There are volcanoes. What is the difference between linear volcanoes and central ones. When did the most famous volcanic eruptions occur?

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 are Great chance their awakenings.
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 a single piece of stone. It has its own structure. Above - a thin solid "shell", which scientists call the lithosphere. Its thickness is only 1% of the radius of 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 peace? 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 constantly disturbing local residents. 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 own island, however, thanks to the lava that he spewed from 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 most big volcano 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. This is the absolute height 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, 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.

In open areas, 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.

Volcanic eruptions in the minds of people have always given rise to catastrophic associations...

Boiling red-hot lava, boundless clouds of volcanic ash eclipsing the Sun, dying people and entire cities are the plot of many paintings, books and films. Today, volcanoes "with a bad reputation", which continue to erupt, are popular with tourists, lovers thrill. We will talk about the five most famous active volcanoes on Earth.

Vesuvius

On the conscience of this relatively low (1300 meters above sea level) volcano on the shores of the picturesque Gulf of Naples are two destroyed ancient Roman cities, Pompeii and Herculaneum.

In the memory of the Italians, Vesuvius erupted several times, the last time - in 1944. Eruptions have always been accompanied by destruction and casualties, in 1805 even the city of Naples was destroyed. However, the area around the volcano is densely populated - volcanic ash fertilizes the ground.

Krakatoa

The only one famous volcanoes, who managed to revive after he destroyed himself. In 1883, the most destructive eruption in the history of mankind occurred the Krakatoa volcano, located on the island of the same name between Java and Sumatra.

In the sea, 295 Indonesian cities and villages were washed away by a tsunami wave, killing 35 thousand people. Was destroyed and the island of Krakatau, and the volcano itself. However, in 1927, the volcano broke through the ocean and announced itself with a new eruption. The new volcano was named Anak-Krakatau, it is believed that it has a serious impact on the climate of the entire Earth. The last activity of the Krakatoa volcano was observed in 2014.

Fujiyama

The Japanese have a peculiar attitude towards Fujiyama, they do not experience mortal horror, rather the opposite. Followers of the Shinto religion consider Fujiyama a shrine, a symbol of the immortality of the soul, and even built a temple on its top, next to post office and meteorological station. Fujiyama, along with tourists from all over the world, is visited annually by thousands of Shinto pilgrims.

Hekla

Since then, there have been about three dozen significant eruptions. All - completely different from one another and unpredictable. Some are short, a few days, others can last for months. And the eruption, which began in March 1947, ended only in April 1948. Icelanders believe that the longer the “hibernation” of the volcano lasts, the more catastrophic the consequences of the earthquake will be.

Klyuchevskaya Sopka

Outside the Caucasus, Klyuchevskaya Sopka is the highest mountain in Russia (4800 meters). And the highest active volcano on the Eurasian continent. Klyuchevskaya Sopka is the most active of the 29 active volcanoes in Kamchatka. last eruption happened in 2013.

Despite the restless and unpredictable nature of the volcano, climbers and mountain tourists often climb Klyuchevskaya Sopka. The volcano also attracts tourists with an amazing natural phenomenon - lenticular clouds. Large white clouds hang over the crater of Klyuchevskoy Sopka and remain motionless even with very strong winds.

It is difficult to find a person who at least once would not take an interest in volcanoes. Most of them read books about them, with bated breath watched footage from the sites of eruptions, at the same time admiring the power and splendor of the elements and rejoicing that this does not happen next to them. Volcanoes are something that leaves no one indifferent. So what is it?

The structure of the volcano

Volcanoes are special geological formations that arise when the hot substance of the mantle rises from the depths and comes to the surface. Magma rises up the cracks and faults in the earth's crust. Where it breaks out, active volcanoes form. This occurs at the boundaries of lithospheric plates, where faults arise due to their separation or collision. And the plates themselves are involved in movement when the mantle substance moves.

Most often, volcanoes look like conical mountains or hills. In their structure, a vent is clearly distinguished - a channel through which magma rises, and a crater - a depression at the top through which an outpouring of lava occurs. The volcanic cone itself consists of many layers of products of activity: solidified lava, and ash.

Since the eruption is accompanied by the release of hot gases, glowing even during the day, and ash, volcanoes are often called "fire-breathing mountains." In ancient times, they were considered gates to the underworld. And they got the name in honor of the ancient Roman It was believed that fire and smoke fly from his underground forge. Such interesting facts about volcanoes fuel the curiosity of a variety of people.

Types of volcanoes

The existing division into active and extinct is very conditional. active volcanoes are those that erupted in the memory of mankind. There are eyewitness accounts of these events. There are a lot of active volcanoes in the areas of modern mountain building. These are, for example, Kamchatka, the island of Iceland, East Africa, Andes, Cordillera.

Extinct volcanoes are those that have not erupted for thousands of years. In the memory of people, information about their activity was not preserved. But there are many cases when a volcano, which was considered inactive for a long time, suddenly woke up and brought a lot of troubles. The most famous of them is the famous eruption of Vesuvius in 79, glorified by Bryullov's painting The Last Day of Pompeii. 5 years before this catastrophe, rebels hid on its top. And the mountain was covered with lush vegetation.

The extinct volcanoes include Mount Elbrus - the highest peak in Russia. Its two-headed top consists of two cones merged at the bases.

Volcanic eruption as a geological process

An eruption is the process of ejection to the earth's surface of incandescent magmatic products in a solid, liquid and gaseous state. For each volcano it is individual. Sometimes the eruption is quite calm, liquid lava pours out in streams and flows down the slopes. It does not interfere with the gradual release of gases, so strong explosions do not occur.

This type of eruption is typical for Kilauea. This volcano in Hawaii is considered one of the most active in the world. With a diameter of about 4.5 km, its crater is also the largest in the world.

If the lava is thick, it plugs up the crater from time to time. As a result, the released gases, finding no way out, accumulate in the vent of the volcano. When the gas pressure becomes very high, powerful explosion. It lifts large volumes of lava into the air, which subsequently falls to the ground in the form of volcanic bombs, sand and ash.

The most famous explosive volcanoes are the already mentioned Vesuvius, Katmai in North America.

But the most powerful explosion, which led to a cooling around the world due to volcanic clouds, through which the sun's rays could hardly break through, occurred in 1883. Then I lost most of it. A column of gas and ash rose up to 70 km in the air. The contact of ocean water with red-hot magma led to the formation of a tsunami up to 30 m high. In general, about 37 thousand people became victims of the eruption.

Modern volcanoes

It is believed that now in the world there are more than 500 active volcanoes. Most of them belong to the zone of the Pacific "ring of fire", located along the boundaries of the lithospheric plate of the same name. Every year there are about 50 eruptions. At least half a billion people live in their zone of activity.

Volcanoes of Kamchatka

One of the most famous areas of modern volcanism is located on the Russian Far East. This is an area of ​​modern mountain building, belonging to the Pacific Ring of Fire. Volcanoes of Kamchatka included in the list world heritage UNESCO. They are of great interest not only as objects of scientific research, but also as natural monuments.

It is here that the highest active volcano in Eurasia is located - Klyuchevskaya Sopka. Its height is 4750 m. Plosky Tolbachik, Mutnovskaya Sopka, Gorely, Vilyuchinsky, Gorny Tooth, Avachinsky Sopka and others are also widely known for their activity. In total, there are 28 active volcanoes in Kamchatka and about half a thousand extinct ones. But here are some interesting facts. Much is known about the volcanoes of Kamchatka. But along with this, the region is known for a much rarer phenomenon - geysers.

These are sources that periodically throw out fountains of boiling water and steam. Their activity is connected with magma that has risen along cracks in the earth's crust close to the earth's surface and heats groundwater.

The famous Valley of Geysers, located here, was discovered in 1941 by T. I. Ustinova. It is considered to be one of the wonders of nature. The area of ​​the Valley of Geysers is no more than 7 sq. km, but there are 20 large geysers and dozens of springs with boiling water. The largest geyser, the Giant, throws out a column of water and steam to a height of about 30 m!

Which volcano is the tallest?

It is not so easy to determine this. Firstly, the height of active volcanoes can increase with each eruption due to the growth of a new layer of rocks or decrease due to explosions destroying the cone.

Secondly, a volcano that was considered extinct may wake up. If it is high enough, it can push back the already existing leader.

Thirdly, where to calculate the height of the volcano - from the base or from sea level? This gives completely different numbers. After all, the cone, which has the highest absolute height, may not be the largest in comparison with the surrounding area, and vice versa.

Currently, among the active volcanoes, Lluillaillaco is considered the largest in South America. Its height is 6723 m. But many volcanologists believe that Cotopaxi, located on the same mainland, can claim the title of the greatest. Let it have a lower height - “only” 5897 m, but on the other hand, its last eruption was in 1942, and at Lluillaillaco - already in 1877.

The Hawaiian Mauna Loa can also be considered the highest volcano on Earth. Although its absolute height is 4169 m, this is less than half of its true value. The cone of Mauna Loa starts from the very ocean floor and rises more than 9 km. That is, its height from the sole to the top exceeds the dimensions of the Chomolungma!

mud volcanoes

Has anyone heard about the Valley of Volcanoes in Crimea? After all, it is very difficult to imagine this peninsula shrouded in the smoke of eruptions, and the beaches filled with red-hot lava. But do not worry, because we are talking about mud volcanoes.

This is not such a rare occurrence in nature. mud volcanoes- this is a semblance of real ones, but they do not throw out lava, but streams of liquid and semi-liquid mud. The cause of eruptions is the accumulation in underground cavities and cracks of a large amount of gases, most often hydrocarbons. The pressure of the gas powers the volcano, tall pole mud sometimes rises to several tens of meters, and the ignition of gas and explosions give the eruption a rather formidable appearance.

The process can continue for several days, accompanied by a local earthquake, underground rumble. As a result, a low cone of solidified mud is formed.

Areas of mud volcanism

In Crimea, such volcanoes are found on Kerch Peninsula. The most famous of them is Dzhau-Tepe, which greatly frightened the locals with its short eruption (only 14 minutes) in 1914. A column of liquid mud was thrown 60 m up. The length of the mud stream reached 500 m with a width of more than 100 m. But such large eruptions are rather an exception.

The areas of action of mud volcanoes often coincide with oil and gas production sites. In Russia they are found on Taman Peninsula, on Sakhalin. From neighboring countries Azerbaijan is "rich" in them.

In 2007, the volcano became more active, flooding a vast territory with its mud, including many buildings. According to local population, this was due to the drilling of a well that disturbed deep layers of rocks.

Edinburgh Castle in Scotland erected on top extinct volcano. And most Scots don't even know it.

It turns out that volcanoes can be actors! In the film "The Last Samurai" in the role sacred mountain Japanese Fujiyama was made by Taranaki, considered the most beautiful in New Zealand. The fact is that the surroundings of Fuji with its urban landscapes were in no way suitable for filming a picture about the events of the late 19th century.

In general, New Zealand volcanoes do not have to complain about the inattention of filmmakers. After all, Ruapehu and Tongariro became famous largely thanks to the film "The Lord of the Rings", in which Orodruin was depicted, in the flame of which the Ring of Omnipotence was created and subsequently destroyed in the same place. The lone mountain in Erebor in The Hobbit movie is also one of the local volcanoes.

And the Kamchatka geysers and waterfalls became the backdrop for the filming of the film "Sannikov Land".

The eruption of Mount St. Helens (USA) in 1980 is considered the most powerful in the entire 20th century. The explosion, in its power equal to 500 bombs dropped on Hiroshima, fell ashes on the territory of four states.

Eyyafyadlayokudl became famous for throwing ash and smoke into chaos air traffic European countries spring 2010. And its name has baffled hundreds of radio and television announcers.

The Philippine volcano Pinatubo last erupted in 1991. At the same time, two American military bases were destroyed. And after 20 years, the Pinatubo crater was filled with rainwater, forming an amazingly beautiful lake, the slopes of the volcano were overgrown with tropical vegetation. This made it possible for travel agencies to organize a vacation with swimming in the volcanic lake.

Eruptions often produce interesting rocks. For example, the lightest stone is pumice. Numerous air bubbles make it lighter than water. Or "Pele's hair" found in Hawaii. They are long thin strands of rock. Many buildings in the capital of Armenia, Yerevan, are built of pink volcanic tuff, which gives the city a unique flavor.

Volcanoes are a formidable and majestic phenomenon. Interest in them is caused by fear, curiosity, and a thirst for new knowledge. It is not for nothing that they are called windows to the underworld. But there are purely utilitarian interests. For example, volcanic soils are very fertile, which makes people settle near them for centuries, despite the danger.

Volcanoes are geological formations on the Earth's surface where magma comes out in the form of lava. These mountains are not only on Earth, but also on other planets. So, the Olympus volcano on Mars reaches a height of several tens of kilometers. Such formations are dangerous not only with lava, but also with the release of a large amount of dust and ash into the atmosphere.

eruption Icelandic volcano Eyyafjallayekul in 2010 made a lot of noise. Although it was not the most destructive in terms of strength, its proximity to Europe led to the impact of emissions on transport system mainland. However, history knows many other cases of the destructive effects of volcanoes. Let's talk about the ten most famous and large-scale of them.

Vesuvius, Italy. On August 24, 79, the volcano Vesuvius erupted, which destroyed not only the well-known city of Pompeii, but also the cities of Stabiae and Herculaneum. Ashes even reached Egypt and Syria. It would be a mistake to assume that the catastrophe destroyed Pompeii alive, out of 20 thousand people, only 2 thousand died. Among the victims was the famous scientist Pliny the Elder, who approached the volcano on a ship in order to explore it and thus found himself practically at the epicenter of the disaster. During the excavations of Pompeii, it was found that under a multi-meter layer of ash, the life of the city froze at the time of the disaster - objects, houses with furnishings remained in their places, people and animals were found. Today, Vesuvius remains the only active volcano on the continental part of Europe, more than 80 of its eruptions are known in total, the very first one supposedly happened 9 thousand years ago, and the last one took place in 1944. Then the cities of Massa and San Sebastiano were destroyed, and 57 people died. Naples is located 15 kilometers from Vesuvius, the height of the mountain is 1281 meters.

Tambora, Sumbawa Island. The cataclysm on this Indonesian island happened on April 5, 1815. This is the largest number dead people and by the amount of material released into modern history eruption. The catastrophe associated with the eruption and the ensuing famine killed 92,000 people. In addition, the Tambora culture, which Europeans had only met shortly before, completely disappeared from the face of the earth. The volcano lived for 10 days, decreasing during this time in height by 1400 meters. Ashes for 3 days hid the territory within a radius of 500 kilometers from the sun. According to the testimony of the British authorities in those days in Indonesia, it was impossible to see anything at arm's length. Most of Sumbawa Island was covered with a meter layer of ash, under the weight of which even stone houses crumbled. 150-180 cubic kilometers of gases and pyroclassics were thrown into the atmosphere. The volcano therefore had a strong impact on the climate of the entire planet - ash clouds poorly transmitted the rays of the Sun, which led to a noticeable decrease in temperature. 1816 became known as "the year without summer", in Europe and America the snow melted only in June, and the first frosts appeared already in August. The result was massive crop failures and famine.

Taupo, New Zealand. 27 thousand years ago, a strong volcanic eruption occurred on one of the islands, surpassing even Tamboru in strength. Geologists consider this cataclysm the last such force in the history of the planet. As a result of the work of the supervolcano, Lake Taupo was formed, which today is the object of attention of tourists, as it is very beautiful. The last eruption of the giant took place in 180 AD. The ash and the blast destroyed half of all life on the North Island, about 100 cubic kilometers of tectonic matter fell into the atmosphere. The speed of the rock eruption was 700 km/h. The ash that rose into the sky painted sunsets and sunrises all over the world with purple, which was reflected in the ancient Roman and Chinese chronicles.

Krakatau, Indonesia. The volcano, located between the islands of Sumatra and Java, produced on August 27, 1883 the largest explosion of its kind in modern history. During the cataclysm, a tsunami up to 30 meters high appeared, which simply washed away 295 villages and cities, while about 37 thousand people died. The roar from the explosion was heard on 8% of the entire surface of the planet, and pieces of lava were thrown into the air to an unprecedented height of 55 kilometers. The wind carried the volcanic ash so much that after 10 days it was found at a distance of 5330 kilometers from the scene. The mountain-island then split into 3 small parts. The wave from the explosion circled the earth from 7 to 11 times, geologists believe that the explosion was 200 thousand times stronger than the nuclear strike on Hiroshima. Krakatau woke up before, so, in 535, his activity significantly changed the climate of the planet, perhaps then the islands of Java and Sumatra were divided. On the site of the volcano destroyed in 1883, during an underwater eruption in 1927, a new volcano, Anak Krakatau, which is still quite active today. Its height is now 300 meters due to new activities.

Santorini, Greece. Approximately one and a half thousand years BC, a volcanic eruption occurred on the island of Thera, which put an end to the entire Cretan civilization. Sulfur covered all the fields, which made further farming unthinkable. According to some versions, it is Thera that is the very Atlantis described by Plato. Someone also believes that the eruption of Santorini entered the annals, like a pillar of fire seen by Moses, and the parted sea is nothing more than the consequences of the disappearance of the island of Thera under water. However, the volcano continued its activity, in 1886 its eruption lasted whole year, while pieces of lava flew straight out of the sea and rose to a height of 500 meters. As a result - several new islands nearby.

Etna, Sicily. About 200 eruptions of this Italian volcano are known. Among them were quite powerful ones, so, in 1169, about 15 thousand people died during the cataclysm. Today, Etna remains an active volcano with a height of 3329 meters, waking up about once every 150 years and destroying one of the nearby villages. Why don't people leave the slopes of the mountain? The fact is that the frozen lava helps the soil to become more fertile, which is why the Sicilians settle here. In 1928, besides, a miracle happened - the flow of red-hot lava stopped in front of the Catholic procession. This inspired the believers so much that in 1930 a chapel was erected on this site, 30 years later the lava stopped in front of it. The Italians protect these places, so in 1981 the local government created a reserve around Etna. It is curious that a blues music festival is even arranged on a calm volcano. Etna is quite large, exceeding the size of Vesuvius by 2.5 times. The volcano has from 200 to 400 side craters, lava erupts from one of them every three months.

Montagne Pele, Martinique island. The volcanic eruption on the island began in April 1902, and on May 8 a whole cloud of vapors, gases and red-hot lava hit the city of Saint-Pierre, located 8 kilometers away. A few minutes later he was gone, and of the 17 ships that were in the harbor at that moment, only one managed to survive. The ship "Roddam" escaped from the clutches of the elements with broken masts, smoking and littered with ashes. Of the 28 thousand inhabitants of the city, two escaped, one of them was called Opost Siparis, and he was sentenced to death. He was saved by the thick stone walls of the prison. Subsequently, the prisoner was pardoned by the governor, spending the rest of his life traveling the world with stories about what happened. The force of the blow was such that the monument on the square, weighing several tons, was thrown aside, and the heat was such that even the bottles melted. It is interesting that the outpouring of liquid lava did not directly occur, the impact was caused by vapors, gases and pulverized lava. Later, a sharp lava plug 375 meters high came out of the crater of the volcano. It also turned out that the bottom of the sea near Martinique had sunk several hundred meters. The city of Saint-Pierre, by the way, became famous for the birth of Napoleon's wife, Josephine Beauharnais, in it.

Nevado del Ruiz, Colombia. A volcano 5400 meters high, located in the Andes, splashed out lava flows on November 13, 1985, and the main blow fell on the city of Armero, located 50 kilometers away. It took only 10 minutes for the lava to destroy it. The death toll exceeded 21 thousand people, and in total at that time about 29 thousand lived in Armero. Sadly, no one listened to the volcanologists' information about the impending eruption, since the specialists' information was repeatedly not confirmed.

Pinatubo, Philippines. Until June 12, 1991, the volcano was considered extinct for 611 years. The first signs of activity appeared in April and the Philippine authorities managed to evacuate all residents within a radius of 20 kilometers. The eruption itself claimed the lives of 875 people, while the US naval base and the US strategic air base, located 18 kilometers from Pinatubo, were destroyed. The ejected ash covered an area of ​​125,000 km2 of the sky. The consequences of the disaster were a general decrease in temperature by half a degree and a reduction in the ozone layer, due to which a very large ozone hole formed over Antarctica. The height of the volcano before the eruption was 1486 meters, and after - 1745 meters. At the site of Pinatubo, a crater with a diameter of 2.5 kilometers was formed. Today, earthquakes regularly occur in this area, preventing any construction within a radius of tens of kilometers.

Katmai, Alaska. The eruption of this volcano on June 6, 1912 was one of the largest in the 20th century. The height of the ash column was 20 kilometers, and the sound reached the capital of Alaska, the city of Juneau, located 1200 kilometers away. At a distance of 4 kilometers from the epicenter, the ash layer reached 20 meters. Summer in Alaska turned out to be very cold, as the rays could not break through the cloud. After all, thirty billion tons of rocks were taken into the air! In the crater itself, a lake with a diameter of 1.5 kilometers formed, and it became the main attraction of the Katmai National Park and Reserve formed here in 1980. Today, the height of this active volcano is 2047 meters, and the last known eruption occurred in 1921.

VOLCANOES
individual elevations above channels and cracks in the earth's crust, along which eruption products are brought to the surface from deep magma chambers. Volcanoes usually have the shape of a cone with a summit crater (several to hundreds of meters deep and up to 1.5 km in diameter). During eruptions, sometimes a collapse of a volcanic structure occurs 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. When magma rises, the external pressure weakens, the gases and liquid products associated with it break out to the surface and the volcano erupts. If ancient rocks, rather than magma, are brought to the surface, and water vapor, formed during heating, prevails among gases groundwater, then such an eruption is called phreatic.

MAIN TYPES OF VOLCANOES The extrusive (lava) dome (left) has a rounded shape and steep slopes cut by deep furrows. A plug of solidified lava can form in the vent of a volcano, which prevents the release of gases, which subsequently leads to an explosion and destruction of the dome. The steeply sloping pyroclastic cone (right) is composed of alternating layers of ash and cinders.

THE GREATEST MOUNTAIN OF JAPAN FUJIYAMA (3776 m a.s.l.) - the cone of the "sleeping" volcano since 1708, covered with snow for most of the year.

Collier Encyclopedia. - Open society. 2000 .