Volcanoes and types of volcanic eruptions presentation. Volcanoes presentation

a geological formation that occurs above channels and cracks in the earth's crust, along which molten rocks (lava), hot gases, ash, water vapor and rock debris erupt onto the earth's surface

The main parts of the volcano

At the top of the volcano there is a deep depression - a crater. A vent goes into the crater - a channel through which liquid magma rises from the bowels of the Earth.

Types of volcanoes:

Active

• central volcanoes

• linear volcanoes

• Active volcano Etna

• Dormant Parinacota Volcano

Volcanoes are: active, dormant, extinct .

• Extinct Mount Fuji

• There are about 500 volcanoes on Earth. About 370 of them are located on the shores and island arcs of the Pacific Ocean (Aleutian, Kuril, Japanese, Philippine, Sunda Islands) and on the outskirts of the continents of North America, Central America, in the Andes in the west South America... 9 active volcanoes are located in Antarctica. Several volcanic islands are in Indian Ocean... There are only 45 of them in the Atlantic Ocean.

Volcanoes in Russia.

In Russia, Kamchatka, Kuriles, Sakhalin are at risk of volcanic eruptions. There are extinct volcanoes in the Caucasus.

• Hot lava flows (their speed is up to 100 km / h)
• Scorching avalanches (consisting of blocks, sand, ash and volcanic gases with a temperature of 700 degrees C)
• Clouds of ash and gases (thrown to a height of 15-20 km)
• Blast wave and scatter of debris
• Water and mud-stone flows (travel speed up to 90-100 km / h)
• Sharp climate fluctuations (greenhouse effect can be created)

Actions in the event of a volcanic eruption.

In the event of a volcanic eruption: 1 ) protect sensitive devices; 2) close the drinking water tanks; 3) follow the shelter; 4) periodically it is necessary to go out and sweep the ashes from the roofs and shake them off the trees.

Actions in the event of a volcanic eruption in the immediate vicinity

• What are the types of volcano
• List the parts of the volcano
• Actions in the event of a volcanic eruption

Knowledge check

1) Tremors and vibrations of the earth's surface arising from sudden displacements and ruptures in the earth's crust are called ...

Knowledge check

2. Of the listed consequences, indicate which of them relate to earthquakes:

a) scorching avalanches;

b) failures and rise of the earth's surface;

d) industrial accidents;

f) sharp climate fluctuations;

Knowledge check

3 . Of the listed consequences, indicate which of them relate to volcanoes:

a) sinkholes and rise of the earth's surface;

b) scorching avalanches;

c) destruction of buildings and structures;

d) clouds of ash and gases;

e) blast wave and scatter of debris;

f) sharp climate fluctuations;

g) vibrations, shocks and cracks in the soil.

Knowledge check

4. What not to do during an earthquake:

a) stand near windows

b) stand in the doorway;

c) hide in a cast iron bath;

d) use the elevator;

e) light matches, candles, use open fire;

f) approach dilapidated houses.

Knowledge check

5. Identify the types of earthquakes by origin:

a) tectonic;

b) active;

c) guided;

d) sleeping;

e) seaquake;

f) landslide.

Knowledge check

6. A geological formation that occurs above channels and cracks in the earth's crust, along which molten rocks (lava), hot gases, ash, water vapor and rock debris erupt onto the earth's surface are called ...

Knowledge check

7. Define the types of volcanoes:

a) landslide;

b) active;

c) guided;

d) sleeping;

e) tectonic.

Check

the answers

Grading criteria

1) Earthquake

20 points-19 points- "5"

18 points-15 points- "4"

14 points-10 points- "3"

Less than 10 points- "2"

• b, d, e, f
• and where

• In the event of a volcanic eruption in the immediate vicinity, protect your respiratory system and follow for cover.

• In 79 A.D. e. the volcano Vesuvius suddenly awakened, which had not been active before in historical time. A terrible catastrophe wiped out the cities of Pompeii, Herculaneum and Stabia from the face of the Earth, almost all of their inhabitants died.

The study of the features of volcanoes, the phenomenon of volcanism is engaged in volcanologists and geomorphologists.

Structure: hearth, vent, crater. A hearth is a place in the earth's crust or mantle. A vent is a channel through which magma rises. Crater - hole, funnel, bowl on top of a volcano mountain.

Volcanoes are classified by location, shape and activity.

By activity: extinct, dormant, active. This classification is rather arbitrary. The extinct ones have not erupted for more than 1000 years: they retain their general shape, the crater and slopes undergo changes. Sometimes they are active. Example: Mont Pele in Martinique, Valley of Volcanoes in Buryatia, Kalara volcanoes.

Sleepers are volcanoes in which the likelihood of eruption is higher than that of extinct ones. Some of them are called supervolcanoes - Toba in Sumatra, Taulo in New Zealand, volcanoes in Kamchatka.

Active ones are the main object of interest of volcanologists, they erupt frequently. They are located in the belts of young mountains, where mountain building continues. There is no consensus among scientists on how to accurately classify these geological formations. The most active volcanism: South and Central America, Hawaii, Japan, the Sunda Islands.

They are classified by location: subglacial, terrestrial, underwater. The types are distinguished according to the shape: dome, cinder cone, thyroid, stratovolcano, complex species.

On the basis of the general structure, formations of the central and linear types are distinguished. The former have a central channel through which lava comes to the surface. The second type is fissure, the channels through which the lava rises have an elongated shape. Scientists distinguish the areal type, but there are no such ones on Earth, at least in our time. They are believed to have existed when the planet was forming.

The eruption is considered an emergency, a disaster. It can be an hour, a month, a year, several years. The consequences of the eruption: the formation of depressions, calderas, geysers, fumaroles. Low mountains and islands may appear. Lakes are formed in the craters.

Types of eruption: Hawaiian (basalt lava comes to the surface, accompanied by smoky clouds, fire avalanches), hydroexplosive (a lot of steam is released, confined to water bodies).

A mud volcano is a formation, as a result of the activity of which mud, gases, and not magma, come to the surface. They are found on the territory of Russia, Central Asia.

The largest formations: San Pedro, Cotopaxi, Ojos del Salado in the Andes, Elbrus in the Caucasus, Fujiyama in Japan, Etna and Vesuvius in Italy, Klyuchevskaya Sopka in Kamchatka.

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

Eruption type
Expl
lively
th
index
c (E,
%)
Characteristic
lava.
Temperature,
° C.
Coeff.
viscosity, poise
Composition
volcanics
Basalts
Liquid.
T - 12001100 °.
– 103-104
Strombolians
cue
3050,
sometimes
Yes
100
Basalts,
basal andesite
you
Liquid,
semi-plastic
th.
T - 11501050 °.
– 104-105
Vulkansky
60-80
and
more
Andesites,
dacites (less often
basal andesite
you and
rhyolites)
Viscous.
Lava
streams are rare.
T - 1050-950.
– 105-106
Plinian
(Vesuvian
90 and
more
Rhyolites,
dacites.
Rarely
andesites
basalts
Lava
outpourings
very rare.
T 1050
Peleisky
100
Andesites,
dacites,
rhyolites
100
Rhyolites,
dacites,
andesites
Hawaiian
10,
rare
about 15
Katmay
and
Lava not
characteristic
Lava not
characteristic
Types of volcanoclastic rocks
Characterization of pyroclastic material
juvenile
resurgent,
alien
(qty)
Curly
bombs,
slags.
Drop-shaped (“Pele's tears”),
hairy (“Pele's hair”)
vitroclasts,
sometimes
idiomorphic
crystalloclasts
(crystallopilli)
Not
characteristic
Small block
lavoclastites
Agglutinates. Tuffs of various
dimensions, various structures. Composite tuffs and
crystalloclastic
Figure bombs, lapilli, slags
angular shape
Minor
Blocky
lavoclastites
Tuffs of various sizes.
Prevail
psephitic.
Xenotuffs (rare)
The form
debris
angular,
breadcrust bombs
More than 10%
Blocky
lavoclastites
Tuffs of various dimensions.
Prevail
ash
vitroclastic, pumiceoclastic. Xenotuffs
Pumiceous
lithoclasts,
angular
crystalloclasts,
flail vitroclasts
A lot of
–
Tuff
ash
vitroclastic crystals,
pumice-clastic. Xenotuffs
Angular,
sharp-angled
debris of various dimensions with
predominance
ash.
hot up to 400-600 С
A lot of,
highly
a lot of
–
Ash tuffs. Xenotuffs,
eruptive breccias
Hot (600-800 C),
gas-rich material
(pyroclastic flows),
porous lithoclasts,
idiomorphic crystal clasts,
acute-angled vitroclasts
10-20%
Tufolavas
(clastolavas)
lavoclastic
pyroclastic
Ignimbrites.
Xenoignimbrites.
agglomerate
Tuff

1.1. The Hawaiian type of eruption is characterized by low (10,
rarely 15) explosive index and represents a calm
outpouring of liquid basaltic lava, accompanied by weak
explosions. Basaltic lava flows with characteristic
wavy, rope (pakhoye-lava) and small-block
(aa-lava) surfaces, interbedded with a small
the amount of pyroclastic material, lie at an angle
2-3 °, rarely 5 °. Pyroclastic material is usually
thrown out in a liquid state, forming shaped bombs
(ball, ellipsoidal, pear-shaped, disc,
tape, cylindrical, slag). Characteristically
the formation of slags, which are sintered in the crater part
into agglutinates. The thinnest material formed when
explosions, is drop-shaped ("Pele's tears") and
hair-like ("Pele's hair") debris. maybe
ejection of crystals (crystal pills) in the form
prepared plagioclase individuals up to 3-5 cm in size
across. Longwall temperature 1200-1100 ° С, coefficient
viscosity 103-104 poise.
This type is characteristic of the Hawaiian shield volcanoes.
islands. Described for volcanoes Nyiragongo (Africa), Plosky
Tolbachik (Kamchatka), Southern breakthrough of the BTTI (Kamchatka).

1.2. The Strombolian type of eruption is most common when
volcanic eruptions producing basic products. For this
type is characterized by emissions of incandescent luminous material and
the outpouring of more viscous lava flows than Hawaiian
eruption. Explosive index 30-50, sometimes up to 100. Composition
volcanic products are basaltic and basaltic andesite. Viscosity
lava can range from liquid to semi-plastic, which
causes a wide variety of explosive material:
figured bombs (spherical, ellipsoidal,
cakes), lapilli, angular slags. The size
pyroclastics varies widely: from large blocks to
ash particles, but more often coarse-grained (2-10 mm)
material. Discarded together with juvenile material
resurgent and alien, represented by the rubble of the foundation
volcano. Longwall temperature 1150–1050 ° С, viscosity coefficient 104–
105 poise.
The prototype of the eruption is described on the volcano Stromboli (Mediterranean
sea). The Strombolian type was noted during the eruption of Klyuchevsky
volcano (Kamchatka) Northern Breakthrough, BTTI (Kamchatka) (Fig. 2),
Alaid and Tyatya (Kuril Islands).
Fig. 2. Strombolian type of eruption at the Northern Outbreak of the BTTI
(first slag cone June 1975)

Strombolian type eruption at the Northern Outburst of the BTTI (first cinder cone June 1975)

1.3. The volcanic type of eruption is widespread and usually combined
with strombolian. The composition of volcanic products is andesite and
dacitic, less often basaltic andesite and rhyolite. With this type of eruption
heated, but not plastic, explosive material of various
coarseness and rare lava flows. Lava flows are usually short with
blocky surface. Lumps are much larger than in basalt and
basaltic andesite streams of Strombolian eruptions. Are characteristic
a kind of volcanic bombs - like "bread crust", having a smooth
highly fractured surface. Explosive index 60-80 and more. The form
fragments are angular, their dimension from dusty (0.01 mm) to lumps with a diameter
1 m or more, but ash (less than 2.0 mm) particles predominate, which more often
in total are represented by angular (acute-angled) fragments of volcanic
glass. Slags are usually absent. Mixture of alien and resurgent
material more than 10%.
Ash material during volcano-strombolian explosions rises by
height up to the first kilometers and depending on the strength and direction of the wind
covers significant areas near the volcano. Smallest material
(10-15%), mainly vitroclastic, belongs to
volcanic structure and is part of the soil-pyroclastic covers
and volcano-terrigenous deposits. For the ash of volcanic eruptions not
characteristic porous, drop-like, melted form of fragments. So much for
fragments of ash from the Karymsky volcano of the eruptions of 1966, 1979 was noted
the shape is close to isometric with angular protrusions of crystals, but sharply
no angular shapes were observed. According to E.F. Maleev (1982) mineral
the composition of the ashes changes as the particle size increases. In large
fractions, the amount of crystals is 10-15%, and in small fractions - 40-45%, which
probably due to the separation of volcanic glass and its removal to
separate areas. In the ashes, about 10% of resurgent and retroclastic
debris that, after weak explosions, again fell into the crater and,
undergoing repeated heating, they acquired a red color.
The lava temperature is 1050–950 ° C, the viscosity coefficient is 105–106 poise.
The prototype is described on the island of Vulcano in the Aeolian Islands group. Vulkansky
the type of eruption is typical for the volcanoes Avachinsky, Karymsky (Kamchatka),
manifested widely in combination with Strombolian on the Northern Break

1.4. The Plinian type of eruption is characterized by a large
the amount of explosive material and the almost complete absence
lava. Explosive index of 90 or more. This type is characterized by
strong gas saturation of magma, which is manifested in a significant
crushing volcanic products and throwing them into a large
height. Explosions are usually vertical, and therefore the patterns of occurrence
pyroclastics and the degree of its differentiation depend on the direction and
explosion forces. Juvenile material is often pumiceous,
crystalloclasts are usually fragmented, vitroclasts have
flyer shape. Together with the juvenile, materials are carried out up to
25% alien material represented by debris
the base of the volcano.
Plinian type of eruption is more typical for volcanoes,
spewing acidic products (but can be andesitic and
basalt) and therefore enjoyed wide distribution in
previous eras, when acid volcanism was powerfully manifested. IN
within the Kuril-Kamchatka arc, the Plinian type was observed at
the eruption of the Ksudach volcano in 1907
Named after the name of the ancient Roman scholar Pliny the Younger,
who described the eruption of Vesuvius in 79 AD. Fresh temperature
of pyroclastic material in Vesuvius supposedly had
1050 ° C (Vlodavets, 1984) Sometimes described as Vesuvian type
eruptions (Rudich, 1978; Vlodavets, 1984).

1.5. The Peleus type of eruption is characterized by directional
explosions, as a result of which scorching clouds are formed, consisting of
mobile suspension of gases and finely divided volcanic material.
The temperature of the scorching cloud is 400-600 ° C. The scorching cloud thrown out of
volcano Mont Pele (1902) had a temperature of about 800 ° C, and
Lacroix's observations, the temperature of the caking cloud at the exit from the bocca
was about 1100 ° С and 210-230 ° С at a distance of 6 km from the crater (Vlodavets,
1984). Explosiveness index 100. Pyroclastic material
predominantly juvenile, with an admixture of alien and resurgent,
formed as a result of the destruction of a volcanic structure. Composition
pyroclastic material from andesite to rhyolite. The form
fragments angular and acute-angled, size from large blocks to dust with
the predominance of the latter. As a result of eruptions of the Peleus type
fast (within a few minutes) settling occurs
pyroclastic material on an area from several tens to
thousands of kilometers, accompanied by air separation: close
volcanic edifices accumulate lithoclasts and crystal clasts, and
in the distance - vitroclasts. The thickness of pyroclastic deposits
material is measured in centimeters and less often in the first tens
centimeters.
Directional explosions are formed due to periodic breakouts
gases accumulating in the channel of the volcano under the plug of viscous lava,
frozen in the mouth of a volcano. It is typical to squeeze the plug over the dome in
the form of a monolithic obelisk. On the volcano Mont Pele, such an obelisk has
height 375 m and diameter 100 m. The formation of obelisks is typical for
volcanoes with very viscous practically non-flowing lava with a coefficient
viscosity 108-1010 poise. Volcanic coarse rocks here
specific and are formed mainly due to the destruction of the dome or in
the process of extrusion movement. V.I. Vlodavets (1973) allocates for such
volcanoes are dome-type eruptions.

1.6. The Katmai type of eruption is characterized by the formation of incandescent
(600-800 ° C) and gas-saturated pyroclastic flows of juvenile
material, up to 10-30 km long, filling low parts of the relief.
The main feature of this type of eruption is the location
the epicenter of the explosion at a considerable depth. This leads to the fact that the gases are not in
able to shatter and throw a powerful column of juvenile material into
atmosphere and raises it only to the edge of the crater, where it, being strong
gas-saturated, pours out like a liquid stream (Maleev, 1982). At the same
time Rittmann (A., 1963) explains the mechanism of formation
pyroclastic ignimbrite flows due to their proximity to
the day surface of the explosive level of viscous magmas (see Ch. 4).
Pyroclastic flows are divided into ignimbrite, pumice, ash,
agglomerate. Partial destruction possible during the Katmai eruption
volcanic edifice (Bezymyanny volcano, 1956, Shiveluch, 1964) (Fig.
3).
The pyroclastic material is represented by porous lumps with rounded,
due to chipping, corners (resembling boulders), often good
prepared crystals and angular acute-angled particles
volcanic glass. As the pyroclastic flows move
the corners and edges of the crystals are chipped off. Alien material
present in an amount of 10-20% and is represented by fragments of rocks from previous
eruptions.
The classic for this type is the eruption of the Katmai volcano in Alaska
in 1912, in Kamchatka, similar eruptions were observed for volcanoes
Avachinsky, Nameless, Shiveluch. Although the mechanism of the eruption of the Nameless
volcano (1956) (Fig. 4) was the same as on the Katmai volcano, but
their volcanic products were different. This is due to the fact that
the initial temperature of Katmai volcano was high, which led to sintering
ash and ignimbrite formation. This did not happen on the Nameless One, because
the temperature of the gas-ash cloud was lower, which makes it possible to release
for this it has its own unnamed type of eruption (Maleev, 1977).

The destroyed volcanic edifice of the Bezymyanny volcano during the 1956 Katmay eruption.

Destroyed volcanic
construction of the Bezymyanny volcano
during the Katmai eruption
1956 g.

Katmay type of eruption of Bezymyanny volcano (1956).

1.7. Phreatic (Bandaysan, ultravolcanic) type of eruption
gives only explosive material in a cold and rarely hot state.
A large amount of rock fragments of the basement of the volcano (75-100%) in the absence of juvenile material is characteristic. Phreatic eruptions can
partially destroy the volcanic structure, which leads to the accumulation of
lowered parts of the relief of huge masses of coarse material
near-crater facies. These are usually complex mixtures of lava and tuff fragments with
differently oriented layering. Explosiveness index 100. Debris
rocks are thrown out by steam due to contact of overheated
(thermal) waters with groundwater or when lava sinks in the volcano channel below
groundwater level.
The peculiarity of phreatic eruptions is rapid (during
several tens of seconds) gaining power, which usually does not decrease to
end of the eruption. The famous French volcanologist Garun Taziev observed in
1976 a similar phenomenon from start to finish (more than 30 minutes) on a volcano
Soufriere (Guadeloupe Island), thirteen eruptions of which were
phreatic. The most famous example of this type is
eruption of the Bandai-San volcano (Japan, 1888).
Phreatic explosions are also possible when lava flows enter
glaciers covering the slopes of stratovolcanoes. So in July 1993 during
eruptions of Klyuchevskoy volcano, introduction of lava flow into Erman glacier
was accompanied by a series of powerful phreatic explosions that reached
altitudes of 2-3 km (Fedotov et al., 1995).
The above classification is clear, but applicable, the main
way, to simple eruptions. Complex eruptions can
be characterized by several types of activity at the same time. However, they
so intertwined with each other that they break the eruptions into segments with
certain type of activity can be difficult. So unique Big
fissure Tolbachik eruption in Kamchatka (1975-1976)
was characterized by the manifestation of elements of almost all types of activity:
Vulcan, Strombolian, Peleian, Plinian, and Hawaiian.

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

• The mystery of the causes of volcanism has always aroused fear and keen interest in people, and the tragic consequences of eruptions forced them to explore this element.

• Volcano formation

• When a magma chamber is formed in the bowels of the Earth, molten liquid magma presses down on the tectonic plate with such force that it begins to crack. Along cracks and faults, magma rushes upward, melting the rock and expanding the cracks. This forms the excretory canal. It passes in the center of the volcano, along which molten magma pours out from the volcano's vent in the form of fiery liquid lava. The products of the eruption - pumice, lava, tuff - settle on the slopes of the volcano, forming a cone. At the top of the volcano there is a depression - a crater. At the bottom of the crater, you can see the mouth of the volcano - the opening of the outlet channel through which ash, hot gases and water vapor, lava and rock fragments are erupted. The vents of the volcano can be gaping - empty or filled with molten lava. If the lava solidifies in the vent, then a solid plug is formed, which can only be broken by a strong volcanic eruption, while a powerful explosion occurs.

• Types of volcanoes

• Active volcanoes

• Volcanoes occasionally spew molten rock, ash, gases, and rocks. This is because deep below them there is a magma chamber, similar to a huge furnace, in which the rock melts, turning into fiery liquid lava.

• Those volcanoes are also considered active if there is any evidence of their eruptions in the history of mankind.

• Extinct volcanoes

• Extinct volcanoes were active only in prehistoric times. The hearth under them has long gone extinct, and they themselves are so badly destroyed that only the studies of geologists reveal traces of ancient volcanic activity.

• Dormant volcanoes

• Dormant volcanoes in historical time did not erupt, but at any moment their catastrophic eruption can begin, because the magma chamber under them has not died out. Sleep volcanoes show signs of life: they can smoke - smoke comes from their crater, gases and steam are released from cracks in the mountain, hot springs flow. The longer a dormant volcano is at rest, the more dangerous it is: the power of its explosive awakening can be catastrophic.

• Types of eruptions

• Explosive eruptions

• A volcanic explosion occurs when volcanic gases are released from thick magma. During such eruptions, the tops of the mountains are destroyed and millions of tons of ash are thrown into the sky to a great height.
• Ashes, gases and steam rise into the sky for tens of kilometers in the form of curly clouds.

• Effusive eruptions

• During an effusive volcanic eruption, liquid lava flows freely with the formation of lava flows and sheets

• Extrusive eruptions

• From the crater of the volcano, a huge amount of burning gases and hot lava dust are emitted. Spreading around the volcano with great speed, this scorching cloud instantly burns out everything over a very large area.

• Eruption products

• Everything that comes out of the bowels of the Earth during volcanic eruptions is called eruption products.

• They are liquid, solid and gaseous.

• Lava is a liquid eruption product.

• Lava- this is magma poured onto the surface of the earth

• Lava flow types.

• It has a smooth or slightly wrinkled surface and is composed of liquid lava. When solidified, such lava forms a flat, smooth surface, sometimes with long wriggling wrinkles in the form of snakes and thick ropes - ropes. Often it is called “rope lava”.

• Has an uneven surface with cracks. This lava is very thick and viscous, so the flow moves slowly. When the lava begins to cool, it cracks into pieces, but they continue to move like clockwork on the hot lava that has not yet cooled down. The upper solidified layer of lava resembles piles of slag that is formed from the combustion of coal.

• Lava flow "ah-ah"

• Lava flow "pa-hoe-hoe"

• Pyroclasts

• The fragments of rocks that are scattered with gases during volcanic eruptions are called pyroclasts

• Volcanic gases

• Volcanic phenomena are associated with the action of gases. If the magma is very liquid, gases are released unhindered and do not threaten explosions. Gases can foam even viscous magma, forming a porous pumice stone, pulverize magma into small particles - volcanic ash and sand - and, combining with them, form a deadly scorching cloud.
• And finally, gases can scatter rock debris from the volcano's mouth for hundreds of meters.

• Volcanoes in Kamchatka

• Volcano Nameless

• Bezymianny volcano is located near Klyuchevaya Sopka He was considered extinct, and the power of his awakening was enormous. On March 30, 1956, a terrible explosion blew away the entire upper part of the volcano. Ash clouds shot up almost 40 km, from

• a powerful jet of hot gas, volcanic sand and ash burst out, which burned out all vegetation for 25 km around the volcano. A lava dome began to grow from the craters. Now the base of this dome is 750 m, and the height is 320 m. Fortunately, despite all the fury of the eruption, no one died - not a single living soul was in the hours of the eruption within a radius of 45 km from the volcano.

• Tolbachinskaya Sopka

• Volcano Tolbachik is a very active volcano. At its summit, 3085 m high, there was a huge caldera with a crater 300 m in diameter and 150 m deep. From time to time a small lake of hot lava appeared in the crater. In 1975-1976, an Icelandic-type fissure eruption took place. It lasted 520 days continuously.

• In a very short time, many cracks more than a kilometer long were formed. All this was accompanied by the spilling and gushing of lava. During the eruption of Tolbachik from the depths of the Earth, two cubic km of volcanic products were thrown to the surface. This is the largest known volcanic eruption in Kamchatka and the Kuril Islands.

• Volcano in the Philippines

• Mayon volcano, the most active on the island of Luzon. On October 23, 1776, it caused the death of 2,000 people when a huge amount of lava was thrown out of its crater.

• Mayon volcano

• The longest Mayon eruption was observed in 1897. It lasted from 23 to 30 June and claimed 400 lives.

• Volcanoes of the Mediterranean

• Stromboli volcano

• In the south of Italy, near the island of Vulcano. The island is the volcano Stromboli. It has a very restless character, and it has been operating for several millennia almost without interruption. From time to time, explosions occur in its crater, and hot slag and volcanic bombs fly upwards for tens, and sometimes hundreds of meters, but lava usually does not flow from it.

• One of the most powerful eruptions of Stromboli was noted in 1930, and at the beginning of the fifteenth century there were already seven of them.

• Volcanoes of the Atlantic

• In the south of Iceland is the volcanic Laki mountain range, which contains more than a hundred cones.
• The ridge reaches 818 m in height and 25 km in length.

• June 8, 1783.
• Not far from the town of Vatnajo-kull in the southeast of Iceland, a powerful eruption of the Laki volcano began. It lasted 8 months, the length of the flow of the escaped 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.

• Lucky volcano

• Volcanoes of Africa

• Kilimanjaro volcano

• Kilimanjaro is a volcanic mountain range in eastern Africa
• The massif consists of three peaks - Kibo, Mawenzi and Shira. The volcanoes Mawenzi and Shira have long gone extinct, and Kibo continues to smoke with volcanic gases through holes on the slopes.

• Volcanoes of the Pacific Ocean

• Volcano st helens

• In North America, in the Cordilleras, Mount St. Helens is perhaps the lowest of any other peaks, at just 2950 meters.
• On March 20, 1980, four powerful tremors shook the area, and on March 27, 47 tremors with a force of up to three points. At noon of the same day, a deafening explosion was heard near the very top.
• This monstrous explosion took the lives of 62 people.

Working with a geographic map

• Show the following volcanoes on the map:
• Nameless, Tolbachinskaya Sopka, Mayon, Stromboli, Laki, Kilimanjaro, St. Helens
• Show on the map the volcanoes that have erupted over the past year

• Questions about the material covered

• 1. What are the volcanoes?

• 3. What types of eruptions do you know?

• 5. What are the products of the eruption?

• 2.How are volcanoes formed?

• 4. Give a brief description of each type of eruption.