Download the presentation on the topic volcano apo. Volcanoes of the earthVolcanoes of the earth. The objectives of the lesson are to talk about volcanoes and volcanic eruptions as dangerous natural phenomena. form an idea. A hot spring constantly boils at its foot

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 among people, and the tragic consequences of eruptions forced them to study this element.

Volcano formation

When a magma chamber forms in the depths of the Earth, molten liquid magma presses from below on the tectonic plate with such force that it begins to crack. Magma rushes upward along cracks and faults, melting the rock and widening the cracks. This creates an exit channel. It passes through the center of the volcano, through which molten magma pours out from the crater of the volcano to the outside in the form of fiery liquid lava. The products of the eruption - pumice, lava, tuffs - 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 crater of the volcano - the opening of the outlet channel through which ash, hot gases and water vapor, lava and rock fragments erupt. Volcano vents can be gaping, empty, or filled with molten lava. If lava hardens in a crater, a solid plug is formed, which can only be broken through by a strong volcanic eruption, resulting in a powerful explosion.

Types of volcanoes

Active volcanoes

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

Those volcanoes are also considered active if there is any evidence of eruptions in human history.

Extinct volcanoes

Inactive volcanoes were active only in prehistoric times. The hearth beneath them has long gone out, and they themselves are so badly destroyed that only geological research reveals traces of ancient volcanic activity.

Dormant volcanoes

Dormant volcanoes have not erupted in historical times, but a catastrophic eruption may begin at any moment, because the magma chamber beneath them has not gone out. Dormant 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 gush out. The longer a dormant volcano remains dormant, the more dangerous it is: the power of its explosive awakening can be catastrophic.

Types of eruptions

Explosive eruptions

A volcano explosion occurs when volcanic gases are released from thick magma. During such eruptions, mountain tops are destroyed and millions of tons of ash are thrown into the sky to great heights.
Ash, gases and steam rise tens of kilometers into the sky in the form of curly clouds.

Effusive eruptions

During an effusive volcanic eruption, liquid lava flows freely to form lava flows and sheets

Extrusive eruptions

Ejected from the crater of a volcano great amount burning gases and hot lava dust. Spreading around the volcano with tremendous speed, this scorching cloud burns everything over a very large area with lightning speed.

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.

The liquid products of an eruption include lava.

Lava- this is magma that spills onto the surface of the earth

Types of lava flow.

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

It 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 had time to cool. The upper hardened layer of lava resembles piles of slag, which is formed from the combustion of coal.

Lava flow "ah-ah"

Pa-hoe-hoe lava flow

Pyroclasts

Rock fragments that are thrown out by 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 freely and do not threaten explosions. Gases can foam even viscous magma, forming porous pumice, disperse magma into small particles - volcanic ash and sand - and, combining with them, form a deadly scorching cloud.
And finally, gases can scatter rock fragments hundreds of meters from the crater of a volcano.

Volcanoes in Kamchatka

Bezymyanny Volcano

Bezymyanny volcano is located near Klyuchevaya Sopka. It was considered extinct, and the power of its awakening was gigantic. On March 30, 1956, a terrible explosion destroyed the entire upper part of the volcano. Clouds of ash shot up almost 40 km, from

From the vent, a powerful stream of hot gas, volcanic sand and ash burst out, which burned out all the 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 within a radius of 45 km from the volcano during the hours of the eruption.

Tolbachinskaya Sopka

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

For very a short time Many cracks more than a kilometer long formed. All this was accompanied by the spilling and gushing of lava. During the eruption of Tolbachik, two cubic kilometers of volcanic products were thrown to the surface from the depths of the Earth. 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 huge amounts of lava were ejected from its crater.

Volcano Mayon

Mayon's longest eruption occurred in 1897. It lasted from June 23 to June 30 and claimed 400 lives.

Volcanoes of the Mediterranean

Volcano Stromboli

In the south of Italy, near the island of Vulcano. Located volcano island Stromboli. He has a very restless character, and he has been acting for several millennia almost without interruption. From time to time, explosions occur in its crater, and hot slag and volcanic bombs fly up 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 since the fifteenth century there have already been seven of them.

Volcanoes of the Atlantic

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

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 lava that came to light 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 579 square kilometers.

Volcano Laki

Volcanoes of Africa

Mount Kilimanjaro

Kilimanjaro is volcanic mountain range in east Africa
The massif consists of three peaks - Kibo, Mawenzi and Shira. The Mawenzi and Shira volcanoes have long been extinct, and Kibo continues to smoke volcanic gases through openings on the slopes.

Volcanoes of the Pacific Ocean

Mount St. Helens

IN North America, in the Cordillera, Mount St. Helens is perhaps the lowest among other peaks - its height is only 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 claimed the lives of 62 people.

Working with a geographic map

Show the following volcanoes on the map:
Nameless, Tolbachik Sopka, Mayon, Stromboli, Lucky, Kilimanjaro, St. Helens
Show on the map the volcanoes that erupted in the last year

Questions about the material covered

1.What types of volcanoes are there?

3.What types of eruptions do you know?

5.What are the products of the eruption?

2.How are volcanoes formed?

4.Give brief description each type of eruption.

Lesson objectives: Talk about volcanoes and volcanic eruptions as dangerous natural phenomena. To form an idea of the diversity of volcanic eruptions. To develop knowledge about the areas where volcanoes occur in the world. Continue learning how to work with an atlas map.

The birth of a volcano As soon as a crack appears in the earth's crust, coming from the depths of the Earth's surface, the pressure under it drops sharply and the deep substances turn into a fiery liquid mass - magma. It rises through cracks, losing some of the gases and pours onto the surface of the Earth, forming lava.

Volcanoes Active Extinct Dormant volcanoes that erupted today or in historical times. There are 800 of them (in Kamchatka). There is no information about their activities, but sometimes they begin to act. have been inactive for many thousands of years. (Crimea, Transbaikalia).

Determine the world's volcanoes by geographic coordinates. Which of these volcanoes are active and which are extinct? Mark on contour map volcanoes °N, 160°E °N, 44°E °N, 138°E Define geographical coordinates for volcanoes: 1. Vesuvius, 2. Krakatau, 3. Kilimanjaro, 4. Etna, 5. Orizabo, 6. Llullaillaco. Practical task

Types of volcanic eruptions: Hawaiian type This youngest and most active volcano on the planet woke up in 2007 in Hawaii. Hot lava flowed from the slopes of the mountain directly into Pacific Ocean. Kilauea's last significant eruptions occurred in 1952, 1954 and 1955. The volcanic eruption poses no danger to local residents, moreover, brings them good income, since thousands of tourists come to Hawaii to see the fire streams with their own eyes.

Types of volcanic eruptions: Vesuvian type The mouth of Vesuvius opened the smoke, a cloud of flames gushed out, It developed widely, like a battle flag. The earth is shaking from the shaky columns. Idols are falling! The people, driven by fear, Under the rain of stones, under the inflamed ashes, In crowds, old and young, fleeing from the city. (A.S. Pushkin)

Quiz. 1.What is the name of the complex process in which magma rises from the depths of the earth and, breaking through the earth’s crust, pours out to the surface? 2. What is lava? 3. What is a volcano crater? 4. What is a vent? 5. Name the products of volcanic eruptions.

Volcanoes presentation was prepared by a student of class 5-A of MKOU “Secondary School No. 16” Ershov Ivan Head: Mostovaya Alla Nikolaevna

Volcanoes is the name of the ancient god of fire, the patron of blacksmithing. According to myths, his forge was located in the bowels of the earth, and smoke and flames from it came out through the crater of Mount Etna.

The ancient Greeks considered volcanoes to be the forge of the god Hephaestus and treated them with great respect

If a crack appears in the earth’s crust, a hot, molten substance – magma – rises along it from the depths of the planet, under enormous pressure.

The ancient Romans feared the unpredictable wrath of volcanoes. On August 24, 79, the Roman cities of Pompeii, Herculaneum and Stabia were destroyed by the eruption of Vesuvius

If magma pours onto the surface of the Earth, hot gases escape from it, and it is already called lava.

Cooled lava forms a raised surface around cracks in the ground. It grows and turns into a mountain - a cone. This is how a volcano grows. At its top there is a depression - a crater.

Sometimes the volcano “sleeps” for many years and people forget about it

cities grow on its slopes

Volcanoes are divided into: active, currently erupting constantly or periodically; asleep, about whose eruptions there is no information, but they have retained their shape and local earthquakes occur under them; extinct, heavily destroyed and eroded volcanoes without any manifestations of volcanic activity

Jets and steam gases rise from cracks on the bottom and walls of the crater. Sometimes they calmly emerge from under stones and crevices, and sometimes they escape with a whistle and hiss. The volcano can quietly smoke for months and years until an eruption occurs. This event is often preceded by an earthquake; An underground rumble is heard, the release of vapors and gases intensifies, clouds thicken over the top of the volcano.

Vulcan wakes up

eruption begins

View of an erupting volcano from an airplane

Eruptions can be long-term (over several years, decades and centuries) and short-term (measured in hours). After a strong eruption, the volcano returns to a state of rest for several years and even decades.

Scientists study the volcano during an eruption

After the eruption, a scorched desert remains, and life will not appear in this place soon

A volcanic bomb is pieces of cooled lava ejected during volcanic eruptions in a liquid or plastic state and taking on round, spindle-shaped and other shapes.

There are more than 800 on earth active volcanoes. Volcano Etna Cotopaxi, Ecuador

We have about 70 of them in Russia. Karymsky Volcano is located in the central part of the volcanic belt of Kamchatka. Nowadays, the Karymsky volcano is one of the most active in the world.

Maly Semyachik Volcano is part of the Karymsky group of volcanoes and is located 15 km northeast of the Karymsky volcano.

Volcanic eruptions also occur at the bottom of seas and oceans.

Sailors learn about this when they suddenly see a column of steam above the water.

or “stone foam” floating on the surface - pumice.

Some underwater volcanoes form cones that protrude above the surface of the water in the form of islands.

Volcanologists and geomorphologists study the characteristics of volcanoes and the phenomena of volcanism.

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

Volcanoes are classified by location, shape and activity.

By activity: extinct, dormant, active. This classification is quite 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 Pelée in Martinique, Valley of Volcanoes in Buryatia, Kalara volcanoes.

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

Active ones are the main object of interest for 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. Most active volcanism: Southern and Central America, Hawaii, Japan, Sunda Islands.

They are classified by location: subglacial, terrestrial, underwater. The following types are distinguished by shape: dome, cinder cone, shield-shaped, stratovolcano, complex type.

Based on the general design, formations of central and linear types are distinguished. The first 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 area type, but no such type has been recorded 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 happen in an hour, a month, a year, several years. Consequences of the eruption: formation of caldera depressions, geysers, fumaroles. May occur low mountains, islands. Lakes form in craters.

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

A mud-type volcano is a formation, as a result of whose activity mud and gases, rather than magma, come to the surface. Found in Russia and Central Asia.

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

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

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