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The volcano is unnamed. Nameless volcano Devastating consequences of the eruption

Prior to the massive eruption of 1955–1956, Bezymyanny Volcano was considered inactive and was a typical stratovolcano formed about 10,000–11,000 years ago on the basis of earlier dacitic domes. It is known to have been active repeatedly between 7050 BC and 950, after which it calmed down and remained calm for more than 1000 years. Everything changed in 1955, when the giant unexpectedly returned to life and gradually became one of the most active in Kamchatka.

Location: Eastern Range, Kamchatka
Height: 2882 m
Type: stratovolcano
Number of eruptions: 65 in the last 10,000 years

Bezymyanny rises in the eastern part of the peninsula, 40 km from Klyuchevskaya Sopka and the volcanological station of the village of Klyuchi, which monitors the Klyuchevskaya volcanic group. It includes a young active stratovolcano and the remains of an ancient peak destroyed during the 1956 eruption. Numerous lava flows stretch on the slopes of the giant, and at the foot there are 16 small cones of different structure and age.

The top of the destroyed old volcano is occupied by a giant crater measuring 1.3 by 2.8 km and a depth of 700 meters, inside which there is a younger dome. Nameless is much smaller than its closest neighbors - Klyuchevskoy and Kamen. Its height is only 2882 meters.

Bezymyanny eruption in 1955–1956

After a thousand years of inactivity, the volcano suddenly awakened in September 1955. Its eruption was preceded by a series of underground shocks with a hypocenter directly under the base of the dome. By the first days of October, dozens of earthquakes were recorded daily on the summit, and by the beginning of eruptive activity on October 19, their number reached hundreds.

The eruption began with emissions of ash and smoke, which until March 1956 were of a moderate nature. Simultaneously with the formation of ash columns on the eastern slope, surface uplift was observed, reaching a height of about 100 meters by March. The final stage of the disaster occurred on March 30. The collapse of the eastern slope led to the descent of a debris avalanche, after which a powerful explosion thundered, which received the VEI-5 index on an 8-point explosive scale.

Eruption of Bezymyanny in October 1955. ©Photo by G.S. Gorshkov

A column of ash 35 km high shot up over the top of Bezymyanny, pyroclastic flows rushed to the foot, rolling up to 20 km. As a result of the explosion, the old volcano was destroyed, and a giant horseshoe-shaped crater was formed in its upper part, resembling an American crater.

Immediately after the explosion in the horseshoe, an outpouring of lava began, which gradually led to the emergence of a young stratovolcano. The formation of a new dome continues to this day and is accompanied by moderate eruptions. After activity in 1955–1956, more than 50 eruptive episodes were recorded on Bezymyanny, which occurred at intervals of 3 months to 2–3 years. The last time the giant erupted was in 2010-2013.

Volcano Nameless(Bezymyanny) belongs to the Klyuchevskaya group of volcanoes, Kamchatka.

Nameless
stratovolcano

"
Height2 882 meters
Minimum depth (for underwater volcanoes)(((Depth)))
LocationKamchatka, RF
Coordinates56°04"N, 160°43"E
Geodynamic settingActive continental margin
Last eruption 2012

Eruption 1955-1956

Dedicated to the description of this eruption.

Recent eruptions

Eruptions of the Bezymyanny, which are distinguished by great force and short duration, occur about twice a year.

  • On October 14, 2007, an ash plume of the Bezymyanny volcano was noted. According to the KB GS RAS, the explosive volcanic eruption occurred from 14:27 UTC on October 14 to 14:00 UTC on October 15. According to satellite data, ash plumes spread mainly in eastern directions from the volcano at an altitude of 10 km above sea level on October 14 and at an altitude of 7-8 km above sea level on October 15-16. A pyroclastic flow and a lava flow with a length of about 400 m
  • On May 14, 2007, a thermal anomaly and a pyroclastic flow (an incandescent debris avalanche) were noted in the Bezymyanny area. For the settlements of the Bezymyanny peninsula, it does not pose a danger. Meanwhile, ash plumes, saturated with particles of igneous material up to 2 mm in diameter, pose a threat to aviation. Volcanic ash can cause poisoning in humans and animals.
  • December 24, 2006. Explosive eruption accompanied by ejection of an eruptive column up to 13-15 km above sea level, ashfall to the northeast of the volcano and pyroclastic flows.
  • On May 9, 2006, an explosive eruption of moderate strength occurred. Its description is given in the article Droznin V.A., Droznin D.V. "Activity of Bezymyanny Volcano on May 9, 2006" // Bulletin of KRAUNC, Earth Sciences, 2007, No. 1, Issue No. 9, p.105-110.
  • On December 16-17, 2009, an explosive eruption occurred.
  • June 1, 2010 - Explosive eruption accompanied by westward ashfall, pyroclastic flows and lava flow outpouring.
  • April 2011 - explosive eruption: ashfall westward from the volcano, pyroclastic flows.
  • March 8, 2012 at 21:30 (UTC) another explosive volcanic eruption occurred. The ash cloud rose 8 km above sea level and by the morning of March 9 stretched 700 km northeast of the volcano. Increased seismic activity was observed three days before the culmination of the eruption. On March 9, the volcanic eruption continues, but activity gradually decreases. Information about the eruption was obtained thanks to seismic data and visual observations from nearby settlements. According to satellite data, on March 9-10, an ash plume stretched for 1250 km to the northeast of the volcano. On March 10, after the end of the explosive phase of the eruption, a powerful steam-gas plume was observed, stretching to the north-northeast of the volcano. A large thermal anomaly was registered in the area of ​​the volcano, associated with the squeezing of a viscous lava flow onto the slope of the dome and hot deposits of pyroclastic flows at its foot. Aviation color code changed from red to orange.

Photos of the volcano

Volcano Nameless (left), Stone (in the center), Klyuchevskoy (right). July 2010

Volcano Bezymyanny with a valley of pyroclastic flows to the west of the volcano. July 2010

Volcano Nameless. The photo clearly shows the lava and pyroclastic flows of the 2010 eruption.

Volcanic bomb from the pyroclastic flow of the 2009 eruption of the Bezymyanny volcano.

Fumaroles with sulfur deposits on the slope of Bezymyanny volcano. July 2010


See also

Literature

Bibliography on the Nameless Volcano on a separate page.

  • Abdurakhmanov A.I., Bulgakov R.F., Guryanov V.B. The results of the analysis of the thermal anomaly of the products of the Bezymyanny volcano eruption on October 6-8, 1995 according to the spectral zonal information of the NOAA satellite // Vulkanology and seismology. 2001. No. 5. With. 68-72. [pdf (Russian)]
  • Almeev R.R., Ariskin A.A., Ozerov A.Yu., Kononkova N.N. Problems of stoichiometry and thermobarometry of magmatic amphiboles (on the example of hornblendes from andesites of the Bezymyanny volcano, Eastern Kamchatka). // GEOCHEMISTRY, 2002, No. 8, p. 803-819. [pdf (english)]
  • Belousov A.B., Belousova M.G. Deposits and sequence of events of the March 30, 1956 Bezymyanny volcano eruption (Kamchatka): deposits of a directed explosion. // Volcanology and seismology. 2000. No. 2. C. 3-17. [pdf (Russian)]
  • Bogoyavlenskaya G.E., Braitseva O.A., Melekestsev I.V., Maksimov A.P., Ivanov B.V. Volcano Bezymyanny // Active volcanoes of Kamchatka. T. 1. M.: Nauka. 1991. C. 168-182.
  • Braitseva O.A., Kiryanov V.Yu. On past activity of Bezymyanny volcano according to tephrochronological data // Volcanology and Seismology. 1982. No. 6. With. 44-45.
  • Braitseva O.A., Melekestsev I.V., Bogoyavlenskaya G.E., Maksimov A.P. Volcano Bezymyanny: history of formation and dynamics of activity // Volcanology and seismology. 1990. No. 2. With. 3-22.
  • Girina O.A. Study of volcanic eruptions of the northern group of Kamchatka (Bezymyanny, Klyuchevskoy, Shiveluch) in March 2005 //Vestnik KRAUNC, Earth Sciences, 2005, No. 5, p.166-167. [pdf (Russian)]
  • Girina O. A., Manevich A. G., Ushakov S. V., Melnikov D. V., Nuzhdaev A. A., Konovalova O. A., Demyanchuk Yu. V. Activity of Kamchatka volcanoes in 2010 // In the collection "Materials of the annual conference dedicated to the day of the volcanologist (March 30 - April 1, 2011)". Petropavlovsk-Kamchatsky, 2011, pp. 20-25. [pdf (Russian)]
  • Girina O.A., Nuzhdina I.N., Ozerov A.Yu., Zelensky M.E., Demyanchuk Yu.V. Eruption of Bezymyanny Volcano on August 7, 2001 // Volcanology and Seismology. 2005. No. 3. P.3-8.
  • Girina O.A., Demyanchuk Yu.V. Bezymyanny volcano eruption in 2012 according to KVERT data // In the collection "Materials of the conference dedicated to the Volcanologist's Day, March 29–30, 2012". Petropavlovsk-Kamchatsky, 2012, pp. 32-35. [pdf (Russian)]
  • Girina O.A., Manevich A.G., Melnikov D.V., Ushakov S.V., Nuzhdaev A.A., Demyanchuk Yu.V. Volcanic activity in Kamchatka in 2011 // In the collection "Materials of the conference dedicated to the Volcanologist's Day, March 29-30, 2012". Petropavlovsk-Kamchatsky, 2012, pp. 36-41. [pdf (Russian)]
  • Gorshkov G.S., Bogoyavlenskaya G.E. Bezymyanny volcano and features of its last eruption in 1955-1963. // Publishing house "Science". Moscow. 1965
  • Dvigalo V. N., Svirid I. Yu., Shevchenko A. V., Sokorenko A. V., Demyanchuk Yu. V. The state of active volcanoes in Northern Kamchatka according to the data of aerial photography overflights and photogrammetric processing of images in 2010 // In the collection "Materials annual conference dedicated to the Volcanologist's Day (March 30 - April 1, 2011)". Petropavlovsk-Kamchatsky, 2011, pp. 26-36. [pdf (Russian)]
  • Droznin V.A., Droznin D.V. Bezymyanny volcano activity on May 9, 2006 // Bulletin of KRAUNC, Earth Sciences, 2007, No. 1, Issue No. 9, pp. 105-110. [pdf (Russian)]
  • Kadik A.A., Maksimov A.P., Ivanov B.V. Physical and chemical conditions of crystallization and genesis of andesites (on the example of the Klyuchevskaya group of volcanoes). M.: Nauka, 1986. 157 p.
  • Karpov G.A., Ozerov A.Yu. The Furious Nameless One became active again. // Far Eastern scientist. 1995. No. 22. P.3.
  • Kiryanov V.Yu., Storcheus A.V. On the mechanism of the Bezymyanny volcano eruption on December 5, 1997 // Volcanology and seismology. 2001. No. 2. With. 24-29. [pdf (Russian)]
  • Maksimov A.P., Firstov P.P., Girina O.A., Malyshev A.I. The eruption of Bezymyanny volcano in June 1986 // Volcanology and seismology. 1991 #1. With. 3-20.
  • Ozerov A.Yu., Ariskin A.A., Kyle F., Bogoyavlenskaya G.E., Karpenko S.F. Petrologo-geochemical model of the genetic relationship of basalt and andesite magmatism of Klyuchevskoy and Bezymyanny volcanoes (Kamchatka) // Petrology. T.5. No. 6. 1997. pp. 614-635. [pdf (english)] [pdf (english)]
  • Ozerov A.Yu., Demyanchuk Yu.V., Storcheus A.V., Karpov G.A. The eruption of Bezymyanny volcano on October 6-8, 1995 // Volcanology and seismology. 1996. No. 3. S. 107-110. [pdf (Russian)]
  • Plechov P.Yu., Tsai A.E., Shcherbakov V.D., Dirksen O.V. "Hornblende in andesites of Bezymyanny volcano eruption on March 30, 1956 and conditions of their opacitization" // Petrology, 2008, vol.16, no.1, pp.21-37. [pdf (Russian)]
  • Serovetnikov S.S., Titkov N.N., Bakhtiarov V.F. GPS monitoring of the Bezymyanny volcano area (Kamchatka). // In the collection "Materials of the conference dedicated to the Volcanologist's Day, March 27–29, 2008". Petropavlovsk-Kamchatsky, 2008, pp. 264-268. [pdf (Russian)]
  • Sobolevskaya O.V., Senyukov S.L. Retrospective analysis of the change in the temperature of the thermal anomaly at the Bezymyanny volcano in 2002-2007, as a precursor of its eruptions, according to the AVHRR sensor data from the NOAA 16 and 17 satellites // Vestnik KRAUNC, Earth Sciences, 2008, No. 1, Issue No. 11, p. 147-157. [pdf (Russian)]
  • Tolstykh M.L., Naumov V.B., Bogoyavlenskaya G.E., Kononkova N.N. Andesite-dacite-rhyolite melts during the crystallization of andesite phenocrysts from the Bezymyanny volcano, Kamchatka. // Geochemistry. 1999. No. 1. With. 14-24. [pdf (english)] [pdf (english)]
  • Almeev R., Kimura J., Ariskin A., Ozerov A. Decoding crystal fractionation in calc-alkaline magmas from the Bezymianny Volcano (Kamchatka, Russia) using mineral and bulk rock compositions // Journal of Volcanology and Geothermal Research, 2013, vol .263, p.141-171. [pdf (english)]
  • Almeev, R., Holtz, F., Ariskin, A., Kimura, J. Storage conditions of Bezymianny Volcano parental magmas: results of phase equilibria experiments at 100 and 700 MPa. Contributions to Mineralogy and Petrology, 2013. 166(5): p. 1389-1414. [pdf (english)]
  • Belousov, A. (1996) Deposits of 30 March 1956 directed blast at Bezymianny volcano, Kamchatka, Russia, Bulletin of Volcanology, 57: 649-662. [pdf (english)]
  • Belousov, A., Voight, B., Belousova, M., Petukhin, A. (2002) Pyroclastic surges and flows from the 8-10 May 1997 explosive eruption of Bezymianny volcano, Kamchatka, Russia, Bulletin of Volcanology, 64 (7 ): 455-471. [pdf (english)]
  • Kayzar, T.M., Nelson, B.K., Bachmann, O., Bauer, A.M., and Izbekov, P.E., 2014, Deciphering petrogenic processes using Pb isotope ratios from time-series samples at Bezymianny and Klyuchevskoy volcanoes, Central Kamchatka Depression: Contributions to Mineralogy and Petrology, v. 168, no. 4, p. 1-28. DOI:10.1007/s00410-014-1067-6
  • Shcherbakov, V., Plechov, P., Izbekov, P., and Shipman, J., 2011, Plagioclase zoning as an indicator of magma processes at Bezymianny Volcano, Kamchatka: Contributions to Mineralogy and Petrology, v. 162, no. 1, p. 83-99. DOI:10.1007/s00410-010-0584-1
  • Shcherbakov, V.D., Neill, O.K., Izbekov, P.E., and Plechov, P.Y., 2013, Phase equilibria constraints on pre-eruptive magma storage conditions for the 1956 eruption of Bezymianny Volcano, Kamchatka, Russia: Journal of Volcanology and Geothermal Research, v. 263, no. 0, p. 132-140. DOI:10.1016/j.jvolgeores.2013.02.010
  • Shcherbakov, V.D., and Plechov, P.Y., 2010, Petrology of mantle xenoliths in rocks of the Bezymyannyi Volcano (Kamchatka): Doklady Earth Sciences, v. 434, no. 2, p. 1317-1320.

Bezymyanny is an active volcano in Kamchatka, near Klyuchevskaya Sopka, about 80 km from the village of Klyuchi, Ust-Kamchatsky region.
Height 2882 m (before 1956 - 3075 m), the composition includes the remains of an old volcano destroyed by the 1956 eruption (in the southeastern part of the massif), a young active stratovolcano and a crater on the site of the old volcano with a diameter of 1.3x2.8 km. On the slopes - numerous lava flows, at the foot - 16 extrusive domes.
The famous catastrophic volcanic eruption on March 30, 1956 was highlighted by G.S. Gorshkov and G.E. Bogoyavlenskaya into an independent type - “directed explosion” or “Bezymianny type”, which is recognized by world volcanology (“directed blast”, “lateral blast”, “type Bezymianny”).

Eruption 1955-1956 was the first in the historical period (in this area since 1697) and occurred, according to tephrochronological studies, after a 1000-year period of dormancy. Before the eruption, the volcanic edifice had the shape of a regular cone 3,085 m high (a stratovolcano of predominantly andesitic composition, complicated by apical and secondary extrusive domes). The eruption began on October 22, 1955 after a 23-day earthquake swarm. Until March 30, 1956, the eruption had a moderate, Vulcan character (pre-climax stage). During this period, a crater 800 m in diameter formed on the top of the volcano, from which frequent ash emissions occurred to a height of 2-7 km. At the end of November, the dome of viscous lava began to be squeezed out in the crater. Simultaneously with the growth of the intracrater dome, a strong swelling of the southeastern slope of the volcano began. The magnitude of the deformation, estimated from photographs, reached 100 m. The deformation of the slope was due to the fact that part of the magmatic melt was intruded in the form of cryptocoulol (near-surface intrusion) into the volcano edifice.

The catastrophic eruption on March 30, 1956 (culminating stage) was provoked by the collapse of the eastern slope of the volcanic structure with a volume of 0.5 cubic meters. km. The collapse turned into a cold one (< 100°С) обломочную лавину, скорость которой превышала 60 м/с. Обломочная лавина образовала три ветви, вложенные в речные долины. Максимальный путь (22 км) прошла центральная ветвь. В процессе распространения обломочная лавина сдирала и толкала перед собой вал материала подножья вулкана (снег, почву, аллювий, растительность), который образовал протяженные грязевые потоки. Сразу за обрушением последовал кастрофический направленный взрыв, вызванный тем, что обвал резко уменьшил литостатическое давление на магму, внедрившуюся в постройку на докульминационной стадии извержения. Материал, выброшенный взрывом (0,2 куб.км.), распространился вдоль восточного подножия вулкана в виде пирокластической волны (турбулентный поток горячей смеси газа и пирокластики). Скорость потока превышала 60 м/с, температура составляла около 300 градусов С. После направленного взрыва произошло извержение пирокластических потоков протяжённостью более 20 км. Высота эруптивного облака извержения достигла высоты около 35 км. В результате извержения образовался подковообразный кратер диаметром ~1,3 км, открытый на восток. У восточного подножья вулкана на площади ~500 кв. км деревья и кустарники были сломаны и повалены в направлении от вулкана. В зоне разрушений возник покров специфических пирокластическлх отложений (отложения направленного взрыва). После пароксизма (посткульминационная стадия) в подковообразном кратере начал выжиматься купол вязкой лавы, формирование которого продолжается до настоящего времени.

Once lost among its neighbors, an inconspicuous, extinct volcano with a barely visible outline of a small crater, now one of the most famous, active and observed not only in Kamchatka, but throughout the world. It is a natural monument and is located on the territory of the Klyuchevskoy Natural Park.

Volcano Nameless in Kamchatka, or Bezymyanny Sopka, belongs to the Klyuchevskaya group and is located in its central part. The most famous active members of this group are Klyuchevskaya Sopka and Plosky Tolbachik.

By its appearance, Bezymyanny represents an array elongated in width, the top of which was destroyed by a recent eruption. Refers to active volcanoes. The closest settlement is the village of Klyuchi, 60 km to the south, and the village of Kozyrevsk, 50 km away.

Most of the volcanoes in Kamchatka got their names from the local Itelmen tribes, and some of them were named after distinguished hunters and scientists. Nameless is considered an exception. At the time of the development of the Kamchatka Peninsula, the hill "slept", therefore the absence of a name as such is associated with a long period of rest. In addition, in comparison with its neighbors, volcanoes Klyuchevskoy Sopka, Tolbachik and Kamen, Bezymyanny did not stand out very much.


The formation of the building dates back to the Ice Age, which began more than 2.5 million years ago. In its place were several domes, formed by squeezing lava onto the surface of the Earth. When studying, scientists gave them names such as Smooth, Correct, Dissected, and so on. More than 10,000 years ago, an old building began to form, which was called Pra-Nameless, and about 5,000 years ago, the Nameless itself. The "remains" of Pra-Nameless have been preserved on the eastern side of the modern volcano, and the dome, formed more than 5000 years ago, has been shifted half a kilometer to the west.

Bezymianny activity in Kamchatka was observed in all periods. Eruption dates, which have been reconstructed from the debris and the volcanic structure itself, indicate that in some time cycles it was active for 400 years. Thus, activation occurred in periods from 2400 to 1700 years ago, from 1350 to 1000 years ago and from 1955 to the present. The culminating moments of eruptions are usually timed to coincide with the beginning and end of the period. Such long-term eruptions with subsequent catastrophic consequences, as a rule, are similar to each other in terms of the nature of the eruptions and the lowering of the relief.


At present, the height of Bezymyanny volcano in Kamchatka is 2882 m. Before the catastrophic eruption that occurred in 1956, its height reached more than 3050 m. 1.3 by 2.8 m. Before the incident, only a slight crater flaunted on its top and the volcano was considered extinct. The slopes are filled with numerous lava flows, and 16 domes are located at the foot. One of them has survived from the time of early activity and is called Plotina. The walls of the dome are very similar to logs, from which this place is called "Pilennitsa" and has the status of a natural monument.

The eruption of 1956 put Bezymyanny among the most famous giants on the planet. The study of the geological structure of the volcano began in the 1980s by G.S. Gorshkov, and its history over the past couple of thousand years was obtained from the studies of O.A. Braitseva and V.Yu. Kiryanov. Later, scientific research was carried out in more depth, because. his activity grew, and the information received was not enough.


One of the most powerful eruptions in the history of the volcano and the whole of Kamchatka was the catastrophe of 1956. Hundreds of earthquakes a day, columns of fire and gas up to 40 km high. Lightning and deafening noise. Impenetrable darkness from the ashes. The 1956 eruption was truly devastating not only for the volcano itself, but for the entire surrounding natural complex as a whole. After the incident at Bezymyanny, this type of eruption was singled out by the Society of International Volcanology as an independent one and to this day is called a "directed explosion".

The volcano can pose a danger to international and local airlines visiting the airspace of Kamchatka, i.e. its ash plumes can grow up to 15 km, and ash clouds stretch in different directions for hundreds of kilometers. At the moment, the volcano has a yellow aviation hazard code. There is also constant visual, seismic and satellite monitoring.


An interesting fact is the presence on the planet of a very similar eruptions (directed explosion) giant St. Helens. It is located in the USA. According to scientists, the volcanoes of St. Helens and Nameless may be somehow connected. It was after the eruption in 1980 that St. Heles began to closely monitor this "couple". Its neighbors, Klyuchevskaya Sopka and Kamen, also have a direct influence on the formation of the character of the Bezymyanny volcano. So, collapses or movements of the bowels of these buildings directly increase the pressure in Bezymyanny, and also contribute to the descent of debris avalanches. The entire Klyuchevskaya group is characterized by volcanic processes with a pronounced manifestation. The composition of the rocks here is in constant change. Sometimes researchers find gold and platinoids. The uniqueness of this group attracts here both scientists and tourists and climbers. Every year, many tourists pass along the routes. However, there is little natural attraction in the eastern sector of Bezymyanny. There are scorching clouds, lifeless fields, covered lava flows and heaps of boulders. However, subject to weather conditions, the state of the volcano and safety precautions, it is possible to climb to the edge of the crater, from where you can admire the very impressive panoramas of these places.


Watch our new video from the unique tour "Legends of the North"

You can go to the north of the peninsula, where the largest volcanoes and little-visited places are located, in groups or individually

In an independent type - "directed explosion" or "Nameless type", which is recognized by world volcanology ("directed blast", "lateral blast", "type Bezymianny").

Eruption 1955-1956

Eruption 1955-1956 was the first in the area since 1697 and occurred, according to tephrochronological studies, after a 1000-year period of dormancy. Before the eruption, the volcano had the shape of a regular cone 3085 m high (a stratovolcano of predominantly andesitic composition, complicated by apical and secondary extrusive domes). The eruption began on October 22, 1955 after a 23-day earthquake swarm. Until March 30, 1956, the eruption had a moderate, Vulcan character ( pre-climax stage). During this period, a crater 800 m in diameter formed on the top of the volcano, from which frequent ash emissions occurred to a height of 2-7 km. At the end of November the dome of viscous lava began to be squeezed out in the crater. Simultaneously with the growth of the intracrater dome, a strong swelling of the southeastern slope of the volcano began. The magnitude of the deformation, estimated from photographs, reached 100 m. The deformation of the slope was due to the fact that part of the magmatic melt was intruded in the form of a cryptodome (near-surface intrusion) into the edifice of the volcano.

Catastrophic eruption on March 30, 1956 ( climax) was provoked by the collapse of the eastern slope of a volcanic structure with a volume of 0.5 cubic meters. km. The collapse turned into a cold one (< 100 °С) обломочную лавину , скорость которой превышала 60 м/с. Обломочная лавина образовала три ветви, вложенные в речные долины . Максимальный путь (22 км) прошла центральная ветвь. В процессе распространения обломочная лавина сдирала и толкала перед собой вал материала подножья вулкана (снег, почву, аллювий , растительность), который образовал протяжённые грязевые потоки. Сразу за обрушением последовал катастрофический направленный взрыв, вызванный тем, что обвал резко уменьшил литостатическое давление на магму , внедрившуюся в постройку на докульминационной стадии извержения. Материал, выброшенный взрывом (0,2 куб.км.), распространился вдоль восточного подножия вулкана в виде пирокластической волны (турбулентный поток горячей смеси газа и пирокластики). Скорость потока превышала 60 м/с, температура составляла около 300 °C. После направленного взрыва произошло извержение пирокластических потоков протяжённостью более 20 км. Высота эруптивного облака извержения достигла высоты около 35 км. В результате извержения образовался подковообразный кратер диаметром ~1,3 км, открытый на восток. У восточного подножья вулкана на площади ~500 км² деревья и кустарники были сломаны и повалены в направлении от вулкана. В зоне разрушений возник покров специфических пирокластических отложений (отложения направленного взрыва). После пароксизма (post-climax stage) in the horseshoe-shaped crater, a dome of viscous lava began to be squeezed out, the formation of which continues to this day.

Formation of the "New" dome

The formation of the "New" dome began immediately after the culminating stage on March 30, 1956. During the first years, rigid obelisks were continuously squeezed out on the dome. Subsequently, the growth of the dome became discontinuous and, along with rigid blocks, from 1977 viscous lava flows began to be squeezed out. The viscosity of the lava continues to gradually decrease and the length of the lava flows gradually increases (the decrease in viscosity is due to the gradual decrease in the content of silicic acid). Currently, lava flows cover the entire surface of the dome, which almost filled the 1956 crater. The formation of the dome throughout its history is accompanied by weak and moderate explosive eruptions with the deposition of small blocky-ash pyroclastic flows and associated pyroclastic ash cloud waves. The frequency of eruptions reaches 1-2 per year. Among the explosive eruptions accompanying the growth of the dome, relatively strong eruptions of 1977, 1979, 1985, and 1993 can be conventionally identified. The most extended pyroclastic flows associated with the growth of the Novy dome covered a distance of 12.5 km (1985). Until 1984, pyroclastic flows did not have a noticeable eroding effect. During subsequent eruptions, pyroclastic flows began to cut trenches on the slope of the dome. Simultaneously with the intensification of the eroding effect of pyroclastic flows during eruptions, large collapses of the old parts of the dome began to occur. The largest collapse of the dome occurred during the 1985 eruption.

Eruption of two volcanoes

In March 2019, Bezymyanny threw a column of smoke 15 kilometers high into the air, and its neighbor Shiveluch volcano 4 kilometers.