Satellite observations and numerical simulation results for the comprehensive analysis of ash clouds transport during the explosive eruptions of Kamchatka volcanoes (2017)
Sorokin A.A., Girina O.A., Loupian E.A., Malkovskii S.I., Balashov I.V., Efremov V.Yu., Kramareva L.S., Korolev S.P., Romanova I.M., Simonenko E.V. Satellite observations and numerical simulation results for the comprehensive analysis of ash clouds transport during the explosive eruptions of Kamchatka volcanoes // Russian Meteorology and Hydrology. 2017. Vol. 42. № 12. P. 759-765. doi: 10.3103/S1068373917120032.
Ash clouds resulting from explosive volcanic eruptions pose a real threat to human (for aircraft flights, airports operations, etc.); therefore, the detection, monitoring, and forecast of their movement is an urgent and important issue. The features and examples of application of the new tool developed on the basis of "Monitoring of active volcanoes of Kamchatka and the Kurile Islands" information system (VolSatView) are described. It allows the integrated monitoring and forecasting of ash cloud transport using the data of remote sensing and mathematical modeling as well as the assessment of the parameters of explosive events.
Scenario of the 1996 volcanic tsunamis in Karymskoye Lake, Kamchatka, inferred from X-ray tomography of heavy minerals in tsunami deposits (2018)
Falvard S., Paris R., Belousova M., Belousov A., Giachetti T., Cuven S. Scenario of the 1996 volcanic tsunamis in Karymskoye Lake, Kamchatka, inferred from X-ray tomography of heavy minerals in tsunami deposits // Marine Geology. 2018. № 396. P. 160-170.
Sector collapses and large landslides on Late Pleistocene–Holocene volcanoes in Kamchatka, Russia (2006)
Ponomareva Vera V., Melekestsev Ivan V., Dirksen Oleg V. Sector collapses and large landslides on Late Pleistocene–Holocene volcanoes in Kamchatka, Russia // Journal of Volcanology and Geothermal Research. 2006. Vol. 158. № 1-2. P. 117-138. doi:10.1016/j.jvolgeores.2006.04.016.
On Kamchatka, detailed geologic and geomorphologic mapping of young volcanic terrains and observations on historical eruptions reveal that landslides of various scales, from small (0.001 km3) to catastrophic (up to 20–30 km3), are widespread. Moreover, these processes are among the most effective and most rapid geomorphic agents. Of 30 recently active Kamchatka volcanoes, at least 18 have experienced sector collapses, some of them repetitively. The largest sector collapses identified so far on Kamchatka volcanoes, with volumes of 20–30 km3 of resulting debris-avalanche deposits, occurred at Shiveluch and Avachinsky volcanoes in the Late Pleistocene. During the last 10,000 yr the most voluminous sector collapses have occurred on extinct Kamen' (4–6 km3) and active Kambalny (5–10 km3) volcanoes. The largest number of repetitive debris avalanches (> 10 during just the Holocene) has occurred at Shiveluch volcano. Landslides from the volcanoes cut by ring-faults of the large collapse calderas were ubiquitous. Large failures have happened on both mafic and silicic volcanoes, mostly related to volcanic activity. Orientation of collapse craters is controlled by local tectonic stress fields rather than regional fault systems.
Specific features of some debris avalanche deposits are toreva blocks — huge almost intact fragments of volcanic edifices involved in the failure; some have been erroneously mapped as individual volcanoes. One of the largest toreva blocks is Mt. Monastyr' — a ∼ 2 km3 piece of Avachinsky Somma involved in a major sector collapse 30–40 ka BP.
Long-term forecast of sector collapses on Kliuchevskoi, Koriaksky, Young Cone of Avachinsky and some other volcanoes highlights the importance of closer studies of their structure and stability.
Seismic tomography of the Pacific slab edge under Kamchatka (2009)
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.
Seismicity observed during the precursory process and the actual eruption of Kizimen Volcano, Kamchatka in 2009-2013 (2014)
Firstov P.P., Shakirova A.A. Seismicity observed during the precursory process and the actual eruption of Kizimen Volcano, Kamchatka in 2009-2013 // Journal of Volcanology and Seismology. 2014. Vol. 8. № 4. P. 203-217. doi: 10.1134/S0742046314040022.
Seismological Studies on the Mechanism of the Large Tolbachik Fissure Eruption, 1975-1976 (1980)
Fedotov S.A., Gorelchik V.I., Stepanov V.V. Seismological Studies on the Mechanism of the Large Tolbachik Fissure Eruption, 1975-1976 // Bulletin Volcanologique. 1980. Vol. 43. № 1. P. 73-84.
Seismological observations provided consistent information on the course and mechanism of the complicated large fissure eruption at Tolbachik volcano in Kamchatka from July 6, 1975 to December 10, 1976. Seismicity indicates that the initial magnesian basalts were rising ten days before the eruption from depths of more than 20 km. The formation of new feeding dykes was accompanied by earthquake swarms which decreased sharply one to two days before the opening of new eruptive fissures. The seismological data indicate that the main source of the different erupted basalts (2 km) was a vast system (diameter ca. 80 km) of hydraulically connected magma
chambers located in the lower crustal layers or in the crust-mantle transition layer.
Shiveluch volcano: seismicity, deep structure and forecasting eruptions (Kamchatka) (1997)
Gorelchik V.I., Shirokov V.A., Firstov P.P., Chubarova O.S. Shiveluch volcano: seismicity, deep structure and forecasting eruptions (Kamchatka) // Journal of Volcanology and Geothermal Research. 1997. Vol. 78. № 1–2. P. 121 - 137. doi: 10.1016/S0377-0273(96)00108-4.
The deep structure, Wadati-Benioff zone (focal zone) geometry and the magma feeding system of Shiveluch volcano are investigated based on 1962–1994 detailed seismic surveillance. A focal zone beneath Shiveluch is dipping at an angle of 70° at depths of 100–200 km. Based on the revealed interrelations between seismicity at depths of 105–120 km and an extrusive phase of its eruptions in 1980 through 1994, it is inferred that primary magmas, periodically feeding the crustal chamber, are melted at depths of at least 100 km. An upsurge of extrusive-explosive activity at the volcano is preceded and accompanied by the increasing number and energy of both volcanic earthquakes beneath the dome and tectonic or volcano-tectonic earthquakes in the zones of NW-striking crustal faults near the volcano.The eruption of April 1993 has been the most powerful since 1964. It was successfully predicted based on interactive use of all seismic data. At the same time the influence of seismicity at depths of 105–120 km under the volcano on the style (and consequently on prediction) of its activity is decisive.
Small but important: new data about activity and composition of Zarechny volcano (Central Kamchatka depression) (2018)
Gorbach N.V., Ponomareva V.V., Pendea I. Florin, Portnyagin M.V. Small but important: new data about activity and composition of Zarechny volcano (Central Kamchatka depression) // 10th Biennual workshop on Japan-Kamchatka-Alaska subduction processes (JKASP-2018). Petropavlovsk-Kamchatsky, Russia, August 20-26. 2018. P. 83-85.
Solubility of H2O- and CO2-bearing fluids in tholeiitic basalts at pressures up to 500 MPa (2010)
Shishkina T.A., Botcharnikov R.E., Holtz F., Almeev R.R., Portnyagin M.V. Solubility of H2O- and CO2-bearing fluids in tholeiitic basalts at pressures up to 500 MPa // Chemical Geology. 2010. Vol. 277. № 1–2. P. 115 - 125. doi: 10.1016/j.chemgeo.2010.07.014.
The solubility of H2O- and CO2-bearing fluids in tholeiitic basalts has been investigated experimentally at temperature of 1250 °C and pressures of 50, 100, 200, 300, 400 and 500 MPa. The concentrations of dissolved H2O and CO2 have been determined using FTIR spectroscopy with an accurate calibration of the absorption coefficients for hydrogen- and carbon-bearing species using synthesized standards of the same tholeiitic composition. The absorption coefficients are 0.65 ± 0.08 and 0.69 ± 0.08 L/(mol cm) for molecular H2O and OH groups by Near-Infrared (NIR), respectively, and 68 ± 10 L/(mol cm) for bulk H2O by Mid-Infrared (MIR). The carbonate groups determined by MIR have an absorption coefficient of 317 ± 23 L/(mol cm) for the band at 1430 cm−1.The solubility of H2O in the melt in equilibrium with pure H2O fluid increases from about 2.3 ± 0.12 wt.% at 50 MPa to about 8.8 ± 0.16 wt.% at 500 MPa, whereas the concentration of CO2 increases from about 175 ± 15 to 3318 ± 276 ppm in the melts which were equilibrated with the most CO2-rich fluids (with mole fraction of CO2 in the fluid, XflCO2, from 0.70 to 0.95). In melts coexisting with H2O- and CO2-bearing fluids, the concentrations of dissolved H2O and CO2 in basaltic melt show a non-linear dependence on both total pressure and mole fraction of volatiles in the equilibrium fluid, which is in agreement with previous studies. A comparison of new experimental data with existing numerical solubility models for mixed H2O–CO2 fluids shows that the models do not adequately predict the solubility of volatiles in basaltic liquids at pressures above 200 MPa, in particular for CO2, implying that the models need to be recalibrated.
The experimental dataset presented in this study enables a quantitative interpretation of volatile concentrations in glass inclusions to evaluate the magma storage conditions and degassing paths of natural island arc basaltic systems. The experimental database covers the entire range of volatile compositions reported in the literature for natural melt inclusions in olivine from low- to mid-K basalts indicating that most melt inclusions were trapped or equilibrated at intermediate to shallow levels in magmatic systems (< 12–15 km).