What happens after the eruption of the volcano. Why and how volcanoes erupt

Signs of pregnancy after embryo implantation

Lesson 8

CONSEQUENCES OF THE ERUPTION OF VOLCANOES. PROTECTION OF POPULATION

Item: OBJ.

Date of the meeting: "____" _____________ 20___

Compiled by: OBZ teacher Hamatgaleev E. R.

Goal:  to get acquainted with the consequences of volcanic eruptions and the main measures to protect the population from the consequences of volcanic activity.

Course of lessons

Herbert Poempel of the World Meteorological Organization said that all the indicators for the second part of the week and the weekend are positive. On the other hand, in Europe, there may be a problem of low dust retention in landing and landing aircraft.

Maps of the British Meteorological Bureau show that at noon he will be present only in France, Ireland and West England, as well as in Eastern and Central Europe, with the exception of Poland. Airlines that reported losses of up to a billion dollars criticize the decision to close the airspace. Scientists shared opinions on this issue.

    Class organization.

Greeting. Checking the list composition of the class.

    Message of the topic and purpose of the lesson.

    Knowledge updating.

    What is a volcano and what are the causes of its eruption?

    What is the volcanic eruption, and what are the precursors of the eruption?

    What are the volcanoes?

    The Icelandic volcano, paralyzing air travel in Europe, throws lava. The Icelandic volcano, paralyzed by European air traffic, began lava. Thanks to the crater, more steam and less dust are formed. According to the latest data from the British Meteorological Bureau, a cloud of volcanic dust from Iceland partially overflows Poland. The situation in Europe can change with each passing hour.

    This is a powerful cloud of volcanic ash, which hinders the operation of airports throughout Europe. Thousands of people are waiting for the resumption of passenger flights. Perhaps they will soon be able to continue their journey. According to the Icelandic geologist from the meteorological office, the smoke still comes from the volcano, but their color is brighter than before. This means that more steam is produced than volcanic dust.

    Where do volcanoes meet?

    Check the homework.

Listening to the answers of several students for homework (at the choice of the teacher).

    Work on new material.

The most dangerous phenomena for humans and the environment during the eruption of volcanoes are formed in this case products of volcanic eruptions.  They are liquid, solid and gaseous. According to this, volcanoes can erupt:

The volcano is still at the eruption stage - the tremors increase, and the lava flows out of the crater and lands on the surrounding snow. It used to be believed that dust would remain only in northwestern Poland, but now, according to the British Meteorological Office, in the morning and at noon the dust will be located just above the south and southeast of Poland. Yesterday, the Polish Air Navigation Services Agency opened six airports in northern and central Poland - in Warsaw, Lodz, Bydgoszcz, Poznan, Szczecin and Tri-City.

On Sunday in Europe there were four thousand, or about 16 percent of the planned flights, EU experts hope to launch at least half of the planned airships on Monday. EU Commissioner for Transport Siim Kallas said that Brussels should first provide security, secondly, cope with economic losses and, finally, help passengers who are in a difficult situation.

    lava flows;

    volcanic mud flows;

    solid volcanic products;

    scorching volcanic cloud;

    volcanic gases.

Liquid volcanic products -it is, above all, magma itself, poured out in the form of lava. ( Lava -  it is a magma that is poured out during the eruption of a volcano, which has lost some of the gases and water vapor contained therein.)

The dusty cloud paralyzes the airports in Europe

Since Thursday 64,000 flights have been canceled in Europe. According to some analysts, despite some optimistic information, traffic violations can continue until the end of the next weekend. In Northern Europe, all airports are closed. Flights canceled. This is the result of a dust cloud that travels from Iceland after the eruption of the volcano Eyyafyallayokul.

In Scotland and London, all airports were closed. Air traffic controllers said that from 0000 on Polish time no aircraft will be released or released from the United Kingdom. Airports in Norway, Sweden, Finland, the Netherlands and Ireland are also closed. Hazel Rimer, a geophysicist at the British Open University, says it is unclear how the cloud of volcanic dust will move. "It will change during the day," he said.

The shape, dimensions, and features of the lava flows depend on the nature of the magma.

Most common flows of basaltic lavas.  Initially heated to 1000-1200 0 C, basalt lavas retain fluidity, cooling down to a temperature of 700 0 C. The speed of basalt lavas is up to 40-50 km / h. Leaving on a flat place, they spread out over vast areas.

About 800 people were evacuated from the vicinity of the volcano, and high temperatures melted from the local glacier. A large, important bridge is under threat. According to experts, in some areas dust may fall, which creates difficulties with breathing. The last eruption of the volcano Eyyafyallayokul occurred on March 20, and at the beginning of the year.

Is, the Radio Information Agency. How do you kill one of the most dangerous volcanoes in the world? Scientists have asked this question for many years, even if hundreds of thousands of people live in close proximity to Vesuvius. And - despite the warnings - they are still going. You will have to warn them during the upcoming cataclysm. Researchers are trying to determine when this will happen. To this end, they hear the murmur from the depths of Vesuvius, but they also analyze the course of the eruption, which led to the destruction of Pompeii.

When volcanic eruptions can occur volcanic mud flows,which pose a great danger to man and the environment. In the Colombian Andes in the north of South America, 150 km northwest of Colombia's capital Bogota, the Arekas volcano is located. Last time it erupted in 1595 and was considered dormant. On November 13, 1985, the volcano suddenly woke up. The explosions that started during its eruption caused the rapid melting of snow and ice in the crater of the volcano. A huge mass of water, mud, rocks and ice rushed to the valley of the Lagunilla River, sweeping away everything in its path.

Knowing this will allow you to learn about the habits of the volcano. "This volcano is like a barrel of powder," commented Peter Baxter, professor of medicine at Cambridge University. For two decades he studied how volcanoes kill people. It appears everywhere, where a volcanic eruption caused casualties. He looks at the wounds, examines the wounds, tries to determine the immediate cause of death. As the first assumption that these people can kill a heat wave. They escaped from volcanic bombs and ash, but although they were well hidden, Vesuvio's hot breath caught them.

About 40 km from the volcano, in the river valley, there was the town of Armero with a population of 21 thousand people, and in the surrounding villages there were 25 thousand more people. On November 13 at 23 hours, a stream of mud covered the city with a 5-6-meter layer, and 20,000 people almost instantly died in a raging mush of mud. Only those who managed to escape were those who heard the approaching rumbling, jumped out of the houses and ran to the nearest hills.

Baxter, Mastororenzo and many other Italian scientists are also involved in research in other dangerous volcanic mountains. Teide in the Canary Islands, Side Cedades in the Azores and in the Soufriere mountains on the British Caribbean island of Montserrat. It was an explosion similar to Vesuvius's explosion in 79-a small lava, but a lot of gases and dust. Therefore, he is so diligently studied by the Italians. The explosion in Montserrat destroyed many cities, but only about 20 people were killed there, as thousands of them were able to evacuate.

And how many would have died today under Vesuvius? So far, the trailer of such a great cataclysm can not be seen. However, they can appear at any time. And then events usually follow quickly. He was weaker than the one that destroyed Pompeii, and still lost 4000. people. Based on written documents, it was found that dense gas fumes started to leave the cracks only 2-3 weeks before the explosion, and in a week it was possible to feel the first clearer earth tremors. Probably, a modern seismic device would have detected noise under the volcano much earlier, and tourists would have left the region in danger of extinction, but what about the locals?

Killed not only the city of Armero, but also a number of villages, coffee plantations were destroyed, thousands of people were injured, oil pipelines and roads were damaged.

When volcanic eruptions occur solid volcanic productsthey are thrown into the environment from the mouth of the volcano with powerful explosive eruptions. The most common solid volcanic products are volcanic bombs.

Of course, the explosion will also happen, because it does not exist. Vesuvius can get a little scared and fall asleep, but he can also act for months and even years, preparing for the final explosion. Vesuvius exploded, the inhabitants of Rome had no chance. The cloud of hot gas and ash dropped sharply, and then moved down the slope at a speed that initially exceeded 300 kilometers per hour. The people in Pompeii were strangled with volcanic ash, which blocked their lungs. The course of extermination was dramatic. In the initial stage of the explosion, rain fell on volcanoes.

They destroyed many houses in Pompeii. But the worst was. A few minutes later, six clouds of warm dust and gas flowed from the volcano. Each next wave - volcanologists call this phenomenon a pyroclastic flow - was more powerful than the previous one. The first three did not reach the city, until the fourth, she devastated it with a small layer of ash three centimeters thick and stopped immediately behind the southern pitchforks. The last two, the most powerful clouds had a range of more than 15 kilometers. They covered Pompeii with a thick layer of ash, from which they were excavated only a dozen or so centuries ago.

Volcanic bombs -  this is a fragment of the rock more than 7 cm long. When they are released from the vale of the volcano, they are still in a molten state, but after flying hundreds of meters, they cool in the air and fall to the ground already hardened. Sometimes large blocks - more than 1 m long are thrown out. Volcanic debris less than 7 cm is called lapilli  ("Ball", "small stone").

They buried the same city, but when it appeared, it was after the pogrom, scientists showed. Because it was not them, but the fourth wave - the weakest of those who swept the city - killed most of its inhabitants. Going to a certain place lasted from 30 seconds to 2, 5 minutes. More precisely, it is difficult to calculate, because it is not known how big it is. Over Pompeii, at the southern end of her range, she fell sharply. She was barely ash. This amount did not threaten. He could not do more harm, "says Giuseppe Mastrolorenzo.

And yet it was she who collected the greatest mortal harvest. Petron again analyzed the plaster casts of the dead and looked at thousands of archival photographs confirming earlier anthropological studies. He came to the conclusion that the victims of the fourth wave died almost immediately. People suddenly died, they were frozen in the place where their death was. Many of them raised their hands to the head. Previous interpreters interpreted this as an attempt to protect against volcanic ash. Additional evidence was provided by Guarino, who examined the bones of people and animals killed by a cloud of gas dust under a scanning microscope.

Volcanic particles of less than 2 mm in size are called ashes.  This ash is not a product of combustion. It looks like a dust cloud. These are fragments of volcanic glass, which are the instantly frozen thin partitions of expanding gas bubbles released from magma during an explosive eruption. Being thrown up, they will fall to the ground in the form of glassy ash.

He noted that many of them have traces of high-temperature activity, among others. modified color and characteristic cracks. The researchers agreed on how hot the blast was, heating the bones belonging to a recently dead man and horse. When the temperature changed, they changed color and properties. Then they were compared to bone material from Pompeii. Both were located seven kilometers from the crater and therefore closer than Pompeii.

So many victims immediately evaporated all the soft tissues. Mastororenzo emphasizes that both his previous and current studies prove that Vesuvius is more dangerous than it seems. Even where the ashes discarded by him can no longer cause more harm, it is still so hot that within a few seconds anyone who is within the reach of the heat wave will die. You can not hide inside the house. This is another serious warning signal for the agglomeration of Naples, - the scientist emphasizes.

Powerful volcanic eruptions throw small ash into the upper atmosphere, where it can be very long.

In the history of eruptions, powerful ash falls are known. Let's recall the picture of the outstanding Russian painter Karl Bryullov "The Last Day of Pompeii". August 24, 79 unexpectedly erupted Vesuvius volcano. In the picture Bryullov depicts people leaving Pompeii and trying to hide from ash falls and rockfall. These phenomena and became disastrous for the city. The ash falls above Vesuvius intensified gradually, and the city was buried under a 4-meter layer of volcanic sand and ash.

Volcanism is the process of extracting magma from the earth's surface and many other processes closely related to this problem, such as gas expulsions, lava flows or pyroclastic material. This cone-shaped hill, from which during the eruption of lava-magma-lava spills on the surface of the Earth as a result of volcanic eruptions. It consists of molten silicon oxides, metal oxides, silicates and gases. More Geographic dictionary and throw away the pyroclastic material in the form of a bomb, lapilli and ash.

Very often the volcano emits smoke from the top of the volcano, creating a characteristic volcanic trail. On the volcanoes, Herodotus was already in the air. The Greeks regarded the volcanoes as the underground forge of Hephaestus, where he made weapons for the gods. The curiosity of people grew. The first victim of "learning" was Empedocles from Akragas. To find out the secret of Etna, he went to the top of the mountain, but unintentionally fell into his big crater.

In June 1912, after the eruption of the volcano Kamtai in Alaska, the finest glassy ash fell for two days. It covered a layer of 25 cm thick Kodiak islands and other islands. Residents were forced to evacuate.


The powerful eruption of the volcano Klyuchevskaya Sopka in Kamchatka in September 1994 raised ash masses to a height of 10-20 km, which made it difficult to fly planes in those areas.

When volcanic eruptions from a cluster of incandescent ash and gases can form scorching cloud,it poses a mortal threat to people and the environment.

An example of this is the eruption of the Mon-Pele volcano on the island of Martinique (Lesser Antilles), which occurred in May 1902. At 7:50 am of the colossal power, the explosions shook the volcano, and powerful ash clouds swept to a height of more than 10 km. Simultaneously with these explosions, which followed continuously one after another, a black cloud emerged from the crater, flashing crimson flaws. At a speed of more than 150 km / h, it rushed down the slope of the volcano to the city of Saint-Pierre, which was 10 km from the volcano Mont-Pele. This heavy red-hot cloud pushed a dense clot of hot air in front of him, which turned into a rush of a hurricane and flew into the city a few seconds after the eruption of the volcano began. And another 10 with a cloud covered the city. In a few minutes, 30,000 residents of Saint-Pierre were dead. The scorching cloud of the Mon-Pele volcano in the blink of an eye erased the city of Saint-Pierre.

When erupting volcanoes, in addition to liquid and solid products, various gaseous volcanic products,the share of which in the total volume of volcanic products is very high.

Gases are an indispensable companion of volcanic processes and are released not only during turbulent eruptions, but also during periods of weakening of volcanic activity. Through cracks in the craters or on the slopes of volcanoes calmly or vigorously, cold or heated to a temperature of 1000 0 C gases burst out.

Volcanic gases are dominated by water vapor (95-98%). The second place after water vapor is carbon dioxide (carbon dioxide CO 2), followed by gases containing sulfur, hydrogen chloride (HCl) and other gases.

The places of escape of volcanic gases on the surface of the Earth are called fumaroles.

Often, fumaroles produce a cold gas with a temperature of about 100 0 C and lower. Such allocations are called fuming  (from the Latin word "evaporation"). In their composition, carbon dioxide, which, accumulating in the lowlands, represents a mortal danger for all living things. So, in Iceland in 1948, during the eruption of the volcano Hekla, carbon dioxide accumulated in the hollow at the foot of the volcano. The sheep that were there died.

The emission of gases is observed in volcanos that have not been erupted for a long time. So, in the mountains of the Greater Caucasus, on the slope of the eastern peak of Elbrus at an altitude of more than 5 km, there is a small fumarolic field, free from snow and ice even in winter. There is a constant smell of sulfur.

The history of eruptions of volcanoes indicates that, it would seem, long extinct volcanoes can wake up in hundreds of years. The example is the eruption of the Bezymyanny volcano, located to the south of the volcanoes Klyuchevskaya Sopka and Kamenka in Kamchatka. He was considered extinct, but on September 22, 1955, he unexpectedly began to erupt. During the eruption, gas-ash clouds reached an altitude of 5-8 km. March 30, 1956 gigantic force blast struck the top of the volcano, formed a crater up to 2 km in diameter. The explosion occurred at an angle of 45 0   to the horizon and was directed to the east. The explosion was such a force that in 25-30 km from the volcano destroyed all the trees. Giant cloud of ash and gases rose to a height of 40 km. The speed of the expansion of the cloud was 500 km / h. At 10-15 km from the volcano, the ash layer reached a depth of 50 cm. After the explosion, streams of red-hot rock fragments rushed from the crater, instantly melting snow. Powerful mud streams with a width of up to 6 km were formed, all swept away on their almost 100-kilometer path, up to the Kamchatka River. It is noted that such a catastrophic eruption is very characteristic of volcanoes, "silent" for many hundreds and even thousands of years.


Protection of the population

To ensure the protection of the population from the consequences of volcanic eruptions, constant monitoring of the precursors of this phenomenon is organized.

The precursors of the eruption are volcanic earthquakes, which are associated with the pulsation of magma moving upward along the supply channel. Special instruments record changes in the inclination of the earth's surface near volcanoes. Before the eruption, the local magnetic field and the composition of the volcanic gases released from the fumaroles change.


In the areas of active volcanism, special stations and points have been set up, in which continuous monitoring of dormant volcanoes is conducted.

A reliable system of alerting the management bodies of industrial enterprises and the public about the threat of a volcanic eruption is organized.

At the foot of volcanoes, construction of enterprises, residential buildings, roads and railroads is prohibited. Near the volcanoes, blasting operations are prohibited.

Evacuation is the most reliable way to protect the population from the consequences of a volcanic eruption. Therefore, residents of cities located in close proximity to volcanoes, should know the location and order of evacuation. When a signal is received about the threat of a volcanic eruption, it is necessary to leave the building immediately and arrive at the evacuation point.

    Work on the studied material.

Questions and tasks:

    What is the composition of the lava flows?

    What are volcanic mud flows?

    What is the danger of solid volcanic products?

    What are the characteristics of a scorching volcanic cloud?

    What are the elements of volcanic gases? What is the danger of gaseous volcanic products?

    The result of the lesson.

Teacher. Draw a conclusion on the lesson.

Learners. Volcanoes can erupt lava flows, volcanic mud flows, solid volcanic products, scorching volcanic cloud, volcanic gases.

The protection of the population from the consequences of volcanic eruptions lies in the organization of:

    constant monitoring of volcanoes;

    a warning system for the management of industrial enterprises and the public about the threat of a volcanic eruption;

    evacuation.

    End of the lesson.

    Homework.Situational challenge (in writing). In the safety diary, write down the main phenomena that are typical for the eruption of the volcano. On examples from the history of volcanic eruptions, show their danger to humans and the environment. Make a plan of action in case you find yourself in the area of ​​the volcanic eruption. eruptions volcanoes  and protection of population. Protection of population  from landslides. Theme 3. Emergencies of meteorological origin and protection of population. Protection of population ...

  1. Working curriculum on the basics of life safety 5 9 classes

    Work Curriculum

    Educational subject matter « ... lessons life safety fundamentals ... Effects eruptions volcanoes. Protection of population. Effects eruptions volcanoes. Protection of population. Lava flows, volcanic rocks, mud flows Organization of protection of population  from consequences eruptions volcanoes ...

  2. Work program on the Fundamentals of Safety of Life 7 class

    Working programm

    Intersubject communications, with objects  geography, biology, social studies ... eruption volcanoes, location volcanoes  on the ground. Combined Gaseous volcanic products §2.5, communication 8 Effects eruptions volcanoes .Protection of population ...

  3. Work program on the course "Fundamentals of life safety"

    Working programm

    ... life safety fundamentals  ... for academic subjects. Basics ... lesson  Subject lesson  date lesson ... of population  with earthquakes. 7 Volcanoes, eruptions volcanoes, location volcanoes  on the ground. 8 Effects eruptions volcanoes. Protection of population. 9 Landslides, their effects, protection of population ...

Bamburov Alexey

I assumed that. Studying various sources of information, I decided to find out for myself what the volcano is and how it erupts.

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Why and how do volcanos erupt?  - A study of Alexey Bamburov, a student of grade 3 A, MBUU "Gymnasium No. 34", Ulyanovsk, supervisor Ya.M. Bragin.

Very often, events and events from our daily life or human behavior remind us of natural phenomena, for example:

  1. If you shake a bottle with a heavily carbonated beverage and open the lid, the liquid and gases contained in the bottle will rush outward;
  2.   Have you ever boiled up, losing your temper, and then calming down? It was your way to "let off steam" (remember what happens when we remove the lid from a boiling kettle).

I suggested thatvolcanoes - is the way the planet emits steam. Studying various sources of information, I decided to find out for myself what the volcano is and how it erupts. Our planet Earth resembles an egg: on top of a thin hard shell -earth's crust , under it is a viscous layer of hotmantles , and in the center - a solidcore . The Earth's crust is calledlithosphere , which in Greek means "stone shell". The thickness of the lithosphere averages about 1% of the radius of the globe. On land, it is 70-80 kilometers, and in the depths of the oceans there may be only 20 kilometers. The temperature of the mantle is thousands of degrees. Closer to the core - the temperature of the mantle is greater, closer to the bark - less. Because of the difference in temperature, the mantle material mixes: hot masses rise upward, and cold ones go down (just like boiling water in a pot or kettle, but it only happens thousands of times slower). The mantle, although heated to great temperatures, but because of the colossal pressure in the center of the Earth, it is not liquid, but viscous, like a very dense resin. The lithosphere seems to float in a viscous mantle, plunging into it a little under the weight of its weight.

Reaching the base of the lithosphere, the cooling mass of the mantle moves horizontally along a hard rock "shell" for a while, but then, once cooled, it again descends toward the center of the earth. As long as the mantle moves along the lithosphere, pieces of the earth's crust (lithospheric plates) are involuntarily moving along with it, while parts of the stone mosaic collide and creep one upon another.

Part of the plate, which was on the bottom (on which the other slab crawled), gradually plunges into the mantle and begins to melt. This is howmagma - a dense mass of molten rocks with gases and water vapor. Magma is lighter than surrounding rocks, so it slowly rises to the surface and accumulates in so-called magmatic foci. They are located most often along the line of collision of plates.

The behavior of the hot magma in the igneous foci and truth resembles a yeast dough: magma increases in volume, occupies all free space and rises from the depths of the earth through cracks, striving to break free. As the dough lifts the lid of the pan and flows over the edge, so does magma break through the earth's crust in the weakest places and break free to the surface. This is the volcanic eruption.

The eruption of the volcano is due todegassing magma, that is, the release of gases from it. The process of degassing is known to everyone: if you gently open a bottle of carbonated beverage (lemonade, coca-cola, kvass or champagne), cotton is heard, and smoke appears from the bottle, and sometimes the foam - it comes out of the drink (ie, it degasses) . If a bottle of champagne before shaking is opened or heated, then a powerful jet will escape from it, and it is impossible to keep this process. And if the bottle is not tightly closed, then this jet can itself knock out the cork from the bottle.

How is the volcano formed? Imagine that a can of mineral water is the surface of the Earth, and a lid with a detachable tongue is a weak spot on the earth's surface. If the jar shakes, carbon dioxide expands and can make a hole at the junction of the tear-off tab and the lid. Similarly, hot gases and magma can press a hole in weak places of the earth's crust and spill out.

Hot ash, cold climate

After the eruption of the volcano, sunsets across the Earth can turn red for many months - this is clear evidence that volcanoes affect the atmosphere. When the ashes are rising in the air and flying around the globe, it hangs in the atmosphere, dissipating the sunlight and coloring the sunsets in brighter colors.

But the influence of volcanoes on the atmosphere of the planet is not limited only to spectacular sunsets. Let us recall, for example, what happened several hundred million years ago in Siberia. If you go there today, you will see the so-called Siberian trap - a huge piece of solid rock of volcanic origin, stretching for 1400 km. The scientists who studied this piece say that they are more than 250 million years old. Before cooling, it was a liquid hot lava. And judging by the size of this piece, the erupting volcano should have been monstrously large.

Scientists believe that for 600,000 years, Siberian volcanoes repeatedly erupted the streams of hot lava from the depths of the earth. And each time during the eruption they threw tons of ash into the sky. They also spewed deadly suffocating gases. Melting minerals gave off sulfates, which when heated were converted to sulfur dioxide. The ashes and gases of the Siberian volcanoes rose high into the atmosphere. The ash prevented the penetration of sunlight into the Earth. Sulfuric gas, reacting with water in the air, turned into sizzling sulfuric acid. The droplets of acid reflected some of the sun's rays, and the heat could not reach the surface of the planet, which means that the atmosphere, oceans and land began to cool down.

Gradually the temperature on Earth fell. Ice caps on the poles grew rapidly, the oceans were covered with a thick ice crust. In the end, most of the Earth was icebound. That's how the volcanoes laid the foundation for a new glacial period. From the cooling atmosphere, acid in the form of snow and rain fell on the surface of the planet.

During this planetary catastrophe, more than 90% of all plants and animals in the seas of the Earth gradually perished, leaving as memories of themselves only fossilized remains in sedimentary rocks. According to some scientists, mass extinction, which lasted hundreds of years, and the chain reaction of events that followed it, are explained precisely by these eruptions.

The gas escaping from volcanoes consists of 50-85% of water vapor. More than 10% is carbon dioxide (the same as in soda), about 5% is sulfur dioxide gas, 2-5% is hydrogen chloride and 0.02-0.05% is hydrogen fluoride. Sometimes in volcanic gases there are hydrogen sulphide and gaseous sulfur, hydrogen, methane and carbon monoxide, as well as very small admixtures of various metals.

There are cases when volcanoes erupted, which were silent for 300, 500, 800 years. Volcanoes, which at least once erupted in the memory of a person (and can earn again), are calledsleeping . Extinct (or ancient) volcanoes are those that worked in the distant geological past. For example, the capital of Scotland, the city of Edinburgh stands on an ancient volcano that erupted more than 300 million years ago (then there were no dinosaurs either).

The eruption of the chain of Luck volcanoes, located in the south of Iceland along the tectonic fissure, in 1783 was one of the strongest in the history of our planet. It lasted eight months, the length of the flow of lava bursting into the light was almost 70 km. The scorching mass moved at a speed of over 45 km / h and spilled over an area of ​​579 km2 .

Let's sum up.

As a result of the motion of lithospheric plates, magma foci may appear. If the liquid magma breaks to the surface of the Earth, an eruption of the volcano begins. Often the eruption of the volcano is accompanied by powerful explosions, this is due to the degassing of magma and the explosion of combustible gases. The volcano falls asleep if the supply of new portions of magma from the magma chamber stops, but it can wake up if the plates move on and the magma chamber is refilled. Volcanoes will fade completely, if the movement of plates in this area ceases.

The most famous volcanic eruptions:

Santorini, Greece - 1450 BC.
Vesuvius, Italy - 79 g.
Taupo, New Zealand - 150 g.
Tambora, Sumbava Island - 1815
Krakatau, Jawa Island - 1883
Montagne Pele, Martinique Island - 1902
Katmay, Alaska - 1912
St. Helena Mountain, USA - 1980.
Nevado de Ruiz, Colombia - 1985
Pinatubo, Philippines - 1991
Eyjafjallajökull, Iceland - April 2010

Volcanoes of the world.

Etna (Italy)   (which means "mountain fire" in Arabic) is the highest and most active volcano in Europe (3326 m). Fixed more than 200 of its eruptions. It is interesting that Etna varies in height from the eruption to the eruption. For example, at present it is 21.6 m lower than in 1865. Approximately every 150 years, Etna destroys one of the neighboring villages, but despite this, the nearby territories are densely populated. The fact is that volcanic ash makes the soil fertile. According to recent studies, the danger of Ethna's extensive eruption is growing. Because of the constant activity, Etna was chosen as the "UN Volcano of the Decade".

Popocatepetl (also called Popo and Don Goyo) is an active volcano in Mexico. It reaches an altitude of 5,426 m and is the second largest at the highest level in the country. Popocatepetl got its name from the word Nahuatl "popōca" (smoke) and tepētl ("mountain"), which means "Smoking of the Mountain" and fully justifies its name. Until the nineties, Popo was a favorite vacation spot - a snowboard center. In 1947, he began a new cycle of activity with a major eruption. At present, scientists carefully study it. Residents of neighboring towns are admiring the snowy white mountain of Popocatepetl for most of the year.

Fujiyama   is the active volcano and the highest peak of Japan (3776 m). Its last eruption dates from 1707 and 1708. Fujiyama is distinguished by its almost perfectly symmetrical cone, clearly visible from Tokyo in clear weather, which is one of the symbols of Japan.

Redout (Alaska)   is a stratovolcano with a crater at an altitude of 2700 m. Its most active eruptions in the 20th century date back to 1902, 1966 and 1989. In the last eruption in 2009, 6 explosions were recorded that threw a column of ash more than 9 miles into the air. It was the biggest volcanic eruption in almost 20 years.

Ruapehu   is an active volcano in New Zealand, the height of 2797 m. It is considered one of the most active volcano in the world and the largest active volcano in New Zealand. Ruapehu got its name from the Maori language, on which this word means "chasm of explosion". The last eruption is dated September 25, 2007. Despite the fact that the eruption began, like all the previous ones, suddenly, it is often visited by tourists.

And finally ... Scientists now know how and why volcanic eruptions occur. In the last decades volcanologists have made many valuable observations and conclusions on the activities of volcanoes. For us the picture of the preparation of the eruption and the eruption of various volcanoes is now clear. But, unfortunately, this limits human knowledge in this area. We can only observe and explain the eruptions. It is impossible for a person to stop, change, even prevent these formidable phenomena of nature. Yes, this is understandable, because the forces acting at eruptions are enormous. They are associated with those underground forces that form earth folds - mountains and mountain ranges. Of course, we can not influence these forces, even to a small extent.They are too powerful!

List of used literature

Aprodov VA Volcanoes. - Moscow: Thought, 1982. - 158s.

Aprodov VA The Breath of the Earth: volcanoes and earthquakes. - Moscow: Geografgiz, 1963. - 180s.

Wlodavets V.I. Volcanoes of the Earth. - Moscow: Nauka, 1973. - 160s.

Guschenko I.I. Eruption of the volcanoes of the world. - Moscow: Nauka, 1979. - 124s.

Children about everything in the world. - Interactive encyclopedia for children. M: Machaon - 2011. - 31s.

Lebedinsky VI Volcanoes and people. - Moscow: Nedra, 1967. - 240s.

MacDonald G.A. Volcanoes. - Trans. with English. - Moscow: Mir, 1975. - 210s.

Marakushev A.A. Volcanism of the Earth / / Nature. - 1984.-№9. - 175s.

Markhinin E.K. Volcanism. - Moscow: Nedra, 1985. - 93s.

Ritman A. Volcanoes and their activities. - Trans. with English. - Moscow: Mir, 1964. - 190s.

Taziev G. Volcanoes. - Trans. with frants. - Moscow: Thought, 1963. - 220s.

Publications on the topic