The most famous and largest volcanoes in the world. The structure of volcanoes

Translated from Latin "volcano" means "flame, fire". In the bowels of the planet, due to the very high temperature, rocks are melted with the formation of magma. In this case, a huge amount of gaseous substances is released, which increases the volume of the melt and its pressure on the surrounding solid rocks. Magma rushes to areas with less pressure upward towards the Earth's surface. Cracks in the earth's crust are filled with heated liquid rocks, layers of the earth's crust are torn and rise. Partially, magma solidifies in the earth's crust with the formation of igneous veins and laccoliths. The rest of the hot magma comes to the surface during volcanic eruptions, in the form of lava, volcanic ash, gases, hardened lava ingots, rock fragments. The term "volcanism" refers to the movement of molten magma from the deep layers of the Earth to the land surface or the ocean floor.

In the structure of each volcano, a channel is distinguished through which lava moves. This so-called vent usually ends in a crater - a funnel-shaped extension. The diameter of the craters varies from hundreds of meters to several kilometers. For example, the diameter of the Vesuvius crater is more than 0.5 km. Excessively large craters are called calderas. Thus, the caldera of the Uzon volcano, which is located in Kamchatka, has a diameter of 30 km.

Lava and eruptions

The height and shape of volcanoes is determined by the viscosity of the lava. If the lava is liquid and drains quickly, a cone-shaped mountain will not form, such as the Kilauza volcano in the Hawaiian Islands. The crater of this volcano looks like a rounded lake with a diameter of about 1 km. The crater is filled with hot liquid lava, and its level at times rises, then falls, sometimes splashing over the edge.

Most volcanoes are characterized by viscous lava, which, when cooled, forms a volcanic cone. The structure of such a cone is usually layered. On this basis, it can be judged that the eruptions were carried out repeatedly, due to which the volcano grew gradually with each ejection of lava.

The height of volcanic cones is different and can range from tens of meters to several kilometers. A very high volcano in the Andes - Aconcagua (6960 m) is widely known.

There are about 1,500 volcanoes all over the Earth, among them there are both active and extinct. For example, Klyuchevskaya Sopka in Kamchatka, Elbrus in the Caucasus, Kilimanjaro in Africa, Fujiyama in Japan, etc.

The vast majority of active volcanoes are located along the perimeter Pacific Ocean. They make up the Pacific Ring of Fire. The Mediterranean-Indonesian belt is also considered a zone of active volcanism. For example, there are 28 active volcanoes in Kamchatka, and there are more than 600 in total. There is a certain regularity in the location of active volcanoes. They are localized in mobile areas of the earth's crust - in seismic belts.

In the ancient geological epochs of our planet, volcanism was more active than at present. In addition to typical (central) eruptions, fissure eruptions were also noted. From huge faults in the earth's crust, tens and hundreds of kilometers long, bubbling lava was thrown to the surface. In this case, the formation of lava covers, both continuous and discontinuous, took place. These covers leveled the terrain. The thickness of the lava layer could reach 2 km. Such processes led to the formation of lava plains. These include some sections of the Central Siberian Plateau, the Armenian Highlands, the Deccan Plateau in India, and the Columbia Plateau.

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On August 24, 79, people looked in horror at their patron and could not understand: why did they anger the gods so much. How did it happen that their protector suddenly began to spew fire that spread across the ground and destroyed everything in its path? The inhabitants of Pompeii already knew: unexpectedly for everyone, a volcano woke up. What is it, what are volcanoes and why do they suddenly wake up, we will consider 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 spewing pyroclastic flows (a mixture of ash, gas and stones), volcanic gases, and also lava. It is in zones of volcanic activity that opportunities for the use of geothermal energy open up.

Types of volcanoes

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

1. Volcanoes that erupt during a historical period of time are called active volcanoes. It is thanks to them that one can understand what a volcano is and the mechanisms that make it work, because direct observation of the process provides much more information than the most thorough excavations.
2. Sleeping volcanoes are called, which are currently not active, however, there is a high probability of their awakening.
3. Extinct volcanoes include those that were active in the past, but today the probability of their eruption is equal to zero.

What shape are volcanoes?

If you ask a schoolboy what shape a volcano has, he will undoubtedly say that it looks like a mountain. And he will be right. The volcano really has the shape of a cone, which 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 crater always ends in a crater. It is into it that all materials are thrown during the eruption. An interesting fact is that the mouth is open only during the active period of the volcano. The rest of the time it is closed, until the next manifestation of activity.

The time during which a volcanic cone formed is individual. Basically, it depends on how much material the volcano throws out during its eruption. Some take 10,000 years to do so, while others can form it in a single eruption.

Sometimes the opposite happens as well. During an eruption, the volcanic cone collapses, and a large depression, the caldera, forms in its place. The depth of such a depression is at least one kilometer, and the diameter can reach 16 km.

Why do volcanoes erupt?

What is a volcano, we figured it out, but why does it erupt?

As you know, our planet does not consist of whole piece stone. It has its own structure. Above - a thin solid "shell", which scientists call the lithosphere. Its thickness is only 1% of the radius the globe. In practice, this means between 80 and 20 kilometers, depending on whether it is land or the bottom of the oceans.

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

As a result of the fact that the 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, perhaps, it is necessary to explain what magma is and what chambers it can form.

Being in constant motion (albeit invisible to the naked eye of a person), lithospheric plates can collide or crawl into each other. Most often, the plates, the dimensions of which are larger, "win" those whose thickness is less. Therefore, the latter are forced to sink 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. In its structure, it is more liquid than the mantle, and also lighter.

How does a volcano erupt?

Due to the named features of the magma structure, it begins to slowly rise and accumulate in places called foci. Most often, such foci are places of a break in the earth's crust.

Gradually, magma occupies all the free space of the hearth and, in the absence of another way out, begins to rise along cracks in the earth's crust. If magma finds a weak point, it does not miss the opportunity to break out to the surface. At the same time, thin sections of the earth's crust break 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 figure it out...

1. Merapi (Indonesia). It is the largest volcano in Indonesia and also the most active. He does not let the locals forget about him even for one day, constantly releasing smoke from his crater. At the same time, small eruptions occur every two years. But large ones do not have to wait long: they happen every 7-8 years.
2. If you want to know where the 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 been a constant concern for the locals. Its activity does not even think 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 he spewed out of himself, he managed to connect with the Osumi Peninsula.
3. Aso. And Japan again. This country is constantly suffering from volcanic activity, and the Aso volcano is proof of this. In 2011, an ash cloud appeared over it, the area of ​​\u200b\u200bwhich was more than 100 kilometers. Since that time, scientists have been constantly recording tremors, which can only indicate one thing: the Aso volcano is ready for a new eruption.
4. Etna. This is the largest volcano in Italy, which is interesting in that it has not only the 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.
5. Vesuvius. The legendary volcano is almost half the size of its Italian brother, but this does not prevent him from setting many of his own records. Vesuvius, for example, is the volcano that destroyed Pompeii. However, this is not the only city that has suffered from his activity. According to scientists, Vesuvius destroyed cities that were not lucky enough to be close to its slopes more than 80 times. The last major eruption happened in 1944.

Which volcano on the planet can be called the highest?

There are quite a few record holders among these volcanoes. But what can bear the title "The highest volcano on the planet"?

Keep in mind: when we say "highest", we do not mean the height of the volcano above the surrounding area. It's about about the absolute altitude above sea level.

So, scientists call the Chilean Ojos del Salado the highest active volcano in the world. For a long time he was referred to as sleeping. This status of the Chilean allowed the Argentinean Lullaillaco to bear the title of "The Highest Volcano in the World". However, in 1993, Ojos del Salado produced an ash ejection. After that, he was carefully examined by scientists who managed to find fumaroles (outlets of steam and gas) in his mouth. 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.

For the sake of justice, it must be said that Ojos del Salado does not have a high volcanic cone. It rises above the surface only 2000 meters. While the relative height of the Lullaillaco volcano is almost 2.5 kilometers. However, it is not for us to argue with scientists.

The Truth About 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 high volcano, but for some reason it is called a supervolcano. What is the matter here? And why was it possible to discover Yellowstone only in the 60s of the last century, and even then with the help of satellites?

The fact is that the cone of Yellowstone collapsed after its eruption, resulting in the formation of a caldera. Given 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 magma chamber under the Yellowstone crater. According to the calculations of scientists, its temperature exceeds 800 ° C. Thanks to this, many thermal springs have formed in Yellowstone, and, in addition, jets of steam, hydrogen sulfide and carbon dioxide constantly come out 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. Given the frequency of eruptions, we can conclude that we may witness the following. I must say that if this really happens, the Earth will face the next Ice Age.

What troubles do volcanoes bring?

Even if you 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 cannot be called harmless either. They lead to huge 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. Do not forget about the poisonous gases that spread over vast areas. In addition, the eruption is accompanied by ash emissions, which can cover vast areas.

What to do if the volcano "comes to life"?

So, if you were at the wrong time and in the wrong place when the volcano suddenly woke up, what to do in such a situation?

First of all, you need to know that the speed of the lava is not that great, only 40 km / h, so it is quite possible to run away, or rather, leave 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 seek shelter on a hill. It is necessary to take into account the likelihood of a fire, therefore, if possible, it is necessary to clean the shelter from ash and incandescent debris.

On the open area a body of water can save you, although much depends on its depth and the force with which the volcano erupts. The photos that were taken after the eruption show that a person is often defenseless in front of such a powerful force.

If you were among 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 the destruction confirm this), but there is not always someone to tell about it.

A report about volcanoes, geological formations on the surface of the crust, in which magma comes to the surface and forms volcanic gases, lava, stones.

Message about volcanoes

What is a volcano?

From the Latin word "volcano" means fire, flame. In the bowels of the Earth under the influence high temperatures there is a melting of rocks with magmatic formation. During this process, a large amount of gaseous substances are released. The volume of the melt and the pressure on solid rocks increase significantly. Magma begins to move towards areas of lower pressure up to the surface. Cracks in the earth's crust begin to fill with mountain liquid rocks, and, bursting, raise entire layers of the crust.

Magma can partially lag, forming laccoliths and magma veins. Another part during volcanic eruptions comes to the surface in the form of volcanic ash, lava, gases, rock fragments and lava ingots.

Types of volcanoes

These geological formations are of 2 types:

• Fissure

They do not rise above the surface of the Earth high enough. Fissure volcanoes are fissures from which magma flows to the surface. But there are very few of them on the planet.

• Central

They are a cone of great height, from which magma and lava come out during eruptions. Such a volcano has a vent (magma flows through it) and craters (a hole from which magma comes to the surface).

Volcanoes are also divided into extinct, active and dormant. Dormant volcanoes this moment do not erupt, although local earthquakes constantly occur under them. And extinct means that there is no volcanic activity.

How many volcanoes are on Earth?

There are 1500 volcanoes on the planet, both active and extinct. The most famous of them are Klyuchevskaya Sopka (Kamchatka), Elbrus (Caucasus), Kilimanjaro (Africa), Fujiyama (Japan).

Most of them are located along the perimeter of the Pacific Ocean. They form the so-called "ring of fire". The most active volcanic zone is the Mediterranean-Indonesian belt. The eruption of volcanoes is carried out according to a certain pattern - their placement in seismic areas, mobile areas.

• The largest volcano on the planet is Mauna Loa. It occupies almost the entire part of the Hawaiian island and is the most active.

Famous volcanic eruptions in history: interesting facts

• (Italy). The eruption occurred on August 24, 79. It destroyed the city of Pompeii, covering it with an 8 m layer of dust, as well as Herculaneum and Stabiae. Ashes of Vesuvius flew to Syria and Egypt. Today it is the only active volcano in Europe. In total, more than 80 eruptions have been recorded. The last one was in 1944.
• Tambora (Sumbawa Island). The eruption occurred on April 5, 1815. V modern history this is the largest eruption in terms of the volume of ejected material and the number of deaths. He completely destroyed the Tambora culture, which Europeans had discovered shortly before. The volcano erupted for 10 days and decreased by 1400 m in height. It covered an area of ​​500 km with ashes, and for 3 days the sun did not show through it.
• Volcano Taupo (New Zealand). The eruption occurred 27 thousand years ago, and scientists consider it the most powerful in the history of the planet. As a result of his vigorous activity, Lake Taupo was formed. The volcano last erupted in 180 AD. e. Its blast wave and ash destroyed half of the North Island. 100 km 3 of tectonic matter was thrown into the atmosphere.
• Volcano Krakatau (Indonesia). The eruption occurred on August 27, 1883. It caused a 30-meter tsunami that washed away 295 towns and villages. Pieces of lava flew to a height of 55 km. Ashes covered an area of ​​5330 km. The blast wave circled the planet up to 11 times. The Krakatoa explosion was 200,000 times more powerful than the Hiroshima explosion. Scientists suggest that he previously woke up in 535 and from his activities, the islands of Sumatra and Java may have formed. After the eruption of 1883, the Krakatoa volcano collapsed. And in its place in 1927 a new active volcano appeared - Anak Krakatoa.
• Volcano Santorini (Greece). The eruption occurred 1.5 thousand years BC. And it destroyed the Cretan civilization, and also contributed to the sinking of the island of Thera. This is not his only eruption. In 1886, for a whole year, he spewed pieces of lava directly from the sea to a height of 500 meters.
• Volcano Montagne Pele (Martinique). The eruption began in April 1902. Already on May 8, he covered the city with dust, located in an 8-kilometer zone from him. Near Martinique, the seabed sank a couple of hundred meters.
• Volcano Nevado del Ruiz (Colombia). The eruption began on November 13, 1985, and in just 10 minutes the city of Armero with a population of 29,000 people was destroyed.
• Mount Pinatubo (Philippines). For a long 622 years, it was considered extinct. But on June 12, 1991, he destroyed 18 km of territory along himself. The consequence of such a catastrophe is a decrease in temperature and a decrease in the ozone layer, which contributed to the formation of a large ozone hole.
• Volcano Katmai (Alaska). Its eruption on June 6, 1912 was the largest in the history of the twentieth century.

We hope that the report about volcanoes for children helped you prepare for the lesson. And you can leave your message about volcanoes through the comment form below.

All tourists and travelers are interested in learning about the largest volcano in the world. A volcano is a formation on the surface of the Earth, from which magma comes out, forming lava, stones and volcanic gases. There are a huge number of such formations on our planet. Some of them are considered active, as they were active in the historical period.

Many of the volcanoes are extinct and dormant. The latter include those whose eruption is already unlikely, while the former have the possibility of manifestation of activity. Some volcanoes reach incredible sizes and are distinguished by their extraordinary power and beauty.

Of great interest to all travelers are, of course, active volcanoes. They are extraordinarily beautiful and fascinate with their danger of eruption at any moment. Having seen such a phenomenon once, a person receives a lot of incredible impressions that remain in memory for a lifetime. Llullaillaco is considered the highest active volcano in the world. It is located in Argentina in the Peruvian Andes. The height of its peak is 6739 m. The last time the eruption occurred in 1877.

At the top of this volcano is eternal glaciation. It is shaped like a cone. This natural formation has been considered an archaeological site since 1999, as human mummies were found on its top. These were the children of the Incas. There is a possibility that they were sacrificed about 500 years ago.

Mauna Loa Volcano

In terms of volume, Mauna Loa is considered the largest active volcano. The height of its summit is 4169 m, and the volume is estimated at 75,000 km. It is located on the island of Hawaii in the United States. The last time the eruption occurred relatively recently - in 1984.

This volcano, more precisely, its summit and southeastern slope, is part of national park Hawaiian volcanoes. This park is included in famous List UNESCO World Heritage Site. Mauna Loa is home to animals and plants called endemics. This means that they have a small habitat. Very often, such animals are considered rare, therefore they are listed in the Red Book.

Dangerous volcano Merapi

The most dangerous volcano in the world is Merapi. It is located in Indonesia on the island of Java. Large eruptions occur every 7 years. Small eruptions happen 2 times a year. This mountain destroyed many settlements. Back in 1006, he wiped out the Javanese-Indian kingdom from the face of the Earth, and in 1673 one of the most destructive eruptions occurred. It destroyed several cities and villages at once, which were located at the foot.

In 1930, the volcano also caused major damage. This eruption killed 1,300 people. After 44 years, Merapi destroyed 2 villages, and a year later - another village, 5 bridges, killing 29 people. Moreover, the eruptions overtook many scientists and tourists. The last action of the Merapi volcano was recorded in 2010. This time around 350,000 people were initially evacuated. Some residents did return. Among them, 353 people died, who fell into the flow of volcanic gases, ash and stones.

Volcano with the strongest eruption in history

This is an active volcano, which in the 19th century demonstrated the strongest eruption. The volcano is located in Indonesia. Now its height is 813 m. Before its famous eruption in 1883, it was much higher. Moreover, it was one big island. During the strongest action of the volcano, the main part of the island was destroyed.

The rumble from the eruption was heard even 5000 km from the volcano itself. The volcanic edifice spread over 500 km. The ash rose 30 km, and the gas-ash column - 70 km. Scientists estimated the strength of the explosion at 6 points. The result of such a strong eruption was 37,000 dead and 300 destroyed villages.

There are a lot of different volcanoes in the world, which differ either in their height, or volume, or actions. Some of them are the most dangerous or the oldest. Scientists have not yet compiled an accurate list of volcanoes by their size or degree of danger. Each of them is interesting and unique in its own way. There are volcanoes that are known to every traveler and tourist. The most popular of them are Vesuvius, Fujiyama, Etna. These are the active volcanoes of the world.

Vesuvius has been attracting tourists for many years. Those who visit Naples usually do not miss the opportunity to admire and even climb this famous volcano. Previously, it was possible to climb the mountain using a funicular, and then a regular lift. However, the transport was destroyed by the next eruptions. They did not begin to restore it, so at the moment you can climb the mountain only on foot along a hiking trail.

Mount Fuji located on the Japanese island of Honshu. It is a popular tourist destination. Residents consider it sacred. The mountain is also a place of religious pilgrimage for Buddhist and Shinto cults. A temple was built on top of it. In addition, there is a weather station and even a post office. Scientists believe that Fuji is a weakly active volcano, since the last eruptions occurred at the beginning of the 18th century.

A popular volcano located in Italy is. It has many craters, from time to time at least one of them erupts lava. Sometimes the actions of Etna are destructive in relation to the nearest settlements, but, despite this, new residents do not stop settling here. At the foot of the mountain fertile soil which allows you to grow various vegetables and fruits.

Tourists have the opportunity to visit this extraordinary mountain. It must be climbed on foot. The tourist base can be reached by bus. For lovers of souvenirs, there are shops on the mountain itself where you can buy some kind of souvenir or even a popular 70-degree liquor.

All these and many other volcanoes are extraordinarily beautiful and interesting for residents, travelers and tourists. Each mountain has its own history. Before climbing any volcano, it is necessary to find out the exact information about its activity and the possibility of an eruption, since such natural formations can begin their actions at any moment. Therefore, having decided to admire the extraordinary beauty of volcanoes, protect yourself from accidents.

A volcanic eruption is a spectacle that boggles the imagination. This makes the volcano an interesting object of study. What is a volcano? A volcano is a geological formation on the surface of the earth through which red-hot magma comes out. Magma that has come to the surface forms lava, stones, volcanic gases. The volcano itself usually looks like a mountain, inside of which there is a break in the earth's crust. Now volcanoes still continue to form, but much less frequently than before.

What is a volcano made of?

The volcano consists of two main parts - the vent and the crater. The mouth of a volcano is the mouth through which magma comes to the surface. The depression at the top of the mountain, to which the vent leads, is called a crater.

What is a volcanic eruption?

Volcanoes appear in unstable, seismically active places on the planet, where there is movement underground slabs and cracks form in the earth's crust. A liquid, red-hot, molten mixture of rocks (magma) from the depths of our planet accumulates inside and is gradually squeezed out. Magma comes out under great pressure and sooner or later breaks through the mouth of the volcano. During a volcanic eruption, a huge amount of ash and smoke is released into the air, clods of lava and stones fly, often the eruption is accompanied by an earthquake.

Types of volcanoes

Not all volcanoes erupt equally intensely. Depending on their activity, they can be active, dormant and dormant. Those volcanoes are considered active, the eruption of which is possible in the foreseeable future, extinct - those whose eruption is unlikely, dormant ones are no longer able to erupt. Also in science, there are many types of volcanic eruptions based on the spread of lava, smoke and ash.