Fedotov S.A. Crustal Deformations Related to the Formation of New Tolbachik Volcanoes in 1975-1976, Kamchatka // Bulletin Volcanologique. 1980. V. 43. № 1. P. 35-46.
The paper discusses the results of geodetic investigations performed in the region of the large 1975-1976 Tolbachik fissure eruption in Kamchatka. Using data from repeated triangu-lation and trigonometric levelings, horizontal and vertical displacements have been detected in an area of 3,500 km2. Two zones have been recognized: the tension and uplift zone that is probably due to magma intrusion from depths to the surface along the line of new cones and the extensive compensative subsidence zone located at a distance of 20-50 km from the nearest newly-formed cones.??Measurements made with small distance measuring device showed the dynamics of feeding basalt dykes intrusion and made it possible to determine their width (a little greater than 1 m) and magma and gas overpressure (50-250 bar). Data have been obtained on dimensions and growth of cones and on vertical ground deformation in the area of new cones during and after the eruption.??
Fedotov S.A. Enterance magma temperature, formation, dimensions and evolution of magma chambers of volcanoes // Arc Volcanism: Physics and Tectonics. Proceedings of a 1981 IAVCEI Symposium, Arc Volcanism, August-September, 1981, Tokyo and Hakone. Tokyo: Terra Scientific Publishing Co. 1981. P. 90
Fedotov S.A. Eruption Forecasting of Volcanoes in Kamchatka and Kurile Islands // Kagoshima International Conference on Volcanoes: Proceedings of the International Conference on Volcanoes, Japan, Kagoshima, 19-23 July 1988. Kagoshima: Kagoshima Prefectural Government. 1988. P. 172-178.
Fedotov S.A. Eruption Forecasting of Volcanoes in Kamchatka and Kurille Islands // Kagoshima International Conference on Volcanoes: Proceedings of the International Conference on Volcanoes, Japan, Kagoshima, 19-23 July 1988. 1988. P. 172-178.
Fedotov S.A. Estimates of heat and pyroclast discharge by volcanic eruptions based upon the eruption cloud and steady plume observations // Journal of Geodynamics. 1985. V. 3. № 3-4. P. 275-302. doi:10.1016/0264-3707(85)90039-0.
Fumarolic steam plumes and eruption clouds rise like convetive turbulent columns into the atmosphere. Formulae are presented here for estimating the heat power of plumes, the production rate of juvenile pyroclasts ejected during eruptions and the heat output of fumaroles. Their accuracy is tested using the well-studied examples of eruptions of Kamchatkan volcanoes.
The Briggs (1969) formula may be used in observing the ascending part of a plume in crosswinds. The best results have been obtained using the CONCAWE formula which permits estimation of the heat power in crosswinds based on the axis height of a horizontal part of a maintained plume. Three connected equations have been suggested for a stable atmosphere and calm weather conditions. The first one, which is applicable for heights ranging from 100 m to 1 km, is the formula proposed by Morton et al. (1956). This equation changes for higher layers of the troposphere (1–10 km) and stratosphere (10–55 km).
A classification scale was constructed allowing us to compare volcanic eruptions and fumarolic activity in terms of the intensity of their plumes.
The described method is useful for volcano surveillance; it helps in the study of the energetics and mechanics of volcanic and magmatic processes.
Fedotov S.A. Magma rates in feeding conduits of different volcanic centres // Journal of Volcanology and Geothermal Research. 1981. V. 9. № 4. P. 379-394. doi:10.1016/0377-0273(81)90045-7.
A quasi-stationary magma flow rate in asthenospheric and crustal conduits of central type volcanoes and volcanic centres was studied analytically under the following conditions. Magma rises through cylindrical channels in which the magma temperature does not change with time, but the wall rocks are gradually heated. The magma rates were calculated for basaltic, andesitic and dacitic volcanoes using the “continental” and “oceanic” geotherms. It follows from these calculations that the magma supply rate may determine the kind of activity of a volcanic centre, being constant for large and very active volcanoes, intermittent for usual volcanic centres of island arcs or sporadic for volcamic fields, clusters of cinder cones and areal volcanism. Theoretical conclusions are consistent with observational data.
Fedotov S.A. Mechanism of magma ascent and deep feeding channels of island arc volcanoes // Bulletin Volcanologique. 1975. V. 39. № 2. P. 241-254. doi: 10.1007/BF02597830.
The paper discusses the mechanism of deep magma activity beneath island are volcanoes and similar structures on the basis of data from geophysical investigations in Kamchatka; the analyses of forces that cause the ascent of magma; and related phenomena that are due to hydrostatic forces.
It is shown that the ascent of magma through the astnenosphere occurs most likely in magma columns with a diameter of approximately 700–2,000 m and with a velocity of about 0.8–3 m/year. A regular line of such columns spaced in Kamchatka at a distance of about 30 km gives rise to a chain of separate Etrge volcanoes or volcanic centers.
Ultrabasic magmas are most likely accumulated near the M discontinuity, whereas the apparent place of andesitic magma accumulation is in the earth’s crust near the boundary between the basement and sediments.
Fedotov S.A. On Deep Structure, Properties of the Upper Mantle, and Volcanism of the Kuril-Kamchatka Island Arc According to Seismic Data // The Crust and Upper Mantle of the Pacific Area. Washington, DC: American Geophysical Union. 1968. V. 12. P. 131-139. № doi:10.1029/GM012p0131.
The results of detailed seismic investigations during the period 1961 to 1964 are described. Accurate data of focus location for Kamchatka and the Commander Islands are cited. The majority of earthquakes are located in the Pacific focal zone and the others are found in such remarkable tectonic regions as the east Kamchatka ranges, the continental slope of the Commander Islands, etc. The focal zone seismic activity decreases with increasing depth. The seismic activity at a depth of 250 km is 100 times less than the activity at a depth of 0–20 km. Kamchatka earthquake locations in relation to the Kuril-Kamchatka Island arc and deep water trench are approximately the same as those of the south Kuril Island earthquakes. The Kamchatka active volcano belt coincides with the region of earthquakes having focal depths of 100–200 km, especially between 125 and 175 km. S-wave screening in the magma chambers under the volcanoes is observed. The Avacha volcanic cluster magma chamber at a depth of 20–80 km has the form of a column, 25 km in diameter. P-wave velocity in the upper mantle under the Pacific Ocean and between the Aleutian trench and the Kuril-Kamchatka trench is about 8.2 km/sec, and under Kamchatka 7.7 km/sec. Local velocity decreases to basaltic range (Vp = 72 km/sec) in the upper mantle at a depth near 70 km under the east Kamchatka active volcano belt.
Fedotov S.A. On deep structure properties of the upper mantle and volcanism of the Kuril Island arc // Abstracts of papers related with geophysics: XI Pacific Science Congress: Proceedings. Tokyo. 1966. V. 3. P. 37
Fedotov S.A. Temperatures of Entering Magma, Formation and Dimensions of Magma Chambers of Volcanoes // Bulletin Volcanologique. 1982. V. 45. № 4. P. 333-348.
A mechanism, of formation of magma chambers that feed volcanoes is discussed. Heat conditions and dimensions of magma chambers which have existed for more than several thousand years may become stable. The approximate equations of heat balance of these chambers are derived by calculating the temperature T1 of the magma entering chambers and the radii a of chambers. Calculations show that the radius of the shallow "peripheral" chambers of the Avachinsky volcano is less than 3-3.5 km. Possible maximum radii of "peripheral" magma chambers were estimated for the Kamchatkan volcanoes of medial size. The temperature difference in their chambers may reach 100-200 "C. This method can be applied to the calculations of "roots" of central-type volcanoes.
Fedotov S.A., Balesta S.T., Droznin V.A., Masurenkov Yu.P., Sugrobov V.M. On a Possibility of Heat Utilization of the Avachinsky Volcanic Chamber // Proceedings Second United Nations Symposium on the Development and Use of Geothermal Resources. 1976. V. 1. P. 363-369.
The sources of geothermal energy of Kamchatka are hydrothermal systems, local blocks of high heated rocks, and peripheral magma chambers of active volcanoes in particular. According to gravimetric, magnetic and seismic data, under the Avachinsky volcano there exists an anomalous zone which is suspected to be a peripheral magma chamber. It is localized at the boundary of the Upper Cretaceous basement and an overlying volcanogenous stratum at a depth of 1.5 km from sea level. Its geophysical data are as follows: the radius is 5.2±0.9 km; the density of rocks is 2.85 to 3.15 g/cm3, the velocity of longitudinal waves is 2200 m/sec, the viscosity of rocks is 105 to 108 poise. The temperature distribution in the near-chamber zone was calculated by clcctrointegrator at 0°C at the Earth's surface and 1000°C at the chamber surface for stationary and non-stationary (the period of 20 000 years) heating. Heat extraction may be possible if a system of artificial jointing iscreated. The capacity of a thermal reservoir with a volume of one cubic km at a depth of 5 km and a distance of 6 km from the volcano would be 2 x Ю14 kcal, extractable under non-stationary conditions, which could provide the work of power stations with a total capacity of 250 MW for a period of 100 years.
Fedotov S.A., Chirkov A.M. The large fissure eruption in the region of Plosky Tolbachik volcano in Kamchatka, 1975–1976 // Bulletin Volcanologique. 1980. V. 43. № 1. P. 47-60. doi: 10.1007/BF02597610.
The paper describes the course of the Large Tolbachik fissure eruption taking place in Kamchatka from July 6, 1975 to December 10, 1976. The eruption zone extended for 30 km. The formation of monogenic scoria cones nearly 300 m high, lava tubes and basalt sheets up to 80 m thick and more than 40 km2 in area and subsidence of the Plosky Tolbachik summit caldera to a depth of more than 400 m were observed during the eruption. The volume of eruption products amounted to more than 2 km3. It was the largest basalt eruption which has taken place in the Kurile-Kamchatka volcanic belt in historic time.
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. V. 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.
Fedotov S.A., Gorelchik V.I., Zharinov N.A. Deformations and earthquakes of Kliuchevskoi Volcano: a model of its activity // Comptes rendus of the XIX General Assembly of the I.U.G.G.: Vancouver, August 9-22, 1987. 1987. V. 2. P. 392
Fedotov S.A., Ivanov B.V. The Main Eruptions of Volcanoes in Kamchatka and Kurile Islands in the 1980 // Comptes rendus of the XIX General Assembly of the I.U.G.G.: Vancouver, August 9-22, 1987. 1987. V. 2. P. 422
Fedotov S.A., Khrenov A.P., Zharinov N.A. Le Volcan Klychevskoy: son Activite de 1932 a 1988 et son Developpement Possible // L` Association Volcanologique Europeenne. 1989. № 18. P. 11-24.
Fedotov S.A., Markhinin Ye.K. The Great Tolbachik Fissure Eruption: Geological and Geophysical Data 1975–1976. Cambridge: Cambridge University Press. 1983. 354 p.
In 1975–1976 a remarkable volcanic eruption took place on the Kamchtka peninsula, part of the Soviet Union's arc of active volcanoes. Dr Fedotov and his colleagues studied the largest basaltic eruption in history, one of the most important volcanic events in the twentieth century. During this prolonged eruption they carried out extensive seismological, geophysical, geodetic and geochemical investigations. The results of this detailed and thorough investigation were collected as a series of papers under the editorship of S. A. Fedotov and collected into this volume, which was originally published by Cambridge in 1983. The result is a classic descriptive work of a major volcanic eruption.
Fedotov S.A., Sugrobov V.M., Utkin I.S., Utkina L.I. On the possibility of using heat stored in the magma chamber of the Avachinsky volcano and the surrounding rock for heat and power supply // Journal of Volcanology and Seismology. 2007. V. 1. № 1. P. 28-41. doi:10.1134/S0742046307010022.
The results of geological and geophysical studies, including recent ones, which make it possible to verify the existence of a liquid magma chamber below the Avachinsky volcano on Kamchatka, and to estimate the chamber depth and approximate dimensions, are analyzed. The heat stored in the host rock heated by the volcanic magma chamber from the time of chamber origination to the present is estimated, taking variable chamber dimensions during the process of evolution into account. The geological-geophysical prerequisites for using the thermal energy of the heated rock which surrounds the magma chamber to supply heat and power to Petropavlovsk-Kamchatskii are analyzed. The creation of an underground geothermal circulation system (fracture heat exchanger) using deep boreholes is proposed.
Fedotov S.A., Tocarev P.I. Earthquakes, properties of the upper mantle, and their connections with volcanism in Kamchatka // The Crust and Upper Mantle of the Pacific Area. // ХV Генеральная ассамблея Международного геодезического и геофизического союза. , Москва. 1971.
Fedotov S.A., Zharinov N.A., Gontovaya L.I. The magmatic system of the Klyuchevskaya group of volcanoes inferred from data on its eruptions, earthquakes, deformation, and deep structure // Journal of Volcanology and Seismology. 2010. Т. 4. № 1. С. 1-33. doi:10.1134/S074204631001001X.
Abstract-The study of magmatic plumbing systems of volcanoes (roots of volcanoes) is one of the main tasks facing volcanology. One major object of this research is the Klyuchevskaya group of volcanoes (KGV), in Kamchatka, which is the greatest such group that has been found at any island arc and subduction zone. We summarize the comprehensive research that has been conducted there since 1931. Several conspicuous results derived since the 1960s have been reported, emerging from the study of magma sources, eruptions, earthquakes, deformation, and the deep structure for the KGV. Our discussion of these subjects incorporates the data of physical volcanology relating to the mechanism of volcanic activity and data from petrology as to magma generation. The following five parts can be distinguished in the KGV plumbing system and the associated geophysical model: the source of energy and material at the top of the Pacific Benioff zone at a depth of about 160 km, the region of magma ascent in the asthenosphere. the region of magma storage in the crust-mantle layer at depths of 40-25 km,
magma chambers and channelways in the crust, and the bases of volcanic edifices. We discuss and explain the properties of and the relationships between these parts and the mechanisms of volcanic activity and of the KGV plumbing system as they exist today. Methods for calculating magma chambers and conduits, the amount of magma in the system, and its other properties are available.
Изучение магматических питающих систем вулканов, корней вулканов, является одной из основных задач вулканологии. К числу главных объектов таких исследований принадлежит Ключевская группа вулканов (КГВ) наиболее мощная на островных дугах и в зонах поддвига литосферных плит. Сообщается о всесторонних исследованиях, которые ведутся здесь с 1931 г. Приводится ряд показательных результатов, полученных с 1960-х годов при изучении источников магм, извержений, землетрясений, деформаций и глубинного строения КГВ. При их рассмотрении учитываются данные физической вулканологии о механизме вулканической деятельности и данные петрологии о формировании магм. В магматической питающей системе КГВ и ее геофизической модели выделяются следующие пять частей: источник энергии и вещества у верхней границы тихоокеанского сейсмофокального на глубине около 160 км, область подъема магм в астеносфере, область накопления магм в коромантийном слое на глубинах 40-25 км, магматические очаги и каналы в земной коре, основания построек вулканов. Рассматриваются и объясняются свойства, связь этих частей, механизм деятельности вулканов и магматической питающей системы КГВ в ее современном состоянии. Имеются способы расчета магматических каналов, очагов, количества магмы в системе и других ее свойств.