Types of volcanic eruptions. Presentation "Volcanoes" Volcanoes and Types of Volcanic Eruptions Presentation

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1.1. Hawaiian type of eruption is characterized by low (10, rarely 15) by the exposive index and represents a calm outpouring of liquid basalt lava, accompanied by weak explosions. Basalt lava flows with characteristic wavy, cable (smelly-lava) and small-leaf (aa-lava) surfactants, releasing with a small amount of pyroclastic material, occur at an angle of 2-3 °, rarely 5 °. Pyriclastic material is usually thrown into a liquid state, forming curly bombs (ball, ellipsoidal, pear, disc, ribbon, cylindrical, slag). Challats are characterized by the formation of slags, which in the coat part are bodied in agglutinates. The most thin material formed during the explosions is the drop-shaped ("pele tears") and hair-shaped ("pele hair") debris. It is possible to throw crystals (crystalpillary) in the form of reproved individuals of plagioclase up to 3-5 cm in diameter. Lava temperature 1200-1100 ° C, viscosity coefficient 103-104 Poise. 1.1. Hawaiian type of eruption is characterized by low (10, rarely 15) by the exposive index and represents a calm outpouring of liquid basalt lava, accompanied by weak explosions. Basalt lava flows with characteristic wavy, cable (smelly-lava) and small-leaf (aa-lava) surfactants, releasing with a small amount of pyroclastic material, occur at an angle of 2-3 °, rarely 5 °. Pyriclastic material is usually thrown into a liquid state, forming curly bombs (ball, ellipsoidal, pear, disc, ribbon, cylindrical, slag). Challats are characterized by the formation of slags, which in the coat part are bodied in agglutinates. The most thin material formed during the explosions is the drop-shaped ("pele tears") and hair-shaped ("pele hair") debris. It is possible to throw crystals (crystalpillary) in the form of reproved individuals of plagioclase up to 3-5 cm in diameter. Lava temperature 1200-1100 ° C, viscosity coefficient 103-104 Poise. This type is characteristic of the shield volcanoes of the Hawaiian Islands. It is described for Niiragongo volcanoes (Africa), a flat Tolbachik (Kamchatka), a southern breakthrough BTTI (Kamchatka).

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1.3. Vulcan type of eruption is widespread and is usually combined with Strombolian. The composition of the volcanic products Andesitic and Daqite, less often Andesibasalt and Rolyite. At the same time, the type of eruption is thrown out heated, but not plastic, exposive material of various size and rare lava flows. Lava streams are usually short with a lump surface. Blinds are much larger than in basalt and andesibasalt streams of Stromombolian eruptions. A kind of volcanic bombs are characterized - the type of "bread crust", having a smooth strongly fractured surface. Exposive index 60-80 or more. The shape of the wreckage is angular, the dimension of them from dust (0.01 mm) to the lump diameter in 1 m or more, but the ash (less than 2.0 mm) particles are most often presented with angular (acute) fragments of volcanic glass. Slags are usually absent. An admixture of alien and respected material more than 10%. 1.3. Vulcan type of eruption is widespread and is usually combined with Strombolian. The composition of the volcanic products Andesitic and Daqite, less often Andesibasalt and Rolyite. At the same time, the type of eruption is thrown out heated, but not plastic, exposive material of various size and rare lava flows. Lava streams are usually short with a lump surface. Blinds are much larger than in basalt and andesibasalt streams of Stromombolian eruptions. A kind of volcanic bombs are characterized - the type of "bread crust", having a smooth strongly fractured surface. Exposive index 60-80 or more. The shape of the wreckage is angular, the dimension of them from dust (0.01 mm) to the lump diameter in 1 m or more, but the ash (less than 2.0 mm) particles are most often presented with angular (acute) fragments of volcanic glass. Slags are usually absent. An admixture of alien and respected material more than 10%. The ash material with volcano-Stromombolian explosions rises to height to the first kilometers and, depending on the strength and direction of the wind, covers significant areas near the volcano. The smallest material (10-15%), mainly whirlwind, refers to the limits of volcanic construction and is part of soil-pyroclastic covers and volcano-terrigenous sediments. For the ashes of Vulcan eruptions, a porous, drop-like, melted form of debris was not typical. So for fragments of the Karym volcanic eruptions of 1966, 1979. There was a form close to isometric with angular projections of crystals, but no sharply angular forms were observed. According to E.F. Maleyev (1982), the mineral composition of the ashes varies as the dimension of particles increases. In large fractions, the number of crystals is 10-15%, and in small - 40-45%, which is probably due to the separation of volcanic glass and its removal into separate sections. In the ashes about 10% of the respected and retriclastic fragments, which, after weak explosions, got into the crater and, exposed to repeated warming up, acquired a red color. Lava temperature 1050-950 ° C, viscosity coefficient 105-106 Poise. The prototype is described on the island of Wolcano in the Lamp Islands group. The Vulcan type of eruption is characteristic of the volcanoes Avachinsky, Karymsky (Kamchatka), was widely manifested in conjunction with Strombolian on the Northern BTTI breakthrough (Kamchatka).

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1.7. Freatic (Bandaisan, Ultravalkan) The type of eruption gives only the exposive material in cold and rarely hot. A large amount of fragments of the foundation of a volcano (75-100%) are characterized in the absence of juvenile material. Freatic evessets can partially destroy volcanic buildings, which leads to the accumulation in low parts of the relief of the huge masses of the throat-free material of the concrete facies. Typically, these are complex mixtures of love and tuffs with different-detected lamination. Exposure Index 100. The fragments of rocks are thrown by steam due to contacting of superheated (thermal) water with soil or when lowering the lava in the volcanic channel below the groundwater level. 1.7. Freatic (Bandaisan, Ultravalkan) The type of eruption gives only the exposive material in cold and rarely hot. A large amount of fragments of the foundation of a volcano (75-100%) are characterized in the absence of juvenile material. Freatic evessets can partially destroy volcanic buildings, which leads to the accumulation in low parts of the relief of the huge masses of the throat-free material of the concrete facies. Typically, these are complex mixtures of love and tuffs with different-detected lamination. Exposure Index 100. The fragments of rocks are thrown by steam due to contacting of superheated (thermal) water with soil or when lowering the lava in the volcanic channel below the groundwater level. The peculiarity of the final eruptions is the fast (for several tens of seconds) a set of power, which is usually not reduced to the end of the eruption. Famous French volcanologist Garun Taziev watched in 1976. A similar phenomenon from beginning to end (more than 30 minutes) on the Soufferier volcano (Guadeloupe island), whose thirteen eruptions were freak. The most famous example of this type is the eruption of the Bandai-san volcano (Japan, 1888). Freatic explosions are also possible when introducing lava flows into glaciers covering the slopes of stratovulkanov. So in July 1993, during the eruption of the Klyuchevsky volcano, the introduction of a lava flow in the Herman glacier was accompanied by a series of powerful freak explosions, which reached a height of 2-3 km (Fedotov et al., 1995). The above classification has visuality, but apparently, mainly to simple eruptions. The complex eruptions can be characterized simultaneously by several types of activity. At the same time, they are so intertwined among themselves, which breaks the eruptions to segments with a certain type of activity is difficult. So a unique large fractive Tolbachinsky eruption in Kamchatka (1975-1976) was characterized by the manifestation of the elements of almost all types of activity: the Vulcan, Strombolian, Pelev, Plinian and Hawaiian.

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Volcanic eruptions remind us of formidable and indomitable forces that are hidden in the depths of the Earth.
The mystery of the causes of vulcanism has always caused people and the most lively interest, and the tragic consequences of the eruptions were forced to explore this element.

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Formation of volcano
When a magmatic focus is formed in the depths of the Earth, the molten liquid magma with such a force presses from the bottom to the tectonic slab that it starts to crack. In terms of cracks and faults, Magma rushes up, spending the rock and expanding the cracks. So the output channel is formed. It takes place in the center of the volcano, on it, the molten magma is poured out of the volcano vulcan in the form of fire-liquid lava. The products of eruption - PEMZA, LAVA, tufy- settlements on the slopes of the volcano, forming a cone. At the top of the Vpadina Volcano - Crater. At the bottom of the crater, the vulcan can be seen - the hole of the output channel, through which the ashes is erupted, hot gases and pairs of water, lava and fragments of rocks. The volcano vulcan can be gaping- empty or filled with molten lava. If the lava is frozen in Gerl, then a solid cork is formed, which only a strong eruption of the volcano can break through, while the powerful explosion occurs.

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Existing volcanoes
Volcanoes from time to time spew the molten rock, ashes, gases, and stones. This is because deep beneath them is a magmatic hearth, similar to a huge oven, in which rock rock melts, turning into a fire-liquid lava.
These volcanoes are also considered, the eruptions of which are preserved any evidence in the history of mankind.

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Extinct volcanoes
The extinct volcanoes were active only in prehistoric time. The focus under them is long the ground, and they themselves are so much destroyed that only research of geologists detect traces of ancient volcanic activity.

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Sleeping volcanoes
Sleeping volcanoes have not been erupted in historical time, but at any moment their catastrophic eruption can begin, because the magmatic hearth is not too much. Asleep volcanoes show signs of life: they can smoke - from their crater there are haze, out of cracks in the mountain gases and steam are distinguished, they beat hot springs. The longer the sleeping volcano is in the rest stage, the more dangerous: the power of his explosive awakening can be catastrophic.

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Types of eruptions

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Exposive eruptions
The explosion of the volcano occurs when the volcanic gases are released from a thick magma. With such eruptions, the peaks of the mountains are destroyed and millions of tons of ashes are thrown into the sky to a huge height. Ashes, gases and steam climb into the sky for tens of kilometers in the form of curly clouds.

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Effusion eruption
With the effusive eruption of the volcano, the liquid lava spreads freely with the formation of lava flows and covers

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Volcanic gases
Volcanic phenomena are associated with the action of gases. If the magma is very liquid, the gases are released freely and do not threaten the explosions. Gases can foam even a viscous magma, forming a porous pumice, spraying a magma on small particle-volcanic ashes and sand and, connecting with them, to form a deadly scattering cloud. Finally, gases can scatter from the volcano vulcan for hundreds of rock fragments.

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Nameless volcano
Near the keypopters, the volcano is located Unnamed. He was considered extinct, and his awakening strength was a giant. On March 30, 1956, a terrible power burst demolished the entire top of the volcano. The clouds of the ash shot up almost 40 km away, from
garl escaped a powerful jet of hot gas, volcanic sand and ashes, which lifted all the vegetation by 25 km around the volcano. Lava dome began to grow from the craters. Now the foundation of this dome is 750 m, and height is 320 m. Fortunately, despite all the rage of eruption, no one has had a perpetrator of a single living soul during an eruption clock within a radius of 45 km from the volcano.

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Tolbachinskaya Natka
Volcano Tobachik - very active volcano. A huge caldera with a crater with a diameter of 300 m and a depth of 150 meters was located on its top of 3085 m. From time to time, a small lake of hot lava arose in the crater. In 1975-1976, a fractured Icelandic eruption occurred. It continued continuously 520 days.
For a very short time, many cracks longer than a kilometer were formed. All this was accompanied by springs and fontanilation of the lava. During the eruption of the Tobachchi from the depths of the Earth, two cubic km of volcanic products was thrown into the surface. This is the largest of famous volcanic eruptions in Kamchatka and the Kuril Islands.

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Maison Volcano, the most active on Luzon Island. On October 23, 1776, he was the cause of the death of 2000 people, when a huge amount of lava was thrown out of his crater.
Maison Volcano.
Maison's longest eruption was observed in 1897. It lasted from June 23 to June 30 and carried out 400 lives.

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Strombol volcano
In the south of Italy, not far from Wulcano Island. Located is the island of the volcano Stromboli. It is very restless, and it has been acting for several millennia for almost no interruptions. From time to time, explosions occur in its crater, and the hot slag and volcanic bombs fly up to dozens, and sometimes hundreds of meters, but the lava is usually not flowing.
One of the strongest eruptions of Stromomboli was noted in 1930, and first of the fifteenth century there were already seven.

The study of the features of volcanoes, the phenomena of volcanism are engaged in volcanologists and geomorphologists.

Structure: Foci, Zhero, Crater. The hearth is a place in the earth's crust or mantle. Zherlo - a channel for which Magma rises. Crater - a hole, funnel, bowl on the top of the mountain volcano.

Volcanoes are classified by location, form and activity.

According to activity: extinct, sleeping, valid. Such a classification is sufficiently conditional. Extricates are not erupted more than 1000 years: Keep the general form, the changes are exposed to the crater, the slopes. Sometimes they show activity. Example: Mont-Pele on Martinique, Valley of Volcanoes in Buryatia, Calara Volcanoes.

Sleeping - volcanoes in which the probability of eruption is higher than that of extinct. Some of them are called supervulcans - Toba on Sumatra, Taulo in New Zealand, Camchatka volcanoes.

Existing - the main object of interest of volcanologists, erupts often. Located in the belts of young mountains, where the property continues. Among scientists there is no consensus on how to accurately classify these geological education. The most active vulcanism: South and Central America, Hawaii, Japan, Stern Islands.

Classified by location: Conto, terrestrial, underwater. The form distinguishes types: dome, slag cone, thyroid, stratovolcan, complex look.

As a characteristic of the general design, the formation of central and linear types. The first have the central channel, along which the lava comes to the surface. The second type is fissure, the channels for which the lava rises have an elongated form. Scientists identify an area of \u200b\u200btype, but there are no such ones, at least in our time. It is believed that they existed when the planet was formed.

The eruption is considered an emergency, disaster. It may occur for an hour, month, year, a few years. The effects of eruption: the formation of the Vpadin Calder, Geyser, Furolol. Low mountains can occur, island. Lakes are formed in the craters.

Types of eruption: Hawaiian (basalt lava comes to the surface, accompanied by smoking clouds, fiery aids), hydroexplosive (a lot of steam is distinguished, timed to water objects).

Vulcan of mud - education, as a result of the activity of which dirt, gases, and not a magma comes to the surface. Meets in Russia, Central Asia.

The largest entities: San Pedro, Kotophah, Has-del Salado in Andes, Elbrus in the Caucasus, Fujiima in Japan, Etna and Vesuvius in Italy, Klyuchevskaya Natka in Kamchatka.

Fixed not only on Earth. If on other planets of the solar system and their satellites.

Type of eruption
Expl
Ozivna
J.
Indka
C (E,
%)
Characteristic
Love.
Temperature,
° С.
Coeff.
Viscosity, Poise
Structure
Vulcanitov
Basalt.
Liquid.
T - 12001100 °.
– 103-104
Strombolians
Kiy.
3050,
Inog.
Yes
100
Basalts,
Andesibazal
you
Liquid
Polebandism
Oh.
T - 11501050 °.
– 104-105
Vulcanian
60-80
and
more
Andesitis,
Dacitals (less often
Andesibazal
you and
Riolitis)
Viscous.
Lava
Rare streams.
T - 1050-950.
– 105-106
Plinic
(Vesuviana
90 I.
more
Riolitis
Dacitats.
Seldom
Andesites
Basalt.
Lava
Thinking
Very rare.
T 1050.
Pelsky
100
Andesitis,
Dacitats,
Rioliths
100
Riolitis
Dacitats,
Andesites
Hawaiian
10,
rare
O 15.
Katmai
and
Lava N.
characteristic
Lava N.
characteristic
Types of volcanocalastic breeds
Characteristics of pyroclastic material
Juvenile
response
alien
(count)
Figured
bombs
Slags.
Capper ("Pele Tears"),
Hair-shaped ("Pele Hair")
Vitrolasts,
sometimes
idomorphic
Crystallasts
(Crystalolapilli)
Not
Character
Melcoles
Loveclastites
Agglutinate. Different tuffs
dimension, various structures. Comclassic tuffs I.
Crystaloclastic
Curly bombs, lapilli, slags
angular shape
Minor
Blind
Loveclastites
Tufy different dimension.
Dominate
psefitovy.
Xenotuofa (rarely)
The form
Oblovekov
angular
bombs like "bread crust"
More than 10%
Blind
Loveclastites
Tuffs of different dimensions.
Dominate
ash
Vitrolastic, pimplastic. Ksenotufa.
Pembzid
litocclasts
angular
crystallasts
Fish vitrolasts
Lot
–
Tufy
ash
crystaloclastic,
PEMZOCLASTIC. Ksenotufa.
Angular
Otterugal
wreckage of different dimensions with
predominance
ash.
Rassed up to 400-600 s
Lot,
highly
lot
–
Pepling tuffs. Xenotuofa
Easy breccia
Red (600-800 s),
Gas-saturated material
(Pyriclastic flows),
porous litoclasts,
Idomorphic crystallasts,
Ottoid vitrochlasts
10-20%
Tuffs
(clustela)
laveoclastic
Pyriclastic
IgnamBrites.
Xenoigmbrits.
Agglomerate
Tufy

1.1. Hawaiian type of eruption is characterized by low (10,
rarely 15) exposive index and is a calm
The outpouring of liquid basalt lava, accompanied by weak
blasts. Basalt lava flows with characteristic
Wavy, cable (smelly lava) and small
(AA-Lava) superficial, remembering with a little
the number of pyroclastic material, occur at an angle
2-3 °, rarely 5 °. Pyriclastic material usually
ejected in liquid state, forming curly bombs
(ball, ellipsoidal, pear, disk,
Ribbon, cylindrical, slag). Characteristic
The formation of slags that born in the glove part
in agglutinate. The finest material formed when
explosions, is the drowned ("pele tears") and
Hair-shaped ("Hair Pele") Chips. maybe
Digging of crystals (crystalpillary) in the form
Refireed Individuals Plagioclase up to 3-5 cm
in diameter. Lava temperature 1200-1100 ° C, coefficient
Viscosity 103-104 Poise.
This type is characteristic of Hawaiian shield volcanoes.
Islands. Described for Niiragongo volcanoes (Africa), flat
Tolbachik (Kamchatka), South Breakthrough BTTI (Kamchatka).

1.2. Strombolian type of eruption is most common when
Eruptions of volcanoes that give products of the main composition. For this
type are characterized by emissions of hot luminous material and
The outpouring of more viscous lava flows than with Hawaiian
eruption. Exposive index 30-50, sometimes up to 100. Composition
Volcanic products basalt and Andesibasalt. Viscosity
lava can range from liquid to semisolastic that
Causes a wide variety of exposive material:
curly bombs (spherical, ellipsoidal,
Lepsels), lapilli, slags angular shape. The size
Pyriclastics fluctuate widely: from large blocks to
ash particles, but more often prevails large-chip (2-10 mm)
material. Together with the juvenile material is thrown
Resort and alien represented by Fundament Chips
Volcano. Lava temperature 1150-1050 ° C, viscosity coefficient 104-
105 Poise.
The prototype of the eruption is described on the Strombol Volcano (Mediterranean
sea). Strombolian type was celebrated when the Kuevsky eruption
Volcano (Kamchatka) of the Northern Breakthrough, BTTI (Kamchatka) (Fig. 2),
Alaid and toy (Kuril Islands).
Fig.2. Strombolian type of eruption on the Northern breakthrough BTTI
(The first slag cone June 1975)

Strombolian type of eruption on the northern breakthrough BTTI (the first slag cone June 1975)

1.3. Vulcan type of eruption is widespread and usually combined
with Strombolian. The composition of volcanic products Andesitic and
Daucit, less often Andesibasalt and Rolyite. With this type of eruptions
The heated, but not plastic, exposive material is different
The size and rare lava flows. Lava streams are usually short with
Blind surface. Blinds are much larger than in basalt and
Andesibasalt streams of Strombolian eruptions. Characteristic
peculiar volcanic bombs - type "bread crust" having a smooth
Strongly fractured surface. Exposive index 60-80 or more. The form
Chips angry, dimension from dusty (0.01 mm) to lump diameter
in 1 m or more, but the ashes dominated (less than 2.0 mm) particles that are more often
Total represented angular (acutely angry) fragments of volcanic
Glass. Slags are usually absent. Admixture of alien and response
Material more than 10%.
The ash material at volcano-stromombolian explosions rises to
height to the first kilometers and depending on the strength and direction of the wind
covers significant areas near the volcano. The smallest material
(10-15%), mainly whitoberous, refers to
volcanic buildings and is part of soil-pyroclastic covers
and volcano-terrigenous sediments. For the ashes of Vulcan eruptions not
Characteristic porous, drop-like, melted fragment form. So for
Fragments of ashes of the Karym volcano of eruptions 1966, 1979. Noted
The form is close to isometric with angular projections of crystals, but sharply
The angular forms were not observed. According to E.F. Maleyev (1982) mineral
The composition of the ashes changes as the dimension of particles increases. In large
fractions The number of crystals is 10-15%, and in small - 40-45%, which
probably due to the separation of volcanic glass and its removal on
Separate sections. In the ashes about 10% of the respected and retriclastic
wreckage that, after weak explosions, again fell into the crater and,
Subject to repeated heating, they purchased a red color.
Lava temperature 1050-950 ° C, viscosity coefficient 105-106 Poise.
The prototype is described on the island of Vulcano in the Lamp Islands group. Vulcanian
The type of eruption is characteristic of Avachinsky volcanoes, Karymsky (Kamchatka),
Widely manifested in conjunction with Strombolian on the Northern breakthrough

1.4. Plinica type of eruption is characterized by large
the number of exposive material and almost complete absence
Love. Exposive index 90 or more. For this type is characteristic
Strong gas saturation of the magma, which is manifested in significant
crushing volcanic products and emit them to a large
Height. Explosions are usually vertical, and therefore
Pyriclastics and its degree of differentiation depend on the direction and
Explosion force. Juvenile material often pembed,
Crystallasts are usually fragmented, whirloclasts have
Fuck shape. Together with the juvenile materials is made to
25% of alien material presented by fragments
The bases of the volcano.
Plinica type of eruption is more characteristic of volcanoes,
erupting the products of source (but maybe theezite and
basalt) and therefore enjoyed to spread
Previous era when acidic vulcanism was powerful. IN
The limits of the smoke-Kamchatka arc plinic type was observed at
The eruption of the Xudach volcano in 1907
Named by the name of the ancient Roman scientist Pole junior,
Described by the eruption of Vesuviya in 79 G.N. Fresh temperature
Vesuvia pyroclastic material was allegedly
1050 ° С (Vlodaisa, 1984). Side is described as Vesuvian Type
Eruption (Rudich, 1978; Vlodais, 1984).

1.5. Pelian type of eruption is characterized by directional
explosions, as a result of which scorching clouds consisting of
movable suspension of gases and finely dredged volcanic material.
The temperature of the scorching clouds 400-600 ° C. The scorching cloud discharged from
Mont-Pele volcano (1902 g) had a temperature of about 800 ° C, and
Observations of Lyakraa The temperature of the sintering clouds at the exit of the loaf
It was about 1100 ° C and 210-230 ° C at a distance of 6 km from the crater (Vlodais,
1984). Exposure Index 100. Pyroclastic material
predominantly juvenile, with an admixture of alien and respected,
Formed due to the destruction of volcanic buildings. Structure
Pyroclastic material from Andesite to Rolyithovoy. The form
The wrecks are angular and acute-angled, size from large blocks to dust with
The predominance of the latter. As a result of Pelian-type eruptions
Fast (within a few minutes) deposition
Pyroclastic material on the square from several tens to
Thousands of kilometers accompanied by air separation: near
volcanic buildings accumulate litterlasts and crystallasts, and
In removal - whirlwinds. Power of deposits of pyroclastic
Material is measured by centimeters and less often than tens
Santimeters.
Directional explosions are formed due to periodic breakthroughs
gases accumulating in the volcanic channel under the velvet's veil,
Frozen in Zherel Volcano. Characterized by squeezing cork over the dome in
The form of monolithic obelisk. On the Volcano Mont-Pele Such Obelisk has
The height of 375 m and the diameter of 100 m. The formation of obeliskov is characteristic of
volcanoes with a very viscous practically non-current lava with a coefficient
Viscosity 108-1010 Poise. Volcanogenic threshing breeds here
specific and formed mainly due to the destruction of the dome or in
The process of movement of extrusion. V.I.Vlodavets (1973) stands out for such
Volcanoes dome type of eruption.

1.6. The Kathmay type of eruption is characterized by the formation of hot
(600-800 ° C) and gas-saturated juvenile pyroclastic flows
Material, up to 10-30 km long, performing reduced parts of the relief.
The main feature of this type of eruption is located
Epicenter explosion at considerable depth. This leads to the fact that gases are not in
the state of crushing and throw away the powerful column of juvenile material in
the atmosphere and raises it only to the edge of the crater, where he, being strong
Gas-saturated, poured like a liquid flow (Maleev, 1982). At the same
Ritman's time (Rittmann A., 1963) explains the education mechanism
Pyriclastic IgniMabrite streams at the expense of a similar location to
Day surface of the exposive level of viscous magmas (see ch. 4).
Pyroclastic flows are divided into ignitors, pepkel, ash,
Agglomerate. With Katmai eruption, partial destruction is possible
volcanic building (Unnamed volcano, 1956, Shivech, 1964) (Fig.
3).
Pyriclastic material is represented by porous blocks with rounded,
due to rocking, angles (remind of boulders), often good
Refireed crystals and angular acute parties
volcanic glass. With the movement of pyroclastic flows
The corners and the edges of the crystals take place. Alien Material
present in an amount of 10-20% and is represented by fragments of breeds of previous
eruptions.
Classic for this type is the eruption of the cat's volcano on Alaska
In 1912, on Kamchatka, such eruptions were observed for volcanoes.
Avachinsky, Unnamed, Shivelch. Although the mechanism of eruption of the nameless
volcano (1956) (Fig. 4) was the same as on the Volcano Kathmai, but
Volcanic products they turned out different. This is due to the fact that
The initial temperature of the cat's volcano was high, which led to sintering
ashes and the formation of the game namebrids. On the nameless this did not happen, because
The temperature of the gas-pepper cloud was lower, which allows you to highlight
For this, own nameless type of eruption (Maleev, 1977).

Destroyed volcanic building of a volcano nameless during the Katmai eruption of 1956

Destroyed volcanic
Building a volcano Unnamed
during the Kamai eruption
1956

Kathmay type of volcanic eruption of Unnamed (1956).

1.7. Freatic (Bandaisan, Ultravulkansky) Type of eruption
Gives only exposive material in cold and rarely hot.
A large amount of fragments of the formation of the foundation of the volcano (75100%) are characterized in the absence of juvenile material. Freatic evessets can
partially destroy volcanic buildings, which leads to accumulation in
reduced parts of the relief of tremendous masses of the threshold material
Primary facies. It is usually complex mixtures of fragments of laure and tuffs with
Multi-oriented lamination. Exposure Index 100. Debris
breeds are thrown by ferry due to contact suspended
(thermal) waters with soil or when lowering the lava in the volcano channel below
Groundwater level.
The peculiarity of the freak eruptions is the fast (within
a few tens of seconds) power set, which is usually not reduced to
The end of the eruption. Famous French Volcanologist Garun Taziev watched
1976. A similar phenomenon from beginning to end (more than 30 minutes) on a volcano
Soufrier (Guadeloupe Island), whose thirteen eruptions were
Freatic. The most famous example of this type is
The eruption of the Bandai-san volcano (Japan, 1888).
Freatic explosions are also possible in the introduction of lava flows in
Glaciers covering the slopes of stratovulkanov. So in July 1993 during
The eruption of the Klyuchevsky volcano introduction of a lava flow in the Herman glacier
accompanied by a series of powerful freak explosions that reached
Heights of 2-3 km (Fedotov et al., 1995).
The above classification has visibility, but applies the main
For simple eruptions. The complex eruptions can
It is simultaneously characterized by several types of activity. At the same time they
so intertwined among themselves that breaking the eruptions to segments with
A certain type of activity is difficult. So unique large
Cracked Tolbachin eruption in Kamchatka (1975-1976)
Characterized by the manifestation of elements of almost all types of activity:
Vulcan, Strombolian, Pelev, Plinian and Hawaiian.

• Volcanic eruptions remind us of formidable and indomitable forces that are hidden in the depths of the Earth.

• The mystery of the causes of vulcanism has always caused people and the most lively interest, and the tragic consequences of the eruptions were forced to explore this element.

• Formation of volcano

• When a magmatic focus is formed in the depths of the Earth, the molten liquid magma with such a force presses from the bottom to the tectonic slab that it starts to crack. In terms of cracks and faults, Magma rushes up, spending the rock and expanding the cracks. So the output channel is formed. It takes place in the center of the volcano, on it, the molten magma is poured out of the volcano vulcan in the form of fire-liquid lava. The products of eruption - PEMZA, LAVA, tufy- settlements on the slopes of the volcano, forming a cone. At the top of the Vpadina Volcano - Crater. At the bottom of the crater, the vulcan can be seen - the hole of the output channel, through which the ashes is erupted, hot gases and pairs of water, lava and fragments of rocks. The volcano vulcan can be gaping- empty or filled with molten lava. If the lava is frozen in Gerl, then a solid cork is formed, which only a strong eruption of the volcano can break through, while the powerful explosion occurs.

• Types of volcanoes

• Existing volcanoes

• Volcanoes from time to time spew the molten rock, ashes, gases, and stones. This is because deep beneath them is a magmatic hearth, similar to a huge oven, in which rock rock melts, turning into a fire-liquid lava.

• These volcanoes are also considered, the eruptions of which are preserved any evidence in the history of mankind.

• Extinct volcanoes

• The extinct volcanoes were active only in prehistoric time. The focus under them is long the ground, and they themselves are so much destroyed that only research of geologists detect traces of ancient volcanic activity.

• Sleeping volcanoes

• Sleeping volcanoes have not been erupted in historical time, but at any moment their catastrophic eruption can begin, because the magmatic hearth is not too much. Asleep volcanoes show signs of life: they can smoke - from their crater there are haze, out of cracks in the mountain gases and steam are distinguished, they beat hot springs. The longer the sleeping volcano is in the rest stage, the more dangerous: the power of his explosive awakening can be catastrophic.

• Types of eruptions

• Exposive eruptions

• The explosion of the volcano occurs when the volcanic gases are released from a thick magma. With such eruptions, the peaks of the mountains are destroyed and millions of tons of ashes are thrown into the sky to a huge height.
• Ashes, gases and steam climb into the sky for tens of kilometers in the form of curly clouds.

• Effusion eruption

• With the effusive eruption of the volcano, the liquid lava spreads freely with the formation of lava flows and covers

• Extrusive eruptions

• A huge amount of burning gases and hot lava dust is thrown from the crater of the volcano. Spreading around the volcano with a huge speed, this scorching cloud lightningly burns everything on a very large area.

• Products eruption

• All that comes out of the depths of the earth during the eruption of volcanoes is called eruption products.

• They are liquid, solid and gaseous.

• The liquid eruption products include lava.

• Lava- This is a magma that is empty to the surface of the earth

• Types of lava flow.

• It has a smooth or slightly wrinkled surface and consists of liquid lava. Thoroughly, such a lava forms a flat, smooth surface, sometimes with long shocking wrinkles in the form of snakes and thick ropes of ropes. He is called, "cable lava".

• It has an uneven surface with cracks. Such a lava is very thick and viscous, so the flow is moving slowly. When the lava begins to cool, it cracks into pieces, but they continue to move as oil on the oil that has not yet succeeded to cool the hot lava. The upper hardened layer of lava resembles piles of slag, which is formed from coal combustion.

• Lava flow "Ah-ah"

• Lava flow "Pa-cheeie"

• Pyriclasts

• Thrust rocks that are scattered with gases during volcanic eruptions are called pyriclasts

• Volcanic gases

• Volcanic phenomena are associated with the action of gases. If the magma is very liquid, the gases are released freely and do not threaten the explosions. Gases can foam even a viscous magma, forming a porous pumice, spraying a magma on small particle-volcanic ashes and sand and, connecting with them, to form a deadly scattering cloud.
• Finally, gases can scatter from the volcano vulcan for hundreds of rock fragments.

• Volcanoes on Kamchatka

• Nameless volcano

• Near the keypopters, the volcano is located Unnamed. He was considered extinct, and his awakening strength was a giant. On March 30, 1956, a terrible power burst demolished the entire top of the volcano. The clouds of the ash shot up almost 40 km away, from

• garl escaped a powerful jet of hot gas, volcanic sand and ashes, which lifted all the vegetation by 25 km around the volcano. Lava dome began to grow from the craters. Now the foundation of this dome is 750 m, and height is 320 m. Fortunately, despite all the rage of eruption, no one has had a perpetrator of a single living soul during an eruption clock within a radius of 45 km from the volcano.

• Tolbachinskaya Natka

• Volcano Tobachik - very active volcano. A huge caldera with a crater with a diameter of 300 m and a depth of 150 meters was located on its top of 3085 m. From time to time, a small lake of hot lava arose in the crater. In 1975-1976, a fractured Icelandic eruption occurred. It continued continuously 520 days.

• For a very short time, many cracks longer than a kilometer were formed. All this was accompanied by springs and fontanilation of the lava. During the eruption of the Tobachchi from the depths of the Earth, two cubic km of volcanic products was thrown into the surface. This is the largest of famous volcanic eruptions in Kamchatka and the Kuril Islands.

• Volcano on the Philippines

• Maison Volcano, the most active on Luzon Island. On October 23, 1776, he was the cause of the death of 2000 people, when a huge amount of lava was thrown out of his crater.

• Maison Volcano.

• Maison's longest eruption was observed in 1897. It lasted from June 23 to June 30 and carried out 400 lives.

• Volcanoes of the Mediterranean

• Strombol volcano

• In the south of Italy, not far from Wulcano Island. Located is the island of the volcano Stromboli. It is very restless, and it has been acting for several millennia for almost no interruptions. From time to time, explosions occur in its crater, and the hot slag and volcanic bombs fly up to dozens, and sometimes hundreds of meters, but but the lava is usually not flowing.

• One of the strongest eruptions of Stromomboli was noted in 1930, and first of the fifteenth century there were already seven.

• Volcanoes of the Atlantic

• In the south of Iceland, there is a volcanic ridge of varnishes, in which more than a hundred cones.
• In the height of the ridge reaches 818 m, in length-25km.

• June 8, 1783.
• Not far from the town of Watnai-Kudell in the south-east of Iceland began the most powerful eruption of the Varnish volcano. It lasted 8 months, the length of the flow of the battered lava was almost 70 kilometers, and the volume of this mass, moving at a speed of over 45 km / h, was equal to 12,000 cubic meters and occupied an area of \u200b\u200b579 square kilometers.

• Vulcan varnish

• Volcanoes of Africa

• Kilimanjaro volcano

• Kilimanjaro is a volcanic mountain array in the east of Africa
• The array consists of three vertex, Maventi and Shira. Maventi volcanoes and Shira have long been dead, and Cybo continues to smoke with volcanic gases through holes on the slopes.

• Volcanoes of the Pacific Ocean

• Sent-Helens Volcano

• In North America, in Cordillera, the Saint Helens mountain is perhaps the lowest among other vertices, its height is just 2950 meters.
• On March 20, 1980, four powerful underground jolts shocked the terrain, and on March 27, 47 of the underground jolts by force of up to three points. In noon, there was a deafening explosion near the peak itself.
• This monstrous explosion took 62 people.

Work with a geographic map

• Show the following volcanoes on the map:
• Unnamed, Tolbachinskaya Sopka, Maison, Stromboli, Lucky, Kilimanjaro, Sent- Helens
• Show on the card Volcanoes that were erused over the past year

• Questions on the material passed

• 1. What are volcanoes?

• 3. What do you know the types of eruptions?

• 5. What is the eruptions?

• 2. How volcanoes are formed?

• 4. Let the brief description of each type of eruptions.