Мелекесцев И.В., Волынец О.Н., Антонов А.Ю. Кальдера Немо III (о-в Онекотан, Северные Курилы): строение, 14С-возраст, динамика кальдерообразующего извержения, эволюция ювенильных продуктов // Вулканология и сейсмология. 1997. № 1. С. 32-51.
This study is concerned with the structure of Nemo III caldera which came into being 24.500-25.000 B.P. in the north of Onekotan Island, Northern Kurils. We describe the pyroclastics of the caldera- generating eruption sequence, and estimate its volume (9-11 km3) and weight (12-14) * 10^9 t. The composition of juvenile products was found to vary in an antidromous manner during the eruptions from dacytes to basaltic andesites. The pre-caldera rocks and the pyroclastics of the caldera-generating eruption belong to the tholeiitic series, while the post-caldera rocks to the calc-alkalic. Evidence was found in the pumice discharged by the terminal eruption to indicate mixed magmas of dacyte and basaltic andesite (basaltic?) composition. The caldera-generating eruption sequence is supposed to have been caused by a "fresh" basic magma injected into a pre-existing acid magma chamber produced by fractionation of the magma which had been supplied to the pre-caldera volcanic structures.
Мелекесцев И.В., Миллер Т.П. Источник кислотного пика 1645 г. до н.э. в Гренландском ледниковом щите - кальдерообразующее извержение Аниякчак (п-ов Аляска, США) // Вулканология и сейсмология. 1997. № 2. С. 32-35.
The 1645 B.C. oxygen peak in Dye 3 borehole (65.18 N, 43.49 W) drilled in the Greenland ice sheet is shown to have been the catastrophic caldera-generating Aniyakchak eruption (56.88 N, 158.17 W) on Alaska Peninsula, U.S. rather than the famous Minoan eruption (36.404 N, 25.396 E) on Santorin Island, Greece.
Муравьев Я.Д., Федотов С.А., Будников В.А., Озеров А.Ю., Магуськин М.А., Двигало В.Н., Андреев В.И., Иванов В.В., Карташёва Л.А., Марков И.А. Вулканическая деятельность в Карымском центре в 1996 г.: вершинное извержение Карымского вулкана и фреатомагматическое извержение в кальдере Академии Наук // Вулканология и сейсмология. 1997. № 5. С. 38-70.
Data are presented from studies of volcanoes in the Karymsky long-living volcanic center, Kamchatka in 1996. We examine the dynamics and rock composition for eruptions that started simultaneously on Karymsky Volcano and in the Akademia Nauk caldera. The effusive-explosive eruption of Karymsky Volcano was resumed after a 14-year repose period, producing about 30 million tons of andesite-dacite discharges through the summit vent. Long-continued eruptive activity of that volcano is supposed to go on during the near future. Simultaneously with this activity, typical of Karymsky Volcano, a subaquaceous explosive eruption was observed in the lake that occupies the Akademia Nauk caldera 6 km south of the volcano for the first time in Kamchatka during the historical period. An edifice arose in the northern part of Lake Karymsky during 18 hours of this eruption consisting of basaltic and basaltic andesite pyroclastic material surrounding a crater of diameter 650 m. The amount of erupted pyroclastic material is estimated as 0.04 km3, the total weight being over 70 million tons. A discussion is provided of the impact of these eruptions on the environment; we describe renewed hydrothermal activity and the formation of a new group of hot springs in the Akademia Nauk caldera, and estimate the possibility of breakthrough floods from Lake Karymsky etc.
Певзнер М.М., Пономарева В.В., Мелекесцев И.В. Черный Яр - реперный разрез голоценовых маркирующих пеплов северо-восточного побережья Камчатки // Вулканология и сейсмология. 1997. № 4. С. 3-18.
Tephrochronological and radiocarbon investigations of soil-pyroclastic depositsalong the line Shiveluch Volcano - Chernyi Yar - Bering I. have detected and identified the ashes oflargest (for the past 6500 years) eruptions on Shiveluch Volcano in the southeastern sector of the ashabundance area, as well as the ashes of Bezymyannyi, Ksudach, Klyuchevskoi, Avacha and Khangarvolcanoes. A detailed radiocarbon dating of peat deposits in Chernyi Yar has not only improved the agedeterminations of the eruptions themselves but also helped in the determination of ash fall rate for thelower Kamchatka R. valley, namely, once in 191 years. Apart from the 1964 tephra, we suggest for useas regional geochronological markers the ash horizons of Shiveluch Volcano having the followingrounded radiocarbon dates: 265 (SH1), 965 (SH2), 1450, 2800, 3600 (SP), 4105 (SHDV), 4800, as well asthe ashes from Ksudach 1806 (KS1) and Avacha 5489 (AV2) volcanoes.
Федотов С.А. Об извержениях в кальдере Академии Наук и Карымского вулкана на Камчатке в 1996 г., их изучении и механизме // Вулканология и сейсмология. 1997. № 5. С. 3-37.
This paper is concerned with the eruptions that began simultaneously in the Karymsky volcanic center, Kamchatka, in 1996 and associated phenomena. A significant earthquake swarm started occurring there on January 1, 1996 with magnitudes as high as 6.9. A monoton. summit eruption of Karymsky Volcano followed on January 2, which has continued discharging andesite-dacite lava at a rate of 0.8 t/s until March 1997 and later. Basalts were emplaced along a fissure after 28 000 years of repose producing a phreatomagmatic eruption in the Akademia Nauk caldera at pyroclastic discharge rates of over 800 t/s. The distance between the erupting vents is 6 km. Basic tnunamt. waves resulting from underwater explosions and a high tsunami were observed, a new peninsula developed in the caldera lake, the ground surface experienced an extension of more than 2,3 m, and the fresh-water caldera lake of volume 0.47 km3 was transformed into an acid one (pH 3,2). Brief information is provided on the state of the volcanic center by the late 1995, a successful prediction, and the eruptions themselves. We estimate the depth to the pressure center in the primary magma chamber (18,3 ± 0,8 km), the volume of the crustal magma chambers (400 km3), possible dimensions of the emplaced dike in the stronger crustal layers (thickness 0,7 m, length 4700 m). We discuss a likely mechanism for and relations between the observed processes and the eruptions.
Федотов С.А., Михайлова-Филиппова М.И. Непрерывное течение магмы с убывающим расходом по цилиндрическому каналу, питающему вулкан: условия длительного существования // Вулканология и сейсмология. 1997. № 1. С. 3-16.
Adushkin V.V., Zykov Yu.N., Ivanov B.A. Numerical modeling of a rockslide avalanche at Koryakskiy volcano, Kamchatka // Volcanology and Seismology. 1996. Vol. 17. № 6. P. 705-717.
A numerical model is proposed for the mechanism of a rockslide avalanche on the slope of Koryakskiy volcano caused by the emplacement of sheeted intrusive bodies. The model of non-stationary geomechanical processes with abnormally low internal friction is used to calculate an avalanchelike movement during a potential collapse of the cone.
Belousov Alexander Deposits of the 30 March 1956 directed blast at Bezymianny volcano, Kamchatka, Russia // Bulletin of Volcanology. 1996. Vol. 57. № 8. P. 649-662. doi:10.1007/s004450050118.