Internal structure of the earth. The structure of the earth's crust and the composition of its layers. Geochemical method for studying the structure of planets
Layers of the Earth pictures for children. The main condition is that the child has an interest in the topics that this science deals with. You can try to awaken your child's desire to learn more about our planet by watching cartoons, movies or children's programs on this topic.
When studying complex, voluminous topics, try to use visual teaching materials. A very good way is to make these manuals together with your child.
You can include a geography lesson on the structure of the Earth in your child’s education at home. To do this, you will need a cross-sectional drawing of our planet, indicating all its layers: the earth's crust, mantle, outer and inner core.
After this, you can invite your child to color and name the different layers in the drawing of the Earth on their own, as well as estimate its size; for this, the approximate diameter of the globe in kilometers is given below.
For greater clarity, prepare several drawings where all layers are black and white, and one is colored. Attach signs to such drawings with the name of the color layer and a brief description of it.
Also prepare in advance four circles of different diameters from colored paper that matches the color of the layers of the Earth in your drawing. Invite your child to make his own model of the planet. Let him take circles from colored paper, match them with the signs, determining which layer of the Earth each of them corresponds to.
If the child has already learned to read, have him read out loud the corresponding tablet with a brief description. If not, read it yourself. Then you need to properly glue the circles and label all the layers. At the end, repeat all the new information again.
Geography is taught in a similar way to children who cannot yet understand and master too complex topics. Younger children will be interested in making their own model of our planet from a foam ball, painting it with watercolors or gouache. You can use a globe as a sample. First, tell them that the Earth is actually round, and the globe is a small copy of it. As you work, explain to your child that blue on the globe represents seas and oceans, brown represents mountains, green represents plains, and white represents ice.
Depending on how inquisitive your child is, delve into topics that interest him. With a hand-made model of the Earth, you can come up with various games for the development of children: for example, demonstrate how the planet rotates around the Sun and its axis and how night follows day.
Layers of the earth for children in pictures
1. Structure of the Earth
The Earth is spherical in shape and similar to other planets in the solar system. For inaccurate calculations, it is assumed that the Earth is a sphere with a radius equal to 6370 (6371) km. More precisely, the figure of the Earth is triaxial ellipsoid of revolution , although its shape does not correspond to any regular geometric figure. Sometimes she is called spheroid . It is believed to have the shape geoid . This figure is obtained by drawing an imaginary surface, which coincides with the water level in the oceans, under the continents.
Greatest depth (Mariana Trench) – 11521 (11022) m; highest altitude (Everest) – 8848 m.
70.8% of the surface is occupied by water and only 29.2% by land.
The dimensions of the Earth can be characterized by the following figures:
Polar radius ~ 6,357 km. Equatorial radius ~ 6,378 km.
Flattening - 1/298.3. The circumference at the equator is ~ 40,076 km.
The surface of the Earth is 510 million km 2. The volume of the Earth is 1,083 billion km 3.
Earth mass - 5.98.10 27 t Density - 5.52 cm 3.
Density increases with depth: on the surface – 2.66; 500 km – 3.33;. 800 km – 3.76; 1300 km – 5.00; 2500 km – 7.40; 500 km – 10.70; in the center - up to 14.00 g/cm3.
Fig.1. Diagram of the internal structure of the Earth
The Earth consists of shells (geospheres) - internal and external.
Domestic geosphere - the earth's crust, mantle and core.
1. Earth's crust. The thickness of the earth's crust varies in different regions of the globe. Under the oceans it varies from 4 to 20 km, and under the continents - from 20 to 75 km. On average, for oceans its thickness is 7...10 km, for continents - 37...47 km. The average thickness (thickness) is only 33 km. The lower boundary of the earth's crust is determined by a sharp increase in the speed of propagation of seismic waves and is called the section Mohorovicic(southern seismograph), where an abrupt increase in the speed of propagation of elastic (seismic) waves from 6.8 to 8.2 km/s was noted. Synonym – base of the earth's crust.
The bark has a layered structure. There are three layers in it: sedimentary(topmost), granite And basaltic.
The thickness of the granite layer increases in young mountains (Alps, Caucasus) and reaches 25...30 km. In areas of ancient folding (Ural, Altai), a decrease in the thickness of the granite layer is observed.
The basalt layer is ubiquitous. Most often, basalts are found at a depth of 10 km. In the form of separate spots they penetrate into the mantle at a depth of 70...75 km (Himalayas).
The interface between the granite and basalt layers is called the surface Conrad(Austrian geophysicist Konrad V.), also characterized by an abrupt increase in the speed of passage of seismic waves .
There are two types of earth's crust: continental (three-layer) and oceanic (two-layer). The boundary between them does not coincide with the boundary of continents and oceans and runs along the ocean floor at depths of 2.0...2.5 km.
Continental crust type consists of sedimentary, granite and basalt layers. The power depends on the geological structure of the area. In highly elevated areas of crystalline rocks, the sedimentary layer is practically absent. In depressions its thickness sometimes reaches 15...20 km.
Oceanic type of crust consists of sedimentary and basaltic layers. The sedimentary layer covers almost the entire ocean floor. Its thickness varies within hundreds and even thousands of meters. The basalt layer is also widespread under the ocean floor. The thickness of the earth's crust in oceanic basins is not the same: in the Pacific Ocean it is 5...6 km, in the Atlantic - 5...7 km, in the Arctic - 5...12 km, in the Indian - 5...10 km.
Lithosphere– the rocky shell of the Earth, combining the earth’s crust, the subcrustal part of the upper mantle and the underlying asthenosphere (layer of reduced hardness, strength and viscosity).
Table 1
Characteristics of the shells of the solid Earth
|
Geosphere |
Depth interval, km |
Density, g/cm 3 |
of volume,% |
Weight, 10 25 t |
of the mass of the Earth,% |
|
Earth's crust |
|||||
|
Mohorovicic section |
|||||
|
External B |
|||||
|
Transition layer C |
|||||
|
Wichert-Gutenberg section |
|||||
|
External E |
|||||
|
Transition layer F |
|||||
|
Internal G |
|||||
2. Mantle(Greek blanket, cloak) is located at a depth of 30...2900 km. Its mass is 67.8% of the Earth's mass and more than 2 times the mass of the core and crust combined. The volume is 82.26%. The surface temperature of the mantle fluctuates in the range of 150...1000 °C.
The mantle consists of two parts - the lower (layer D) with a base ~ 2900 km and the upper (layer B) to a depth of 400 km. Lower mantle – Mn, Fe, Ni. Ultramafic rocks are common in it, so the shell is often called peridotite or stone. Upper mantle – Si, Mg. It is active and contains pockets of molten masses. Seismic and volcanic phenomena and mountain-building processes originate here. There is also a transition layer Golitsyna(layer C) at a depth of 400...1000 km.
In the upper part of the mantle underlying the lithosphere there is asthenosphere. The upper boundary is about 100 km deep under the continents and about 50 km under the ocean floor; lower – at a depth of 250…350 km. The asthenosphere plays a large role in the origin of endogenous processes occurring in the earth's crust (magmatism, metamorphism, etc.). On the surface of the asthenosphere, lithospheric plates move, creating the structure of the surface of our planet.
3. Core The Earth begins at a depth of 2900 km. The inner core is a solid, the outer core is a liquid. The mass of the core is up to 32% of the mass of the Earth, and the volume is up to 16%. The earth's core is almost 90% iron with admixtures of oxygen, sulfur, carbon and hydrogen. The radius of the inner core (layer G), consisting of an iron-nickel alloy, is ~ 1200...1250 km, the transition layer (layer F) is ~ 300...400 km, the radius of the outer core (layer E) is ~ 3450...3500 km. Pressure - about 3.6 million atm., temperature - 5000 °C.
There are two points of view regarding the chemical composition of the nucleus. Some researchers believe that the core, like iron meteorites, consists of Fe and Ni. Others suggest that, similar to the mantle, the core is composed of Fe and Mg silicates. Moreover, the substance is in a special metallized state (electronic shells are partially destroyed).
External geosphere - hydrosphere (water shell), biosphere (sphere of life of organisms) and atmosphere (gas shell).
Hydrosphere covers the earth's surface by 70.8%. Its average thickness is about 3.8 km, the greatest – > 11 km. The formation of the hydrosphere is associated with the degassing of water from the Earth's mantle. It is in close relationship with the lithosphere, atmosphere and biosphere. The total volume of the hydrosphere in relation to the volume of the globe does not exceed 0.13%. More than 98% of all water resources of the Earth are salty waters of the oceans, seas, etc. The total volume of fresh water is 28.25 million km 3 or about 2% of the entire hydrosphere.
table 2
Hydrosphere volume
|
Parts of the hydrosphere |
The volume of all water |
Volume of fresh water, thousand m3 |
Water exchange intensity, years |
|
World Ocean |
|||
|
The groundwater |
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|
Soil moisture |
|||
|
Atmospheric vapors |
|||
|
River waters |
|||
|
Water in living organisms (biological) |
* – water subjected to active water exchange
Biosphere(the sphere of life of organisms) is connected with the surface of the Earth. It is in constant interaction with the lithosphere, hydrosphere and atmosphere.
Atmosphere. Its upper limit is the altitude (3 thousand km), where the density is almost balanced with the density of interplanetary space. Chemically, physically and mechanically affects the lithosphere, regulating the distribution of heat and moisture. The atmosphere has a complex structure.
From the surface of the Earth upwards it is divided into troposphere(up to 18 km), stratosphere(up to 55 km), mesosphere(up to 80 km), thermosphere(up to 1000 km) and exosphere(sphere of dispersion). The troposphere occupies about 80% of the total atmosphere. Its thickness is 8...10 km above the poles, 16...18 km above the equator. With the average annual temperature for the Earth + 14 o C at sea level at the upper boundary of the troposphere, it drops to – 55 o C. At the Earth’s surface, the highest temperature reaches 58 o C (in the shade), and the lowest drops to – 87 o C. In the troposphere, vertical and horizontal movements of air masses occur, which largely determine cycle water, heat exchange , transfer dust particles.
Magnetosphere
The Earth is the outermost and most extensive shell of the Earth, which is the near-Earth space where the strength of the Earth’s electromagnetic field exceeds the strength of external electromagnetic fields. The magnetosphere has a complex shape, variable in configuration, and a magnetic plume. The outer boundary (magnetopause) is set at a distance of ~ 100...200 thousand km from the Earth, where the magnetic field weakens and becomes comparable with the cosmic magnetic field
> > What does the Earth consist of?
Description composition of the Earth for children with a photo: the structure of the planet in the picture, what the crust, mantle and core consists of, what the upper shell looks like, the thickness of the layers.
Earth is the third planet from the Sun, but also the only planet so far in the Solar System and the known Universe on which an advanced form of life lives. This is a home that children will benefit from exploring. Let's take a closer look at the structure of the Earth, with our photos, diagrams and drawings to help.
Begin explanation for children about the composition of the Earth follows from the fact that we live on a unique planet, since it has water. Of course, there are other worlds, as well as satellites, where there is an atmosphere, ice and even oceans, but only we are lucky to have all the factors to create and maintain life.
For the little ones It is important to know that the earth's oceans occupy approximately 70% of the entire surface, and go 4 km deep. In liquid form, fresh water is found in rivers, lakes and in the form of atmospheric water vapor, which leads to great weather variability.
Should explain to the children that the Earth is multi-layered. The outer one is represented by the bark. It is filled with ocean basins and continents. The earth's crust occupies 5-75 km. The densest parts are hidden under the continents, and the thinnest parts are hidden under the oceans. Now let's study the composition of the Earth in layers: crust, mantle, core.
The Earth's crust - an explanation for children
The earth's crust contains elements such as: oxygen (47%), silicon (27%), aluminum (8%), iron (5%), calcium (4%), and 2% each of magnesium, potassium and sodium. It is created in the form of giant plates that move through the liquid mantle. Important explain to the children, that, although we do not notice, the plates do not stop moving. When they collide, we feel earthquakes, and if one runs over the other, a deep trench or mountains are formed. These movements are described by the theory of plate tectonics.
Earth's mantle - explanation for children
Further, 2890 km thick, is the mantle. It is represented by silicate rocks rich in magnesium and iron. Due to the intense heat, rocks are created. They then cool down and return to the core again. This is believed to be what sets tectonic plates in motion. When the mantle manages to break through the crust, you see a volcanic eruption.
Earth's core - explanation for children
Surely, even for the little ones It is clear that the core is located inside the Earth. Interestingly, it consists of two halves: the inner (solid) with a radius of 1220 km is surrounded by the outer (liquid - an alloy of nickel and iron) with a thickness of 2180 km. While the planet rotates at its usual pace, the inner core rotates separately, forming a magnetic field. You can also tell children about how auroras are formed. After all, for this, charged particles of the solar wind need to pass into the air molecules above the magnetic poles of the planet, and then these molecules begin to shine.
Now you know what the Earth is made of. If children or schoolchildren of any age are curious to learn more interesting facts and details about the third planet from the Sun, then be sure to visit the remaining pages of the section. Don't forget to take advantage of the 3D model of the Solar System, which shows all the planets, as well as a map of Venus, its surface and its orbital features. For the rest, our photos, pictures, drawings, as well as an online telescope that operates in real time, will always help you. The structure of the Earth is incredibly easy to understand if you follow the visuals.
There are internal and external shells that interact with each other.
Internal structure of the Earth
To study the internal structure of the Earth, they use the drilling of ultra-deep wells (the deepest Kola - 11,000 m. It covered less than 1/400 of the Earth's radius). But most of the information about the structure of the Earth was obtained using the seismic method. Based on the data obtained by these methods, a general model of the structure of the Earth was created.
In the center of the planet is the earth's core - (R = 3500 km) presumably composed of iron with an admixture of lighter elements. There is a hypothesis that the core consists of hydrogen, which at high temperatures can transform into a metallic state. The outer layer of the core is a liquid, molten state; the inner core with a radius of 1250 km is solid. The temperature in the center of the core is apparently up to 5 - 6 thousand degrees.
The core is surrounded by a shell - the mantle. The mantle is up to 2900 km thick, its volume is 83% of the planet’s volume. It consists of heavy minerals rich in magnesium and iron. Despite the high temperature (above 2000?), most of the mantle matter, due to the enormous pressure, is in a solid crystalline state. The upper mantle at a depth of 50 to 200 km has a moving layer called the asthenosphere (weak sphere). It is characterized by high plasticity due to the softness of the substance that forms it. It is with this layer that other important processes on Earth are associated. Its thickness is 200 – 250 km. The substance of the asthenosphere that penetrates the earth's crust and flows to the surface is called magma.
The Earth's crust is the hard layered outer shell of the Earth with a thickness of 5 km under the oceans to 70 km under the mountainous structures of the continents.
- Continental (mainland)
- Oceanic
Continental crust is thicker and more complex. It has 3 layers:
- Sedimentary (10-15 km, rocks are mostly sedimentary)
- Granite (5-15 km, the rocks of this layer are mainly metamorphic, their properties are close to granite)
- Balzatovy (10-35 km, the rocks of this layer are igneous)
The oceanic crust is heavier, there is no granite layer in it, the sedimentary layer is relatively thin, it is mainly balsate.
In areas of transition from the continent to the ocean, the crust has a transitional character.
The earth's crust and the upper part of the mantle form a shell called (from the Greek litos - stone). Lithosphere is the solid shell of the Earth, including the earth's crust and the upper layer of the mantle, lying on the hot asthenosphere. The thickness of the lithosphere is on average 70–250 km, of which 5–70 km is in the earth’s crust. The lithosphere is not a continuous shell; it is divided by giant faults into. Most plates include both continental and oceanic crust. There are 13 lithospheric plates. But the largest are: American, African, Indo-Australian, Pacific.
Under the influence of processes occurring in the bowels of the earth, the lithosphere moves. Lithospheric plates move slowly relative to each other at a speed of 1–6 cm per year. In addition, their vertical movements constantly occur. The set of horizontal and vertical movements of the lithosphere, accompanied by the occurrence of faults and folds of the earth's crust, is called. They are slow and fast.
The forces causing the divergence of lithospheric plates arise when the mantle material moves. Powerful upward flows of this substance push the plates apart, tearing apart the earth's crust, forming deep faults in it. Where this substance rises outward, faults appear in the lithosphere, and the plates begin to move apart. The magma intruding along the faults, solidifying, builds up the edges of the plates. As a result, shafts appear on both sides of the fault, and. They are found in all oceans and form a single system with a total length of 60,000 thousand km. The height of the ridges is up to 3000 m. This ridge reaches its greatest width in the southeastern part, where the rate of plate movement is 12 - 13 cm/year. It does not occupy a middle position and is called the Pacific Rise. At the site of the fault, in the axial part of the mid-ocean ridges, there are usually gorges - rifts. Their width ranges from several tens of kilometers at the top to several kilometers at the bottom. At the bottom of the rifts there are small volcanoes and hot springs. In rifts, new oceanic crust is born from rising magma. The further away from the rift, the older the crust.
Along other plate boundaries, collisions of lithospheric plates are observed. It happens in different ways. When a plate with oceanic crust and a plate with continental crust collide, the first one sinks under the second one. In this case, deep-sea trenches, island arcs, and mountains appear on land. If two plates collide with the continental crust, then crushing occurs, volcanism and the formation of mountainous areas (for example, these are complex processes that occur during the movement of magma, which is formed in separate centers and at different depths of the asthenosphere. Very rarely it is formed in the earth’s crust. There are two main types of magmas - basaltic (basic) and granitic (acidic).
As magma erupts onto the Earth's surface, it forms volcanoes. Such magmatism is called effusive. But more often magma penetrates into the earth's crust through cracks. This type of magmatism is called intrusive.
Since time immemorial people have tried to portray diagrams of the internal structure of the Earth. They were interested in the bowels of the Earth as storehouses of water, fire, air, and also as a source of fabulous wealth. Hence the desire to penetrate with thought into the depths of the Earth, where, as Lomonosov put it,
hands and eyes are forbidden by nature (i.e. nature).
The first diagram of the internal structure of the Earth
The greatest thinker of antiquity, the Greek philosopher, who lived in the 4th century BC (384-322), taught that inside the Earth there is a “central fire” that bursts out from the “fire-breathing mountains.” He believed that the waters of the oceans, seeping into the depths of the Earth, fill the voids, then through the cracks the water rises again, forming springs and rivers that flow into the seas and oceans. This is how the water cycle occurs. The first diagram of the structure of the Earth by Athanasius Kircher (based on an engraving from 1664). More than two thousand years have passed since then, and only in the second half of the 17th century - in 1664 - appeared the first diagram of the internal structure of the Earth. Its author was Afanasy Kircher. She was far from perfect, but quite pious, as is easy to conclude by looking at the drawing. The earth was depicted as a solid body, inside of which huge voids were connected to each other and the surface by numerous channels. The central core was filled with fire, and the voids closer to the surface were filled with fire, water, and air. The creator of the diagram was convinced that fires inside the Earth warmed it and produced metals. The material for underground fire, according to his ideas, was not only sulfur and coal, but also other mineral substances of the earth's interior. Underground water flows generated winds.Second diagram of the internal structure of the Earth
In the first half of the 18th century there appeared second diagram of the internal structure of the Earth. Its author was Woodworth. Inside, the Earth was no longer filled with fire, but with water; the water created a vast water sphere, and channels connected this sphere with the seas and oceans. A thick solid shell, consisting of rock layers, surrounded the liquid core.
Second diagram of the structure of Woodworth's Land (from an engraving of 1735). Rock layers
About how they are formed and located rock layers, was first pointed out by the outstanding Danish nature researcher Nikolai Stensen(1638-1687). The scientist lived for a long time in Florence under the name Steno, practicing medicine there. Stensen (Steno) contrasted the fantastic views of the authors of diagrams of the structure of the Earth with direct observations from the practice of mining. Miners have long noticed the regular arrangement of layers of sedimentary rocks. Stensen not only correctly explained the reason for their formation, but also the further changes to which they were subjected. These layers, he concluded, settled from the water. Initially the sediments were soft, then they hardened; At first the layers lay horizontally, then, under the influence of volcanic processes, they experienced significant movements, which explains their tilt. But what was correct in relation to sedimentary rocks cannot, of course, be extended to all other rocks that make up the earth’s crust. How were they formed? Are they from aqueous solutions or from fiery melts? This question attracted the attention of scientists for a long time, right up to the 20s of the 19th century.Dispute between Neptunists and Plutonists
Between supporters of water - Neptunists(Neptune - the ancient Roman god of the seas) and supporters of fire - plutonists(Pluto is the ancient Greek god of the underworld) heated debates arose repeatedly. Finally, researchers proved the volcanic origin of basaltic rocks, and the Neptunists were forced to admit defeat.Basalt
Basalt- a very common volcanic rock. It often comes to the surface of the earth, and at great depths it forms a reliable foundation earth's crust. This rock - heavy, dense and hard, dark in color - is characterized by a columnar structure in the form of five-six-gonal units. Basalt is an excellent building material. In addition, it can be melted and is used for the production of basalt casting. The products have valuable technical qualities: refractoriness and acid resistance. High-voltage insulators, chemical tanks, sewer pipes, etc. are made from basalt casting. Basalts are found in Armenia, Altai, Transbaikalia and other areas. Basalt differs from other rocks in its high specific gravity. Of course, it is much more difficult to determine the density of the Earth. And this is necessary to know in order to correctly understand the structure of the globe. The first and quite accurate determinations of the Earth's density were made two hundred years ago. The density was taken on average from many determinations to be 5.51 g/cm 3 .Seismology
Science has brought significant clarity to ideas about seismology, studying the nature of earthquakes (from the ancient Greek words: “seismos” - earthquake and “logos” - science). There is still a lot of work to be done in this direction. According to the figurative expression of the largest seismologist, academician B.B. Golitsyn (1861 -1916),All earthquakes can be likened to a lantern that lights up for a short time and, illuminating the interior of the Earth, allows us to see what is happening there.With the help of very sensitive recording devices, seismographs (from the already familiar words “seismos” and “grapho” - I write) it turned out that the speed of propagation of earthquake waves across the globe is not the same: it depends on the density of the substances through which the waves propagate. Through the thickness of sandstone, for example, they pass more than two times slower than through granite. This allowed us to draw important conclusions about the structure of the Earth. Earth, By modern according to scientific views, can be represented in the form of three balls nested inside each other. There is such a children's toy: a colored wooden ball consisting of two halves. If you open it, there is another colored ball inside, an even smaller ball inside, and so on.
- The first outer ball in our example is Earth's crust.
- Second - the Earth's shell, or mantle.
- Third - inner core.
Modern diagram of the internal structure of the Earth. The thickness of the walls of these “balls” is different: the outer one is the thinnest. It should be noted here that the earth’s crust does not represent a homogeneous layer of equal thickness. In particular, under the territory of Eurasia it varies within 25-86 kilometers. As determined by seismic stations, i.e. stations that study earthquakes, the thickness of the earth's crust along the Vladivostok - Irkutsk line is 23.6 km; between St. Petersburg and Sverdlovsk - 31.3 km; Tbilisi and Baku - 42.5 km; Yerevan and Grozny - 50.2 km; Samarkand and Chimkent - 86.5 km. The thickness of the Earth's shell, on the contrary, is very impressive - about 2900 km (depending on the thickness of the earth's crust). The core shell is somewhat thinner - 2200 km. The innermost core has a radius of 1200 km. Let us recall that the equatorial radius of the Earth is 6378.2 km, and the polar radius is 6356.9 km. Substance of the Earth at great depths
What's going on with substance of the Earth, making up the globe, at great depths? It is well known that temperature increases with depth. In the coal mines of England and in the silver mines of Mexico it is so high that it is impossible to work, despite all sorts of technical devices: at a depth of one kilometer - over 30° heat! The number of meters that must be descended deep into the Earth for the temperature to rise by 1° is called geothermal stage. Translated into Russian - “the degree of heating of the Earth.” (The word “geothermal” is made up of two Greek words: “ge” - earth, and “therme” - heat, which is similar to the word “thermometer”.) The value of the geothermal stage is expressed in meters and varies (ranging between 20-46) . On average it is taken at 33 meters. For Moscow, according to deep drilling data, the geothermal gradient is 39.3 meters. The deepest borehole so far does not exceed 12000 meters. At a depth of over 2200 meters, superheated steam already appears in some wells. It is successfully used in industry. And what can you discover if you penetrate further and further? The temperature will continuously increase. At a certain depth it will reach such a value at which all rocks known to us should melt. However, in order to draw the right conclusions from this, it is also necessary to take into account the effect of pressure, which also continuously increases as it approaches the center of the Earth. At a depth of 1 kilometer, the pressure under the continents reaches 270 atmospheres (under the ocean floor at the same depth - 100 atmospheres), at a depth of 5 km - 1350 atmospheres, 50 km - 13,500 atmospheres, etc. In the central parts of our planet, the pressure exceeds 3 million atmospheres! Naturally, the melting temperature will also change with depth. If, for example, basalt melts in factory furnaces at 1155°, then at a depth of 100 kilometers it will begin to melt only at 1400°. According to scientists, the temperature at a depth of 100 kilometers is 1500° and then, slowly increasing, only in the most central parts of the planet reaches 2000-3000°. As laboratory experiments show, under the influence of increasing pressure, solids - not only limestone or marble but also granite - acquire plasticity and show all signs of fluidity. This state of matter is characteristic of the second ball of our diagram - the shell of the Earth. Foci of molten mass (magma) directly associated with volcanoes are of limited size.Earth's core
Shell substance Earth's core viscous, and in the core itself, due to the enormous pressure and high temperature, it is in a special physical state. Its new properties are similar in terms of hardness to the properties of liquid bodies, and in terms of electrical conductivity - with the properties of metals. In the great depths of the Earth, the substance transforms, as scientists say, into a metallic phase, which is not yet possible to create in laboratory conditions.Chemical composition of the elements of the globe
The brilliant Russian chemist D.I. Mendeleev (1834-1907) proved that chemical elements represent a harmonious system. Their qualities are in regular relationships with each other and represent successive stages of the single matter from which the globe is built.- In terms of chemical composition, the earth's crust is mainly formed only by nine elements out of more than a hundred known to us. Among them, first of all oxygen, silicon and aluminum, then, in smaller quantities, iron, calcium, sodium, magnesium, potassium and hydrogen. The rest account for only two percent of the total weight of all listed elements. The earth's crust was called sial, depending on its chemical composition. This word indicated that in the earth's crust, after oxygen, silicon (in Latin - “silicium”, hence the first syllable - “si”) and aluminum (the second syllable - “al”, together - “sial”) predominate.
- There is a noticeable increase in magnesium in the subcortical membrane. That's why they call her sima. The first syllable is “si” from silicium - silicon, and the second is “ma” from magnesium.
- The central part of the globe was believed to be mainly formed from nickel iron, hence its name - nife. The first syllable - "ni" indicates the presence of nickel, and "fe" - iron (in Latin "ferrum").
Chemical analysis of meteorites
The correctness of our ideas about the composition of the internal parts of the Earth is also confirmed chemical meteorite analysis. Some meteorites are predominantly iron - that's what they're called. iron meteorites, in others - those elements that are found in rocks of the earth's crust, which is why they are called stony meteorites.
Meteor falling. Stone meteorites represent fragments of the outer shells of disintegrated celestial bodies, and iron meteorites represent fragments of their internal parts. Although the external features of stony meteorites are not similar to our rocks, their chemical composition is close to basalts. Chemical analysis of iron meteorites confirms our assumptions about the nature of the central core of the Earth. 
