What is an active volcano for children? "Mysteries of nature: volcanoes." GCD for experimental activities of children of senior preschool age. Types of volcanic structures

In Ancient Rome, the name Vulcan was borne by the mighty god, the patron of fire and blacksmithing. We call volcanoes geological formations on the surface of the land or on the ocean floor, through which lava emerges from the deep bowels of the earth to the surface.

Often accompanied by earthquakes and tsunamis, large volcanic eruptions have had a significant impact on human history.

Geographical object. The importance of volcanoes

During a volcanic eruption, magma comes to the surface through cracks in the earth's crust, forming lava, volcanic gases, ash, volcanic rocks and pyroclastic flows. Despite the danger that these powerful natural objects pose to humans, it was thanks to the study of magma, lava and other products of volcanic activity that we were able to gain knowledge about the structure, composition and properties of the lithosphere.

It is believed that thanks to volcanic eruptions, protein forms of life were able to appear on our planet: the eruptions released carbon dioxide and other gases necessary for the formation of the atmosphere. And volcanic ash, settling, became an excellent fertilizer for plants due to the potassium, magnesium and phosphorus it contained.

The role of volcanoes in regulating the climate on Earth is invaluable: during an eruption, our planet “releases steam” and cools, which largely saves us from the consequences of global warming.

Characteristics of volcanoes

Volcanoes differ from other mountains not only in their composition, but also in their strict external outlines. From the craters at the top of the volcanoes, deep narrow ravines formed by flows of water stretch down. There are also entire volcanic mountains formed by several nearby volcanoes and the products of their eruptions.

However, a volcano is not always a mountain breathing fire and heat. Even active volcanoes can appear as straight cracks on the surface of the planet. There are especially many such “flat” volcanoes in Iceland (the most famous of them, Eldgja, is 30 km long).

Types of volcanoes

Depending on the degree of volcanic activity there are: current, conditionally active And extinct (“dormant”) volcanoes. The division of volcanoes by activity is very arbitrary. There are cases when volcanoes, considered extinct, began to exhibit seismic activity and even erupt.

Depending on the shape of volcanoes there are:

Stratovolcanoes- classic “fire mountains” or volcanoes of the central type, cone-shaped with a crater at the top.
Volcanic fissures or fissures- fractures in the earth's crust through which lava comes to the surface.
Calderas- depressions, volcanic cauldrons formed as a result of the failure of a volcanic peak.
Panel- so called because of the high fluidity of the lava, which, flowing for many kilometers in wide streams, forms a kind of shield.
Lava domes - formed by the accumulation of viscous lava above the vent.
Cinder or tephra cones- have the shape of a truncated cone, consist of loose materials (ash, volcanic stones, blocks, etc.).
Complex volcanoes.

In addition to land-based lava volcanoes, there are underwater And mud(they spew out liquid mud, not magma) Underwater volcanoes are more active than land-based ones; 75% of the lava erupted from the bowels of the Earth is released through them.

Types of volcanic eruptions

Depending on the viscosity of lavas, the composition and amount of eruption products, there are 4 main types of volcanic eruptions.

Effusive or Hawaiian type- a relatively calm eruption of lava formed in craters. The gases released during an eruption form lava fountains from drops, threads and lumps of liquid lava.

Extrusion or dome type- is accompanied by the release of gases in large quantities, leading to explosions and the emission of black clouds from ash and lava debris.

Mixed or Strombolian type- abundant lava output, accompanied by small explosions with the release of pieces of slag and volcanic bombs.

Hydroexplosive type- typical for underwater volcanoes in shallow water, accompanied by a large amount of steam released when magma comes into contact with water.

The largest volcanoes in the world

The tallest volcano in the world Ojos del Salado, located on the border of Chile and Argentina. Its height is 6891 m, the volcano is considered extinct. Among the active "fire mountains" the highest is Llullaillaco- volcano of the Chilean-Argentine Andes with a height of 6,723 m.

The largest (among terrestrial) volcano in terms of area occupied is Mauna Loa on the island of Hawaii (height - 4,169 m, volume - 75,000 km 3). Mauna Loa also one of the most powerful and active volcanoes in the world: since its “awakening” in 1843, the volcano has erupted 33 times. The largest volcano on the planet is a huge volcanic massif Tamu(area 260,000 km2), located at the bottom of the Pacific Ocean.

But the most powerful eruption in the entire historical period was produced by the “low” Krakatoa(813 m) in 1883 in the Malay Archipelago in Indonesia. Vesuvius(1281) - one of the most dangerous volcanoes in the world, the only active volcano in continental Europe - located in southern Italy near Naples. Exactly Vesuvius destroyed Pompeii in 79.

In Africa, the highest volcano is Kilimanjaro (5895), and in Russia it is a double-peaked stratovolcano Elbrus(North Caucasus) (5642 m - western peak, 5621 m - eastern).

Geography for the little ones.
Volcanoes.
1. Tell your child the legend about the ancient god Vulcan (in Ancient Rome) or Hephaestus (in Ancient Greece):

In Ancient Greece, power over volcanoes belonged to a god named Hephaestus - fire. He was a strange god: ugly, lame. But he is very hardworking and strong. Hephaestus managed to subjugate fire. He was the first to forge weapons and make jewelry. And then he taught it to people. And if steam and fire appeared above the volcano, it means Hephaestus got to work. The ancient Romans gave this god the name Vulcan. It also means fire. And his house was called a volcano.

There lived a god named Vulcan. He liked blacksmithing: standing at the anvil, hitting iron with a heavy hammer, fanning the fire in the forge. He built himself a forge inside a tall mountain. And the mountain stood right in the middle of the sea. When the volcano was active, the mountain trembled from top to bottom, and the roar and roar echoed far around. From the hole at the top of the mountain, hot stones, fire and ash flew with a deafening roar. “The volcano is working,” people said with fear and went to live away from the mountain, so that the fire would not burn their homes and cover their gardens and fields with ashes. They say since then, all fire-breathing mountains began to be called volcanoes.

Exercise:
Look at pictures of volcanoes with your child. Please note that it looks like an ordinary mountain, but inside it there is a very hot liquid - magma, and while the magma lives in its house, the volcano is considered dormant, but this is the same mountain only with magma, fire, smoke erupting from it - it is active volcano. Look at the shape of the volcano, what does it look like? (on a cone, pyramid). What does the top look like? (a large hole, a funnel is called a crater)
Watch the presentation Fire-Breathing Mountains http://depositfiles.com/files/19ciup3u2

2.Read the poem about volcanoes:
Volcanoes began to "volcano" -
Spew lava from the crater.
Lava flowed down the slopes
And the Earth was badly burned.
Centuries later, the evil one coughed
The volcano is both ash and ash.
The volcano is thundering! The volcano is chugging!
How menacing he looks now!
But then he began to get tired -
The fire in him began to fade.
The last time I breathed fire -
And he fell asleep for decades.
Centuries will pass...
And the volcano will wake up again,
And lava will flow from his insides.

3.Make a volcano with your child
1. Take paper, scissors, tape, compass, ruler
2.Cut out a large circle
3. Cut in half
4. Fasten the edges of the segment to form a cone
5.Make a volcano crater from a paper cylinder (you can use a base of paper towels or foil) and attach it to a surface (cardboard, candy box, etc.)
6.Place the cone onto the cylinder and secure it
7. Cover the entire structure with tape (paper) and cover with glue
8.Sprinkle with colorful sand and grains
9.Color the volcano
10.Eruption: 1 tsp. soda, a little red dry paint and 5 drops of washing liquid, 5 drops of vinegar.
There is another option for creating a volcano http://subscribe.ru/archive/home.child.toy/200711/30134924.html

4.Tell that different volcanoes erupt in different ways. Sometimes they seem to explode, throwing magma up and to the sides. A huge mountain shakes with a terrible roar, a huge column of smoke and ash rises above it, stone rain sprinkles the slopes of the mountains. And sometimes lava flows out “calmly”. We have many volcanoes in our country. Almost all of them are located in the Far East, Kamchatka, and the Kuril Islands.
Exercise:
Try to find with your child on the map where volcanoes are located in our country and in the world, what color they are indicated by.
Look at photographs of different volcanoes and read interesting facts about them
o 10 most dangerous volcanoes on the planet - http://www.geo-cafe.ru/Reviews/Articles/review350.php
o Interesting facts about volcanoes - http://katya.gorod.tomsk.ru/index-1163550018.php
o Walk through the volcanoes of South and North America - http://www.geo-cafe.ru/Reviews/Articles/review154.php

5. Explain to your child why a volcano erupts in the first place using experience:
Inflate and lightly squeeze the balloon in your fist, continue to inflate. The ball will swell between your fingers. The same thing happens with magma, when mountains are pressed down from above, and magma with gases rises. As a result, some kind of explosion occurs.
6. Explore volcanic rocks with your child:
Material: a bowl of water, stones and a piece of pumice.
Look carefully at the stones and pumice. Compare them to each other: there are a lot of holes in pumice. Ask your child what he thinks: are the holes empty or is there something in them? (air is hidden in the holes, so pumice is lighter than ordinary stone). Suggest placing a piece of pumice in a bowl of water. Are there any bubbles? Does pumice float or sink? Why? The child makes a discovery: pumice is a stone with many holes in which air accumulates. Pumice does not sink, but floats on the surface of the water.

Information for mothers:
How volcanoes form
To understand the nature of volcanoes, you need to know the structure of the Earth. The earth consists of several layers formed by different rocks. We live on the outer, thinnest layer called the earth's crust. The bark is so thin, as if a sticker was stuck on a ball (think of it as the Earth), or rather a lot of stickers next to each other. After all, the crust consists of about 20 large and small plates, which are called tectonic. The plates seem to float on the surface of a viscous, pasty molten substance called magma. The word magma is translated from Greek as dough or paste.
The places where the largest plates touch each other are called faults. Most active volcanoes are concentrated at the boundaries of these plates. The most active zone on Earth is called the Ring of Fire and is located along the edges of the Pacific Ocean. There are many mountains and islands in these places that were formed on the site of ancient volcanoes.

What happens during an eruption
Sometimes hot magma seeps out through the cracks. If a powerful flow of magma is blocked by rocks in the earth's crust, the pressure of the magma rushing out increases. When it gets too large, magma breaks through the crust. Then a volcanic eruption occurs, accompanied by a powerful release of magma, ash, gases and pieces of rock.
Magma released from a volcano is called lava. It flows out of the crater of the volcano in the form of a stream. At the beginning, the lava flow has a temperature of 1000 degrees and flows along the slopes of the volcano at speeds of up to 50 kilometers per hour. But in air, the lava cools and hardens, forming a volcanic mountain around the hole in the earth's crust. Pieces of frozen lava - pumice. There are air bubbles inside this pebble. This is because the lava boiled and seethed, and then froze.
Volcanic ash looks like ordinary ash, but if you look at it under a microscope, you can clearly see that these are fragments of volcanic glass. The eruption throws ash to a very high altitude, sometimes even several kilometers. Huge gray clouds of ash are carried by the wind over long distances from the eruption site, and then they settle on the Earth in a thick layer.
Volcanic gases are hot gases. During an eruption, their temperature reaches 800-1000 degrees. Hot heavy gases rush down the slope of the volcano at a speed of over 300 kilometers per hour, destroying trees, houses and people. Volcanic gases include water vapor, carbon dioxide and gases containing sulfur, ammonia and chlorine.

What types of volcanoes are there?
Volcanic eruptions occur in different ways. The nature of the eruption depends on many factors - mainly the viscosity of the magma and the amount of volcanic gases.
There are volcanoes - they are called Shield volcanoes - they are predictable, rarely accompanied by explosions. Lava constantly erupts to the surface.
Other volcanoes - Stratovolcanoes - are the highest. During an eruption, a lot of ash, stones, and lava are formed.
The most terrible volcanoes of the Caldera - these volcanoes explode so strongly that they destroy themselves, and in their place only a large crater remains.

What harm do volcanoes cause?
There are more than a thousand volcanoes on our planet. Most of them went out, and... it would seem forever. But they are only sleeping and can wake up every minute. Some volcanoes wake up very rarely. Once every 100 or even 1000 years. There are volcanoes that don’t even think about pretending to be asleep; they smoke without ceasing. Every ten minutes, stones, ash, steam and lava flow out of them.
One of the most powerful eruptions on Earth occurred in 1883. The Krakatoa volcano has awakened in Indonesia. The voice of the volcano spread over thousands of kilometers. The air explosions caused air waves of such force that they circled the globe three times. Stones flew into the air to a height of 55 kilometers. The waves rose up to 40 meters in the sea. The volcano spat out so much ash that a cloud covered the sun, and then black dirt fell from the sky. This cloud of dust flew around the entire planet. For a while, twilight fell across the entire Earth. Nothing can stop a volcano. Cities, islands and even countries perish under ash and lava.
Currently, scientists who study volcanoes are sometimes able to predict an eruption in advance and residents can leave cities and escape. But when the Vesuvius volcano, which had been dormant for many centuries, woke up, there were no seismologists yet and the disaster took people by surprise. Residents sought shelter in their houses and tried to escape, but no one managed to escape. When the eruption ended, it turned out that the flourishing cities had completely disappeared from the face of the earth. Almost seventeen centuries passed when the remains of dead cities were accidentally discovered under a layer of compressed volcanic ash. Excavations have begun. Almost the entire city of Pompeii was cleared of ashes. Houses with household items, temples, and monuments appeared before the amazed archaeologists. Everything remained as it was on the day Vesuvius woke up.
A terrible tragedy that happened in the distant past made a huge impression on the Russian artist Karl Bryullov, who depicted it on his canvas The Last Day of Pompeii.

Are there any benefits from volcanoes?
A volcanic eruption is a disaster for people. Every year there are 10,000 eruptions on Earth, of which approximately 150 are very strong. Cities are destroyed, people die. However, volcanoes also have benefits for people. Thanks to them, the rocks that make up the earth's crust are formed. Volcanoes, like elevators, bring many useful substances to the surface. Therefore, the soil around them is very fertile. Volcanic dust is used to make medicines, fertilizers, and water purifiers. Houses are built from hardened lava. Volcanoes also supply us with carbon, nitrogen and other gases from the bowels of the earth, without which life on Earth is impossible.

Target: introducing preschoolers to a natural phenomenon - a volcano.

Tasks:

Develop ideas about volcanoes, the dangers they pose, and their benefits.
Encourage children to independently form conclusions based on the results of the experiment, relying on their early knowledge.
Cultivate interest in cognitive and research activities, determination, perseverance, and independence.

Dictionary: mountain, volcano, crater, lava.

Preliminary work:

GCD cycle “Mysteries of Nature” (stones, mountains)
Reading the children's encyclopedia "Everything about Everything", the Great Encyclopedia "Pochemuchek", looking at photographs and illustrations of various volcanoes. Conversations about volcanoes with facts. Making a model of a volcano.

Material: illustrations of volcanoes (electronic presentation), model of a volcano, mixture for an eruption (soda, red paint, liquid soap, vinegar)

PROGRESS

TEACHER: I’ll read you a riddle, and you try to guess what we’ll be talking about today:

I spit fire and lava
I am a dangerous giant!
I am famous for my bad fame,
What's my name?

(Volcano)

- That's right, today we will talk about such a mysterious, enigmatic, amazing and formidable natural phenomenon as a volcano.

Guys, remember what a volcano is?

(This is a large mountain with steep sides, from which smoke first comes out, then stones fly, and then lava erupts.)

TEACHER: That's right, guys. You have already learned a little about volcanoes. And today I will tell you a legend about the volcano. (slide)

“There lived a god named Vulcan. And he liked blacksmithing: standing at the anvil, hitting iron with a heavy hammer, fanning the fire in the forge. He built himself a forge inside a tall mountain. And the mountain stood right in the middle of the sea. When Vulcan worked with his hammer, the mountain trembled from top to bottom, and the roar and roar echoed far around. From the hole at the top of the mountain, hot stones, fire and ash flew with a deafening roar. “The volcano is working,” people said with fear, and went to live away from this place. Since then, people began to call all fire-breathing mountains volcanoes.”

— This is an interesting legend about the origin of the name volcano.

Now let's look at the volcano. (volcano model)

What shape is the volcano? (cone).

At the very top of the volcano there is a crater. The crater is a huge bowl with steep slopes, and at the bottom there is a hole going deep into the ground - this is the crater of a volcano,

When volcanoes “sleep” they differ little from other mountains. But sometimes they “wake up” and then a strong underground rumble begins, flames, ash, hot stones, and volcanic bombs burst out from their tops. They are shrouded in smoke, explosions sound, and a real fiery stream - lava - flows down the slopes. Lava is molten, very hot rocks. Lava rises from underground through the mouth of a volcano and is released from the crater. The temperature inside the Earth is so high that rocks turn from solid to liquid. When pieces of lava harden, new stones are formed.

(Loud music plays).

Guys, it seems our volcano (a model of a volcano made in advance) is “coming to life”, let’s move away from the volcano.

(The teacher carefully pours vinegar into the prepared mixture. Children watch the volcanic eruption)

Volcanoes began to “volcano” -
Spew lava from the crater.
Lava flowed down the slopes
And it burned the earth badly.
Centuries later, the evil one coughed
Volcano and ash and ash.
The volcano is thundering, the volcano is chugging!
How menacing he looks now!
But then he began to get tired -
The fire in him began to fade.
The last time I breathed fire
And he fell asleep for decades.

Volcanoes erupt in different ways. Sometimes they seem to explode, throwing magma up and to the sides. A huge mountain shakes with a terrible roar, a huge cloud of smoke and ash rises above it, and stone rain showers the slopes. And sometimes it flows out “calmly.” Interesting?!

Do you want to do an experiment on your own in the laboratory: a volcanic eruption? Professor Know-It-All will help us here too. He prepared a diagram for this experiment for us (the teacher explains the sequence of the experiment using diagrams)

Now let's go to the laboratory of “amazing discoveries.” There we have everything ready to conduct experiments.

Let's get a look:

— What will we make the base of the volcano from? (from the cone we made in advance)

— What will we make a volcano crater from? You can insert an empty plastic jar inside the cone.

We put all this on trays.

Using the experiment scheme, we begin to work.

- Add a spoonful of soda. Add red paint. 5 drops of washing liquid. Now attention!

This liquid has a special symbol for me. What does it mean? (You can’t use it yourself) This is vinegar, only an adult can pour it. I will add it myself when you have everything ready.

The teacher adds vinegar to the prepared mixtures.

TEACHER: What are you observing? Watch your volcano erupt. It erupts calmly.

Well done guys, you were attentive, worked carefully and everything worked out great! Now do you know what a volcano is and how it erupts?

And now we will draw a volcano and fill out our young researcher’s folder on the topic “Mysteries of Nature: Volcanoes.”

(Children draw, the teacher selects drawings suitable for filling out the “Young Researcher’s Folder.)

References:

1. Tugusheva G.P., Chistyakova A.E. experimental activities of children of middle and senior preschool age: Methodological manual. – SPb.: DETSTVO-PRESS, 2010. – 128 p.

Volcanoes are geological formations on the surface of the Earth's crust or the crust of another planet where magma comes to the surface, forming lava, volcanic gases, rocks (volcanic bombs) and pyroclastic flows.

The word “volcano” comes from ancient Roman mythology and comes from the name of the ancient Roman god of fire, Vulcan.

The science that studies volcanoes is volcanology and geomorphology.

Volcanoes are classified by shape (shield, stratovolcanoes, cinder cones, domes), activity (active, dormant, extinct), location (terrestrial, underwater, subglacial), etc.

Volcanic activity

Volcanoes are divided depending on the degree of volcanic activity into active, dormant, extinct and dormant. An active volcano is considered to be a volcano that erupted during a historical period of time or in the Holocene. The concept of active is quite inaccurate, since a volcano with active fumaroles is classified by some scientists as active, and by others as extinct. Dormant volcanoes are considered to be inactive volcanoes where eruptions are possible, and extinct volcanoes are considered to be those where they are unlikely.

However, there is no consensus among volcanologists on how to define an active volcano. The period of volcanic activity can last from several months to several million years. Many volcanoes exhibited volcanic activity tens of thousands of years ago, but are not considered active today.

Astrophysicists, from a historical perspective, believe that volcanic activity, caused, in turn, by the tidal influence of other celestial bodies, can contribute to the emergence of life. In particular, it was volcanoes that contributed to the formation of the earth's atmosphere and hydrosphere, releasing significant amounts of carbon dioxide and water vapor. Scientists also note that too active volcanism, such as on Jupiter's moon Io, can make the planet's surface uninhabitable. At the same time, weak tectonic activity leads to the disappearance of carbon dioxide and sterilization of the planet. “These two cases represent potential boundaries for planetary habitability and exist alongside the traditional parameters of habitable zones for systems of low-mass main sequence stars,” the scientists write.

Types of volcanic structures

In general, volcanoes are divided into linear and central, but this division is arbitrary, since most volcanoes are confined to linear tectonic faults (faults) in the earth’s crust.

Linear volcanoes or fissure-type volcanoes have extensive supply channels associated with a deep split in the crust. As a rule, basaltic liquid magma flows out of such cracks, which, spreading to the sides, forms large lava covers. Along the cracks, gentle spatter shafts, wide flat cones, and lava fields appear. If the magma has a more acidic composition (higher silicon dioxide content in the melt), linear extrusive ridges and massifs are formed. When explosive eruptions occur, explosive ditches can appear tens of kilometers long.

The shapes of central-type volcanoes depend on the composition and viscosity of the magma. Hot and easily mobile basaltic magmas create vast and flat shield volcanoes (Mauna Loa, Hawaiian Islands). If a volcano periodically erupts either lava or pyroclastic material, a cone-shaped layered structure, a stratovolcano, appears. The slopes of such a volcano are usually covered with deep radial ravines - barrancos. Volcanoes of the central type can be purely lava, or formed only by volcanic products - volcanic scoria, tuffs, etc. formations, or be mixed - stratovolcanoes.

There are monogenic and polygenic volcanoes. The former arose as a result of a single eruption, the latter as a result of multiple eruptions. Viscous, acidic in composition, low-temperature magma, squeezed out of the vent, forms extrusive domes (Montagne-Pelé needle, 1902).

In addition to calderas, there are also large negative forms of relief associated with subsidence under the influence of the weight of erupted volcanic material and a pressure deficit at depth that arose during the unloading of the magma chamber. Such structures are called volcanotectonic depressions. Volcanotectonic depressions are very widespread and often accompany the formation of thick strata of ignimbrites - volcanic rocks of acidic composition, having different genesis. They are lava or formed by sintered or welded tuffs. They are characterized by lens-shaped segregations of volcanic glass, pumice, lava, called fiamme, and a tuff or tofo-like structure of the main mass. As a rule, large volumes of ignimbrites are associated with shallow magma chambers formed due to the melting and replacement of host rocks. Negative relief forms associated with central-type volcanoes are represented by calderas - large rounded failures several kilometers in diameter.

Classification of volcanoes by shape

The shape of a volcano depends on the composition of the lava it erupts; Five types of volcanoes are usually considered:

Shield volcanoes, or "shield volcanoes". Formed as a result of repeated ejections of liquid lava. This form is characteristic of volcanoes that erupt low-viscosity basaltic lava: it flows for a long time both from the central vent and from the side craters of the volcano. Lava spreads evenly over many kilometers; Gradually, a wide “shield” with gentle edges is formed from these layers. An example is the Mauna Loa volcano in Hawaii, where lava flows directly into the ocean; its height from its base on the ocean floor is approximately ten kilometers (while the underwater base of the volcano is 120 km long and 50 km wide).
Cinder cones. When such volcanoes erupt, large fragments of porous slag are piled up around the crater in layers in the shape of a cone, and small fragments form sloping slopes at the foot; With each eruption the volcano gets higher. This is the most common type of volcano on land. They are no more than a few hundred meters in height. An example is the Plosky Tolbachik volcano in Kamchatka, which exploded in December 2012.
Stratovolcanoes, or "layered volcanoes". Periodically erupt lava (viscous and thick, quickly solidifying) and pyroclastic matter - a mixture of hot gas, ash and hot stones; as a result, deposits on their cone (sharp, with concave slopes) alternate. Lava from such volcanoes also flows out of cracks, solidifying on the slopes in the form of ribbed corridors that serve as the support of the volcano. Examples - Etna, Vesuvius, Fuji.
Dome volcanoes. They are formed when viscous granite magma, rising from the depths of the volcano, cannot flow down the slopes and hardens at the top, forming a dome. It clogs its mouth, like a cork, which over time is expelled by the gases accumulated under the dome. Such a dome is now forming over the crater of Mount St. Helens in the northwestern United States, formed during the 1980 eruption.
Complex (mixed, composite) volcanoes.

Eruption

Volcanic eruptions are geological emergencies that can lead to natural disasters. The eruption process can last from several hours to many years. Among the various classifications, general types of eruptions are distinguished:

Hawaiian type - emissions of liquid basaltic lava, often forming lava lakes, which should resemble scorching clouds or red-hot avalanches.
Hydroexplosive type - eruptions that occur in shallow conditions of oceans and seas are characterized by the formation of a large amount of steam that occurs when hot magma and sea water come into contact.

Post-volcanic phenomena

After eruptions, when the activity of the volcano either stops forever, or it “dormants” for thousands of years, processes associated with the cooling of the magma chamber and called post-volcanic processes persist on the volcano itself and its surroundings. These include fumaroles, thermal baths, and geysers.

During eruptions, a volcanic structure sometimes collapses with the formation of a caldera - a large depression with a diameter of up to 16 km and a depth of up to 1000 m. As the magma rises, the external pressure weakens, associated gases and liquid products escape to the surface, and a volcanic eruption occurs. If ancient rocks, and not magma, are brought to the surface, and the gases are dominated by water vapor formed when groundwater is heated, then such an eruption is called phreatic.

Lava that rises to the earth's surface does not always reach this surface. It only raises layers of sedimentary rocks and hardens in the form of a compact body (laccolith), forming a unique system of low mountains. In Germany, such systems include the Rhön and Eifel regions. In the latter, another post-volcanic phenomenon is observed in the form of lakes filling the craters of former volcanoes that failed to form a characteristic volcanic cone (the so-called maars).

Heat sources

One of the unresolved problems of volcanic activity is determining the heat source necessary for local melting of the basalt layer or mantle. Such melting must be highly localized, since the passage of seismic waves shows that the crust and upper mantle are usually in a solid state. Moreover, the thermal energy must be sufficient to melt huge volumes of solid material. For example, in the USA in the Columbia River basin (Washington and Oregon states) the volume of basalts is more than 820 thousand km³; the same large strata of basalts are found in Argentina (Patagonia), India (Deccan Plateau) and South Africa (Great Karoo Rise). Currently there are three hypotheses. Some geologists believe that the melting is caused by local high concentrations of radioactive elements, but such concentrations in nature seem unlikely; others suggest that tectonic disturbances in the form of shifts and faults are accompanied by the release of thermal energy. There is another point of view, according to which the upper mantle under conditions of high pressure is in a solid state, and when, due to fracturing, the pressure drops, it melts and liquid lava flows through the cracks.

Areas of volcanic activity

The main areas of volcanic activity are South America, Central America, Java, Melanesia, the Japanese Islands, the Kuril Islands, Kamchatka, the northwestern part of the USA, Alaska, the Hawaiian Islands, the Aleutian Islands, Iceland, and the Atlantic Ocean.

Mud volcanoes

Mud volcanoes are small volcanoes through which it is not magma that comes to the surface, but liquid mud and gases from the earth's crust. Mud volcanoes are much smaller in size than ordinary ones. Mud typically comes to the surface cold, but the gases emitted by mud volcanoes often contain methane and can ignite during the eruption, creating what looks like a miniature volcano eruption.

In our country, mud volcanoes are most common on the Taman Peninsula; they are also found in Siberia, near the Caspian Sea and in Kamchatka. On the territory of other CIS countries, the most mud volcanoes are in Azerbaijan; they are found in Georgia and Crimea.

Volcanoes on other planets

Volcanoes in culture

Painting by Karl Bryullov “The Last Day of Pompeii”;
Movies "Volcano", "Dante's Peak" and a scene from the film "2012".
The volcano near the Eyjafjallajökull glacier in Iceland during its eruption became the subject of a huge number of humorous programs, television news stories, reports and folk art discussing events in the world.

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For many uninitiated people, volcanoes seem like something fantastic and incomprehensibly menacing. In order to get a more complete picture of these objects, we present interesting facts about volcanoes.

The only volcanic rock floating on the surface of the water is volcanic pumice. Characterized by its gray color, this stone is riddled with hollow holes formed when the stone cooled. This process was accompanied by the release of gases, which formed the holes.

Eruptions of the largest volcanoes, called supervolcanoes, often cause horrific consequences. This includes the rain of fire that rains down for many miles around the volcano itself, and global climate changes caused by ash entering the atmosphere. Fortunately, such volcanoes erupt on average several times every 100,000 years. Scientists say that one of them, located in Yellowstone National Park, is in all likelihood ready for another eruption.

The largest eruption observed is considered to be the activity of the Tambora volcano on the Indonesian island of Sumbawa. The eruption killed 100,000 people. According to researchers, Indonesia has the largest number of historically active volcanoes. There are 76 of them in total.

Most volcanoes appear at the boundaries of tectonic plates that form the earth's surface. Other volcanoes, such as Yellowstone, are located in other “hot spots” with magma bursting from the depths of the earth.

Iceland, also called the land of fire and ice, is blessed by nature with the largest number of volcanoes in a region called the "mid-Atlantic ridge". The recent eruption of Eyjafjallajoku, which shocked many, was incomparably weaker than the explosion of Skaptar, which caused terrible damage to the island's food supplies and caused a famine that led to the death of twenty percent of the population.

Citing interesting facts about volcanoes, one cannot help but talk about the dire consequences of the 1991 eruption of Mount Pinatubo in the Philippines. As a result of the volcano's release of 22 million tons of sulfur compounds into the planet's atmosphere, the temperature dropped by 0.5 degrees.

The ability of volcanoes to grow is interesting - accumulating lava and ash increase its height.

Volcanoes are called extinct when scientists believe that they will no longer erupt. Volcanoes with activity that has subsided for a while are said to be dormant.

If during a volcanic eruption the walls holding back the lava are destroyed, a huge crater appears, called a caldera.

Kelimutu Volcano, located in Indonesia, has three unusual lakes at its summit. The water in each of them periodically acquires different colors - turquoise, green, black or red. These transformations are caused by the reaction of volcanic gases entering into a chemical reaction with various minerals that are dissolved in water. This is what causes the change in color of the lakes.

Mauna Loa in Hawaii is considered the highest volcano on Earth. Its height is 4 thousand meters above sea level. There are five volcanoes on this island.

Volcanic eruptions release small ash particles into the atmosphere that can scatter the sun's rays. This gives the atmosphere coral and orange hues and adds color to the sunsets.

Most of the islands in the Atlantic Ocean were formed as a result of volcanic activity.

Among the attractions of the island of Lanzarote from the Canary Islands is a restaurant with the sonorous name El Diablo (translated from Spanish as “the devil”). The chefs of this restaurant prepare food directly above the mouth of an active volcano. Note that its temperature exceeds 400 °C.

Scientists classify the Indonesian archipelago as a part of the earth's crust that is in the process of formation. At the same time, some islands gradually or unexpectedly emerge from the depths of the sea, while others plunge into it. This is a consequence of frequent earthquakes, the effects of a large number of active volcanoes, as well as the growth of coral reefs. Such changes require frequent amendments to the Indonesia map.

Located on the island of Kiu Shiu in Japan, the volcano called Aso is the largest volcano in the world. The crater of the volcano is 14 kilometers wide, 23 kilometers long and 500 meters deep.

The eruption frequency of the Izalco volcano in El Salvador is 8 minutes. Over the two hundred years of activity of the volcano, over 12 million eruptions occurred.

Interesting video. Volcano of Fear: