibin Seismic tomography of the Pacific slab edge under Kamchatka // Tectonophysics. 2009. Vol. 465. № 1–4. P. 190 - 203. doi: 10.1016/j.tecto.2008.11.019.
We determine a 3-D P-wave velocity structure of the mantle down to 700 km depth under the Kamchatka peninsula using 678 P-wave arrival times collected from digital seismograms of 75 teleseismic events recorded by 15 portable seismic stations and 1 permanent station in Kamchatka. The subducting Pacific slab is imaged clearly that is visible in the upper mantle and extends below the 660-km discontinuity under southern Kamchatka, while it shortens toward the north and terminates near the Aleutian–Kamchatka junction. Low-velocity anomalies are visible beneath northern Kamchatka and under the junction, which are interpreted as asthenospheric flow. A gap model without remnant slab fragment is proposed to interpret the main feature of high-V anomalies. Combining our tomographic results with other geological and geophysical evidences, we consider that the slab loss may be induced by the friction with surrounding asthenosphere as the Pacific plate rotated clockwise at about 30 Ma ago, and then it was enlarged by the slab-edge pinch-off by the asthenospheric flow and the presence of Meiji seamounts. As a result, the slab loss and the subducted Meiji seamounts have jointly caused the Pacific plate to subduct under Kamchatka with a lower dip angle near the junction, which made the Sheveluch and Klyuchevskoy volcanoes shift westward.
Krasheninnikov Stepan, Portnyagin Maxim, Ponomareva V.V., Bergal-Kuvikas Olga, Mironov Nikita Periodic volcanic activity of Klyuchevskoy and Ushkovsky volcanoes during the early Holocene inferred from tephra study 2009.
Neal C.A., Girina O.A., Senyukov S.L., Rybin A.V., Osiensky J., Izbekov P., Ferguson G. Russian eruption warning systems for aviation // Natural Hazards. 2009. Vol. 51. № 2. P. 245-262. doi: 10.1007/s11069-009-9347-6.
More than 65 potentially active volcanoes on the Kamchatka Peninsula and the Kurile Islands pose a substantial threat to aircraft on the Northern Pacific (NOPAC), Russian Trans-East (RTE), and Pacific Organized Track System (PACOTS) air routes. The Kamchatka Volcanic Eruption Response Team (KVERT) monitors and reports on volcanic hazards to aviation for Kamchatka and the north Kuriles. KVERT scientists utilize real-time seismic data, daily satellite views of the region, real-time video, and pilot and field reports of activity to track and alert the aviation industry of hazardous activity. Most Kurile Island volcanoes are monitored by the Sakhalin Volcanic Eruption Response Team (SVERT) based in Yuzhno-Sakhalinsk. SVERT uses daily moderate resolution imaging spectroradiometer (MODIS) satellite images to look for volcanic activity along this 1,250-km chain of islands. Neither operation is staffed 24 h per day. In addition, the vast majority of Russian volcanoes are not monitored seismically in real-time. Other challenges include multiple time-zones and language differences that hamper communication among volcanologists and meteorologists in the US, Japan, and Russia who share the responsibility to issue official warnings. Rapid, consistent verification of explosive eruptions and determination of cloud heights remain significant technical challenges. Despite these difficulties, in more than a decade of frequent eruptive activity in Kamchatka and the northern Kuriles, no damaging encounters with volcanic ash from Russian eruptions have been recorded.
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. Vol. 1. P. 178-181.
Ozerov A.Yu. Cluster Regime – The New Regime Of Flowing Of Gas-Liquid Mixture In Vertical Columns (Based On Experimental Data) // 6th International Symposium on Multiphase Flow, Heat Mass Transfer and Energy Conversion. Xi’an, China, 11-15 July 2009. 2009. P. FG-30.
Базанова Л.И., Дирксен О.В., Кулиш Р.В., Карташева Е.В. Эволюция новейшего вулканизма Жупанова хребта (Камчатка) // Вулканизм и геодинамика. Материалы IV Всероссийского симпозиума по вулканологии и палеовулканологии, Петропавловск-Камчатский, 22-27 сентября 2009 г. Петропавловск-Камчатский: ИВиС ДВО РАН. 2009. Т. 1. С. 265-268.
Базанова Л.И., Сулержицкий Л.Д. Вулкан Корякский: реконструкция динамики эруптивной активности за последние 10-12 тысяч лет // Вулканизм и геодинамика. Материалы IV Всероссийского симпозиума по вулканологии и палеовулканологии, Петропавловск-Камчатский, 22-27 сентября 2009 г. Петропавловск-Камчатский: ИВиС ДВО РАН. 2009. Т. 1. С. 269-272.