Earth layers. What will happen if the Earth cools down? Whychek Club. Physical and chemical composition of the Earth

"! In today's episode of the Club I will answer the question from mother Anya and her son Dani (7 years old): "If there was no magma, would the Earth cool?"

In order for me to answer this question, we need to understand the structure of the Earth. And an ordinary egg will help us with this. The top of the egg is covered with a thin layer of hard but fragile shell. If we clear it, there will be a layer of white substance underneath - protein. And in the very middle we will see a yellow ball - the yolk.

The process of accretion that formed the Earth was not a simple or peaceful process. For billions of years, the Earth has been bombarded daily by space debris of all sizes, from objects the size of peas to objects the size of Mars. This process is still ongoing, but nothing like this has happened in the past. Today, the Earth receives about one ton of space debris every year.

During the early accretion period, the earth was bombarded by much larger objects. Scientist currently believe that the Earth was nearly destroyed three times during its accretion. The last of these impacts is believed to be so massive that it completely destroyed the Earth and sent space debris towards the Earth. It is this debris that is believed to have formed our Moon.

Our Earth is structured in much the same way. Thin layer on top earth's crust. Then comes a layer called the mantle, and in the very middle is the core.

Let's do a thought experiment and take a trip deep into the Earth. Your baby has probably already tried to dig a deep, deep hole in a sandbox or on the beach? But no matter how much he dug, he could not dig deeper than the uppermost layer of the earth's crust - the soil (remember, we already examined the structure of the soil in one of the previous issues of the Club). If people whose specialty was drilling deep, deep wells—drillers—came to his aid, they could help him get to a depth of 4-5 km. There you can find ancient rocks that were formed back in the days when the Earth was young, as well as what are called minerals - oil, gas, various ores. But everything that people extract from the depths of the Earth is still in the very top layer, in that “shell” that surrounds the egg planet.

In addition to forming our lunar accretion, or more precisely, the heat generated by accretion is also responsible for the differentiation of the Earth. It is the division of the Earth into distinct layers that can be described based on the compositional properties of the materials contained within. The Earth can be divided into three different component layers: the crust, the mantle, and the core.

Physical and chemical composition of the Earth

The crust is the relatively thin outer layer of the Earth. This is the layer we are most familiar with and the layer in which we live. At its thinnest, on oceanic ridges, the crust can be only 3 kilometers thick. However, in mountain zones the crust can penetrate up to 70 kilometers. Below the mantle is the core.

Even the deepest well that people managed to drill in the earth's crust never reached the next layer of the earth's interior - the mantle. This well is located in Russia, on Kola Peninsula, and goes 12 km deep into the earth’s surface. This is so deep! But compared to the Earth, such a well is the same as a needle prick for a large apple, which did not even pierce its skin!

Internal structure of the Earth

The Earth's interior is characterized by a gradual increase in temperature, pressure and density. Depending on temperature and pressure, the material exposed may behave as a brittle solid, deform plastically, or melt and become liquid. Because of this, the three main layers can be further divided and described based on their physical properties.

The lithosphere is the outermost layer of the Earth, consisting of the crust and the uppermost mantle. Because this region of the Earth is relatively cold and under low pressure, lithosphere materials behave like brittle solids. The lithosphere is on average about 100 kilometers thick but can extend up to 250 kilometers beneath the continents.

Therefore, scientists cannot say for sure what is happening inside the Earth. We can obtain information about everything that is deeper only indirectly (that is, we learn not from experience, but by inference). For example, studying volcanic eruptions and waves that travel across the globe after earthquakes or powerful explosions.

Today, most scientists adhere to this model of the structure of the Earth:

Below the lithosphere, high temperatures and relatively low pressures allow a small amount of melting, which separates the lithosphere from the underlying asthenosphere, allowing the lithosphere to move independently. The asthenosphere extends below the lithosphere through the upper mantle to a depth of approximately 600 kilometers.

Below the asthenosphere is the mesosphere. In this region the rock is extremely hot and under enormous pressure. Although the solid rocks of the mesosphere are capable of very gradual flow caused by convection. Beneath the mesosphere is an outer core consisting of liquid iron and nickel alloys. The convective flow inside the outer core generates the Earth's magnetic field below the outer core in the inner core. In this region, the pressures are so intense that iron-nickel alloys cannot melt and the materials behave like a solid.

Inside the Earth there is a solid inner core with a radius of 1300 km, consisting mainly of an iron-nickel alloy with an admixture of other heavy elements. The temperature in the center of the Earth is enormous - according to some estimates, it reaches 5500 degrees Celsius! This is almost the same as on the surface of the Sun!


Around it to a depth of 2900 km there is a layer of the outer core. It consists of the same substance, only in a molten, viscous-flowing state.




He reached 5 miles, a third of the required distance. The hole to the Kola superdeep well is now welded.


The boundary between the light crust and the denser mantle, called the Moho gap, is between 3 and 6 miles below the ocean floor and 12 to 55 miles below the continents.

Recent discoveries have shown that this is an active region, transporting material to and from the surface. These rocks were formed near the Moho gap and are now exposed at the surface in Newfoundland.


"Diamonds are nature's heaviest substance and are formed when carbon is subjected to intense heat and pressure for 1 to 3 months, typically 9 to 118 miles in the mantle."

Further, to a depth of 1000 km, there is a layer of mantle - a hot solid substance (its temperature varies from 500 to 4000 degrees Celsius). It contains almost the entire volume of the planet’s matter (85%) and accounts for 2/3 of the mass of the entire Earth. The mantle is divided into lower and upper.

In the upper layer of the mantle there is a separate layer of viscous plastic substance called the asthenosphere. This is what they “float” on. lithospheric plates- areas of the uppermost, solid layer of the Earth, which make up the earth's crust. Its thickness is small: 5 km under the oceans and 30-40 km under the continents. Due to the movement of lithospheric plates (slow or catastrophic - in the form of earthquakes), a change in shape occurs earth's surface: new mountains, seas and other relief elements are formed.




Most earthquakes occur at depths less than 186 miles. Below this depth, the rock is plastic and deforms slowly, rather than in jumps. But every year there are on average twenty earthquakes that cause serious damage, and one strikes every few years.

The thinnest layer of the planet




The main changes in the structure of rocks occur in the mantle at depths of 273 and 410 miles. The changes make up the world's most common stone, Bridgmanite, named after the pioneering scientist Percy Bridgman, who subjected rocks to great pressure to mimic conditions inside the Earth.

It is here, in the uppermost layers of the Earth - the crust and asthenosphere, at depths from 15 to 250 km, that magmas (liquid silicate melt) are formed, which, pouring out in the form of lava through volcanoes, solidifies, forming igneous rocks (granites, basalts, etc.) .

Invite your child to make everyone's favorite soda-vinegar volcano and watch it erupt. To do this, you can cover a bottle of the mixture with plasticine, put a tablespoon of soda in it and carefully add a little vinegar.




Ultra-deep diamonds formed at a depth of 416 miles are rarer than lunar rocks. Less than a dozen ultra-deep diamonds have been found.


They are called Tuzo and Jason and are the underground continents of our planet. Recent research suggests they are ancient and likely formed 4 billion years ago when the Earth was young.

The main mantle boundary, says Professor Ed Garnero of Arizona State University, is one of the strangest and most significant places on Earth. It contains what could be called "Earth's dark matter."

The outer core is made of molten iron, nickel and several other elements under a pressure of 3 million atmospheres. This deeply affects the nature of our planet and the magnetic field it generates, protecting us from the harshness of space. This metal section of the meteorite is similar in composition to the Earth's outer core.

What will happen if all the Earth's magma cools?

The process of cooling of the Earth has been going on since the very beginning of its existence. Once upon a time the Earth was a hot ball. But gradually its surface cooled, and a solid crust appeared. The crust is constantly moving, drifting and changing its structure due to the fact that there is a layer of liquid mantle material underneath it. If this layer hardens, then volcanoes will stop erupting and all tectonic activity will stop, which means that lithospheric plates will no longer move and the process of mountain building will stop. But this is unlikely to have any impact on life on the planet. But when the Earth cools down completely (what will happen, according to different estimates, in 1-3 billion years), then earthlings will face much bigger troubles.

Whatever the case, with a small radius of 750 miles and a surface area equal to the size of Antarctica, the inner core of solid iron at a pressure of 3 million atmospheres packs more strangeness and mystery into the atmosphere than any other region of Earth.



The first, outermost layer of the Earth is called the crust. The bark can be divided into two parts. These two parts are the oceanic crust and the continental crust. Oceanic crust, also known as sima, makes up only 099% of the Earth's mass. It is the smallest part of the Earth with a depth of 0-6 miles. The ocean layer is primarily composed of basalt, a type of hardened lava. Due to volcanic activity, amounts of basalt accumulated greatly, covering the ocean floor and even creating the islands of Iceland and Hawaii! The continental crust, or crust, is what we stand on, and it is also the only layer of Earth on which we could survive.

First, the Earth will become cold. After all, solar energy is enough to warm the surface of our planet to a depth of only about 30 m. The Earth receives its main heat from its depths. And if this heat is not there, then the difference between day and night temperatures on the planet will become very significant, even a “blanket” of the atmosphere and hydrosphere will not save.

The depth of the continental crust ranges in thickness from 0-31 miles. This layer makes up 374% of the Earth's mass. This layer is slightly larger than oceanic crust and consists of lighter materials. Together, oceanic and continental crust make up about 1% of the Earth's total volume. The Earth's crust is the most common site of earthquakes, shaking of the Earth's crust due to underground volcanic activity or alteration of rock beneath the surface.

The second layer of the Earth is the mantle. The mantle can be described as an underground ocean of liquid rock! In fact, the lava that comes from volcanoes comes from the mantle. Like the crust, the mantle can be divided into two parts, the lower mantle and the upper mantle. The lower mantle is chemically composed of silicon, magnesium and oxygen. The lower mantle plays an important role in controlling the planet's thermal evolution. The upper mantle is made of crystalline forms of olivine.

Secondly, the Earth will lose its magnetic field. According to modern concepts, the magnetic field is generated during the rotation of the planet’s liquid core. If the core freezes and the “geodynamo” stops, then the Earth will remain defenseless against the flow of radiation particles that fly to our planet from the Sun. And this, most likely, will lead to the death of all highly organized forms of life (including humans).

The lower boundary separating the upper and lower mantle is the transition zone. This zone is an area of ​​great complexity; it physically separates the upper and lower mantle. The third layer of the Earth is called the outer core. The outer core is a layer of liquid surrounding a solid inner core. Without the outer core, our world as we know it will cease to exist! The outer core is responsible for creating the Earth's magnetic field. This magnetic field acts as a protective bubble. Otherwise, the solar winds will destroy our atmosphere.

But the cooling of the Earth is not scary for us. After all, by the time the Earth cools down, it will still be impossible to live on it due to the fact that the Sun will increase in size and its radiation will dry up all the oceans on the planet. Therefore, humanity will have to take care in advance to find a new space home and leave their home planet. So the task of future generations (including our children) is to direct their strength and skills to preparing for the future colonization of other planets by earthlings. And the first step in this direction will be the manned flight to Mars planned in the coming decades.

Take a moment to say thank you to the outer core! The last layer of the Earth is the inner core. The inner core is believed to be a solid ball made primarily of iron and nickel. Scientists believe that during the formation of the Earth billions of years ago, the heaviest elements sank into the center and formed this inner core. The high pressure and temperature of the inner core prevents the materials from moving, creating a solid ball.

The earth consists of three layers, each of which has different properties. These are the Crust, Mantle and Core. However, these layers are further divided into sublayers. The cortex consists of two sublayers; oceanic crust and continental crust. The mantle is divided into two parts; upper mantle and lower mantle. The upper mantle is further divided into two layers; lithosphere and asthenosphere. The core consists of two regions; outer core and inner core. So let's take a quick look at each of these layers in Layers of the Earth for Kids.

I hope, Danya, I answered your question?

And so that I can answer your questions, send them to me by email tavika2000 @ yandex.ua(remove spaces) with the note "Whychek Club". All questions sent to the Club, regardless of whether the answer was published or not, will be entered into a prize draw, which will take place on the first Friday of autumn, September 6. I will provide details about it later.

It took nature several billion years for the Earth’s soil to acquire the properties that allowed vegetation to appear on our planet. At first, instead of soil, there were only rocks, which, due to the influence of rain, wind, and sunlight on them, began to gradually become crushed.

The destruction of the soil occurred in different ways: under the influence of the sun, wind and frost, rocks cracked, were polished with sand, and sea waves slowly but surely broke huge blocks into small stones. Finally, animals, plants and microorganisms made their contribution to the formation of soil, adding organic elements (humus), enriching upper layer land with waste products and their residues. The decomposition of organic elements when interacting with oxygen led to various chemical processes that resulted in the formation of ash and nitrogen, which turned rocks into soil.

Soil is the modified loose upper layer of the earth's crust on which vegetation grows. It was formed as a result of the transformation of rocks under the influence of dead and living organisms, sunlight, precipitation and other processes due to which soil erosion occurred.

Due to this transformation of huge, hard rocks into a loose mass, the top layer of soil acquired an absorbent surface: the structure of the soil became porous and breathable. The main importance of soil is that, being penetrated by the roots of plants, it transfers to them all the nutrients necessary for growth, and combines two features necessary for the existence of plants - minerals and water.

Therefore, one of the main characteristics of the soil is a fertile layer of soil, which allows for the growth and development of plant organisms.

In order for a fertile layer of soil to form, the soil must contain a sufficient amount of nutrients and have the necessary supply of water, which would not allow plants to die. The value of land largely depends on its ability to deliver nutrients to the roots of plants and provide them with access to air and moisture (water in the soil is extremely important: nothing will grow if there is no liquid in the soil that will dissolve these substances).

The soil consists of several layers:

  1. The arable layer is the top layer of soil, the most fertile layer of soil, which contains the most humus;
  2. Subsoil - consists mainly of rock remains;
  3. The lowest layer of soil is called “bedrock.”

Soil acidity

A very serious factor that affects soil fertility is soil acidity - the presence of hydrogen ions in the soil solution. The acidity of the soil is increased if the pH is below seven, if it is higher it is alkaline, and if it is equal to seven it is neutral (the concentration of hydrogen ions (H+) and hydroxides (OH-) is the same).

A high level of acidity in the top layer of soil negatively affects plant growth, since it affects its characteristics (size and strength of soil particles), applied fertilizers, microflora and plant development. For example, increased acidity disrupts the structure of the soil, since beneficial bacteria cannot develop normally, and many nutrients (for example, phosphorus) become difficult to digest.


Too much high level acidity makes it possible for toxic solutions of iron, aluminum, manganese to accumulate in the soil, while the intake of potassium, nitrogen, magnesium, and calcium into the plant body decreases. The main feature high level acidity is the presence under the upper dark layer of earth of a light layer, the color of which resembles ash, and the closer this layer is to the surface, the more acidic the soil and the less calcium it contains.

Types of soil

Since absolutely all types of soils are formed from rocks, it is not surprising that the characteristics of the soil largely depend on the chemical composition and physical characteristics of the parent rock (minerals, density, porosity, thermal conductivity).

Also, the characteristics of the soil are influenced by the exact conditions under which the soil was formed: precipitation, soil acidity, wind, wind speed, soil and environmental temperature. Climate also has an indirect effect on the soil, since the life of flora and fauna directly depends on the temperature of the soil and the environment.

Soil types depend largely on the size and number of particles that are present in them. For example, damp and cold clay soils are formed by sand particles tightly adjacent to each other, loamy soil is a cross between clay and sand, and rocky soil contains a lot of pebbles.

But peat soil includes the remains of dead plants and contains very few solid particles. Any soil on which plant organisms grow has a very complex structure, since in addition to rocks it contains salts, living organisms (plants), and organic substances that were formed as a result of decay.

After soil analysis was done in different regions of our planet, a soil classification was created - a set of similar areas that had similar soil formation conditions. Soil classification has several directions: ecological-geographical, evolutionary-genetic.

In Russia, for example, the ecological-geographical classification of soils is mainly used, according to which the main types of soil are turf, forest, podzolic, chernozem, tundra, clayey, sandy, and steppe soils.

Chernozem

Chernozem, which has a lumpy or granular structure, is considered the most fertile soil (humus content is about 15%), characteristic of a temperate continental climate, in which dry and wet periods alternate, and above-zero temperatures predominate. Soil analysis showed that chernozem is rich in nitrogen, iron, sulfur, phosphorus, calcium and other elements necessary for the favorable functioning of plants. Chernozem soils are characterized by high water-air characteristics.


sandy lands

Sandy soil is characteristic of deserts and semi-deserts. It is a crumbly, granular, devoid of cohesion soil, in which the ratio of clay to sand is 1:30 or 1:50. It does not retain nutrients and moisture well, and due to the poor vegetation cover it is easily susceptible to wind and water erosion. Sandy soil also has its advantages: it does not become waterlogged, since water in the soil easily passes through the coarse-grained structure, air reaches the roots in sufficient quantities, and putrefactive bacteria do not survive in it.

Forest lands

Forest soils are characteristic of temperate forests northern hemisphere and their properties directly depend on the forests that grow in it and have a direct impact on the composition of the soil, its air permeability, water and thermal regimes. For example, deciduous trees have a positive effect on forest soils: they enrich the soil with humus, ash, nitrogen, neutralize acidity, creating favorable conditions for the formation of beneficial microflora. But coniferous tree species have a negative impact on forest soils, forming podzolic soil.

Forest soils, no matter what trees grow on them, are fertile, since nitrogen and ash, which are found in fallen leaves and needles, return to the soil (this is their difference from field soil, where plant litter is often removed along with the harvest).

Clay soils

Clay soils contain about 40% clay and are moist, viscous, cold, sticky, heavy, but rich in minerals. Clay soil has the ability to retain water for a long time, slowly become saturated with it and very slowly let it pass into the lower layers.

Moisture also evaporates slowly, allowing plants growing here to suffer less from drought.

The properties of clay soil do not allow the plant root system to develop normally, and therefore most of nutrients remain unclaimed. In order to change the composition of the top layer of soil, it is necessary to apply organic fertilizers over several years.

Podzolic soil

Podzolic soils contain from 1 to 4% humus, which is why they are characterized by a gray color. Podzolic soil is characterized by a very low content of nutrients, high acidity, and therefore it is infertile. Podzolic soils are usually formed near coniferous and mixed forests of the temperate zone, and their formation is strongly influenced by the predominance of precipitation over evaporation, low temperatures, reduced microbial activity, poor vegetation, which is why podzolic soils are characterized by a low content of nitrogen and ash (for example, taiga soils , Siberia, Far East).

To use podzolic soils in agricultural work, farmers need to make a lot of effort: apply large doses of mineral and organic fertilizers, constantly regulate the water regime, and plow the soil.

Sod soil

Soddy soils are fertile and characterized by a low or neutral level of acidity, a high amount of humus (from 4 to 6%), and they also have soil properties such as water and air permeability.

Soddy soils are formed under developed grass cover, mainly in meadows. Soil analysis showed that the turf soil contains a large amount of magnesium, calcium, ash, and humus contains a lot of humic acids, which upon reaction form humates - insoluble salts that are directly involved in the formation of the lumpy-grained structure of the soil.


Tundra land

Tundra soils are poor in minerals and nutrients, very fresh and contain little salt. Due to weak evaporation and frozen soil, tundra soils are characterized by high humidity, and due to the insufficient amount of vegetation and its slow humification, low humus content. Therefore, tundra soils contain a thin peaty layer in their upper layer.

The role of soil

The importance of soil in the life of our planet is difficult to overestimate, since it is an indispensable element of the earth’s crust, which ensures the existence of plant and animal organisms.

Since a large number of different processes (among them organic substances) flow through the upper layer of the earth, it is a connecting link between the atmosphere, lithosphere and hydrosphere: it is in the upper layer of the earth that chemical compounds are processed, decomposed and transformed. For example, plants that grow in the soil, decomposing along with other organic substances, are transformed into minerals such as coal, gas, peat, and oil.


The protective functions of the soil are also important: the soil neutralizes substances found in it that are dangerous to life (this is especially important, since soil pollution has recently become catastrophic). First of all, these are toxic chemical compounds, radioactive substances, dangerous bacteria and viruses. The safety margin of the top layer of the earth has a limit, therefore, if soil pollution continues to increase, it will no longer cope with its protective functions.