home Roach How do volcanoes work? Formation, structure and types of volcanoes

How do volcanoes work? Formation, structure and types of volcanoes

A simple short answer to the question of what volcanoes are is the following: volcanoes are mountains with internal channels (volcanic vents), through which, during an eruption, hot magma is ejected from the bowels of the earth to the surface.

How volcanoes form

The globe is structured in such a way that under the solid crust there is a layer of molten rocks (magma), and under great pressure. When cracks appear in the Earth’s crust (and hills form on the earth’s surface in this place), the magma under pressure in them rushes and comes to the surface of the earth, breaking up into hot lava (500-1200°C), caustic volcanic gases and ash.. Spreading The lava hardens and the volcanic mountain increases in size.

The resulting volcano becomes a vulnerable place in the earth’s crust; even after the end of the eruption, inside it (in the crater) gases constantly come out of the earth’s bowels to the surface (the volcano “smokes”), and with any slightest shifts or shocks in the earth’s crust, such a “dormant” volcano can wake up any time. Sometimes a volcano awakens without obvious reasons. Such volcanoes are called active.

This is a very simplified explanation of what volcanoes are and how they form, but it describes the essence of the phenomenon. The largest active volcano in Russia and the entire Eurasian continent is the Klyuchevskaya Sopka volcano located on the Kamchatka Peninsula (its height is 4750 meters above sea level).

DIY volcano model made from salt dough. Master class with step-by-step photos.

Kushnareva Tatyana Nikolaevna - geography teacher, Secondary School No. 9, Azov, Rostov Region.
Target: Making a model of a volcano from salt dough using the testoplasty technique.
Tasks:
1. Contribute to the formation of a scientific picture of the world, an initial understanding of the types of volcanoes.
2. Develop children's creative research activity.
3. Cultivate interest in cognitive and research activities, determination, perseverance, and independence.

In my work, I invite you to find out whether it is possible to make a volcano at home and look at this dangerous, but it seems to me a very beautiful phenomenon - a volcanic eruption. Schoolchildren aged 10-13, as well as preschool children, can demonstrate their ability to create an artificial volcano.
Technique: Testoplasty, it seems to me, is very well suited for the implementation of my idea.
Purpose: A model for research activities - experiments, as well as use as a visual aid for fixing the external and internal structure of the volcano.

"I spit fire and lava,
I am a dangerous giant
I am famous for my bad fame,
What is my name?" (Vulcan)

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.
Word "Volcano" comes from the name of the ancient Roman god of fire Vulcan. Translated from Latin - the god of fire and blacksmithing.

Probably, of all the possible natural disasters that threaten humans, volcanic eruptions are the most dramatic, if not in terms of the number of victims and destruction, then in the sense of horror and helplessness that grips people in the face of the raging elements generated by the fiery bowels of the planet.
The volcano is a fantastic sight. In a matter of minutes, it can devastate entire cities, kill thousands of people, destroy landscapes and even change the Earth's climate.
Scientists estimate that about 500 million people live near volcanoes today.
Since 1700, volcanic eruptions have killed more than 260,000 people. People will not be able to prevent mass deaths unless they learn to understand and respect volcanoes.
Externally, volcanoes differ from each other; the most common types of volcanoes are conical and shield. Shield volcanoes are wide, flat volcanoes ranging in diameter from a few kilometers to over 100 km, and are usually low and wide. The volcano was formed as a result of repeated outpourings of high-temperature liquid lava.
In this master class I propose to make a conical volcano.
Conical volcano. The slopes of the volcano are steep - the lava is thick, viscous, and cools quite quickly. The mountain has the shape of a cone.

Materials:
Colored paper;
PVA glue";
Vinegar;
Soda;
Scissors;
Flour;
Gouache paints;
Brush;
Sheet of cardboard;
Glass cup.

Step-by-step job description

1. First we need to prepare the salt dough to make the Vulcan Model. To prepare salt dough, we need 400 g. flour, 200 gr. fine salt and 150 ml. water.

2. The dough is ready, you can start working.

3. To make the base of the Layout, we need to prepare a square of green colored paper 20/20 cm and a sheet of cardboard 20/20 cm

4. Apply PVA glue to the cardboard

5. The base of the Vulcan Model is ready

6. Place the dough on the base, make a hole in the center and place a glass cup in it, which will act as a muzzle.

7. Shape the Layout. We need a day for the dough to dry. You can speed up the drying process by placing the mock-up in the oven for 20 minutes, alternating sides.

8. Let’s start painting the layout, using gouache paints. Apply paint layer by layer. We cover the lower part of the slope with green color.

9.Add a few light tones of green paint.

10. Cover the middle and upper part of the slope of the model with brown paint.

11. It is necessary to let the paint dry before applying flowing lava to the Vulcan model using red gouache.

12. The Vulcan model is ready for the experiment

13. For experimental activities, we will need vinegar and soda tinted with red gouache in a small amount.

14. We pour soda into the mouth of the model, and then pour in tinted vinegar. Volcanism begins!

15. We observe how lava flows down the slope.

In the course of research activities, it was confirmed that it is possible to create an artificial volcano through experimental activities.

Volcanoes began to "volcano" -
Emit lava from a vent.
Lava flowed down the slopes
And it burned the Earth badly. (Elena Romankevich)
Thanks everyone for your attention!

Undoubtedly, active volcanoes in the world are one of the most fascinating and beautiful and at the same time terrifying natural phenomena. These geological formations played a key role in the formation of the Earth. Thousands of years ago there were a huge number of them throughout the planet.

Today there are few volcanoes that are still active. Some of them frighten, delight and at the same time destroy entire settlements. Let's figure out where the most famous active volcanoes are located.

Llullaillaco

A typical stratovolcano (has a layered, conical shape) with a height of 6739 m. It is located on the border of Chile and Argentina.

Such a complex name can be interpreted in different ways:

“water that cannot be found despite long searches”;
"a soft mass that becomes hard."

On the side of the Chilean state, at the foot of the volcano, there is a National Park with the same name - Llullaillaco, so the surroundings of the mountain are very picturesque. While climbing to the top, tourists encounter donkeys, many species of birds and guanacos living in natural conditions.

There are two routes to get to the crater:

northern – duration 4.6 km, the road is suitable for traveling by car;
southern – duration 5 km.

If you plan to walk, take special shoes and an ice ax with you, as there are snowy areas along the way.

Interesting fact! During the first ascent in 1952, an ancient Incan repository was discovered on the mountain, and in 1999, the mummies of a girl and a boy were found near the crater. According to scientists, they became ritual victims.

The most powerful eruptions were recorded three times - in 1854 and 1866. The last eruption of an active volcano occurred in 1877.

San Pedro

The 6,145-meter-high giant is located in the Andes, in northern Chile near Bolivia on the Western Cordillera. The peak of the volcano rises above the longest body of water in Chile - Loa.

San Pedro is on the list of the highest active volcanoes. It was possible to climb to the crater for the first time in 1903. Today it is a unique attraction of Chile, which attracts thousands of tourists from different parts of the world. In the 20th century, the volcano reminded itself of itself 7 times, the last time in 1960. For more than half a century, San Pedro has resembled a bubbling cauldron that could explode at any moment. At the foot there are signs that warn that climbing to the crater is only possible with a mask that protects against toxic emissions.

Interesting:

San Pedro is one of the few giant volcanoes that has remained active to this day. Many giants are considered extinct.
San Pedro's neighbor is the San Pablo volcano. It is located to the east and its height is 6150 m. The two mountains are connected by a high saddle.
Residents of Chile tell many legends associated with the San Pedro volcano, since each eruption in the past was considered a heavenly sign and had mystical significance.
For the descendants of migrants from Spain and local indigenous residents, the volcano is a source of constant and considerable income.

El Misti

Among all the active volcanoes in the world on the map, this one is rightfully considered the most beautiful. Its peak is sometimes snow-covered. The mountain is located near the city of Arequipa, its height is 5822 meters. The volcano is notable for the fact that at its summit there are two craters with diameters of almost 1 km and 550 m.

There are unusual parabolic dunes on the slopes. They were the result of constant winds between El Misti and Mount Cerro Tacune, and they stretch for 20 km.

The first active action of the volcano was recorded during the migration of Europeans to Latin America. The most severe, destructive disaster occurred in 1438. In the 20th century, the volcano showed varying degrees of activity several times:

In 1948 for six months;
in 1959;
steam emissions were observed in 1985.

Scientists in Peru concluded several years ago that the seismic activity of the volcano is gradually increasing. This leads to earthquakes, which are not uncommon in this area. Considering that El Misti is located near a large settlement in Peru, this makes it a rather dangerous active volcano.

Popocatepetl

Located in Mexico, the highest point reaches 5500 m above sea level. It is the second highest mountain peak in the state.

The Aztecs believed that worshiping the volcano would bring rain, so they regularly brought offerings here.

Popocatépetl is dangerous because many cities are built around it:

the capitals of the states of Puebla and Tlaxcal;
the cities of Mexico City and Cholula.

According to scientists, the volcano has erupted more than three dozen times over its history. The last eruption was recorded in May 2013. During the disaster, the airport in Puebla was closed and the streets were covered in ash. Despite the hidden danger, thousands of tourists from around the world come to the volcano every year to admire the scenery, listen to the legend and enjoy the grandeur of the mountain.

Volcano Sangay

Sangay rightfully belongs to the top ten active volcanoes, which are the most powerful in the world. The mountain is located in South America, its height is 5230 meters. Translated, the name of the volcano means “fear-inspiring” and this fully reflects its behavior - eruptions are frequent here, and sometimes stones weighing 1 ton fall from the sky. At the top of the mountain, covered with eternal snow, there are three craters with a diameter of 50 to 100 meters.

The age of the volcano is about 14 thousand years; the giant has been particularly active in recent decades. One of the most destructive activities was recorded in 2006; the eruption lasted more than a year.

The first ascent took almost 1 month, today tourists travel comfortably by car, and people cover the final stretch of the journey on mules. The journey takes several days. In general, the journey is assessed as quite difficult, so few people decide to climb to the crater. Tourists who conquer the mountain smell a strong sulfur smell and are surrounded by smoke. As a reward, an amazing landscape opens up from the top.

The volcano is surrounded by the Sangay National Park, whose area is more than 500 hectares. In 1992, UNESCO added the park to its list of endangered sites. However, in 2005 the object was removed from the list.

Interesting fact! The park area contains the three highest volcanoes of Ecuador - Sangay, Tungurahua and El Altar.

Klyuchevskaya Sopka

The volcano is the highest on the Eurasian continent - 4750 meters, and its age is more than 7 thousand years. Klyuchevskaya Sopka is located in the central part of Kamchatka; there are several other volcanoes nearby. The height of the giant increases after each eruption. There are more than 80 side craters on the slopes, so several lava flows are formed during an eruption.

The volcano is one of the most active in the world and makes itself known regularly, approximately once every 3-5 years. The duration of each activity reaches several months. The first happened in 1737. Throughout 2016, the volcano was active 55 times.

The most serious disaster was recorded in 1938, its duration was 13 months. As a result of the cataclysm, a 5 km long crack was formed. In 1945, the eruption was accompanied by a serious rockfall. And in 1974, the active actions of Klyuchevskaya Sopka led to the explosion of the glacier.

During the 1984-1987 eruption, a new peak was formed, and ash emissions rose 15 km. In 2002, the volcano became active; the greatest activity was recorded in 2005 and 2009. By 2010, the height of the mountain exceeded 5 km. In the spring of 2016, another eruption occurred over several weeks, accompanied by earthquakes, lava flows and ash emissions to a height of up to 11 km.

Mauna Loa

The eruption of this huge volcano can be observed from anywhere in Hawaii. Mauna Loa is located in an archipelago formed as a result of volcanic activity. Its height is 4169 meters. The peculiarity is that the crater is not round, so the distance from one edge to the other varies between 3-5 km. Residents of the island call the mountain Long.

On a note! Many tour guides on the island take tourists to the Mauna Kea volcano. It is indeed slightly higher than Mauna Loa, but unlike the latter, it is already extinct. Therefore, be sure to specify which volcano you want to see.

Mauna Loa is 700 thousand years old, of which 300 thousand it was under water. The activity of the volcano began to be recorded only in the first half of the 19th century. During this time, he reminded himself more than 30 times. With each eruption, the size of the giant increases.

The most devastating disasters occurred in 1926 and 1950. The volcano destroyed several villages and a city. And the eruption in 1935 was reminiscent of the plot of the legendary Soviet film “Crew”. The last activity was recorded in 1984; lava poured out of the crater for 3 weeks. Several earthquakes occurred in 2013, indicating that the volcano may soon show what it can do again.

We can say that scientists are showing the greatest interest in Mauna Loa. According to seismologists, the volcano (one of the few in the world) will continuously erupt for another million years.

Cameroon

Located in the republic of the same name, on the shores of the Gulf of Guinea. This is the highest point of the state - 4040 meters. The foot of the mountain and its lower part are covered with tropical forests, there is no vegetation at the top, and there is a small amount of snow.

In West Africa, it is the most active volcano of all active on the mainland. Over the past century, the giant has manifested itself 8 times. Each eruption resembles an explosion. The first mention of the disaster dates back to the 5th century BC. In 1922, volcanic lava reached the Atlantic coast. The last eruption occurred in 2000.

Good to know! The optimal time for climbing is December or January. In February, an annual competition is held here - “Race of Hope”. Thousands of participants climb to the top, competing in speed.

Kerinci

The highest volcano in Indonesia (its height reaches 3 km 800 meters) and the highest point in Sumatra. Located in the central part of the island, south of the city of Padang. Not far from the volcano there is Keinchi Seblat Park, which has national status.

The depth of the crater is more than 600 meters; there is a lake in its northeastern part. A strong eruption was recorded in 2004, when a column of ash and smoke rose 1 km. The last serious disaster was recorded in 2009, and in 2011 the activity of the volcano was felt in the form of characteristic tremors.

In the summer of 2013, the volcano emitted a column of ash 800 meters high. Residents of nearby settlements hastily packed their things and evacuated. The ash colored the sky gray, and the smell of sulfur was in the air. Only 30 minutes passed, and several villages were covered in a thick layer of ash. Tea plantations, which are located near the volcano and were also damaged as a result of the disaster, raised concerns. Fortunately, heavy rain fell after the event, and the consequences of the eruption were washed away.

This is interesting! The climb to the crater takes 2 to 3 days. The route is laid through dense forests, most often the road is slippery. To overcome the path, you will need the help of a guide. There have been cases in history when travelers disappeared while setting out on their own. The best place to start your climb is in the village of Kersik Tua.

Erebus

Active volcanoes on every continent (except Australia) attract the attention of scientists and tourists. Even in Antarctica there is one of them - Erebus. This volcano is located south of other objects that are the object of research by seismologists. The height of the mountain is 3 km 794 m, and the size of the crater is a little more than 800 m.

The volcano has been active since the end of the last century, when a station was opened in the state of New Mexico, its employees monitor its activities. A unique phenomenon of Erebus is the lava lake.

The object is named after the god Erebus. The mountain is located in a fault zone, which is why the volcano is recognized as one of the most active in the world. The gases released cause serious damage to the ozone layer. Scientists note that this is where the thinnest layer of ozone is.

Volcanic eruptions occur in the form of explosions; the lava is thick, hardens quickly and does not have time to spread over large areas.

The main danger is ash, which makes air travel difficult because visibility is sharply reduced. A mud flow is also dangerous, as it moves at high speed, and it is almost impossible to escape from it.

Erebus is an amazing natural creation - menacing, magical and enchanting. The lake in the crater attracts with special mystery.

Etna

Located in Sicily, in the Mediterranean Sea. With a height of 3329 meters, it cannot be classified as the highest active volcano in the world, but it can confidently be considered one of the most active. After each eruption, the height increases slightly. This is the largest volcano in Europe; its top is always decorated with a snow cap. The volcano has 4 central cones and about 400 side cones.

The first activity dates back to 1226 BC. The most terrible eruption occurred in 44 BC, it was so strong that ash completely covered the sky over the capital of Italy and destroyed crops on the Mediterranean coast. Today Etna is no less dangerous than in prehistoric times. The last eruption occurred in the spring of 2008 and lasted almost 420 days.

The volcano is attractive for its diverse vegetation; here you can find palm trees, cacti, pine trees, agaves, spruce trees, biscus trees, fruit trees and vineyards. Some plants are characteristic only of Etna - stone tree, ethnian violet. Numerous myths and legends are associated with the volcano and the mountain.

Kilauea

On the territory of the Hawaiian Islands, this is the most active volcano (although far from the highest in the world). In Hawaiian, Kilauea means highly spreading. Eruptions have occurred continuously since 1983.

The volcano is located on the territory of the Volcanoes National Park, its height is only 1 km 247 meters, but it compensates for its insignificant growth with activity. Kilauea appeared 25 thousand years ago; the diameter of the volcano’s caldera is considered one of the largest in the world - about 4.5 km.

Interesting! According to legend, the volcano is the residence of the goddess Pele (goddess of volcanoes). Her tears are individual drops of lava, and her hair is rivulets of lava.

An amazing sight is the Puuoo lava lake, which is located in the crater. Molten rocks bubble restlessly, creating amazing stains on the surface. Being near this natural phenomenon is dangerous, as fiery lava erupts to a height of 500 meters.

In addition to the lake, you can admire a natural cave here. Its length is more than 60 km. The ceiling of the cave is decorated with stalactites. Tourists note that walking through the cave is reminiscent of flying to the moon.

In 1990, volcanic lava completely destroyed the village; the thickness of the lava layer ranged from 15 to 25 meters. Over the course of 25 years, the volcano destroyed almost 130 houses, destroyed 15 km of road surfaces, and lava covered an area of 120 km.

The whole world watched the powerful eruption of Kilauea in 2014. The eruption was accompanied by periodic earthquakes. Huge volumes of lava destroyed residential buildings and working farms. Evacuation of nearby settlements was carried out, but not all residents showed a desire to leave their homes.

Which continent has no active volcanoes?

There are no extinct or active volcanoes in Australia. This is explained by the fact that the continent is located far from crustal faults and volcanic lava does not have access to the surface.

The opposite of Australia is Japan - the country is located in the most dangerous tectonic zone. Here 4 tectonic plates collide.

On August 24, 79, people looked at their patron in horror and could not understand why they had angered the gods so much. How did it happen that their protector suddenly began to spew out flames that spread across the ground and destroyed everything in its path? The residents of Pompeii already knew: unexpectedly for everyone, the volcano woke up. What it is, what volcanoes are like and why they suddenly wake up, we will look at today in this article.

What is a volcano?

A volcano is a kind of formation on the surface of the earth's crust, which from time to time is capable of erupting pyroclastic flows (a mixture of ash, gas and stones), volcanic gases, and lava. It is in areas of volcanic activity that opportunities for using geothermal energy open up.

Types of volcanoes

Scientists have adopted a classification of volcanoes into active, dormant and extinct.

Active volcanoes are those that erupt during a historical period of time. It is thanks to them that one can understand what a volcano is and the mechanisms that make it act, because direct observation of the process provides much more information than the most thorough excavations.
Dormant volcanoes are called dormant volcanoes that are currently inactive, however, there is a high probability of their awakening.
Extinct volcanoes include those that were active in the past, but today the probability of their eruption is zero.

What shapes do volcanoes come in?

If you ask a schoolchild what shape a volcano has, he will undoubtedly say that it looks like a mountain. And he will be right. The volcano actually has the shape of a cone, which was formed during its eruption.

The volcanic cone has a vent - this is a kind of outlet channel through which lava rises during an eruption. Quite often there is more than one such channel. It may have several branches that serve to bring volcanic gases to the surface. The vent always ends in a crater. It is into this that all materials are thrown out during an eruption. A curious fact is that the vent is open only during the period of volcanic activity. The rest of the time it is closed, until the next manifestation of activity.

The time during which the volcanic cone formed varies individually. It mainly depends on how much material the volcano releases during its eruption. Some require 10 thousand years to do this, others can form it in one eruption.

Sometimes the opposite processes also happen. During an eruption, the volcanic cone collapses, and in its place a large depression is formed - a caldera. The depth of such a depression is at least one kilometer, and the diameter can reach 16 km.

Why do volcanoes erupt?

We figured out what a volcano is, but why does it erupt?

As you know, our planet does not consist of a single piece of rock. It has its own structure. On top is a thin, hard “shell” that scientists call the lithosphere. Its thickness is only 1% of the radius of the globe. In practice, this means from 80 to 20 kilometers, depending on whether it is land or the bottom of the oceans.

Beneath the lithosphere is a layer of mantle. Its temperature is so high that the mantle is constantly in a liquid, or rather viscous, state. At the center is the solid core of the earth.

As a result of the fact that lithospheric plates are in constant motion, magma chambers can arise. When they break out to the surface of the earth's crust, a volcanic eruption begins.

What is magma?

Here, it is probably necessary to explain what magma is and what chambers it can form.

Being in constant motion (albeit invisible to the naked human eye), lithospheric plates can collide or creep onto each other. Most often, slabs whose dimensions are larger “win” those whose thickness is smaller. Therefore, the latter are forced to plunge into the boiling mantle, the temperature of which can reach several thousand degrees. Naturally, at this temperature the plate begins to melt. This molten rock with gases and water vapor is called magma. Its structure is more fluid than the mantle, and also lighter.

How does a volcano erupt?

Thanks to these structural features of magma, it begins to slowly rise and accumulate in places called foci. Most often, such centers become places where the earth's crust breaks.

Gradually, magma occupies all the free space of the source and, for lack of any other way out, begins to rise through cracks in the earth’s crust. If magma finds a weak spot, it does not miss the opportunity to break out to the surface. In this case, thin sections of the earth's crust are broken through. This is how a volcano erupts.

Places of volcanic activity

So what places on the planet, given volcanic activity, can be considered the most dangerous? Where are the most dangerous volcanoes in the world located? Let's find out...

Merapi (Indonesia). This is the largest volcano in Indonesia, and also the most active. It does not allow local residents to forget about itself, even for one day, constantly releasing smoke from its crater. At the same time, small eruptions occur every two years. But you don’t have to wait long for big ones either: they happen once every 7-8 years.
If you want to know where volcanoes are, you should probably take a trip to Japan. This is truly a “paradise” of volcanic activity. Take, for example, Sakurajima. Since 1955, this volcano has constantly disturbed local residents. Its activity shows no sign of decreasing, and the last major eruption occurred not so long ago - in 2009. A hundred years ago, the volcano had its own island, but thanks to the lava that it erupted from itself, it was able to connect with the Osumi Peninsula.
Aso. And again Japan. This country is constantly suffering from volcanic activity, and the Aso volcano is proof of this. In 2011, an ash cloud appeared above it, the area of which was more than 100 kilometers. Since that time, scientists have constantly recorded tremors, which can indicate only one thing: the Aso volcano is ready for a new eruption.
Etna. This is the largest volcano in Italy, which is interesting because it has not only a main crater, but also many small ones located along its slope. In addition, Etna is distinguished by enviable activity - small eruptions occur every two to three months. It must be said that the Sicilians have long been accustomed to such a neighborhood, and are not afraid to populate the slopes.
Vesuvius. The legendary volcano is almost half the size of its Italian brother, but this does not prevent it from setting many of its own records. For example, Vesuvius is exactly the volcano that destroyed Pompeii. However, this is not the only city that has suffered from his activities. According to scientists, Vesuvius more than 80 times destroyed cities that were not lucky enough to be close to its slopes. The last major eruption occurred in 1944.

Which volcano on the planet can be called the highest?

Among the named volcanoes there are quite a lot of record holders. But which one can bear the title “The highest volcano on the planet”?

It is necessary to take into account: when we say “the highest,” we do not mean the height of the volcano above the surrounding area. We are talking about the absolute altitude above sea level.

Thus, scientists call the Chilean Ojos del Salado the highest active volcano in the world. For a long time he was classified as sleeping. This status of the Chilean allowed the Argentinean Llullaillaco to bear the title “The highest volcano in the world.” However, in 1993, Ojos del Salado produced an ash release. After that, it was carefully examined by scientists who managed to discover fumaroles (steam and gas outlets) in its crater. Thus, the Chilean changed his status, and, without knowing it, brought relief to many schoolchildren and teachers, for whom it is not always easy to pronounce the name Llullaillaco.

To be fair, Ojos del Salado does not have a high volcanic cone. It rises above the surface only 2000 meters. While the relative height of the Llullaillaco volcano is almost 2.5 kilometers. However, it is not for us to argue with scientists.

The whole truth about the Yellowstone volcano

You cannot boast that you know what a volcano is if you have never heard of Yellowstone, which is located in the USA. What do we know about him?

First of all, Yellowstone is not a tall volcano, but for some reason it is called a supervolcano. What's the matter here? And why was Yellowstone discovered only in the 60s of the last century, and even then with the help of satellites?

The fact is that the Yellowstone cone collapsed after its eruption, resulting in the formation of a caldera. Considering its gigantic size (150 km), it is no wonder that people could not see it from Earth. But the collapse of the crater does not mean that the volcano can be reclassified as dormant.

There is still a huge chamber of magma under the Yellowstone crater. According to scientists' calculations, its temperature exceeds 800 °C. Thanks to this, many thermal springs were formed in Yellowstone, and, in addition, jets of steam, hydrogen sulfide and carbon dioxide constantly come to the surface of the earth.

Not much is known about the eruptions of this volcano. Scientists believe that there were only three of them: 2.1 million, 1.27 million and 640 thousand years ago. Considering the frequency of eruptions, we can conclude that we may witness the following. It must be said that if this really happens, the Earth will face the next Ice Age.

What troubles do volcanoes bring?

Even if we do not take into account the fact that Yellowstone can suddenly wake up, the eruptions that other volcanoes in the world can prepare for us also cannot be called harmless. They cause enormous destruction, especially if the eruption happened suddenly and there was no time to warn or evacuate the population.

The danger is not only lava, which can destroy everything in its path and cause fires. Don’t forget about toxic gases that spread over vast areas. In addition, the eruption is accompanied by emissions of ash, which can cover vast areas.

What to do if the volcano “comes to life”?

So, if you find yourself at the wrong time and in the wrong place when a volcano suddenly wakes up, what should you do in such a situation?

First of all, you need to know that the speed of the lava is not that high, only 40 km/h, so it is quite possible to escape, or rather, drive away from it. This must be done in the shortest way, that is, perpendicular to its movement. If this is not possible for some reason, you need to look for shelter on a hill. It is also necessary to take into account the likelihood of a fire, therefore, if possible, it is necessary to clear the shelter of ash and hot debris.

In open areas, a body of water can save you, although much depends on its depth and the force with which the volcano erupts. Photos taken after the eruption show that people often find themselves defenseless before such a powerful force.

If you are one of the lucky ones and your house survived the eruption, be prepared to spend at least a week there.

And most importantly, do not trust those who say that “this volcano has been sleeping for thousands of years.” As practice shows, any volcano can wake up (photos of destruction confirm this), but there is not always someone to tell about it.

In this lesson we will learn what volcanoes are, how they are formed, we will get acquainted with the types of volcanoes and their internal structure.

Topic: Earth

Volcanism- a set of phenomena caused by the penetration of magma from the depths of the Earth to its surface.

The word "volcano" comes from the name of one of the ancient Roman gods - the god of fire and blacksmithing - Vulcan. The ancient Romans believed that this god had a forge underground. As Vulcan begins to work in his forge, smoke and flames erupt from the crater. In honor of this god, the Romans named the island and the mountain on the island in the Tyrrhenian Sea - Vulcano. And later all fire-breathing mountains began to be called volcanoes.

The globe is structured in such a way that under the solid crust there is a layer of molten rocks (magma), and under great pressure. When cracks appear in the Earth's crust (and hills form on the earth's surface in this place), the magma under pressure in them rushes and comes to the surface of the earth, breaking up into hot lava (500-1200 ° C), caustic volcanic gases and ash. The spreading lava hardens, and the volcanic mountain increases in size.

Rice. 2. The structure of the volcano ()

Volcano crater- a cup-shaped or funnel-shaped depression on the top or slope of a volcanic cone. The diameter of the crater can be from tens of meters to several kilometers and the depth from several meters to hundreds of meters. At the bottom of the crater there are one or more vents through which lava and other volcanic products rise from the magma chamber through the outlet channel to the surface. Sometimes the crater floor is covered by a lava lake or a small newly formed volcanic cone.

Volcano mouth- a vertical or almost vertical channel connecting the center of a volcano with the surface of the earth, where the vent ends in a crater. The shape of the vents of lava volcanoes is close to cylindrical.

Magma hotspot- a place under the earth's crust where magma collects.

Lava- erupted magma.

Types of volcanoes (according to the degree of their activity).

Active - which erupt, and information about this in the memory of mankind. There are 800 of them.

Extinct - no information about the eruption has been preserved.

Those who have fallen asleep are those who have gone out and suddenly begin to act.

According to their shape, volcanoes are divided into conical and panel.

The slopes of the conical volcano are steep, the lava is thick, viscous, and cools quite quickly. The mountain has the shape of a cone.

Rice. 3. Conical volcano ()

The slopes of a shield volcano are gentle, very hot and liquid lava spreads quickly over considerable distances and cools slowly.

Rice. 4. Shield volcano ()

A geyser is a source that periodically releases a fountain of hot water and steam. Geysers are one of the manifestations of the later stages of volcanism and are common in areas of modern volcanic activity.

A mud volcano is a geological formation that is a hole or depression on the surface of the earth, or a cone-shaped elevation with a crater, from which mud masses and gases, often accompanied by water and oil, constantly or periodically erupt onto the surface of the Earth.

Rice. 6. Mud volcano ()

- a lump or piece of lava ejected during a volcanic eruption in a liquid or plastic state from a vent and obtained a specific shape when squeezed out, during flight and solidification in air.

Rice. 7. Volcanic bomb ()

An underwater volcano is a type of volcano. These volcanoes are located on the ocean floor.

Most modern volcanoes are located within three main volcanic belts: Pacific, Mediterranean-Indonesian and Atlantic. As evidenced by the results of studying the geological past of our planet, underwater volcanoes are significantly larger than volcanoes on land in terms of their scale and volume of ejection products coming from the bowels of the Earth. Scientists believe that this is the main source of tsunamis on Earth.

Rice. 8. Underwater volcano ()

Klyuchevskaya Sopka (Klyuchevskoy volcano) is an active stratovolcano in the east of Kamchatka. With a height of 4850 m, it is the highest active volcano on the Eurasian continent. The age of the volcano is approximately 7000 years.

Rice. 9. Volcano Klyuchevskaya Sopka ()

1. Melchakov L.F., Skatnik M.N. Natural history: textbook. for 3.5 grades avg. school - 8th ed. - M.: Education, 1992. - 240 pp.: ill.

2. Bakhchieva O.A., Klyuchnikova N.M., Pyatunina S.K. and others. Natural history 5. - M.: Educational literature.

3. Eskov K.Yu. and others. Natural history 5 / Ed. Vakhrusheva A.A. - M.: Balass.

3. The most famous volcanoes on Earth ().

1. Tell us about the structure of the volcano.

2. How are volcanoes formed?

3. How is lava different from magma?

4. * Prepare a short report about one of the volcanoes of our country.