Where do volcanoes occur? Where volcanoes arise. Where are the volcanoes of the world?

In the early stages of the Earth, volcanoes were likely to be found in many places on its surface, but then they began to appear along certain belts, huge faults in the Earth, and in the oceans. Most of the volcanoes have not survived. Those volcanic mountains that are now found on the surface of the planet arose relatively recently.

Volcanic belts

Volcanoes are not located randomly on Earth, but are subject to certain patterns.

Modern volcanoes are concentrated on Earth along certain zones (belts) characterized by high tectonic mobility. Destructive earthquakes usually occur in these belts; The heat flow from the bowels of the Earth here is several times higher than in quiet areas. There are three main zones where volcanoes are located: areas where the continental crust borders the oceanic crust; continental group, mainly a system of mountainous countries in Europe and Asia, as well as Africa, advantageous within deep faults; oceanic trenches, especially the Pacific Ocean.

There are thousands of them on the continents. It is not known exactly how many active volcanoes there are on Earth, but the number 500 most likely reflects their number. The largest on our planet is the Pacific Ring of Fire, where there are 526 volcanoes. Of these, 328 erupted in historical times. On our territory, the Pacific Ring of Fire includes the volcanoes of the Kuril Islands (40) and the Kamchatka Peninsula (28). The most active volcanoes in terms of frequency and strength of eruptions are Klyuchevskoy, Narymsky, Shiveluch, Bezymyanny, and Ksudach.

The second large volcanic belt stretches across the Mediterranean, the Iranian plateau to the Sunda archipelago. Within its borders are volcanoes such as Vesuvius. (Italy), Etna (Sicily peninsula), Santorini (Aegean Sea). The volcanoes of the Caucasus and Transcaucasia also fall into this belt. On the Great Caucasus Range there are two volcanoes, Elbrus (5642 m) and the double-peaked Kazbek (5033 m). In Transcaucasia, on the border with Turkey, there is the Ararat volcano with a cone covered with a snow cap. A little to the east in the Elbrus ridge, framing the Caspian Sea from the south, is the beautiful Damavand volcano. There are many volcanoes (63, of which 37 are active) in the Sunda archipelago (Indonesia).

The third large volcanic belt stretches along the Atlantic Ocean. There are 69 volcanoes, of which 39 erupted in historical times. The largest number of volcanoes (40) is on the island of Iceland, located along the axis of the underwater mid-ocean ridge, and 27 of them have already declared their activity in historical times. Iceland's volcanoes erupt quite frequently.

The fourth volcanic belt is relatively small in size. It occupies East Africa (40 volcanoes, of which 16 are active). The most famous volcano in this belt is Kilimanjaro (height 5895 m).

Outside of these four volcanic belts, volcanoes are almost never found on continents.

There are more than 50 volcanoes in Ecuador, and only eight of them are active, that is, in a state of constant or periodic eruption. The largest of them, the Tungurahua volcano, is located several tens of kilometers from the capital of Ecuador, Quito, with a population of just over 2 million people. The height of this volcano is 5,016 km.

But Tungurahua - in the language of the indigenous Quechua Indians this means “Fiery Throat” - is not the most “aggressive” volcano on the planet. Another Latin American country is leading here, Chile, where the Calbuco volcano, located in the southeast of Lake Llanquihue and in the south of the country, is currently erupting. Chile is one of the five countries with the largest number of active volcanoes.

Volcanological experts point out that there are a great many factors accompanying the eruption of any volcano - the nature of the eruption itself, the proximity of the volcano to populated areas, the strength of the eruption, etc., so it is simply impossible to compile a list of the most dangerous. However, they agree on naming the five countries with the most active volcanoes on the planet, noting that due to the lack of monitoring and study of the history of many volcanoes, it is very difficult to determine which volcanoes are the most active. This is also facilitated by the fact that reports compiled by various organizations were sometimes incomplete and their conclusions did not coincide.

Chile. There are about 95 active volcanoes here. Currently, the most active are Villarica, in the south, whose most recent eruption occurred in March this year, and Copahue, located on the border with Argentina, which almost constantly spews columns of gas and, periodically, ash. Other Chilean volcanoes have also been active more recently: Puyehue (2011) and Chaitén (2008). According to Ami Donovan, a volcanologist at the University of Cambridge (UK), it is also important to mention the Lascar volcano in Atacama, in the north of the country, where a new volcanic process began in 2006.

Indonesia. It is believed that there are about 120 active volcanoes in this country. Mount Merapi, 400 km from the capital Jakarta, is one of the most active volcanoes, whose location allows you to observe it in close proximity. Mount Sinabung, in northern Sumatra, erupted in early April this year. Tambora, a super-volcano, triggered the largest eruption on record in 1815, its ash plume reaching more than 30 km in height and the eruption affecting crops across much of Europe, causing famine and disease.

USA. It is estimated that there are 130 active volcanoes here, which are constantly monitored. Deciding whether or not to conduct expensive monitoring of a given volcano, Donovan says, is a difficult decision because eruptions are so rare. Scientists can observe a volcano that has not erupted for thousands of years, but failure to monitor and “awakening” the volcano is fraught with many unpredictable consequences, especially if it is located near populated areas.

Hawaii is home to the Kilauea volcano, the most active on the island and one of the most active in the world as a whole, which erupted in 1993. The United States is also home to Mount Santa Helena, located in Washington County, whose famously devastating eruption in 1980 claimed 57 lives.

Japan. It is the center of the largest number of active volcanoes. According to Bill McGuire, emeritus professor of geophysics and climate disasters at University College London, there are about 66 of them, including the famous Fuji, which could erupt at any time. Sakurahima is another active colossus located in the south of Kuishu Island. Due to its danger, authorities warned the population of the need to evacuate. Another volcano, Ontake, the second highest in the country, is located in the central region. It erupted in September 2014, causing more than 30 deaths and injuring dozens of Japanese.

Russia. Here, most active volcanoes are concentrated on the Kamchatka Peninsula, in the easternmost corner of the vast country. They form part of the Pacific Ring of Fire. It is difficult to strictly determine the exact number of volcanoes located on the Kamchatka Peninsula, from several hundred to more than a thousand. The volcanoes of Kamchatka are characterized by a wide variety of shapes and sizes; they were formed in different periods and are currently active to varying degrees. Most of them are dormant volcanoes that are not currently active, however, some volcanoes are active. Currently, there are about 29 active volcanoes in Kamchatka.

Volcanic eruptions are dangerous primarily due to their direct impact - the release of tons of burning lava, under which entire cities can perish. But, in addition to this, side factors such as the suffocating effects of volcanic gases, the threat of tsunamis, isolation from sunlight, distortion of the terrain and local climate changes also pose a danger.

Merapi, Indonesia

Merapi is one of the largest volcanoes on the Indonesian islands. It is also one of the most active: large eruptions occur once every seven to eight years, and small ones - once every two years. At the same time, smoke appears from the top of the volcano almost every day, not allowing local residents to forget about the threat. Merapi is also famous for the fact that in 1006 the entire medieval Javanese-Indian state of Mataram was seriously damaged by his activities. The volcano is especially dangerous because it is located near the large Indonesian city of Yogyakarta, which is home to about 400 thousand people.

Sakurajima, Japan

Sakurajima has been in constant volcanic activity since 1955, with its last eruption occurring in early 2009. Until 1914, the volcano was located on a separate island of the same name, but frozen lava flows connected the island with the Osumi Peninsula. Residents of the city of Kagoshima are already accustomed to the restless behavior of the volcano and are constantly ready to take refuge in shelters.

Aso Volcano, Japan

The last time volcanic activity was recorded at the volcano was quite recently, in 2011. Then the ash cloud spread over an area of more than 100 km. From that time to the present, about 2,500 tremors have been recorded, which indicates the activity of the volcano and its readiness to erupt. Despite the immediate danger, about 50 thousand people live in the immediate vicinity, and the crater is a popular tourist attraction for daredevils. In winter, the slopes are covered with snow and people go skiing and sledding in the valley.

Popocatepetl, Mexico

One of the largest volcanoes in Mexico is located literally fifty kilometers from. This is a city with a population of 20 million people who are in constant readiness to evacuate. In addition to Mexico City, major cities such as Puebla and Tlaxcala de Xicotencatl are located nearby. Popocatepetl also gives them a reason to be nervous: emissions of gas, sulfur, dust and stones occur literally every month. In recent decades, the volcano has erupted in 2000, 2005 and 2012. Many climbers strive to climb to its peak. Popocatepetl is famous for the fact that in 1955 it was conquered by Ernesto Che Guevara.

Etna, Italy

This Sicilian volcano is interesting because it has not only one main wide crater, but also many small craters on the slopes. Etna is constantly active, with small eruptions occurring every few months. This does not prevent the Sicilians from densely populating the slopes of the volcano, since the presence of minerals and trace elements makes the soil very fertile. The last major eruption was in May 2011, and minor emissions of ash and dust occurred in April 2013. By the way, Etna is the largest volcano in the world: it is two and a half times larger than Vesuvius.

Vesuvius, Italy

Vesuvius is one of Italy's three active volcanoes, along with Mount Etna and Stromboli. They are even jokingly called the “hot Italian family.” In 79, the eruption of Vesuvius destroyed the city of Pompeii and all its inhabitants, who were buried under layers of lava, pumice and mud. One of the last major eruptions, in 1944, killed about 60 people and almost completely destroyed the nearby towns of San Sebastiano and Massa. According to scientists, Vesuvius destroyed nearby cities about 80 times! By the way, this volcano has set many records. Firstly, this is the only active volcano on the mainland, secondly, it is the most studied and predictable, and thirdly, the territory of the volcano is a nature reserve and a national park where excursions are held. You can only go up on foot, since the lift and funicular have not yet been restored.

Colima, Mexico

The volcanic mountain consists of two peaks: the already extinct Nevado de Colima, which is covered with snow most of the time, and the active Colima volcano. Colima is particularly active: it has erupted more than 40 times since 1576. A strong eruption occurred in the summer of 2005, when authorities had to evacuate people from nearby villages. Then a column of ash was thrown to a height of about 5 km, spreading a cloud of smoke and dust behind it. Now the volcano is fraught with danger not only for local residents, but also for the entire country.

Mauna Loa, Hawaii, USA

Scientists have been monitoring the volcano since 1912 - there is a volcanological station on its slopes, as well as solar and atmospheric observatories. The height of the volcano reaches 4169 m. The last strong eruption of Mauna Loa destroyed several villages in 1950. Until 2002, the seismic activity of the volcano was low, until an increase was recorded, which indicates the possibility of eruptions in the near future.

Galeras, Colombia

The Galeras volcano is very powerful: its diameter at the base exceeds 20 km, and the width of the crater is about 320 m. The volcano is very dangerous - every few years, due to its activity, the population of the nearby town of Pasto has to be evacuated. The last such evacuation took place in 2010, when about 9 thousand people found themselves in shelters due to the threat of a strong eruption. Thus, the restless Galeras keeps local residents in constant suspense.

Nyiragongo, Republic of Congo

The Nyiragongo volcano is considered the most dangerous in all: it accounts for about half of all cases of volcanic activity recorded on the continent. Since 1882, there have been 34 eruptions. Nyiragongo lava has a special chemical composition, so it is unusually liquid and flowing. The speed of erupted lava can reach 100 km/h. In the main crater of the volcano there is a lava lake, the temperature of which heats up to 982 Cº, and the bursts reach a height of 7 to 30 m. The last largest eruption occurred in 2002, then 147 people died, 14 thousand buildings were destroyed, and 350 thousand people left homeless.

It is worth noting that scientists have been studying the activity of volcanoes for many years and modern technology recognizes the beginning of their seismic activity. Many volcanoes have webcams that allow you to monitor what is happening in real time. People living nearby are already accustomed to this behavior of volcanoes and know what to do when an eruption begins, and emergency services have the means to evacuate local residents. So every year the likelihood of casualties from volcanic eruptions becomes less and less.

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

What is a volcano?

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

Types of volcanoes

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

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

What shapes do volcanoes come in?

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

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

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

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

Why do volcanoes erupt?

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

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

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

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

What is magma?

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

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

How does a volcano erupt?

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

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

Places of volcanic activity

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

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

Which volcano on the planet can be called the highest?

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

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

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

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

The whole truth about the Yellowstone volcano

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

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

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

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

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

What troubles do volcanoes bring?

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

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

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

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

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

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

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

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