A truly amazing sight is a volcanic eruption. But what is a volcano? How does a volcano erupt? Why do some of them spew huge lava flows at different intervals, while others sleep peacefully for centuries?

What is a volcano?

Outwardly, the volcano resembles a mountain. There is a geological fault inside it. In science, it is customary to call a volcano a formation of geological rock located on the surface of the earth. Through it, magma erupts outward, which is very hot. It is magma that subsequently forms volcanic gases and stones, as well as lava. Most of the volcanoes on earth formed several centuries ago. Today, new volcanoes occasionally appear on the planet. But this happens much less often than before.

How are volcanoes formed?

Briefly explaining the essence of the formation of a volcano, it will look like this. Under the earth's crust is a special layer under strong pressure, consisting of molten rocks, and it is called magma. If cracks suddenly begin to appear in the earth's crust, then hills form on the surface of the earth. Magma comes out through them under strong pressure. At the surface of the earth, it begins to break up into red-hot lava, which then solidifies, causing the volcanic mountain to become larger and larger. The emerging volcano becomes such a vulnerable spot on the surface that it erupts volcanic gases onto the surface with great frequency.

What is a volcano made of?

In order to understand how magma erupts, you need to know what the volcano consists of. Its main components are: volcanic chamber, vent and craters. What is the focus of a volcano? This is where magma forms. But not everyone knows what the mouth and crater of a volcano are? A vent is a special channel that connects the hearth with the surface of the earth. A crater is a small bowl-shaped depression on the surface of a volcano. Its size can reach several kilometers.

What is a volcanic eruption?

Magma is constantly under strong pressure. Therefore, there is a cloud of gases above it at any time. Gradually, they push the red-hot magma to the surface of the earth through the mouth of the volcano. That's what causes the eruption. However, one small description of the eruption process is not enough. To see this spectacle, you can use the video, which you need to watch after you have learned what the volcano consists of. In the same way, in the video you can find out which volcanoes do not exist at the present time and what volcanoes that are active today look like.

Why are volcanoes dangerous?

Active volcanoes are dangerous for a number of reasons. By itself, a dormant volcano is very dangerous. He can “wake up” at any time and start spewing lava flows that spread over many kilometers. Therefore, you should not settle near such volcanoes. If an erupting volcano is located on the island, such a dangerous phenomenon as tsunami may occur.

Despite their danger, volcanoes can serve mankind well.

Why are volcanoes useful?

• During the eruption, a large number of metals appear that can be used in industry.
• The volcano generates the strongest rocks that can be used for construction.
• Pumice, which appears as a result of the eruption, is used for industrial purposes, as well as in the production of stationery gum and toothpaste.

Our Earth is not all solid stone through and through, rather it resembles an egg: on top there is a thin hard shell, under it there is a viscous layer of hot robes, and in the center - a solid core. The earth's "shell" is called lithosphere, which in Greek means "stone shell". The thickness of the lithosphere is on average about 1% of the radius of the globe: on land it is 70-80 kilometers, and in the depths of the oceans it can be only 20 kilometers. The lithosphere is all cut up by faults and resembles a mosaic.

The temperature of the mantle is thousands of degrees: closer to the core the temperature is higher, closer to the shell - less. Due to the temperature difference, the substance of the mantle is mixed: hot masses rise up, and cold masses descend (just like boiling water in a pot or kettle, but this happens thousands of times slower). Although the mantle is heated to enormous temperatures, but due to the enormous pressure in the center of the Earth, it is not liquid, but viscous - like a very thick resin. The “shell” lithosphere, as it were, floats in a viscous mantle, slightly immersed in it under the weight of its own weight.

Reaching the bottom of the lithosphere, the cooling mass of the mantle moves horizontally along the solid stone "shell" for some time, but then, having cooled down, it again descends towards the center of the Earth. While the mantle is moving along the lithosphere, pieces of the "shell" (lithospheric plates) inevitably move along with it, while individual parts of the stone mosaic collide and crawl onto each other.

The part of the slab that was below (on which another slab has crawled) gradually sinks into the mantle and begins to melt. This is how it is formed magma - dense mass of molten rocks with gases and water vapor. Magma is lighter than the surrounding rocks, so it slowly rises to the surface and accumulates in so-called magma chambers, which are most often located along the line of collision of plates. Magma is more liquid than the mantle, but still fairly thick; Translated from Greek, "magma" means "thick paste" or "dough".

The behavior of red-hot magma in a magma chamber really resembles yeast dough: magma increases in volume, occupies all free space and rises from the depths of the Earth along cracks, trying to break free. As the dough lifts the lid of the pan and flows out over the edge, so the magma breaks through the earth's crust in the weakest places and breaks out to the surface. This is a volcanic eruption.

Volcanic eruption is due to degassing magma. Everyone knows the process of degassing: if you carefully open a bottle with a carbonated drink (lemonade, Coca-Cola, kvass or champagne), cotton is heard, and smoke appears from the bottle, and sometimes foam - this is gas coming out of the drink (that is, it is degassed) . If a bottle of champagne is shaken or heated before opening, 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 the cork out of the bottle.

Magma in a magma chamber is under pressure, just like sodas in a closed bottle. In the place where the earth's crust turned out to be "loosely closed", magma can escape from the bowels of the Earth, knocking out the "plug" of the volcano, and the stronger the "plug" was, the stronger the volcanic eruption will be. Rising up, magma loses gases and water vapor and turns into lava- magma depleted of gases. Unlike fizzy drinks, the gases that are released during a volcanic eruption are combustible, so they ignite and explode in the vent of the volcano. The force of a volcano explosion can be so powerful that a huge “funnel” remains in place of the mountain after the eruption ( caldera), and if the eruption continues, then a new volcano begins to grow right in this cavity.

However, it happens that magma manages to find an easy way out to the surface of the Earth, then lava flows out of volcanoes without explosions at all - like boiling porridge, gurgling, overflows over the edge of the pan (for example, volcanoes erupt on the Hawaiian Islands). Magma does not always have enough strength to come to the surface, and then it slowly solidifies at a depth. In this case, the volcano does not form at all.

How does a volcano work anyway? When the "valve" in the Earth opens (the cork of the volcano is knocked out), the pressure in the upper part of the magma chamber decreases sharply; below, where the pressure is still high, the dissolved gases are still part of the magma. In the crater of the volcano, gas bubbles are already beginning to emerge from the magma: the higher, the more of them; these light "balloons" rise up and carry the viscous magma with them. A continuous foamy mass is already forming near the surface (hardened volcanic stone foam is even lighter than water - this is known to everyone pumice). Degassing of magma is completed at the surface, where, breaking free, it turns into lava, ash, hot gases, water vapor and rock fragments.

After a rapid process of degassing, the pressure in the magma chamber decreases, and the volcanic eruption stops. The crater of the volcano is closed by solidified lava, but sometimes not very firmly: enough heat remains in the magma chamber, so volcanic gases can escape to the surface through cracks ( fumaroles) or jets of boiling water ( geysers). In this case, the volcano is still considered active. At any moment, a large amount of magma can accumulate in the magma chamber, and then the eruption process will begin again.

There are cases when volcanoes erupted, silent for 300, 500, and 800 years. Volcanoes that have erupted at least once in human memory (and can start again) are called sleeping.

Extinct (or ancient) volcanoes are those that were active 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 (there were no dinosaurs back then).

Let's summarize.

As a result of the movement of lithospheric plates, magma chambers can arise. If liquid magma erupts to the surface of the Earth, a volcanic eruption begins. Often a volcanic eruption 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 can wake up (come to life) if the movement of the plates continues and the magma chamber is filled again. Volcanoes die out completely if the movement of plates in the area stops.

Answered: Vladimir Pechenkin, Yuri Kuznetsov, Albert

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Let me express a slightly different version of events during volcanic eruptions. Of course, the fact that the solid crust of the lithosphere lies on liquid magma is absolutely true. But the reason for the eruption is likely to be different. It is known that the temperature of magma is about 1000 degrees C. The temperature of the Earth's surface does not exceed 50 degrees C. There is a temperature gradient, which leads to a heat flow from hot magma to a cold surface. And this inevitably causes cooling of the upper layers of magma and its subsidence: it is known that ALL BODIES SHRINK DURING COOLING! In this case, the magma on which the crust "lies" leaves from under the crust. In the center of lithospheric plates, this does not lead to any serious consequences. The bark just settles all over. But in rift zones, i.e. at the points of contact of the lithospheric plates, the continuity of the crust is broken. Moreover, gaps and cavities are observed in these zones in the cortex. It is possible that individual huge fragments of the crust hang over the magma settling as a result of cooling. When the strength of this fragment becomes insufficient to hold it, it settles, putting pressure on the magma, and squeezing it to the surface through the weakest parts of the crust, usually through the vents of volcanoes.
By the way, if a fragment of the crust "hangs" over the magma for a long time, but still, in the end, it collapses into magma, which waits for waves in the magma. At the same time, the earth's crust "swings" on these waves. This is how earthquakes happen. Thank you for your attention. barjer

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Dear PavelS! Do you really think that there is no magma under the oceanic crust? By the way, the crust under the ocean is much thinner than under the continents: 7-6 km against 40-80. Underwater volcanic eruptions are well known. Sometimes they are also accompanied by the collapse of fragments of the crust, which gives rise to tsunamis - single or double, triple waves falling on the continents. The fact that underwater eruptions are more rare only means that under a layer of water, which is a good insulator, cooling of magma occurs more slowly. Therefore, its deposition is a rarer event. However, underwater eruptions, as such, are far from uncommon. Underwater earthquakes are less common, apparently because the crust is less durable and more often it is its subsidence rather than collapse.

Best regards barjer

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Dear Etwas. You are correct in your doubts about the hardness of the core. As for the Earth's magnetic field, it is acquired. The earth is not the generator of its magnetic field. It is wound by them from the m field generated by the Sun. If you want to know more, then read the book by S.M. Isaev "The beginnings of the theory of ether physics and its consequences" (Publishing house "Kom. kniga". Catalog on the Internet: http://URSS.ru). You can also order his new book through the Moscow publishing house of educational and scientific literature URSS "Evre, electron, ether and the Isaikan postulate"

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The version of the authors of the article that the cause of volcanic eruptions are the processes of degassing of magma and the movement of tectonic plates is doubtful. Even just from common sense and the need for huge energies, the version of the spontaneous movement of masses of the mantle matter seems unconvincing. Energy sources for the movement of tectonic plates are purely hypothetical.
At the same time, there is a fundamentally different theory of the global tectonics of the earth, based on the expansion of the Earth from within. There is a rather extensive scientific literature on this topic, where the hypothesis of the Earth's expansion is substantiated on hundreds of facts. In this regard, one can point to the book of the Australian scientist W. Carey "In Search of the Patterns of the Development of the Earth and the Universe" /M. Mir, 1991. 447 p./, works by Chudinov Yu.V. (Geology of active oceanic oceans and global tectonics. M. Nedra, 1985. 248 p.) (Chudinov Yu.V. Key to the problems of global tectonics//Science in Russia 1999, N 5, pp. 54-60). (V.Neiman. Newspaper "Socialist Industry", October 2, 1980) (V.B.Neiman Expanding Earth. M. Geografgiz, 1963. 185 p.)
In these works, the very fact of the expansion of the Earth from within is substantiated, but, alas, this expansion does not find a theoretical explanation. However, as Yu.V. Chudinov "The current absence of a physical explanation for the expansion of our planet is not an argument against it."
According to the concept of the expanding Earth, it is not subduction (crawling of one plate onto another), but abduction, that is, creeping out of one plate from under another. The earth bursts apart from the inside and bursts "at the seams" in the form of earthquakes, magma is squeezed out in weak places in the form of volcanic eruptions.

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• Dear Sergey (sorry, I don’t know the patronymic)! I am not familiar with all the works you listed. I am familiar with the work of Chudinov, "Geology of active oceanic ..." and further, and a number of others in which similar ideas are expressed. In none of them is there not only a theoretical substantiation of this idea, but no reasonable reason for such an expansion is given. Reasonable, I think, is a reason that could somehow be tied to known physical laws or phenomena.
  Tell me why on earth a cooling body - and there should be no doubt that the Earth is cooling, if only because of the presence of a temperature gradient between the bowels and the surrounding space - will expand? Let me remind you that the temperature of magma erupting from the subsoil adjacent to the surface is approximately 1000 degrees C, and the temperature of the stratosphere is somewhere around minus 100 degrees C.

  Further. The authors' references to abduction are refuted by repeated measurements of shear deformations in the lithosphere. So. In the so-called rift zones, i.e. in the contact zones of the lithospheric plates, where subduction or abduction can be observed, the face of compressive stresses, while in the central parts of the lithospheric plates, on the contrary, tensile strains. This means that the lithospheric plates in the places of their contact not only "crawl", but with decent forces PRESSURE on each other. But in the central regions of the plates, a different picture is observed. There, the thickness of the bark is significantly greater than at the edges. On average, the difference is tens of kilometers. Consequently, the cooling, and hence the thermal compression of the subcrustal magma, occurs more slowly than on the periphery. And since the edges of the slab settle faster, in the center the slab is, as it were, propped up by magma, which, like "over the knee", breaks it, causing tensile stresses and cracking. One of the arguments in favor of the expansion of the Earth from within is these same tensile stresses observed in many areas of the mainland crust. But there are no observations that speak of such stresses in rift zones.

  Finally, you are right about "squeezing out" magma. But, excuse me, don't you think that "squeezing" is more simply explained by the subsidence of the edges of the plates, which occurs as a result of the compression of the cooling magma on which they rest? By the way, in this case there is a simple explanation for earthquakes. They occur when large fragments of the crust, gradually losing their support due to the cooling of the magma, do not settle, but break into the magma, causing waves in it, which rock the crust, causing it to crack, break, and hummock. If this happens under water, tsunamis are born, caused by a sharp subsidence or vice versa by uplifting of the bottom.

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  • Dear barjer, (sorry, I don't know your first name)!
    I agree with you that the version of the expansion of the Earth from the inside looks implausible. However, there are many phenomena pointing to this version. I was very impressed by the book by W. Carey, mentioned in the previous message. It not only provides a large amount of empirical material, but also builds a fairly coherent system that interprets the available data. Numerous data acquire consistency precisely in the case of the expansion of the Earth from within. The only thing that is not in this and other publications is the explanation of the nature of the expansion of the Earth from within.
    The data you cited about the nature of the stress at the edges and in the middle of the lithospheric plates, rather than refute, but confirm the version of expansion from the inside. Indeed, when the sphere expands, the curvature of the surface changes (should change), but the petrified slab does not change its curvature and begins not to fit into the changed sphere, thereby crushing the edges into magma. Hence the compressive stress is greater than in the middle. From here, horizontal shear deformations can arise in the upper layers of the lithosphere in rift zones, creating the impression that the plates are crawling on top of each other. But in fact, only the angle between the plates changes, the surface layer of the plate is compressed and the inner layer diverges. Magma rushes into the resulting crevice, which sometimes breaks out in the form of a volcanic eruption.
    As you can see, the interpretation of the same data can be different.
    In the article by Yu.V. Chudinova (Nauka v Rossii, 1999, N 5, p. 56) shows that the age of the oceanic basement decreases, rather than increases, as it approaches the zone of supposed subduction. From this, he concluded that the plates are pushed out one from under the other, and called the process eduction. (In the previous message I have a mistake in the name). Deep-water drilling on the active margins opposite the trenches did not reveal a single area where the age of the base of the sedimentary cover would become older with approaching the trench, on the contrary, it became younger.
    In the zone of subsidence (assumed from considerations of subduction), there should be a decrease in the heat flux above the cold plate descending into the mantle, but, on the contrary, its increase by several times in comparison with the average Earth's heat flux is observed.
    Instead of an increase in the thickness of sediments in the axial parts of the trenches, their unloading and intense crushing, numerous seismic images show the location of undisturbed horizontally deposited sediments of low thickness (from 200 - 100 m to their complete absence), although usually in the ocean the thickness of sediments is 600 - 1000 m.
    In the areas of supposed subduction, there is widespread evidence of the removal to the surface of huge masses of deep-seated material.
    From all this it follows that, alas, nothing is clear, and we must continue to look for a theoretically correct answer.
    I understand your rejection of the expansion of the Earth from within. Indeed, this has no theoretical explanation. But the version is still there. In Carey's book. Now I do not have it at hand, and I can not reproduce verbatim. Carey has a reference to a Russian scientist of the late 19th century, who, 20 years before Einstein, proposed a theory of gravity based on the aether and its absorption into the planets. Being sucked in, it demolishes everything that is in its path, generating attraction. This does not contradict either Newton or Einstein. The proposed approach only introduces a physical meaning into the known laws and gives them a different interpretation without changing the mathematical relationships. So Carey used the idea (I don't remember the name now) of our compatriot and stated that the sucked-in ether goes to increase the mass and size of the Earth.
    You understand that the idea is very bold. But looking at it shows that not everything is so hopeless.?context=369867&discuss=430 444
    With a good deal, you can immediately solve a number of unresolved problems so far.
    Sergei Ivanovich.
    Added on 13.04.07
    I had to go to the library and make clarifications.
    Australian geologist Samuel Warren Carey refers to the work /Yarkovsky I.O. gravity as a consequence of the formation of matter inside celestial bodies. Moscow 1899 (second edition - St. Petersburg 1912) /.
    AND ABOUT. Yarkovsky hypothesized that there is a transition from imponderable matter (ether) to real matter and that it leads to the appearance of planets and stars. Carey further points out that a few decades later this idea was developed in the USSR from a geological standpoint. A small group of authors have produced several articles and books about it. Among them stand out I.B. Kirillov, V.B. Neiman and A.I. Letavin from Moscow and VF Blinov from Kyiv.
    Until the mid-seventies, Carey himself spoke about the reasons for the expansion of the Earth - I don’t know. In the early eighties, a conference was held in Moscow and a collection of articles / Problems of the expansion and pulsation of the Earth was published. Conference materials. - M. Science. 1984./
    Several options are considered as possible reasons for the expansion of the Earth:
    1. Cyclic pulsations due to changes in density.
    2. Accretion. (attachment to the Earth).
    3. Expansion of the superdense core of the Earth.
    4. Change over time of the gravitational constant.
    5. Weight gain.
    Carey concludes that physicists must look for the cause. "The sooner physicists learn the lesson that follows from such examples (indicating the expansion of the Earth - S.Z.), the sooner they will find new laws necessary to explain these facts. Here lies the key to an important new discovery." /With. 358/
    So gentlemen of physics - look.

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    Dear Barjer, You are right that the rift valleys of the Mid-Ocean Ridges are very passive formations and are just as passive as the Atlantic margins of the African or American continents. But you should pay attention to how dynamically active are the transform faults perpendicular to them. If we comprehend this situation, then we can talk about the independent drift of the oceanic crust and not affecting the coast of the Pacific in any way. In the Atlantic region, it drifts from the North and South Poles to the equator, while the continents framing this ocean stopped their similar meridional movement by colliding foreheads. In other words, I urge you to clarify your ideas about global plate tectonics through the cosmo-geodynamic theory of Isaev Sergey Mikhailovich. The URSS publishing house is going to release his new book "Evre, electron, ether and the postulate of Isaikan" one of these days

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Dear Sergey. You are only partly right that the mechanism of motion of the continents is hypothetical. This situation was only until 1987, before the presentation of the report "Cosmogeodynamic evolution of the Earth" by Isaev S.M. at the Leningrad University at the section of planetology in the Space Research Council of the USSR Academy of Sciences. Unfortunately, the revolutionary novelty and open criticism of Einstein's relativism and the coming social changes did not allow the ideas to be shown to the entire scientific community. The community is still in a state of "I heard a ringing, but I don't know where it is." Isaev, along with found and proved a new tangential force of gravitational nature, acting on the hard-crustal formations of the Earth, which is directed from the ecliptic pole to the ecliptic equator of the Earth.

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Comparison and identification of the processes occurring inside the Earth and the kettle has certain limitations. The kettle has heating, as a result of which, in fact, all heat exchange processes occur. The intensity of heating in the kettle significantly exceeds the natural possibilities of heat exchange inside the liquid by heat conduction, resulting in convection flows. In the case of the Earth, there is either no source of heating, or you need to try hard to theoretically substantiate its presence. In the absence of heating of the Earth's substance from the inside, it remains to consider heat exchange processes as the process of cooling the planet from the outside. In this case, convection currents could arise due to uneven cooling of the Earth's surface. But heat transfer depends on the temperature gradient, and cooling is faster where the gradient is larger. That is, the local larger temperature gradient that has arisen (it is not clear how) under natural conditions must certainly decrease. The system, according to the laws of thermodynamics, must strive for thermodynamic equilibrium. Thus, for the emergence and divergence of gradients, reliable sources of energy are needed. So they need to be looked for. And not only for convection currents. They are also needed for the horizontal movement of lithospheric plates, in fact, for the movement of continents. Where are the sources of energy for these movements? There is no intelligible answer.

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• Dear Sergei Ivanovich! Your idea of ​​the possibility of compressive stresses in rift zones when the Earth is expanding does not stand up to scrutiny. Obviously, expanding, whether the inner layers of the mantle or the core, it does not matter, are simply obliged to pull apart the crust in all zones, including rift ones, i.e. stresses everywhere must be tensile. However, in practice, the situation is exactly as I said above: it is compressive stresses that are observed in rift zones. To the literature about which I spoke above, I will add a new bibliography. see, for example, the article by L.M. Rastsvetaeva "Alpine-type orogens: contraction-shear model" in the collection "Fundamental problems of geotectonics" Materials XL of the Tectonic meeting, M. GENS, 2007 p. 129. And in the same place: G.F. Ufimtsev. "Phenomena of the latest continental tectogenesis", p. 253.
  A few words about "ethereal expansion". First, the ether, as such, was not found in the experiments. What Atsyukovsky, for example, is talking about is not some kind of special ether at all, but ordinary transparent material media, if we are talking about the medium of propagation of light (more on this in my book "Physical Essays", which is in Leninka and the store "Fizmat kniga", tal 409 93 28). In addition, it is very difficult, as you rightly say, to imagine what the hell this "ether" will suddenly force its way into the Earth, or who or what will drive it there.
  As regards convection flows in the layer of the Earth's magmatic mantle, of course, they can take place, but they are unlikely to be related to certain stresses in the crust. The source of energy, which leads to the emergence of a temperature gradient that causes the Earth to cool, is precisely the molten magma itself, the temperature of which is not less than 1000 degrees C higher than the outer temperature of the crust. But convection flows in the magmatic mantle can arise only if the dynamic equilibrium in its layers is disturbed, for example, when magma erupts outward.
  Now to the horizontal movements of the plates. Still, the concept of "continental drift", which is associated with millimetric counter movements of the edges of lithospheric plates, is most likely associated with the very subsidence of these edges, caused by cooling and compression of the magmatic mantle.

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Dear Sergey. The source of energy is inside the Earth. Imagine the model of the Earth not as a primitive gravitating ball, but as a real figure of rotation, i.e., an ellipsoid of rotation. Then you will see a zero gravitational potential in the geometric center of the Earth and the center of mass is no longer a point, but the focal circle of the ellipsoid of revolution. You will see that there is a radial acceleration region between the geometric center and the focal circle, and when interpolated to a three-dimensional figure, this acceleration region extends to the poles along the axis of rotation. According to the theory of Isaev mentioned above, in the central region of the Earth there is a natural thermonuclear reactor in the form of the indicated gravitational accelerator.

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Dear bajer! In vain do you doubt that the Earth is cooling down. The presence of a temperature gradient existing near the Earth does not prove anything. The included burner also has a gradient there, while it warms up.

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Why are you, gentlemen scientists, so inattentive and absent-minded. You have such smart discussions, you read and think, there are educated people /here I'm not being very ironic/. And then, rraz, some garbage comes out ... And what should we, losers, think after that? rummage once again in "Google" is also not very hunting ...
At first, the temperature of magma in the upper horizons was 1000 degrees C. And then suddenly "celsius" turned into "kelvin". It's far from the same thing. So who is really "hiding" under the number 1000?

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I read the arguments, I was surprised.
Answer me, gentlemen of physics, simple questions:
1. Stars and planets heat up due to compression. BUT
also due to friction when lowering heavy fractions in depth.
Am I wrong?
2. Is plate movement caused by processes in the mantle? Traffic
there are convection currents in the mantle. So?
3. How can a plate form in the mantle! under another plate!?
Or did I not understand something?

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• Dear AD!
  1. Friction, perhaps, plays some role in the heating of stars and planets, but the main thing is high pressures inside bodies.
  2. The movement of the plates, as such, does not occur, since they have nowhere to move: neighboring plates are in their way. In addition, in order for the plate to move, it is necessary that on the other side it breaks away from the other neighboring one. The movement of the plates is taken to be their settling along the edges as the cooling magma settles. This subsidence is the cause, as I said, of another phenomenon: volcanic eruptions. Settling, the plate squeezes the magma out. Convective magma flows seem to take place. And at the edges of the plates, they are more intense, because it is closer to the surface. This accelerates the cooling of the magma, and hence its subsidence, which in turn causes the plate edges to subside.
  3. Plates have already formed. Now they thicken as the cooling magma crystallizes.

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  • 1. Let's put it simply, when moving heavier fractions inland, there is a huge potential energy goes into heat. By itself, pressure cannot create an influx of energy. Yes, the planet heats up during compression, but to a certain extent, then the compression stops.
    2. It has long been known that continents move, and this movement has been measured both directly and by geological methods.
    Why does magma have to settle as it cools? If that were the case, the continents would have been submerged in magma long ago. From your words, there is a feeling that the Earth is shrinking, but this is not at all the case. Many bodies expand when cooled! For example, ice.
    3. It's just that there was a theory of the expanding Earth...
    By the way, I'm not sure about the thickening.

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    • Reply

      1. Inside the Earth, the density of matter is higher due to more pressure. And the pressure in the bowels of the planets, as I said, increases according to the hydrostatic law, i.e. proportional to density and depth. Therefore, the lighter upper layers are unlikely to settle inwards.

      2. Pressure, of course, does not create an "influx of energy." More important is not the influx, but the flow of energy. It is created by a temperature gradient that apparently takes place between the hot magma and the cold surface of the planet.

      3. The increase in pressure apparently stops at the center of the planet. It's massive there.

      4. Continents could move if there were free spaces, for example, if they were floating in magma. But in this case, there must be places where magma is on the surface. which is not observed. What is thought to be movement is actually the subsidence of plate edges as the magma cools and settles. It is these plate movements that have been "measured".

      5. Magma - common physical body. Obviously she's not ice. Therefore, like any physical body, it must shrink when cooled. By the way, apart from ice, I do not know of any substance that expands when cooled.
      6. The "theory" about the expansion of the Earth may have existed, but it was substantiated by the problematic absorption of the hypothetical "ether". For some reason, at the same time, it was bashfully forgotten that the "ether" was introduced as weightless and all-penetrating. Why would he linger on Earth?

      7. Regarding the thickening of the plates. I wonder where the solidifying magma should go? It is most natural to assume that its crystallization takes place on the "seeds" of the already frozen crust.

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      Dear barger!
      The hypothetical ether in modern terminology is a physical vacuum, which has an internal energy-momentum. Under certain conditions, the vacuum energy is converted into the form of mass, with all the ensuing consequences, including for the expansion of the Earth.
      But this is a separate issue.
      I have a misunderstanding of the reasons why you ignore facts that do not fit into the concept of plate tectonics (subduction). Your attempt to distance yourself from subduction by the version of the "lowering" of the plates or their edges, makes it completely incomprehensible that the age of the base of the ocean floor in the region of the mid-ridges is approaching zero or has estimates in the region of 10-20 million years. What was in this place of the earth's sphere for 30 or more million years? Subduction at least somehow explained this (and continues to explain). According to this concept, in the region of the mid-ocean ridges, lithospheric plates are moving apart, and on their opposite side, subduction occurs, that is, they sink under other plates. Although this theory is untenable, it explained the indicated fact. In your version of the explanation, this fact also hangs.
      True, the version of subduction has some elements of plausibility only for the Pacific region, where, in addition to the mid-ocean fault, there is a marginal fault along the perimeter of the Pacific Ocean. For other oceans, no subduction zones are visible at all. But there is an expansion zone along the Atlantic and Indian oceans.
      For the concept of subduction, it is generally inexplicable that the age of the ocean floor is everywhere much younger than the geological age of the land. For the continents, the age is estimated at 600 - 700 million years, and the base of the ocean floor in the vast majority is from 0 to 100 - 180, in some places up to 200, 300 million years. And what was on the site of the bottom 400 - 600 million years is unknown.
      It should be noted in this regard that modeling the change in the Earth's radius leads to interesting results. All continents and islands converge into a single continent, perfectly mating along the curves of their modern contours. The question of what was on the site of the Earth's surface, whose age is estimated by small values, simply disappears: this surface simply did not exist, the Earth's surface area was much smaller.
      Dear barjer, finally explain the facts, the absence of subduction manifestations, formulated by Yu. Chudinov (see above), and also explain the nature of the difference in the geological age of various places on the earth's surface.

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      • Hello Sergey! I will begin by explaining the small age of the rocks of the ocean floor compared to the mainland. Water, as you know, has a low thermal conductivity, which is less than that of solid rocks. Therefore, the cooling of magmatic masses under the oceans occurs more slowly than in the regions of rift zones, where the thickness of hard rocks of the crust is also the smallest. The subsidence of plate edges in rift zones occurs much faster than in the middle zones of tectonic plates. The fact is that the hotter magma under the middle areas of the plates, as it were, props up these areas of the plates. As a result, "fracturing" of the plate occurs in these areas. It is in these areas that tensile stresses are fixed. By the way, these processes are observed not only in the middle regions of oceanic plates. The same processes lead to the appearance of tensile stresses in the middle of the Eurasian plate in the Baikal region. These data are available in the literature sources already cited by me.

        In the middle regions of the continental plates, the crystallization of solidifying magma is still taking place on great depths- about 40 - 100 km and more. The age of surface rocks is much older, since they crystallized earlier. In oceanic areas, where the thickness of the plates is much less - about 7-10 km, its crystallization occurs, although slowly, but closer to the surface. Therefore, the age of these rocks is less than that of continental sedimentary ones. By the way, the rates of subduction and growth of oceanic rocks are approximately the same, which indicates sufficient synchronism of both processes. The assertion that "the Earth's surface was significantly (!) smaller" is not supported by calculations of the subduction rate and, as it seems, "spreading", but in fact by cracking of the plates. It should also not be forgotten that water spaces on Earth could appear only after the formation of a continuous solid surface. Moreover, after the main processes of the formation of the earth's relief took place. Otherwise, the water would simply evaporate, in contact with the molten mass of magma. Incidentally, these processes are also observed now where the thickness of hard rocks is small, for example, in the area of ​​the Icelandic Islands and in some areas of the Pacific Ocean, where underwater eruptions are not uncommon. True, on a much smaller scale.

        The theory of the primitive subcontinent of Gondwana is not actually supported by calculations of the rate of subduction and growth of the oceanic crust. On the other hand, calculations of the compression of the lithosphere, taking into account the thermal conductivity of the rocks of the lithosphere and the ocean, taking into account the influx of heat from the Sun, correspond quite accurately to the subduction rate.

        Regarding the ether, which, as you say, is "a physical vacuum that has internal energy-momentum." Name at least one experiment in which this "physical vacuum" was discovered? But if he had an impulse, it would not be difficult to detect it. Especially if it is somehow "transformed into the form of mass". So to involve this phenomenon as an element of the theory, at least it is not correct, except perhaps in hypotheses. But after all, it would be good to operate in them not with fantastic, but not too contrary to common sense, physical properties of this "vacuum".

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        • In your answer, the facts cited by Yu.V. Chudinov, are again left without attention. Let me remind them: Why does the age of the plate in the zone of the supposed subduction increase with distance from the basin towards the ocean, why there is no unloading of sediments during subduction, why the thickness of sediments near the basin is less than the average in the ocean, why the heat flow in the subduction zone exceeds the average. Or is it all Chudinov's inventions?
          And one more question: what was on the site of the ocean floor, whose age is estimated at 0 - 180 million years, at an epoch, say, 400 million years ago?
          The fact that the version of the explanation of the expansion of the Earth with the help of the ether is just a hypothesis is not proof of the truth of other hypotheses.

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          • Dear Sergey. In turn, I will also answer Yu. V. Chudinov's questions that you emphasized.
            Firstly, I will make a reservation that I perceive plate tectonics only in principle, that is, the earth's crust has a powerful conveyor horizontal movement and, of course, vertical movements also take place on a smaller scale. The main force that moves the Earth's crust is the tangential component of the gravitational force and it is directed from the ecliptic pole to the ecliptic equator.
            Terrestrial substances have an ecliptic rotation. The Earth's crust began to cool down from the poles. The continents were formed in the same place and subsequently covered with continental glaciation ... As you can see, the scenario is long and completely different, and you will find the answer to all your questions in the cosmogeodynamic theory of Isaev S.M.

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              Until the end of the Paleozoic era, a very peculiar epoch of rotation reigned on Earth, i.e. there was no annual climatic cycle. At this time, the continents were quite firmly consolidated at the poles and even covered with continental glaciation. At the beginning of the Mesozoic, the southern continent split and began to move in split parts to the equator, which led to the kinematics of the rotation of the outer sphere of the Earth (lithosphere) being out of equilibrium. Chronologically, ep. Z. extends from the very formation of the Earth to 230 million years. I imagine the second catastrophe at the time of 150 million years ago - the catastrophic split of the northern mainland against the background of the continuing consequences of the first catastrophe, including the continuation of the process of constant rejuvenation of the oceanic crust.

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              • Studies show that in the area of ​​mid-ocean ridges, the age of the bottom base has a minimum value, and with distance from the ridge, the age of the bottom increases so that the same-aged areas are located symmetrically on both sides of it. These facts led to the conclusion that the mid-ocean ridges are the place of separation of lithosulfur plates.
                Your statement about the constant rejuvenation of the oceanic crust is generally incomprehensible. You can't make a 10 million year old crust into a 5 million year old crust.
                The plates diverging in the middle ridges, with the constant size of the Earth, must inevitably crawl on top of each other from the other side of the plates, or turn into an accordion somewhere in the middle.
                If there is no creeping (subduction) and accordion, then the size of the Earth is increasing.

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                • Dear Sergey. I also consider the data of paleomagnetic studies of the ocean to be correct. The whole problem is that Wegener's theory in terms of interpreting the situation in the area Atlantic Ocean was not correct. Intuitively, Wegeger's predecessor, the American geologist Taylor, was right in assuming that the continents are moving towards the equator. Unfortunately, Wegener's arguments were more convincing in their time and the scientific community went in this direction, and as a result we have a range of problems that you yourself know the mobilists cannot solve.

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                  Dear Sergey. Imagine for a moment that Taylor is right and Isaev is also right about the fact that continents are formed at the poles and a sufficient tangential force moves them along the meridian to the equator. The continent, which covers only the top of the Earth, cannot spread into the expanding latitudes of the spherical Earth without bursting into pieces. And these parts passively diverge from each other as they move to lower broad latitudes. Thus, we come to the ingenious and simple conclusion that the latitudinal Atlantic ridge on a planetary scale is only a passive formation. The mobilists must reject their designs as simply erroneous. It's not difficult to do, you never know, there should be samples. These mistakes are natural, since they did not know the power that was revealed to Isaev.
                  Sergey, you will agree that if the mobilists made a mistake in their designs, this does not mean at all that the size of the Earth should increase.
                  As for the theory of Yarkovsky-Blinov, I think it is not promising. I'm not sure that the balance between the ethereal parts of matter conserved by the Earth and leaving it is disturbed. You don't have to look there.

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                  Is it possible to make a crust with an age of 5 million years from a crust aged 10 million years? Imagine how spatially oriented samples are obtained from many kilometers deep for paleomagnetic research. Once we got the desired age and we are happy about it. Near the mid-Atlantic ridge, luck smiles more often, but what to do in the region of the Angolan thalassacraton (English deep-water basin)? You will not find a well there that would drill down to bedrock. And further. All the same, we are talking about the gradual loss of the old crust by the ocean through constantly emerging transform zones. Some 100 million years have passed (the figure is taken from your question) and we have not been able to find anything older than the age you specified. During this time, the oceanic crust was completely renewed. The formation of a new crust along the rift zones of the mid-ridges occurs in the course of their passive opening, also new bark should also occur at high latitudes. Unfortunately, not enough such studies have been carried out there for a variety of reasons.

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    Hello barger!
    In your phrase "the rates of subduction and growth of oceanic rocks are approximately the same" it is not clear what "growth of oceanic rocks" is.
    Probably in the text the growing parameter is passed. Without specifying this parameter, the significance of the statement about the subduction rate is negligible. In addition, such characteristics as the geological age of the base of the ocean floor, as well as the thickness of sedimentary rocks, have a reverse (for subduction) dynamics of change with distance from the supposed place of subduction towards the ocean, which rather indicates the presence of eduction (movement) of plates, than subduction. Maybe the speed corresponds, only the sign is opposite.
    By the way, for some reason, specific facts confirming the very phenomenon of subduction are not given in the framework of this discussion. It is only indicated that there are many such testimonies. But where is one of them?
    +++++
    Therefore, the age of these rocks is less than that of continental sedimentary ones.
    +++++
    The question is put quite differently. Not why are some rocks older or younger than others, but what was on the site of the earth's surface "before", for example, if the current estimates of the age of the bottom base are 120 million years, what was in this place of the Earth 130 million years?

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From the point of view of modern discoveries, the universe is dominated by vacuum, which is responsible for antigravity. From observations it was found that at large distances all galaxies move away from each other (1929 Hubble). Recent observations have shown that this removal is accelerating (1998 A.G. Riess S. Perlmutter).
As a result, the so-called cosmological constant, which is responsible for antigravity, returned to Einstein's equations. If we write the equation for the Earth (usual Newtonian potential) taking into account the cosmological constant, then we can find that the distances will increase according to the exponential law R(t)=Ro*exp[(((lamda*c^2)/3)^1/2 )*t]
where R(t) is the radius of the earth after time t, Ro is the initial radius of the earth, lamda is the cosmological constant (1.19*10^-35 c^-2), c is the speed of light. t is time in seconds.
From here you can estimate the initial radius of the earth by substituting the modern value and reversing the time (it turns out about 4.8 * 10 ^ 6 m)
it is also possible to obtain an annual expansion of the earth (of the order of 0.46 mm per year.)
Oddly enough, such data was indicated in the books by W. Kerry and P. Jordan "the expanding earth"
True, observational data on the expansion of the Earth have not yet been found. Apparently, there is still no such accuracy of modern instruments. If anyone has met, I will be very grateful.

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Changes in explanations of the causes of volcanic eruptions serve as clear examples of the transition of simple sensory-emotional perceptions of the visible world of volcanism in a person’s head into increasingly complex and fictional (absurd) ones. The beauty and perfection of the real world of the mechanism of volcanic activity by people, unfortunately, is not yet in demand.

The visible world, or fiction: volcanism is caused by the rise of heated deep matter
Observing the outpouring of lava from volcanoes, a person makes an unambiguous conclusion: since lava rises from the depths of the lithosphere, they are hot. It can not be in any other way. But here are a few examples showing that it is unscientific to think this way in natural science. The sun was covered with a dark cloud, and hail began to fall. What, the cloud consists of hailstones? No, from water droplets! Smoke comes out of the boiler chimney. What, is her smoke in the cauldron? No, there is coal, fuel oil, firewood, and smoke is formed during their incomplete combustion. Poop comes out of a man's ass. What, the person is complicated by poop? No, they are formed in the stomach and intestines when food is digested. Maybe lava also arises from the transformation of rocks?

Conviction, without any justification, in the presence of deep energy made it possible to create the following generally accepted idea of ​​the causes and mechanism of volcanism.

There is not the slightest bit of science in the above presentation of the causes and mechanism of volcanic activity. Solid nonsense, or a fictional world.

Lack of deep energy

There is not a single proof of the presence of deep energy, and its absence is numerous.
1. When driving from the 16th century. mines, it was found that with immersion in the bowels of the Earth, the temperature gradually increases. The concept of a geothermal gradient appeared - an increase in temperature when lowering by 100 m. On average, it is 30 C on the planet. Naturally, it was believed that an increase in temperature with depth was caused by the influx of deep heat. Therefore, the deeper you dive, the greater the geothermal gradient will be. The reality turned out to be the opposite.
The temperature of rocks does increase with depth, but not progressively, but regressively, slowing down. The deeper you dive, the lower the temperature increase. From the point of view of common sense, this cannot be. But science operates with real-life facts, not ideas.
2. Direct measurements of temperatures in deep wells indicate first an increase in temperatures, and then a steady decrease. Similar data were obtained when drilling the Kola superdeep well, which was deepened by more than 12 km. The values ​​of the heat flux in it first increased, and from a depth of 5 km they sharply decreased, followed by a stable decrease.
3. The actual distribution of rocks in the observed part of the lithosphere with the change of amorphous with depth to more and more coarse-grained ones prohibits the assumption of the presence of deep energy. During crystallization and recrystallization, with an increase in the size of the crystals, heat is released from the substance, or energy saturation decreases.
4. The presence of the atmosphere, hydrosphere, biosphere and the lithosphere below them indicates that energy comes to the Earth from the Cosmos, and does not rise from its bowels.

A crack cannot reduce pressure at depth, because it does not reduce mass
The lack of deep energy makes further analysis of the generally accepted mechanism of volcanism unnecessary. To show the absurdity of it as a whole, suppose (although this is not the case) that the deep matter is highly heated, but solid. How to transfer it to a molten state? There is only one answer: you need to reduce the pressure. It is proposed to do this with the help of an earthquake crack.
1. The presence of areas where earthquakes occur, but there are no active volcanoes (the mainland Australia, China, Sakhalin, etc.), especially areas of active volcanism, but aseismic (the mainland of Antarctica, the Canary, Seychelles, Hawaiian islands, etc.) indicate that that cracks are not needed for volcanic eruptions.
2. The pressure on the deep matter is caused by the mass of the overlying rocks. A crack, breaking a virtual array (in fact, the stone shell is one) into two blocks, cannot reduce the mass of the substance. In order to reduce the mass and decrease the pressure at depth, it is necessary to remove from the surface of the lithosphere a cover made of rocks several kilometers thick. Nothing like this happens on Earth.
3. A gaping crack at a depth of tens of kilometers can form and cannot exist.
So, even if there were solid highly heated rocks at depth, it would be impossible to transfer them locally to a molten state. Magma cannot form.
Magma cools down as it rises
But let's assume, generally improbable, that in the absence of deep energy, the crack reduced the pressure, and an isolated portion of magma arose. Rising up and in contact with less heated surrounding rocks, according to the second law of thermodynamics, magma must heat these rocks, cooling itself. It will begin to crystallize. The viscosity will increase, the rise will stop. How would you react to a person who claims that in a room with a temperature of 20 degrees. With he put a bucket of hot 90 deg. From the water. The temperature of the water in the bucket will not change after an hour. But the same thing happens with magma.
When degassing, magma cools down and cannot become lava.
Volcanoes pour out lava, not magma. Lava is magma devoid of volatile substances: water vapor and gases. Even if there was magma, its degassing, or a decrease in the content of the most energy-saturated gas fraction in it, would lead to cooling of the molten mass. Lava cannot theoretically form from magma with a temperature close to the beginning of its crystallization. This is another invention!
Explanation of volcanism using magma - an example of a perpetual motion machine of the second (thermal) type
But the lava nevertheless rises, without cooling, to the surface of the lithosphere and there causes a volcanic eruption. The temperature of the lava in the outflowing flow, according to direct measurements, is at least 1200 C, or the same as when magma originated. This is an example of a perpetual motion machine of the second (thermal) type, when heat losses due to the thermal conductivity of a substance are not taken into account. A perpetual motion machine of the first (mechanical) type is imagined without energy losses from friction. Not a single academy of sciences accepts projects of perpetual motion machines, and volcanism is explained with its help, and people do not notice the absurdity of this.
Fictions refer not only to the content of the physical side of the generally accepted view of the mechanism and causes of volcanism, but also to chemistry.
Magma is not a melt, but a solution
First of all, magma does not change its shape throughout its long ascent and contact with host rocks of a different composition. chemical composition. How was basaltic when it appeared in upper mantle, and pours out onto the surface of the lithosphere. The explanation for this is seen in the fact that magma is called melts, although it is not such.
melt, by physical chemistry, is an individual stoichiometric substance in the liquid state, crystallizing at the melting point. In natural science, the concept of "melt" is not respected, not in demand, therefore, for example, in the TSB of the third edition, such a word is absent.
Individual means pure substance. Iron in a molten state is a melt. But as soon as a little carbon gets into it, it becomes a liquid solution of carbon in iron: steel or cast iron. When cooled, steel or cast iron will be a solid solution of carbon in iron. And since there are no pure substances in nature, there are no melts. Even sodium chloride in a molten state (liquid, but without the participation of water) will only be a melt if the ratio of sodium cations to chloride anions is exactly 50:50 (observance of the stoichiometry requirement), which does not happen in reality. A melt, unlike a solution, always keeps its chemical composition constant. This does not apply to a solution.
Magma, as a complex silicate substance, besides containing water vapor and gases, cannot be called a melt. It is, in chemistry, a highly heated liquid solution. Therefore, its chemical composition during the rise would necessarily have to change. Therefore, from the chemical composition of the lava, it would be impossible to speak about the chemical composition of magma in the upper mantle, even if magma did arise.
It is impossible to obtain a layered shell of medium composition from basaltic lava.
From the upper mantle, according to modern geology, basaltic magma rises, which then becomes lava of the same composition. Nothing but small portions of ultramafic magma leaves the depths of the globe. On the surface of the lithosphere, basalt and its tuffs are destroyed, which leads to the formation of an actually observed layered shell from layers of mudstones, sandstones, limestones, and other rocks. The question is, what will be the chemical composition of the substance of the layered shell, if it is formed from basalt? There is only one answer: basalt. But he is different!
The chemical compositions of basalt and layered shell differ significantly. The composition of basalt is basic, and the layered shell is medium. Basalt contains more alumina and iron oxides. Magnesium oxide is more than 2.5 times, calcium oxide - 3 times, sodium oxide - 2 times. At the same time, there is less silica and potassium oxide in basalt than in the material of the layered shell. Nothing of the kind could have happened if the substance of the layered shell was formed due to basalt.
It turns out that basalt does not take part in the formation of the chemical composition of the layered shell, or the primary basaltic magma (lava) does not rise to the surface of the stone shell of the globe. From the generally accepted idea of ​​the causes of volcanism, it follows that buckwheat (basalt) comes from the depths, from which semolina (layered shell) is prepared on the surface during hypergenesis. This is fiction!
How did such a fictional notion of volcanism come about?
V.M. Dunichev

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History of views on the causes of volcanism
Everything unknown in a person causes fear, discomfort. Having found out the obscure, a person feels relieved, and it does not matter whether this explanation is scientific or not. The greatness of volcanoes and the power of volcanic eruptions have always testified to man about the power of nature, prompting him to find out the cause of this terrible phenomenon.
What did the ancient Greeks and Romans think about volcanoes?
At an early stage in the history of mankind, when people did not yet separate themselves from nature (did not call themselves Homo sapiens), the whole world around was perceived as spiritualized (living). Spirits were good and evil. The latter were usually placed underground, in connection with which the idea of ​​\u200b\u200ba scary, frightening underworld was formed. Good spirits lived in the sky, from where came the warmth of the sun and the life-giving power of rain. In addition to the events of everyday life, powerful natural phenomena, such as volcanic eruptions and earthquakes, were also deified. Gradually, various myths arose and then existed for a long time, in which not only formidable natural phenomena, but attempts were also made to explain them even more naively (directly).
Almost 10 thousand years ago, Homer told about the meeting of Odysseus with the Cyclops - a huge idol with a burning eye inserted into his forehead. In anger, the Cyclops throws huge boulders, making a terrible roar. Who does the Cyclops resemble? Yes, this is a volcano with a crater glowing at the top, from which volcanic bombs fly out with noise.
Let's get acquainted with the ancient Greek myth "The struggle of the Olympian gods with the titans." At first there was only eternal boundless dark Chaos. From it arose the world and the immortal gods, including the goddess of the Earth - Gaia. In the immeasurable depths underground, the gloomy Tartarus was born - a terrible abyss full of eternal darkness.
The mighty Earth gave birth to the boundless blue sky - Uranus. Uranus took Gaia as his wife. They had six sons and six daughters - powerful and formidable titans. Gaia also gave birth to three giants - cyclops, and three huge, like mountains, hundred-armed giants - hekatoncheirs. Uranus disliked his giant children and imprisoned them in the deep darkness of Tartarus in the bowels of the goddess Earth. One of the sons of Uranus, Cronus, overthrew his father by cunning and took away his power. In turn, the son of Cronus, Zeus, when he grew up and matured, rebelled against the despotism of his father. Together with other children of Kron, Zeus began the fight with his father and the titans for power over the world. The Cyclopes came to the aid of Zeus, forging thunder and lightning for him, which he threw at the titans.
The struggle lasted ten years, but victory did not come to either side. Then Zeus freed from the bowels of the hundred-armed giants - hekatoncheirs. Coming out of the bowels of the earth, they tore off whole rocks from the mountains and threw them at the titans. A roar filled the air, the earth groaned, everything shook around. Even Tartarus shook from this struggle. Zeus threw his fiery lightning and roaring thunders. The whole earth was engulfed in fire, smoke and stench shrouded everything in a thick veil.
Could not stand it, the titans trembled. Their strength was broken. Zeus with the gods of Olympus bound them and cast them into the gloomy Tartarus, placing a guard of hecatoncheires at the gate so that the mighty titans would not break free.
Gaia was angry with Zeus for such a cruel fate to her defeated children - the titans. Having entered into marriage with Tartarus, she gave birth to a terrible hundred-headed monster - Typhon. He rose like a mountain from the bowels of the Earth, shuddering the air with a wild howl. A bright flame swirled around Typhon. The earth itself shook under his heavy feet. But Zeus was not intimidated by the sight of Typhon. He entered into battle with him, releasing his fiery arrows and peals of thunder. The earth and the vault of heaven shook to their foundations. The earth flared up with a bright flame, just like during the fight against the titans. The seas boiled at the mere approach of Typhon. Hundreds of fiery arrows-lightnings of the Thunderer Zeus rained down. It seemed that even the air and dark thunderclouds were burning from their fire.
Zeus incinerated all one hundred heads of the monster. Typhon collapsed to the ground. Such heat emanated from his body that everything around him melted. Zeus raised the body of Typhon and threw him into Tartarus. But even from there Typhon threatens the gods and all living things. It causes storms and eruptions.
Very figuratively, the myth describes the eruption of pyroclastic material first, and then the outpouring of lava.
Since the time of the ancient Romans, the main terms that characterize the volcano and volcanic activity itself have been established in the minds of people: ash, slag, an extinct volcano, a volcanic focus, and others. The ancient Romans, in a conical shape with a hole at the top, from which smoke and ash come out, lava pours out, saw a huge forge in the volcano. Inside it works the blacksmith god - Vulcan. In the forge, as you know, there is a hearth. Solid combustion products are ash or ash and slag, melted refractory residues. The forge is active and extinct.
Explanation of the mechanism of volcanic activity by combustion in near-surface voids of combustible substances
With the end of the mythological perception of the surrounding world, the time of logos began, when logically consistent conclusions were made based on the observed phenomena. The ancient Greeks, based on the wide development of caves, funnels and depressions on their territory - manifestations of karst, considered the Earth penetrated at a depth of voids and channels connecting them. Air, water and fire circulate through the voids. Movements of water and air shake the surface of the Earth, causing earthquakes. Fire moving through voids and channels, when breaking through to the surface, leads to volcanic eruptions.
The ancient Greeks saw the world as they saw it. Knowledge about any subject corresponds to the essence of the subject itself. The world is the same everywhere. Such representations served as the basis for the creation of sensually visual images of the visible world of nature.
An encyclopedic description of the world from these positions was given by Aristotle (384-322 BC). He took the driving force of volcanic eruptions, compressed air in the depths of the Earth, throwing out ash (ash) and raising lava.
Not coming close to an active volcano, the ancient Greeks saw, especially at night, ejections of fire from it. In fact, red-hot ash is thrown out. If the wind blew from the volcano, then a specific smell was felt, taken for the smell of sulfur, or rather, burning sulfur. Since then, the idea has been established that the essence of volcanism is the release of fire from the crater. It was believed that burning sulfur or asphalt (combustible earth).
It is generally believed that Pompeii and other cities and villas in 79 were covered with the products of the eruption of Mount Vesuvius. But there was no such volcano then. There was Mount Somme, which was not mistaken for a volcano, because in the memory of people there were no eruptions. After the catastrophic eruption of the Somma in 79, a caldera formed on its top. In this caldera, after 93, the next eruption occurred, as a result of which a cone appeared, called Vesuvius, which almost completely blocked the Somme at the present time. The full name of the volcano near Naples is Somma Vesuvius (Monte Somma Vesuvius).
From then until the beginning of the 19th century. it was believed that if you find the reason for the release of fire from the crater, you can explain the mechanism of volcanism. For example, in 1684, M. Lister formulated a hypothesis according to which the activity of volcanoes was caused by ignition in the bowels of the earth under the action of sea ​​water sulfur pyrites (from modern concepts, during the oxidation of pyrite - FeS2).
In 1700, N. Lemery (1645-1715), professor of chemistry at the Sorbonne University in Paris, experimentally confirmed it by modeling a volcanic eruption by spontaneous combustion of a mixture of moistened sulfur and iron filings. He prepared a mixture of sulfur, iron filings and water in front of the public in his garden and asked the lady to bury the mixture in the ground. Through certain time the mixture was so strongly heated that a small cone appeared, through the gaps in which flames came out. The experience produced a special effect at night - the public watched the eruption of a small artificial volcano. It seemed to people then that the mechanism of volcanism was completely elucidated. M.V. Lomonosov (1711-1765) and the first explorer of Kamchatka S.P. Krasheninnikov (1711-1755). As noted by S.P. Krasheninnikov, according to frequent earthquakes, one can speak about the presence of voids and combustible material in the bowels of Kamchatka. The reason for the burning of the hills was seen by them in the contact of salty sea water, penetrating into the depths through cracks, with ores of iron and combustible sulfur, which led to ignition.
In the second half of the XVIII century. and in early XIX in. volcanism was explained by the burning of coal seams. This was substantiated by the professor of the Freiberg Mining Academy in Saxony A.G. Werner (1750-1817) - the founder of the first hypothesis of neptunism in geology.
Explanations of volcanism by the rise of deep energy and matter (outpouring of lava)
Observations of active volcanoes in South America and Indonesia led scientists at the beginning of the 19th century. to the conclusion that the essence of volcanism is not in the release of fire from the crater, but in the outpouring of lava. The first to convince people of this was the German naturalist A. Humboldt (1769-1859), who substantiated the deep nature of volcanism. At that time, the Kant-Laplace hypothesis of the formation of the Earth from a hot fire-liquid ball was adopted by science. Cooling down, the globe was covered with a cooling crust - the earth's crust, 10 miles thick, below which the primary molten material of basalt composition was preserved. Through the cracks that cut through the cracking earth's crust, the melt rises up, causing a volcanic eruption. A. Humboldt concluded that volcanic phenomena are the result of a permanent or temporary connection between the molten interior and the surface of the globe. At first, such explanations of the causes of volcanism seemed strange to people, when it was clear from the ancient Greeks that this was the result of the ignition of combustible substances. What to teach students, what to do with textbooks? But gradually they agreed with them and began to consider them the only possible ones.
One of the mandatory features that characterize science is acceptability. This is expressed in the fact that the previous explanation should be an integral part of ...

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CONTINUED... the next. If the new explanation ignores the previously existing one, then the new one, like the old one, cannot be called scientific knowledge. In this case, volcanism was first explained by the burning of combustible substances in surface conditions, and then by the rise of molten material from the depths. There is no acceptability. Consequently, neither the first nor the second idea has any relation to science.

Meanwhile, by the middle of the XIX century. it was found that there are no molten interiors of the Earth, and the earth's crust could not have formed on a molten ball at all. The fact is that a cooled solid has a higher density (heavier) than a molten one, in which the distances between atoms are greater than in a solid crystalline one. If solid blocks did appear, they would sink down, and the solidification of the planet would have to start from the center. The earth's crust, therefore, is initially a false, unscientific idea. Therefore, this term is not used by me, except in historical references. It is necessary to say not "the earth's crust", but the lithosphere - a stone shell. They do not call the water shell a condensation shell, but call it the hydrosphere according to the constituent substance, excluding ideas about its origin.

In addition, at the same time it turned out that the tides, arising under the influence of the Moon and the Sun, manifest themselves not only in the hydrosphere, causing periodic fluctuations in sea level, but also in a solid stone shell. Insignificant fluctuations of the earth's surface from such ebbs and flows testified to the great elasticity of the substance of the globe, which is impossible in the liquid state of its bowels. If there was a hard crust 10 miles thick on the molten shell, then it would periodically rise and fall several centimeters during the day, which is not observed.

The final proof of the hardness of the bowels of the globe was obtained by those who began in the second half of the 19th century. seismic research. It was found that elastic vibrations arising from tectonic earthquakes, both longitudinal, tension and compression, and transverse, such as shear, can be traced to depths of 3 thousand kilometers, which would be impossible if there was a belt of molten material inside the Earth. Shear-type deformations, i.e. with violation of the continuity of the medium, in liquids are impossible; they are extinguished there. Why? Because in liquids, especially in gases, as amorphous highly energy-saturated substances, atoms constantly move randomly at high speeds (in air, for example, under normal conditions at speeds of several hundred meters per second) and do not allow the appearance of a void.

Naturalists are faced with a strange situation: there is no ready-made liquid melt in the bowels of the globe, and volcanoes reliably pour it out, raised from the depths. So, it was thought then, it is necessary to come up with a mechanism for obtaining at a depth of molten material from solid.

A way out was proposed by E. Reyer, who published in 1887 in Vienna "Physics of Eruptions", and in 1888 in Stuttgart "Theoretical Geology". He suggested that if a crack appears in the overlying solid masses during an earthquake and, as a result, the pressure begins to decrease, then the heated deep matter will turn into liquid state and, breaking out, will cause a volcanic eruption. It was proposed to call such a molten mass formed magma (Vogelsang and Rosenbusch, 1872), and the rocks resulting from its cooling igneous or igneous. This is the basis of modern ideas about the causes and mechanism of volcanism.

So, it turned out that there is no deep energy, as well as magma. If magma had arisen, it would have cooled as it rose, just as it did during degassing. Volcanoes erupt or eject lava that rises from below. Why does lava not cool down upon contact with less heated host rocks and degassing? This question can be formulated differently: can the water temperature of 900 C in a bucket remain for some long time in a room with an air temperature of 200 C? For all the seeming absurdity of the question, the logically demonstrative answer to it is simple: maybe, if the water is heated by an external heat source. There is no heating of lava from below. Heat cannot sink down. Consequently, the lava is heated from the sides.

The generally accepted explanation of volcanism by the rise of deep energy and matter is unscientific. What is the scientifically consistent rationale for the causes of volcanism? Other means the opposite. Energy for volcanic eruptions does not come from the depths of the lithosphere, but to its surface. It's solar power!

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In the new millennium, the most terrible reports of disasters come from countries with high tectonic activity. Earthquakes cause huge destruction, provoke tsunamis that wash away entire cities:

• tsunami in Japan in 2011 (16,000 victims);
• earthquake in Nepal in 2015 (8,000 victims);
• earthquake in Haiti in 2010 (100-500 thousand dead);
• tsunami of 2004 in the Indian Ocean (according to confirmed data 184 thousand in 4 countries).

Volcanoes in the new century bring only minor inconveniences. Emissions of volcanic ash interrupt air traffic, cause discomfort associated with evacuation and the unpleasant smell of sulfur.

But this has not always been (and will not always be) the case. In the past, the largest eruptions caused much more serious consequences. Scientists believe that the longer the volcano sleeps, the stronger its next eruption will be. Today in the world there are 1500 volcanoes up to 100 thousand years old. 500 million people live in the immediate vicinity of the fire-breathing mountains. Each of them lives on a powder keg, because people have not learned how to accurately predict the time and place of a probable disaster.

The most terrible eruptions are associated not only with magma escaping from the depths in the form of lava, but also with explosions, fragments of flying rock, and changes in relief; smoke and ash covering vast areas, carrying chemical compounds deadly to humans.

Consider the 10 most deadly phenomena of the past, which led to a volcanic eruption.

Kelud (about 5,000 dead)

The active Indonesian volcano is located 90 kilometers from the second most populous city in the country - Surabaya, on the island of Java. The strongest of the officially recorded eruptions of Kelud is considered a catastrophe that claimed the lives of more than 5,000 people in 1919. A feature of the volcano is a lake located inside the crater. On May 19 of that year, the reservoir, boiled under the influence of magma, brought down about 38 million cubic meters of water on the inhabitants of nearby villages. Along the way, silt, mud, stones mixed with water. The population suffered, to a greater extent, from the mudflow than from the explosion and lava.

After the incident in 1919, the authorities took measures to reduce the area of ​​the lake. The last eruption of the volcano is dated 2014. As a result, 2 people died.

Santa Maria (5,000 - 6,000 victims)

The volcano, located in the central part of the American continent (in Guatemala), slept until the first eruption in the twentieth century for about 500 years. Having lulled the vigilance of the locals, the earthquake that began in the autumn of 1902 was not given much importance. The most terrible explosion that sounded on October 24 destroyed one of the mountain slopes. In three days, 5,000 residents were killed by 5.5 thousand cubic meters of magma and ruptured rock. A column of smoke and ash from the smoking mountain spread 4,000 km to the American San Francisco. Another 1,000 residents suffered from epidemics triggered by the eruption.

Lucky (over 9,000 dead)

The most powerful known eruption of Icelandic volcanoes lasted 8 months. In July 1783, Lucky woke up quite unhappy. Lava from its mouth filled about 600 square kilometers of the island. But the most dangerous consequences were puffs of poisonous smoke, which could be observed even in China. Fluorine and sulfur dioxide killed the entire crop and most of the livestock on the island. Slow death from starvation and toxic gas overtook more than 9,000 (20% of the population) inhabitants of Iceland.

Other parts of the planet also suffered. Decreased air temperature in the Northern Hemisphere as a result of the catastrophe led to crop failure throughout the United States, Canada and parts of Eurasia.

Vesuvius (6,000 - 25,000 victims)

One of the most famous natural disasters happened in 79 AD. Vesuvius, according to various sources, killed from 6 to 25 thousand ancient Romans. For a long time, this catastrophe was considered a fiction and a hoax by Pliny the Younger. But in 1763, the excavations of archaeologists finally convinced the world of the existence and death, under a layer of ashes, of the ancient city of Pompeii. The smoke screen reached Egypt and Syria. It is authentically known that Vesuvius destroyed as many as three cities (also Stabiae and Herculaneum).

The Russian artist Karl Bryullov, who was present at the excavations, was so impressed with the history of Pompeii that he dedicated the most famous of the paintings of Russian painting to the city. Vesuvius still poses a great danger, it’s not for nothing that our site has an article about the planet itself, in which Vesuvius is given special attention.

Unzen (15,000 dead)

Not a single rating of disasters is complete without the land of the rising sun. The most powerful eruption in the history of Japan took place in 1792. The Unzen volcano (in fact, it is a complex consisting of four volcanic domes), located on the Shimabara Peninsula, is responsible for the death of 15 thousand inhabitants, he played the role of an intermediary. Unzen, which had been erupting for several months, gradually, as a result of tremors, displaced one of the flanks of the Mayu-Yama dome. A landslide caused by rock movement buried 5,000 residents of Kyushu under it. Twenty-meter tsunami waves provoked by Unzen brought great sacrifices (10,000 dead).

Nevado del Ruiz (23,000 - 26,000 victims)

Located in the Colombian Andes, the Ruiz stratovolcano is infamous for its lahars (a stream of mud made from volcanic ash, rock and water). The biggest convergence occurred in 1985 and is better known as "The Tragedy of Armero". Why did people remain so dangerously close to the volcano, because even until the year 85, lahars were the scourge of the region?

It's all about fertile soils, generously fertilized by volcanic ash. The prerequisites for a future disaster became noticeable a year before the incident. A small mudflow blocked the local river, and magma rose to the surface, but the evacuation never took place.

When a column of smoke rose from the crater on November 13, local authorities advised people not to panic. But a small eruption led to the melting of the glacier. Three mud flows, the largest of which reached a width of thirty meters, destroyed the city in a matter of hours (23 thousand dead and 3 thousand missing).

Montagne Pele (30,000 - 40,000 dead)

1902 brought another deadly eruption in our ranking. The resort island of Martinique was hit by the awakened stratovolcano Mont Pele. And again, the carelessness of the authorities played a decisive role. Explosions in the crater, which brought stones down on the heads of the inhabitants of St. Pierre; the volcanic mud and lava that destroyed the sugar factory on May 2 did not convince the local governor of the seriousness of the situation. He personally persuaded the workers who had fled the city to return.

And on May 8, there was an explosion. One of the schooners that entered the harbor decided to leave the port of Saint-Pierre in time. It was the captain of this ship ("Roddam") who informed the authorities about the tragedy. A powerful pyroclastic flow covered the city with great speed, and when it reached the water, it raised a wave that washed away most of the ships in the harbor. In 3 minutes, 28,000 residents were either burned alive or died due to gas poisoning. Many died later from their burns and wounds.

An amazing rescue was given by the local prison. The criminal imprisoned in the dungeon passed both the lava flow and the poisonous smoke.

Krakatoa (36,000 casualties)

The most famous volcanic eruptions to a wide range of people are led by Krakatoa, which collapsed in 1883 with all its fury. The destructive power of the Indonesian volcano impressed contemporaries. And today the catastrophe of the end of the 19th century is included in all encyclopedias and reference books.

An explosion with a capacity of 200 megatons of TNT (10 thousand times more powerful than during nuclear bombing Hiroshima) destroyed the 800-meter mountain and the island on which it was located. The blast wave circled the globe more than 7 times. The sound from Krakatoa (perhaps the loudest on the planet) was heard at a distance of more than 4,000 km from the eruption site, in Australia and Sri Lanka.

86% of the dead (about 30 thousand people) suffered from a powerful tsunami caused by a raging fiery mountain. The rest was littered with the rubble of Krakatoa and volcanic debris. The eruption caused global climate change on the planet. The average annual temperature, due to the negative impact of the emitted smoke and ash, fell by more than 1 degree Celsius and recovered to its previous level only after 5 years. Large casualties were avoided due to the low density of population in the region.

Since 1950, a new volcano has been erupting on the site of the old Krakatoa.

Tambora (50,000 - 92,000 dead)

The diameter of the crater of another Indonesian (that's who lives on a powder keg) volcano reaches 7,000 meters. This supervolcano (a semi-official term for a volcano capable of causing global climate change) is one of only 20 recognized by scientists as such.

The eruption began according to the usual scenario in such cases - with an explosion. But then an out of the ordinary event happened: a huge fiery whirlwind formed, sweeping away everything in its path. The elements of fire and wind completely destroyed the village 40 km from the volcano.

Like Krakatoa, Tambora destroyed not only the civilization around, but also itself. The tsunami, which happened 5 days after the start of activity, claimed the lives of 4.5 thousand inhabitants. A column of smoke blocked the sun for 650 km within a radius of the volcano for three days. Electrical discharges over the volcano accompanied the entire period of the eruption, which lasted three months. It claimed the lives of 12 thousand people.

The crew of the ship that arrived on the island with humanitarian aid was horrified by the picture of destruction they saw: the mountain was leveled with a plateau, the entire Sumbawa was covered with debris and ashes.

But the worst began later. As a result of the “nuclear winter”, more than 50 thousand people died from hunger and epidemics. In the United States, climate changes caused by the volcano provoked June snow, and a typhus epidemic broke out in Europe. Crop failure and famine followed many places on the planet for three years.

Santorini (death of civilization)

Once a large mountain and an island near Greece, in a picture from space, it appears as a volcanic crater flooded by the waters of the Aegean Sea. It is impossible to establish, even approximately, the number of deaths from the eruption of 3.5 thousand years ago. It is only known for certain that as a result of the eruption of Santorini, the Minoan civilization was completely destroyed. According to various sources, the tsunami formed reached from 15 to 100 meters in height, overcoming space at a speed of 200 km / h.

By the way, Santorini is on our list in the world.

There is an assumption that the legendary Atlantis was destroyed by the volcano, which is indirectly confirmed by many sources of the ancient civilizations of Greece and Egypt. Some Old Testament stories are also associated with the eruption.

And although these versions are still just legends, one should not forget that Pompeii, at one time, was also considered a hoax.

The set of phenomena associated with the movement of magma in the earth's crust and on its surface is called volcanism.

Volcanism can be:

• internal- when magma did not reach the earth's surface, but invaded through cracks and channels in the strata of sedimentary rocks, lifting them up;
• external - movement of magma with its release to the surface.

Magma(from the Greek magma - thick ointment) is a molten mass of predominantly silicate composition, which is formed in the deep zones of the Earth. Magma centers are located in the mantle at a depth of 50-70 km or in the depths of the earth's crust. Reaching the earth's surface, magma erupts in the form of lava through cracks or volcanic vents.

Lava differs from magma in the absence of gases escaping during an eruption.

Depending on the conditions and ways of penetration of magma to the surface, there are three types volcanic eruptions:

• areal eruptions- eruptions that led to the formation of extensive lava plateaus (Decan Plateau, Columbia Plateau);
• fissure eruptions- eruptions that occur along cracks (typical of Iceland, as well as mid-ocean ridges);
• eruptions of the central type- eruptions that are associated with certain areas, located, as a rule, at the intersection of two faults, and occur along a relatively narrow channel.

The typical and most striking expression of volcanism on the earth's surface are volcanoes.

Volcanoes are geological formations that arise above channels and cracks in the earth's crust, through which magma erupts onto the earth's surface. Volcanoes are usually individual mountains built from the products of previous eruptions.

Rice. 1. The structure of the volcano: 1 - volcanic bomb; 2, canonical volcano; 3 - a layer of ash, cinders and lava; 4 - like; 5- the mouth of the volcano; 6 - strength; 7 - magma chamber; 8 - shield volcano

Volcanoes are classified into active, dormant and extinct.

Volcanoes that erupt continuously or periodically are called active.

Asleep Volcanoes are called, the eruption of which is not known, but they retain their shape and local earthquakes occur under them.

Extinct volcanoes are considered to be mostly destroyed or eroded, without any manifestations of volcanic activity during historical period. This division is conditional, since it has been repeatedly observed that volcanoes that were considered extinct began to act.

Volcanic eruptions are long and short-term. Eruption products (gaseous, liquid, solid) are ejected to a height of 1-5 km and are transported over long distances. The concentration of volcanic ash is so great that there is darkness like night. The volume of erupted lava reaches tens of cubic kilometers.

In total, there are 4 thousand volcanoes in the world, of which 540 are active. On the territory of Russia, active volcanoes (38 in total) are located in Kamchatka and the Kuril Islands. The most famous is Klyuchevsky (4850 m) - the highest active volcano in Eurasia, located in the east of Kamchatka. Volcanoes Shevelug, Bezymyanny, Narymsky, Ksudach are very active in terms of frequency and strength of eruption.

Large, but extinct volcanoes are located in the Caucasus - Elbrus (5642 m), Kazbek, Ararat.

Consequences of the strongest volcanic eruptions

Primary damaging factors during volcanic eruptions are: air shock wave, flying fragments, ash, volcanic gases (carbon dioxide, sulfur oxide, hydrogen, hydrogen sulfide, sometimes fluorine poisoning water sources), thermal radiation, lava moving along the slope at a speed of up to 80 km / h at temperatures up to 1000 ° C and burning everything in its path.

Secondary damaging factors - tsunamis, fires, explosions, blockages, floods, landslides. The most common causes of death of people and animals in areas of volcanic eruptions are injuries, burns (often of the upper respiratory tract), asphyxia (oxygen starvation), eye damage. For a considerable period of time after the volcanic eruption, there has been an increase in the incidence of bronchial asthma, bronchitis, exacerbation of a number of chronic diseases among the population. Epidemiological surveillance is established in areas of volcanic eruptions.

The most dangerous phenomena accompanying volcanic eruptions, are lava flows, tephra fallout, volcanic mudflows, volcanic floods, scorching volcanic clouds, and volcanic gases.

lava flows- These are molten rocks with a temperature of 900-1000 °. The flow rate depends on the slope of the cone of the volcano, the degree of viscosity of the lava and its quantity. The speed range is quite wide: from a few centimeters to several kilometers per hour. In some and most dangerous cases, it reaches 100 km, but most often does not exceed 1 km / h.

Tephra consists of fragments of solidified lava. The largest are called volcanic bombs, those that are smaller are called volcanic sand, and the smallest are called ash. The precipitation of tephra leads to the destruction of animals, plants, and in some cases to the death of people.

mud streams- these are powerful layers of ash on the slopes of the volcano, which are in an unstable position. When new portions of ash fall on them, they slide down the slope. In some cases, the ash becomes soaked with water, resulting in volcanic mudflows. Their speed can reach several tens of kilometers per hour. Such streams have a significant density and can carry large blocks during their movement, which increases their danger. Due to the high speed of movement, rescue operations and the evacuation of the population are difficult.

Volcanic floods. When glaciers melt during eruptions, huge amounts of water can form very quickly, which leads to floods.

scorching volcanic cloud is a mixture of hot gases and tephra. Its damaging effect is due to the occurrence of a shock wave (strong wind), propagating at a speed of up to 40 km / h, and a wave of heat with a temperature of up to 1000 °.

Volcanic gases. The eruption is always accompanied by the release of gases in a mixture with water vapor - a mixture of sulfur and sulfur oxides, hydrogen sulfide, hydrochloric and hydrofluoric acids in a gaseous state, as well as carbon dioxide and carbon monoxide in high concentrations, deadly to humans. The release of these gases can continue for a very long time even after the volcano has stopped throwing out lava and ash.

About 200 million people live dangerously close to active volcanoes. During their eruption over the past 400 years, more than 300 thousand people have died.

The largest volcanic eruptions

Volcanic eruptions occur less frequently than earthquakes, but also become giant cataclysms with planetary consequences. Explosion of a volcano on about. Santorini (Aegean Sea, 1470 BC) was the cause of the decline of a civilization that flourished in the Eastern Mediterranean. The eruption of Vesuvius (79 AD) led to the death of Pompeii. The thickness of the ash that covered this city reached 8 m.

Krakatoa volcano eruption August 27, 1883 (Indonesia) was the largest environmental disaster of the 19th century. The eruption was explosive. The explosion destroyed 2/3 of the island, a giant underwater crater up to 300 m deep was formed. The roar of the eruption was heard in Central Australia at a distance of 3600 km. Volcanic ash (up to 50 million tons) rose to a height of 80 km, circled the entire globe and stayed in the atmosphere for several years. This led to a decrease in the average annual temperature on Earth by 0.5 °C. The tsunami that arose during the explosion of the volcano caused destruction on the islands of Java and Sumatra and killed more than 36 thousand people.

However, the most powerful eruption of historical time is considered Volcano Tambora eruption on about. Sumbawa in Indonesia in 1815. The initial height of the volcano (> 4000 m) after the explosion decreased to 2850 m. More than 100 km 3 of rocks were thrown into the atmosphere, a crater 6 x 6.5 km in size and 700 m deep days, an area equal to France, in which millions of people lived, was dominated by pitch darkness. The total death toll was several tens of thousands of people.

In the XX century. the largest volcanic catastrophe occurred in March 1956 in Kamchatka. The eruption also had an explosive character, as a result of which the summit was demolished. Volcano Bezymyanny and ejected to a height of up to 45 km the amount of ash exceeding 6.5 billion m3. At a distance of more than 10 km, the thickness of the layer of volcanic sand and ash reached 0.5 m.

Preventive measures to combat volcanic eruptions consist of changing the nature of land use, building dams that divert lava flows, bombarding the lava flow to mix the lava with the earth and turn it into a less liquid (and therefore inactive) mass, and other methods. Nevertheless, the experience of combating volcanic eruptions, lava flows, and mudflows is very limited. It is virtually impossible at the present time to accurately predict the start of an eruption of any volcano and the intensity of the eruption. The lessons of the past, which could help prevent the death of people, reduce environmental and material damage from the elements, are not properly taken into account.

August 24-25, 79 AD an eruption occurred that was considered extinct Mount Vesuvius, located on the shores of the Gulf of Naples, 16 kilometers east of Naples (Italy). The eruption led to the death of four Roman cities - Pompeii, Herculaneum, Oplontius, Stabia - and several small villages and villas. Pompeii, located 9.5 kilometers from the crater of Vesuvius and 4.5 kilometers from the base of the volcano, was covered with a layer of very small pieces of pumice about 5-7 meters thick and covered with a layer of volcanic ash. With the onset of night, lava flowed from the side of Vesuvius, everywhere fires started, the ashes made it hard to breathe. On August 25, along with the earthquake, a tsunami began, the sea receded from the coast, and a black thundercloud hung over Pompeii and the surrounding cities, hiding Cape Mizensky and the island of Capri. Most of the population of Pompeii was able to escape, but about two thousand people died from poisonous sulfurous gases on the streets and in the houses of the city. Among the victims was the Roman writer and scholar Pliny the Elder. Herculaneum, located seven kilometers from the crater of the volcano and about two kilometers from its sole, was covered with a layer of volcanic ash, the temperature of which was so high that all wooden objects were completely charred. The ruins of Pompeii were accidentally discovered at the end of the 16th century, but systematic excavations began only in 1748 and are still ongoing, along with reconstruction and restoration.

March 11, 1669 there was an eruption Mount Etna in Sicily, which lasted until July of that year (according to other sources, until November 1669). The eruption was accompanied by numerous earthquakes. Lava fountains along this crack gradually shifted downward, and the largest cone formed near the city of Nikolosi. This cone is known as Monti Rossi (Red Mountain) and is still clearly visible on the slope of the volcano. Nicolosi and two nearby villages were destroyed on the first day of the eruption. In another three days, the lava flowing down the slope to the south destroyed four more villages. At the end of March, two more major cities, and in early April, lava flows reached the outskirts of Catania. Lava began to accumulate under the fortress walls. Part of it flowed into the harbor and filled it. On April 30, 1669, lava flowed over the upper part of the fortress walls. The townspeople built additional walls across the main roads. This made it possible to stop the progress of the lava, but the western part of the city was destroyed. The total volume of this eruption is estimated at 830 million cubic meters. Lava flows burned 15 villages and part of the city of Catania, completely changing the configuration of the coast. According to some sources, 20 thousand people, according to others - from 60 to 100 thousand.

October 23, 1766 on the island of Luzon (Philippines) began to erupt mayon volcano. Dozens of villages were swept away, incinerated by a huge lava flow (30 meters wide), which descended the eastern slopes for two days. Following the initial explosion and lava flow, Mayon volcano continued to erupt for another four days, spewing large amounts of steam and watery mud. Greyish-brown rivers, 25 to 60 meters wide, crashed down the slopes of the mountain in a radius of up to 30 kilometers. They completely swept away roads, animals, villages with people (Daraga, Kamalig, Tobako) on their way. More than 2,000 residents died during the eruption. Basically, they were swallowed up by the first lava flow or secondary mud avalanches. For two months, the mountain spewed ash, poured lava into the surrounding area.

April 5-7, 1815 there was an eruption Volcano Tambora on the Indonesian island of Sumbawa. Ashes, sand and volcanic dust were thrown into the air to a height of 43 kilometers. Stones up to five kilograms in weight scattered over a distance of up to 40 kilometers. The Tambora eruption affected the islands of Sumbawa, Lombok, Bali, Madura and Java. Subsequently, under a three-meter layer of ash, scientists found traces of the fallen kingdoms of Pekat, Sangar and Tambora. Simultaneously with the volcanic eruption, a huge tsunami 3.5-9 meters high was formed. Receding from the island, the water hit the neighboring islands and drowned hundreds of people. Directly during the eruption, about 10 thousand people died. At least 82 thousand more people died from the consequences of the catastrophe - hunger or disease. Ashes that covered Sumbawa with a shroud destroyed the entire crop and covered the irrigation system; acid rain poisoned the water. For three years after Tambora's eruption, a veil of dust and ash particles enveloped the entire globe, reflecting part of the sun's rays and cooling the planet. The following year, 1816, Europeans felt the effects of a volcanic eruption. He entered the annals of history as "a year without a summer". The average temperature in the Northern Hemisphere has fallen by about one degree, and in some areas even by 3-5 degrees. Large areas of crops suffered from spring and summer frosts on the soil, and famine began in many territories.

August 26-27, 1883 there was an eruption Krakatoa volcano located in the Sunda Strait between Java and Sumatra. From the tremors on the nearby islands, houses collapsed. On August 27, at about 10 am, there was a giant explosion, an hour later - a second explosion of the same force. More than 18 cubic kilometers of rock fragments and ash shot up into the atmosphere. The tsunami waves caused by the explosions instantly swallowed up cities, villages, forests on the coast of Java and Sumatra. Many islands disappeared under water along with the population. The tsunami was so powerful that it bypassed almost the entire planet. In total, 295 cities and villages were swept off the face of the earth on the coasts of Java and Sumatra, more than 36 thousand people died, hundreds of thousands were left homeless. The shores of Sumatra and Java have changed beyond recognition. On the coast of the Sunda Strait, fertile soil was washed away down to the rocky base. Only a third of the island of Krakatoa survived. In terms of the amount of water and rock displaced, the energy of the Krakatoa eruption is equivalent to the explosion of several hydrogen bombs. The strange glow and optical phenomena persisted for several months after the eruption. In some places above the Earth, the sun seemed blue and the moon bright green. And the movement in the atmosphere of dust particles thrown out by the eruption allowed scientists to establish the presence of a "jet" flow.

May 8, 1902 Mont Pelee volcano, located on Martinique, one of the islands of the Caribbean, literally exploded into pieces - four strong explosions sounded like cannon shots. They threw out a black cloud from the main crater, which was pierced by flashes of lightning. Since the emissions did not go through the top of the volcano, but through side craters, all volcanic eruptions of this type have since been called "Peleian". The superheated volcanic gas, which, due to its high density and high speed of movement, floated above the earth itself, penetrated into all the cracks. A huge cloud covered the area of ​​​​complete destruction. The second zone of destruction stretched for another 60 square kilometers. This cloud, formed from super-hot steam and gases, weighed down by billions of particles of incandescent ash, moving at a speed sufficient to carry rock fragments and volcanic eruptions, had a temperature of 700-980 ° C and was able to melt glass. Mont Pele erupted again - on May 20, 1902 - with almost the same force as on May 8. The volcano Mont-Pele, having scattered to pieces, destroyed one of the main ports of Martinique, Saint-Pierre, along with its population. 36 thousand people died instantly, hundreds of people died from side effects. The two survivors have become celebrities. Shoemaker Leon Comper Leander managed to escape within the walls of his own house. He miraculously survived, although he received severe burns to his legs. Louis Auguste Cypress, nicknamed Samson, was in a prison cell during the eruption and sat there for four days, despite severe burns. After being rescued, he was pardoned, soon he was hired by the circus and was shown during performances as the only surviving resident of Saint-Pierre.

June 1, 1912 eruption began Katmai volcano in Alaska, which has been dormant for a long time. On June 4, ash material was thrown out, which, mixed with water, formed mud flows, on June 6 there was an explosion of colossal force, the sound of which was heard in Juneau for 1200 kilometers and in Dawson for 1040 kilometers from the volcano. Two hours later there was a second explosion of great force, and in the evening a third. Then, for several days, an eruption of a colossal amount of gases and solid products went on almost continuously. During the eruption, about 20 cubic kilometers of ash and debris escaped from the mouth of the volcano. The deposition of this material formed a layer of ash from 25 centimeters to 3 meters thick, and much more near the volcano. The amount of ash was so great that for 60 hours there was complete darkness around the volcano at a distance of 160 kilometers. On June 11, volcanic dust fell in Vancouver and Victoria at a distance of 2200 km from the volcano. In the upper layers of the atmosphere, it spread throughout the territory North America and fell in large numbers in the Pacific Ocean. For a whole year, small particles of ash moved in the atmosphere. Summer on the entire planet turned out to be much colder than usual, since more than a quarter of the sun's rays falling on the planet were retained in the ashy curtain. In addition, in 1912 surprisingly beautiful scarlet dawns were observed everywhere. A lake with a diameter of 1.5 kilometers formed on the site of the crater - the main attraction of the Katmai National Park and Reserve, formed in 1980.

December 13-28, 1931 there was an eruption volcano Merapi on the island of Java in Indonesia. For two weeks, from December 13 to 28, the volcano erupted a lava flow about seven kilometers long, up to 180 meters wide and up to 30 meters deep. The white-hot stream burned the earth, burned the trees and destroyed all the villages in its path. In addition, both sides of the volcano exploded, and the erupted volcanic ash covered half of the island of the same name. During this eruption, 1,300 people died. The eruption of Mount Merapi in 1931 was the most destructive, but far from the last.

In 1976, a volcanic eruption killed 28 people and destroyed 300 houses. Significant morphological changes taking place in the volcano caused another disaster. In 1994, the dome that had formed in previous years collapsed, and the resulting massive release of pyroclastic material forced the local population to leave their villages. 43 people died.

In 2010, the number of victims from the central part of the Indonesian island of Java was 304 people. The death toll included those who died from exacerbations of lung and heart diseases and other chronic diseases caused by ash emissions, as well as those who died from injuries.

November 12, 1985 eruption began Volcano Ruiz in Colombia, which was considered extinct. On November 13, several explosions were heard one after another. The power of the strongest explosion, according to experts, was about 10 megatons. A column of ash and rock fragments rose into the sky to a height of eight kilometers. The eruption that began caused the instantaneous melting of vast glaciers and eternal snows lying on the top of the volcano. Main blow fell on the city of Armero located 50 kilometers from the mountain, which was destroyed in 10 minutes. Of the 28.7 thousand inhabitants of the city, 21 thousand died. Not only Armero was destroyed, but also a number of villages. Badly affected by the eruption are settlements like Chinchino, Libano, Murillo, Casabianca and others. Mudflows damaged oil pipelines, fuel supply to the southern and western parts of the country was cut off. As a result of the sudden melting of snow lying in the mountains of Nevado Ruiz, nearby rivers burst their banks. Powerful streams of water washed away roads, demolished power lines and telephone poles, destroyed bridges. According to the official statement of the Colombian government, as a result of the eruption of the Ruiz volcano, 23 thousand people died and went missing, about five thousand were seriously injured and maimed. About 4,500 residential buildings and administrative buildings were completely destroyed. Tens of thousands of people were left homeless and without any means of subsistence. The Colombian economy has suffered significant damage.

June 10-15, 1991 there was an eruption Mount Pinatubo on the island of Luzon in the Philippines. The eruption began quite rapidly and was unexpected, as the volcano came into a state of activity after more than six centuries of dormancy. On June 12, the volcano exploded, sending a mushroom cloud into the sky. Streams of gas, ash and rocks melted to a temperature of 980 ° C poured down the slopes at a speed of up to 100 kilometers per hour. For many kilometers around, all the way to Manila, day turned into night. And the cloud and the ash falling from it reached Singapore, which is 2.4 thousand kilometers away from the volcano. On the night of June 12 and the morning of June 13, the volcano erupted again, throwing ash and flame into the air for 24 kilometers. The volcano continued to erupt on June 15 and 16. Mud streams and water washed away houses. As a result of numerous eruptions, about 200 people died and 100 thousand were left homeless

The material was prepared on the basis of information from open sources