Mantle of the Earth- the shell of the "solid" Earth, located between the earth's crust and the core of the Earth. It occupies 83% of the Earth (without atmosphere) by volume and 67% by mass.

It is separated from the earth's crust by the Mohorovic surface, on which the velocity of the longitudinal seismic waves when moving from the crust to the mantle of the earth, it increases abruptly from 6.7-7.6 to 7.9-8.2 km/sec; The mantle is separated from the core of the Earth by the surface (at a depth of about 2900 km), at which the velocity of seismic waves drops from 13.6 to 8.1 km/sec. The Earth's mantle is divided into lower and upper mantle. The latter, in turn, is divided (from top to bottom) into the substrate, the Gutenberg layer (a layer of low seismic wave velocities) and the Golitsyn layer (sometimes called the middle mantle). At the base of the Earth's mantle, a layer less than 100 km thick is distinguished, in which the velocities of seismic waves do not increase with depth or even slightly decrease.

It is assumed that the Earth's mantle is composed of those chemical elements that were in solid state or were part of solid chemical compounds. Of these elements, O, Si, Mg, Fe predominate. According to modern ideas, the composition of the Earth's mantle is considered to be close to the composition stone meteorites. Of the stony meteorites, chondrites have the closest composition to the Earth's mantle. It is assumed that the direct samples of the mantle substance are rock fragments among basalt lava, brought to the surface of the Earth; they are also found together with diamonds in explosion pipes. It is also believed that the rock fragments raised by the dredge from the bottom of the rifts of the Mid-Ocean Ridges are the substance of the mantle.

characteristic feature the Earth's mantle are, apparently, phase transitions. It has been experimentally established that in olivine under high pressure the structure of the crystal lattice changes, a denser packing of atoms appears, so that the volume of the mineral noticeably decreases. In quartz, such a phase transition is observed twice as the pressure increases; the densest modification is 65 °C denser than ordinary quartz. Such phase transitions are believed to be the main reason why seismic wave velocities in the Golitsyn layer increase very rapidly with depth.

Upper mantle one of the shells the globe, directly underlying the earth's crust. It is separated from the last Mohorovichi by a surface located under the continents at a depth of 20 to 80 km (35 km on average) and under the oceans at a depth of 11-15 km from the water surface. Seismic wave velocity (used as an indirect method for studying internal structure Earth) increases in the transition from the earth's crust to the upper mantle stepwise from approximately 7 to 8 km/s. ). The zone within the depths of 400-900 km is called the Golitsyn layer. The upper mantle is probably composed of garnet peridotites with an admixture in the upper part of the Eclogite.

Eclogite is a metamorphic rock consisting of pyroxene with a high content of quartz and rutile (a mineral containing an admixture of iron, tin, niobium and tantalum TiO 2 - 60% titanium and 40% oxygen).

Important feature structures of the upper mantle - the presence of a zone of low seismic wave velocities. There are differences in the structure of the upper mantle under different tectonic zones, for example, under geosynclines and platforms. In the upper mantle, processes are developing that are the source of tectonic, magmatic and metamorphic phenomena in the earth's crust. In many tectonic hypotheses, the upper mantle is assigned important role; for example, it is assumed that the earth's crust was formed by melting from the substance of the upper mantle , that tectonic movements are associated with movements in the upper mantle; It is usually believed that the Earth's mantle is almost completely composed of olivine [(Mg, Fe) 2 SiO 4 ], in which the magnesium component (forsterite) strongly predominates, but with depth, perhaps, the proportion of the iron component (fayalite) increases. The Australian petrographer Ringwood suggests that the Earth's mantle is composed of a hypothetical rock, which he called pyrolite and which in composition corresponds to a mixture of 3 parts periodite and 1 part basalt. Theoretical calculations show that minerals in the lower mantle of the Earth should decompose into oxides. By the beginning of the 70s of the 20th century, data also appeared indicating the presence of horizontal inhomogeneities in the Earth's mantle.

There is no doubt that the earth's crust separated from the Earth's mantle; The process of differentiation of the Earth's mantle continues today. There is an assumption that the Earth's core is growing due to the Earth's mantle. The processes in the Earth's crust and the Earth's mantle are closely related; in particular, the energy for tectonic movements of the earth's crust appears to come from the earth's mantle.

Earth's lower mantle- an integral part of the Earth's mantle, extending from depths of 660 (boundary with the upper mantle) to 2900 km. The calculated pressure in the lower mantle is 24-136 GPa and the material of the lower mantle is not available for direct study.

In the lower mantle there is a layer (layer D) in which the velocity of seismic waves is anomalously low and has horizontal and vertical inhomogeneities. It is assumed that it is formed by the upward penetration of Fe and Ni into silicates, which are melted by these flows. This is extremely important, as some researchers believe that parts of the subduction plate accumulate 660 km from the boundary, and they become exponentially heavier and sink to the core and accumulate in the D layer.

Earth's crust- the outermost of the solid shells of the Earth. The lower boundary of the earth's crust is considered to be the interface, during the passage of which from top to bottom, longitudinal seismic waves abruptly increase the speed from 6.7-7.6 km / s to 7.9-8.2 km / s (see Mohorovicic surface). This is a sign of a change from a less elastic material to a more elastic and denser one. The layer of the upper mantle that underlies the earth's crust is often referred to as the substratum. Together with the earth's crust, it makes up the lithosphere. The earth's crust is different on the continents and under the ocean. The continental crust usually has a thickness of 35-45 km, in areas of mountainous countries - up to 70 km. The upper part of the continental crust is made up of a discontinuous sedimentary layer, consisting of unaltered or slightly altered sedimentary and volcanic rocks of different ages. The layers are often crumpled into folds, torn and displaced along the gap. In some places (on shields) the sedimentary shell is absent. The rest of the thickness of the continental crust is divided according to the velocities of seismic waves into 2 parts with conventional names: for the upper part - the "granite" layer (velocity longitudinal waves up to 6.4 km / s), for the lower - "basalt" layer (6.4-7.6 km / s). Apparently, the "granite" layer is composed of granites and gneisses, and the "basalt" layer is composed of basalts, gabbro and very strongly metamorphosed sedimentary rocks in various ratios. These 2 layers are often separated by a Konrad surface, at the transition of which the seismic wave velocities increase abruptly. Apparently, the content of silica decreases with depth in the earth's crust and the content of iron and magnesium oxides increases; also in more this takes place during the transition from the earth's crust to the substrate.

The oceanic crust has a thickness of 5-10 km (together with the water column - 9-12 km). It is divided into three layers: under a thin (less than 1 km) layer of marine sediments lies the "second" layer with longitudinal seismic wave velocities of 4-6 km/sec; its thickness is 1-2.5 km. It is probably composed of serpentinite and basalt, possibly with interlayers of sediments. The lower, "oceanic" layer, with an average thickness of about 5 km, has a seismic wave velocity of 6.4-7.0 km/sec; it is probably composed of gabbro. The thickness of the layer of sediments at the bottom of the ocean is variable, in places there is none at all. In the transition zone from the mainland to the ocean, an intermediate type of crust is observed.

The earth's crust is subject to constant movement and change. In her irreversible development mobile areas - geosynclines - turn through long-term transformations into relatively calm areas - platforms. There are a number of tectonic hypotheses that explain the process of development of geosynclines and platforms, continents and oceans, and the reasons for the development of the earth's crust as a whole. Undoubtedly, the main reasons for the development of the earth's crust lie in more deep bowels Earth; therefore, the study of the interaction between the earth's crust and the upper mantle is of particular interest.

The earth's crust is close to a state of isostasy (equilibrium): the heavier, i.e., the thicker or denser any part of the earth's crust, the deeper it is immersed in the substrate. Tectonic forces break isostasy, but when they weaken, the earth's crust returns to equilibrium.

Figure 25 - Earth's crust

Earth's core - the central geosphere with a radius of about 3470 km. The existence of the Earth's core was established in 1897 by the German seismologist E. Wiechert, and the depth (2,900 km) was determined in 1910 by the American geophysicist B. Gutenberg. There is no consensus on the composition of the Earth's core and its origin. Perhaps it consists of iron (with an admixture of nickel, sulfur, silicon or other elements) or its oxides, which acquire metallic properties under high pressure. There are opinions that the core was formed by gravitational differentiation of the primary Earth during its growth or later (first expressed by the Norwegian geophysicist V.M. Orovan and Soviet scientist A.P. Vinogradov, 60-70s).

Mohorovic surface - the interface between the Earth's crust and the Earth's mantle. The Mohorovichi surface was established from seismic data: the velocity of longitudinal seismic waves during the transition (from top to bottom) through the Mohorovichi surface increases abruptly from 6.7-7.6 to 7.9-8.2 km / s , and transverse - from 3.6-4.2 to 4.4-4.7 km / s. Various geophysical, geological and other data indicate that the density of matter also increases abruptly, presumably from 2.9-3 to 3.1-3.5 t/m 3 . It is most likely that the Mohorovic surface separates layers of different chemical composition. Mohorovichić surface is named after A. Mohorovichić, who discovered it.

Of the first three geospheres, the leading role undoubtedly belongs to the earth's crust, since its total mass is many times greater than the total mass of the other two shells. Therefore, data on the relative content of one or another chemical element in the earth's crust can be considered to a large extent as reflecting its content in the biosphere as a whole.

The outer hard shell of the Earth - the earth's crust is more than 99% composed of only 9 main elements: O (47%), Si (29.5%), Al (8.05%), Fe (4.65%), Ca ( 2.96%), Na (2.50%), K (2.50%), Mg (1.87%), Ti (0.45%). In total - 99.48%. Of these, oxygen is absolutely predominant. You can clearly see how much is left for all other elements. This is by weight, that is, in weight percent.

There is another variant of evaluation - by volume (volume percent). It is calculated taking into account the sizes of atomic and ionic radii in specific mineral compounds formed by these elements. The contents in the earth's crust of the most common elements in volume percentages are (according to V.M. Goldshmidt): O - 93.77%, K - 2.14%, Na - 1.60%, Ca - 1.48%, Si - 0.86%, Al - 0.76%, Fe - 0.68%, Mg - 0.56%, Ti - 0.22%.

Quite significant differences in the distribution of atoms of chemical elements by weight and volume are obvious: a sharp decrease in the relative content of Al and especially Si (due to the small size of their atoms, and for silicon, to an even greater extent of ions in its oxygen compounds) is even more clearly emphasized the leading role of oxygen in the lithosphere.

At the same time, "anomalies" in the contents of some elements in the lithosphere were revealed:

the “dip” in the abundances of the lightest elements (Li, Be, B) is explained by the peculiarities of the nucleosynthesis process (the predominant formation of carbon as a result of the combination of three helium nuclei at once); relatively high contents elements that are products of radioactive decay (Pb, Bi, and also Ar among inert gases).

Under Earth conditions, the abundances of two more elements, H and He, are anomalously low. This is due to their "volatility". Both of these elements are gases, and, moreover, the lightest. So atomic hydrogen and helium tend to move into the upper layers of the atmosphere, and from there, not being held by Earth's gravity, they dissipate into outer space. Hydrogen has not yet been completely lost, since most of it is part of chemical compounds - water, hydroxides, hydrocarbonates, hydrosilicates, organic compounds, etc. And helium, which is an inert gas, is constantly formed as a product of the radioactive decay of heavy atoms.

Thus, the earth's crust is essentially a package of oxygen anions, bound friend with other silicon and metal ions, i.e. it consists almost exclusively of oxygen compounds, predominantly aluminum, calcium, magnesium, sodium, potassium and iron silicates. At the same time, as you already know, even elements account for 86.5% of the lithosphere.

The most common elements are called macronutrients.

Elements, the content of which is hundredths of a percent or less, are called microelements. This concept is relative, since a particular element can be a microelement in one environment, and in another, it can be classified as basic, i.e. macroelements (For example, Al in organisms is a trace element, and in the lithosphere it is a macroelement, iron in soils is a macroelement, and in living organisms it is a trace element).

To denote the amount of content of a particular element in a particular environment, the concept of "clark" is used. This term is associated with the name F.U. Clark, an American geochemist who was the first to undertake, on the basis of extensive analytical material, the calculation of the average contents of chemical elements in various types rocks and in the lithosphere as a whole. In memory of his contribution, A.E. Fersman in 1924 suggested calling the average content of any particular element in a particular material medium the clarke of this chemical element. The clarke unit is g/t (since it is inconvenient to use percentage values ​​at low clarks of many elements).

Most challenging task is the definition of clarks for the lithosphere as a whole, since its structure is very.

Inside the rocks, the division of silicates is carried out into acidic and basic.

The concentrations of Li, Be, Rb, TR, Ba, Tl, Th, U, and Ta are relatively elevated in acidic ones.

The main ones are Cr, Sc, Ni, V, Co, Pt.

We give the order of clarks various elements according to V.F. Barabanov:

More than 10,000 g/t - O, Si, Al, Fe, Ca, Mg, Na, K.

1000-10 000 - Mn, Ti.

100-1000 - C, F, P, S, Cl, Rb, Sr, Zr, Ba.

10-100 - Pb, Th, Y, Nb, La, Ce, Nd, Li, B, N, Sc, V, Cr, Co, Ni, Cu, Zn, Ga.

1-10 - Eu, Dy, Ho, Er, Yb, Hf, Ta, W, Tl, U, Ge, As, Br, Mo, Sn, Sc, Pm, Sm, Be.

0.1-1.0 - Cd, Bi, In, Tu, I, Sb, Lu.

0.01-0.1 - Ar, Se, Ag, Hg.

0.001-0.01 - Re, Os, Ir, Ru, Rh, Pd, Te, Pt, He, Au.

According to this gradation, elements with clarks above 1000 g/t will be referred to as macroelements. Those with lower clarks are trace elements.

Accounting for clarks is absolutely necessary for correct understanding patterns of migration processes of chemical elements. The different distribution of elements in nature has an inevitable consequence for many of them, the presence of significant differences in their behavior in laboratory conditions and in nature. With a decrease in the clarke, the active concentration of the element decreases, and it becomes impossible to precipitate an independent solid phase from aqueous solutions and other methods of formation of independent mineral species. Therefore, the ability for independent mineral formation depends not only on the chemical properties of the element, but also on its clarke.

Examples: S and Se are chemically complete analogs, and their behavior in natural processes different. S is the leading element of many natural processes. Hydrogen sulfide plays an important role in chemical processes occurring in bottom sediments and in the depths of the earth's crust, in the formation of deposits of a number of metals. Sulfur forms independent minerals (sulfides, sulfates). Hydrogen selenide does not play a significant role in natural processes. Selenium is in a dispersed state as an impurity in minerals formed by other elements. The differences between K and Cs, Si and Ge are similar.

One of major differences geochemistry from chemistry in that geochemistry considers only those chemical interactions that are realized in specific natural conditions. In addition, accounting for clarks (according to at least their orders) in this sense is a primary requirement for any geochemical constructions.

There are, and even quite common, independent mineral phases of a number of elements with low clarks. The reason is that there are mechanisms in nature that make it possible to ensure the formation of elevated concentrations of certain elements, as a result of which their content in some areas can be many times higher than the clarke ones. Therefore, in addition to the clarke of the element, it is necessary to take into account the value of its concentration in comparison with the clarke content.

The concentration clarke is the ratio of the content of a chemical element in a given particular natural material aggregate (rock, etc.) to its clarke.

Examples of concentration coefficients of some chemical elements in their ore deposits: Al - 3.7; Mn - 350; Cu - 140; Sn - 250; Zn - 500; Au-2000.

On this basis, elements with low clarks are subdivided into two qualitatively already known to you various groups. Those whose distribution is not characterized by high values ​​of QC are called scattered(Rb, Ga, Re, Cd, etc.). Capable of shaping elevated concentrations with high QC values ​​- rare(Sn, Be, etc.).

Differences in the achieved QC values ​​are due to different role certain elements in the history of the material and technical activity of mankind (from antiquity known metals with low clarks Au, Cu, Sn, Pb, Hg, Ag ... - and more common Al, Zr ...).

Big role in the processes of concentration and dispersion of elements in the earth's crust, isomorphism plays - the property of elements to replace each other in the structure of the mineral. Isomorphism is the ability of chemical elements with similar properties to replace each other in varying amounts in crystal lattices. Of course, it is characteristic not only of microelements. But it is precisely for them, especially for scattered elements, that it acquires leading value as the main factor in the regularity of their distribution. A distinction is made between perfect isomorphism - when interchangeable elements can replace each other in any ratio (limited only by the ratios of the contents of these elements in the system), and imperfect - when substitution is possible only up to certain limits. Naturally, the closer Chemical properties, the more perfect isomorphism.

A distinction is made between isovalent and heterovalent isomorphism.

Generality of type chemical bond- what chemists call the degree of ionicity - covalence. Example: chlorides and sulfides are not isomorphic, but sulfates with manganates are isomorphic.

Mechanism of isovalent isomorphism. The uniformity of the chemical formula of the formed compounds and the formed crystal lattice. That is, if rubidium is potentially capable of forming compounds with the same elements as potassium, and the crystal structure of such compounds is of the same type, then rubidium atoms can replace potassium atoms in its compounds.

The division of chemical elements into macro- and microelements, and the latter into rare and scattered has great importance, since in nature not all chemical elements form self connections. This is characteristic mainly of elements with high clarks, or with low clarks, but capable of locally forming high concentrations (that is, rare).

Being in nature in a diffuse state and everywhere (only in various concentrations) is a property of all chemical elements. This fact was first stated by V.I. Vernadsky, and he received the name of the law of scattering of chemical elements by Vernadsky. But part of the elements is capable of being present in nature in addition to the scattered form of being in another form - in the form of chemical compounds. And elements with low concentrations are present only in a diffuse form.

Mechanism of heterovalent isomorphism somewhat more complex. For the first time, the presence of this type of isomorphism drew attention at the end of the 19th century. G. Chermak. He proved that very complex chemical formulas, obtained for most mineral compounds of the silicate class, are such precisely because of heterovalent isomorphism, when whole groups of atoms mutually replace each other. This type of isomorphism is very characteristic of silicate compounds.

Other options for finding scattered atoms of elements in the earth's crust are their localization in the defects of the crystal lattice, in its cavities, as well as in the sorbed state on the surface of other particles, including colloidal ones.

In order to determine the basic properties of the biosphere, we must first understand what we are dealing with. What is the form of its organization and existence? How does it work and interact with the outside world? Ultimately, what is it?

From the appearance of the term at the end of the 19th century to the creation of a holistic doctrine by the biogeochemist and philosopher V.I. Vernadsky, the definition of the concept of "biosphere" has undergone significant changes. It has moved from the category of a place or territory where living organisms live to the category of a system consisting of elements or parts, functioning according to certain rules for achievement specific purpose. It is on how to consider the biosphere that it depends on what properties are inherent in it.

The term is based on ancient Greek words: βιος - life and σφαρα - sphere or ball. That is, it is some shell of the Earth, where there is life. Earth, as an independent planet, according to scientists, arose about 4.5 billion years ago, and a billion years later life appeared on it.

Archean, Proterozoic and Phanerozoic eon. Eons are made up of eras. The latter consists of the Paleozoic, Mesozoic and Cenozoic. Eras from periods. Cenozoic from the Paleogene and Neogene. Periods from epochs. The current - Holocene - began 11.7 thousand years ago.

Borders and layers of propagation

The biosphere has a vertical and horizontal distribution. Vertically, it is conventionally divided into three layers where life exists. These are the lithosphere, hydrosphere and atmosphere. The lower boundary of the lithosphere reaches 7.5 km from the Earth's surface. The hydrosphere is located between the lithosphere and the atmosphere. Its maximum depth is 11 km. The atmosphere covers the planet from above and life in it exists, presumably, at an altitude of up to 20 km.

In addition to vertical layers, the biosphere has a horizontal division or zoning. This change natural environment from the Earth's equator to its poles. The planet has the shape of a ball and therefore the amount of light and heat entering its surface is different. The largest zones are geographical zones. Starting from the equator, it goes first equatorial, above tropical, then temperate, and finally, near the poles - arctic or antarctic. Inside the belts are natural areas: forests, steppes, deserts, tundra and so on. These zones are characteristic not only for land, but also for the oceans. AT horizontal arrangement the biosphere has its own altitude. It is determined by the surface structure of the lithosphere and differs from the foot of the mountain to its top.

To date, the flora and fauna of our planet has about 3,000,000 species, and this is only 5% of the total number of species that have managed to "live" on Earth. About 1.5 million animal species and 0.5 million plant species have found their description in science. There are not only undescribed species, but also unexplored regions of the Earth, the species content of which is unknown.

Thus, the biosphere has a temporal and spatial characteristic, and the species composition of living organisms that fills it varies both in time and in space - vertically and horizontally. This led scientists to the conclusion that the biosphere is not a planar structure and has signs of temporal and spatial variability. It remains to determine, under the influence of what external factor, it changes in time, space and structure. That factor is solar energy.

If we accept that the species of all living organisms, regardless of the spatial and temporal framework, are parts, and their totality is the whole, then their interaction with each other and with the external environment is a system. L von Bertalanffy and F.I. Peregudov, defining a system, argued that it is a complex of interacting components, or a set of elements that are in relationship with each other and with the environment, or a set of interconnected elements that are isolated from the environment and interact with it as a whole.

System

the biosphere as one complete system can be subdivided into constituent parts. The most common such division is species. Each type of animal or plant is taken as an integral part of the system. It can also be recognized as a system, with its own structure and composition. But the species does not exist in isolation. Its representatives live in a certain territory, where they interact not only with each other and the environment, but also with other species. Such a residence of species, in one area, is called an ecosystem. The smallest ecosystem, in turn, is included in the larger one. That in even more and so to the global - to the biosphere. Thus, the biosphere, as a system, can be considered as consisting of parts, which are either species or biospheres. The only difference is that a species can be identified because it has features that distinguish it from others. It is independent and in other types - parts are not included. With biospheres, such a distinction is impossible - one part of the other.

signs

The system has two more significant features. It was created to achieve specific purpose and the functioning of the whole system is more effective than each of its parts separately.

Thus, the properties as a system, in its integrity, synergy and hierarchy. Integrity lies in the fact that the connections between its parts or internal connections are much stronger than with the environment or external ones. Synergy or systemic effect is that the capabilities of the entire system are much greater than the sum of the capabilities of its parts. And, although each element of the system is a system itself, nevertheless, it is only a part of the general and larger one. This is its hierarchy.

The biosphere is a dynamic system that changes its state under external influence. It is open because it exchanges matter and energy with the environment. It has a complex structure, as it consists of subsystems. And finally, it is a natural system - formed as a result of natural changes over many years.

Thanks to these qualities, she can regulate and organize herself. These are the basic properties of the biosphere.

In the middle of the 20th century, the concept of self-regulation was first used by the American physiologist Walter Cannon, and the English psychiatrist and cybernetician William Ross Ashby introduced the term self-organization and formulated the law of required diversity. This cybernetic law formally proved the need for a large species diversity for the stability of the system. The greater the diversity, the higher the probability of the system to maintain its dynamic stability in the face of large external influences.

Properties

Responding to external influence, resisting and overcoming it, reproducing itself and restoring, that is, maintaining its internal constancy, such is the goal of a system called the biosphere. These qualities of the whole system are built on the ability of its part, which is the species, to maintain a certain number or homeostasis, as well as each individual or living organism to maintain its physiological conditions - homeostasis.

As you can see, these properties developed in her under the influence and to counteract external factors.

The main external factor is solar energy. If the number of chemical elements and compounds is limited, then the energy of the Sun is constantly supplied. Thanks to it, the migration of elements along the food chain from one living organism to another and the transformation from an inorganic state to an organic one and vice versa takes place. Energy accelerates the course of these processes inside living organisms and, in terms of the reaction rate, they occur much faster than in the external environment. The amount of energy stimulates the growth, reproduction and increase in the number of species. Diversity, in turn, provides an opportunity for additional resistance to external influences, since there is a possibility of duplication, hedging or replacement of species in the food chain. The migration of elements will thus be additionally ensured.

Human influence

The only part of the biosphere that is not interested in increasing the species diversity of the system is man. He strives in every possible way to simplify ecosystems, because in this way he can more effectively monitor and regulate it, depending on his needs. Therefore, all biosystems artificially created by man or the degree of his influence, on which is significant, are very scarce in terms of species. And their stability and ability to self-healing and self-regulation tends to zero.

With the advent of the first living organisms, they began to change the conditions of existence on Earth to suit their needs. With the advent of man, he already began to change the biosphere of the planet so that his life was as comfortable as possible. It is comfortable, because we are not talking about survival or saving life. Following logic, something should appear that will change the person himself for its own purposes. I wonder what it will be?

Video - Biosphere and noosphere

The structure of the Earth is a combination, interaction and dependence on each other of its main shells. If there were no people on the planet, then perhaps its surface would look different today. Over the course of millions of years, these shells were created, thanks to which life was able to appear and develop, and the general signs of the lithosphere, hydrosphere, atmosphere, biosphere inherent in them currently indicate the strongest anthropogenic impact on them by human activity.

Spheres of the Earth

If we consider the structure of the planet from the point of view of its landscape sphere, then we can see that it includes not only the well-known surface of the earth's crust, but also several "neighboring" shells. It is this close connection between the boundaries that determines the common features characteristic of the atmosphere, hydrosphere, lithosphere and biosphere. They are manifested in the constant exchange of liquid, solid and gaseous components inherent in each of the shells. For example, the water cycle in nature is an exchange between the hydrosphere and the atmosphere.

If there is a volcanic eruption with the release of ash into the air - this is the relationship of the lithosphere with the lower layers of the atmosphere, although some cataclysms can be of such power that they almost reach its middle part. In the event that the volcano is located on an island or at the bottom of the ocean, then all the shells of the Earth will be involved, and the atmosphere, and the hydrosphere, and the lithosphere, and the biosphere. The latter is most often expressed by the death of vegetation and wildlife in the radius of a natural disaster.

Conventionally, the spheres of the Earth can be divided into 4 parts: atmosphere, biosphere, hydrosphere, lithosphere, but some of them consist of several components.

Atmosphere

The atmosphere is called the entire outer gaseous sphere of the planet, surrounding it up to the vacuum in space. If the following shells of the Earth - lithosphere, hydrosphere, atmosphere, biosphere - interact with each other, then this cannot be said about some of their parts. The atmosphere is divided into 3 regions, each of which has its own altitude, for example:

Of greatest interest to scientists and conservationists is the lower region of the troposphere.

Hydrosphere

The water space located on the surface of the earth's crust and under it is called the hydrosphere. This is the totality of all waters, both fresh and salty, that are on the planet. The depth of some reservoirs can reach 3.5 km, which is inherent in the oceans, and in some areas, called depressions, even go deeper than 10 km. The deepest known underwater “trough” is the Mariana Trench, which, according to 2011 data, goes down to 10,994 m.

Since life on Earth depends on the quality of water, the hydrosphere is just as important as air, which is why everything large quantity environmental scientists are concerned about the consequences of human impact on these areas. From the water on the planet, not only everything that exists, but it also depends on it so that life remains on it.

Scientists were able to prove that in place, for example, the Sahara were prairies that crossed deep rivers. When the water left this area, it was gradually filled with sands. If we consider what common features the hydrosphere, atmosphere, lithosphere, biosphere have, then we can see that they are directly dependent on each other, and all of them affect the existence of life on Earth.

If an ecological disaster occurs, due to which rivers dry up (hydrosphere), then vegetation and animals in this region suffer (biosphere), the state of the air changes (atmosphere), and the surface

Biosphere

This shell has appeared since the origin of life on the planet. The concept of "biosphere" was introduced as a term only at the end of the 19th century, and it included all forms and types of life that exist on Earth.

She especially strong connection with the rest of the planet. So various microorganisms are found in the lower part of the atmosphere. People, animals, birds, insects and plants live on the surface and underground (the lithosphere). Rivers, seas, lakes and oceans (hydrosphere) inhabit freshwater and sea ​​fish, microorganisms, plants and animals.

The boundary of the biosphere, as a rule, is determined by the conditions in which living organisms can be, and they are able to change. So, for example, in the oceans, life flows in all layers up to their bottom. Each layer has its own "set" of creatures and microorganisms, which is associated with the saturation of water with salt and the pressure level of the water column. The closer the bottom, the higher it is.

Signs of the biosphere (in other words, the sphere of life) were found at an altitude of 20 km above sea level and at a depth of 3 km from the Earth's surface.

Lithosphere

"Lithos" in Greek means "stone", so the entire earth's crust, which is a rock, was called the lithosphere. She has two parts:

1. The top cover is sedimentary rocks containing granite in their composition.
2. The lower level is basaltic rocks.

A smaller part of the lithosphere (only 30%) falls on land, the rest is covered by the waters of the oceans. The connection of the lithosphere with the atmosphere, hydrosphere, biosphere lies in the upper soil layer. Vegetation and animal life (biosphere) develop there, aerobic bacteria live in it, which need air (atmosphere), nutrition is provided groundwater and in the form of precipitation (hydrosphere).

Human impact on the atmosphere

The main features of the lithosphere, hydrosphere, atmosphere, and biosphere were listed above. Since they interact very closely, the influence on one of them immediately affects the others. This is due to the fact that common feature all these shells of the Earth is the presence of life in them.

Today one can observe the damage caused by the activity of people on the spheres of the planet. So emissions of harmful substances into the atmosphere, cutting down the Amazonian jungle, launching rockets and taking off planes every day gradually destroy the ozone layer. If it becomes smaller (today its size is about 8 km), then all life on the planet can either mutate or die.

According to archaeologists, the Earth has already experienced similar shocks, but in those distant times it was not inhabited by people. Nowadays, everything is different. Not so long ago, there were cities where the level of exhaust gases from cars was so high that people were forced to walk the streets in masks. Scientists and environmental enthusiasts were able to "reach out" to the public in order to reverse the threatening situation.

More and more countries, realizing that the quality of life directly depends on the purity of the air that their population breathes, are switching to alternative sources energy, introduce electric vehicles into everyday life, close or modernize hazardous industries. This gives hope that future generations of earthlings will have clean air.

Man and the hydrosphere

Humans have done no less harm to the water resources of the planet. Considering that only 3% of water is fresh, that is, suitable for life, humanity is again under threat. The close connection of the hydrosphere with the rest of the Earth's shells is carried out through the water cycle in nature.

If a reservoir is polluted, then the water evaporated from its surface can spill contaminated rain in any part of the world, causing damage to the soil (lithosphere), wildlife (biosphere), and turning into a poisonous fog (atmosphere).

Although in the work of cleaning and preserving natural resources many states take part in the planet, this is still not enough. Everyone is well aware of the problems with clean drinking water in countries of Africa and Asia, the population of which is sick precisely because of the pollution of local water bodies.

Violation of the shells of the Earth by man

Since all spheres of the planet are interconnected and have a common feature - the presence of life in them, the imbalance in one is immediately reflected in the others. Deepening people into the bowels of the Earth for the sake of mining, emissions into the atmosphere of harmful chemical substances, oil spills in the seas and oceans - all this leads to the fact that every day the animal disappears or is endangered and vegetable world(biosphere).

If humanity does not stop its wrecking activity, then after several hundred years the disturbances in the shells of the planet will be so significant that all life on the planet will die out. An example would be the same Sahara desert, which was once a flourishing land in which primitive people lived.

Conclusion

Every moment the shells of the Earth exchange their components with each other. They have existed for billions of years, interacting with each other. The definitions of the lithosphere, atmosphere, hydrosphere, biosphere were given above, and until people understand that the planet is a living organism, and if one “organ” is removed from it, the whole body immediately suffers, then the mortality of the population will only increase.

Let us examine in more detail the components of the biosphere.

Earth's crust - it is transformed in the course of geological time hard shell, which is upper part lithosphere of the Earth. A number of minerals in the earth's crust (limestone, chalk, phosphorites, oil, coal, etc.) arose from the tissues of dead organisms. It is a paradoxical fact that relatively small living organisms could cause phenomena of a geological scale, which is explained by their highest ability to reproduce. For example, under favorable conditions, the cholera virion can create a mass of matter equal to the mass of the earth's crust in just 1.75 days! It can be assumed that in the biospheres of previous eras, colossal masses of living matter moved around the planet, forming reserves of oil, coal, etc. as a result of death.

The biosphere exists by repeatedly using the same atoms. At the same time, the share of 10 elements located in the first half of the periodic system (oxygen - 29.5%, sodium, magnesium - 12.7%, aluminum, silicon - 15.2%, sulfur, potassium, calcium, iron - 34.6 %) accounts for 99% of the entire mass of our planet (the mass of the Earth is 5976 * 10 21 kg), and 1% is accounted for by the rest of the elements. However, the significance of these elements is very great - they play an essential role in living matter.

IN AND. Vernadsky divided all the elements of the biosphere into 6 groups, each of which performs certain functions in the life of the biosphere. First group – inert gases (helium, krypton, neon, argon, xenon). Second group – precious metals (ruthenium, palladium, platinum, osmium, iridium, gold). In the earth's crust, the elements of these groups are chemically inactive, their mass is insignificant (4.4 * 10 -4% of the mass of the earth's crust), and participation in the formation of living matter is poorly studied. The third group - lanthanides (14 chemical elements - metals) make up 0.02% of the mass of the earth's crust and their role in the biosphere has not been studied. Fourth group – radioactive elements are the main source of formation of the internal heat of the Earth and affect the growth of living organisms (0.0015% of the mass of the earth's crust). Some elements fifth group - scattered elements (0.027% of the earth's crust) - play an essential role in the life of organisms (for example, iodine and bromine). the biggest sixth group constitute cyclic elements , which, having undergone a series of transformations in geochemical processes, return to their original chemical states. This group includes 13 light elements (hydrogen, carbon, nitrogen, oxygen, sodium, magnesium, aluminum, silicon, phosphorus, sulfur, chlorine, potassium, calcium) and one heavy element (iron).

biota It is the totality of all types of plants, animals and microorganisms. Biota is an active part of the biosphere, which determines all the most important chemical reactions, as a result of which the main gases of the biosphere (oxygen, nitrogen, carbon monoxide, methane) are created and quantitative relationships are established between them. Biota continuously forms biogenic minerals and maintains a constant chemical composition of ocean waters. Its mass is no more than 0.01% of the mass of the entire biosphere and is limited by the amount of carbon in the biosphere. The main biomass is made up of green land plants - about 97%, and the biomass of animals and microorganisms - 3%.

The biota is mainly composed of cyclic elements. Particularly important is the role of such elements as carbon, nitrogen and hydrogen, the percentage of which in biota is higher than in the earth's crust (60 times carbon, 10 times nitrogen and hydrogen). The figure shows a diagram of a closed carbon cycle. Only thanks to the circulation of the main elements in such cycles (primarily carbon), the existence of life on Earth is possible.

Pollution of the lithosphere. Life, the biosphere and the most important link in its mechanism - ground cover, commonly called the earth, constitute the uniqueness of our planet in the universe. And in the evolution of the biosphere, in the phenomena of life on Earth, the importance of the soil cover (land, shallow waters and shelf) as a special planetary shell has invariably increased.

The soil cover is the most important natural formation. Its role in the life of society is determined by the fact that the soil is the main source of food, providing 95-97% of food resources for the world's population. Special property soil cover - fertility , which is understood as a set of soil properties that ensure the yield of agricultural crops. The natural fertility of the soil is associated with the supply of nutrients in it and its water, air and thermal regimes. The soil provides the need for plants in water and nitrogen nutrition, being the most important agent of their photosynthetic activity. Soil fertility also depends on the amount of soil accumulated in it. solar energy. The soil cover belongs to a self-regulating biological system, which is the most important part of the biosphere as a whole. Living organisms, plants and animals inhabiting the Earth fix solar energy in the form of phyto- or zoomass. The productivity of terrestrial ecosystems depends on the heat and water balances of the earth's surface, which determines the variety of forms of energy and matter exchange within the geographic envelope of the planet.

Particular attention should be paid to land resources. The area of ​​land resources in the world is 149 million km2, or 86.5% of the land area. Arable land and perennial plantations as part of agricultural land currently occupy about 15 million km 2 (10% of land), hayfields and pastures - 37.4 million km 2 (25%). The total area of ​​arable land is estimated by various researchers in different ways: from 25 to 32 million km 2. The planet's land resources make it possible to provide more people with food than is currently available and will be in the near future. However, due to population growth, especially in developing countries, the amount of arable land per capita is declining. Even 10-15 years ago, the mental security of the Earth's population with arable land was 0.45-0.5 hectares, at present it is already 0.35-37 hectares.

All usable material components of the lithosphere used in the economy as raw materials or energy sources are called mineral resources . Minerals can be ore if metals are extracted from it, and nonmetallic , if non-metallic components (phosphorus, etc.) are extracted from it or used as building materials.

If the mineral wealth is used as a fuel (coal, oil, gas, oil shale, peat, wood, nuclear energy) and at the same time as an energy source in engines to produce steam and electricity, then they are called fuel and energy resources .

Hydrosphere . Water occupies the predominant part of the Earth's biosphere (71% of the earth's surface) and makes up about 4% of the mass of the earth's crust. Its average thickness is 3.8 km, average depth - 3554 m, area: 1350 million km 2 - oceans, 35 million km 2 - fresh water.

Ground ocean water accounts for 97% of the mass of the entire hydrosphere (2 * 10 21 kg). The role of the ocean in the life of the biosphere is enormous: the main chemical reactions take place in it, which determine the production of biomass and chemical treatment biosphere. So, in 40 days, the surface five-hundred-meter layer of water in the ocean passes through the plankton filtration apparatus, therefore (taking into account mixing) all the oceanic water of the ocean undergoes purification during the year. All components of the hydrosphere (atmospheric water vapor, waters of the seas, rivers, lakes, glaciers, swamps, groundwater) are in constant motion and renewal.

Water is the basis of the biota (living matter is 70% water) and its importance in the life of the biosphere is decisive. One can name such essential functions water like:

1. biomass production;

2. chemical purification of the biosphere;

3. ensuring carbon balance;

4. climate stabilization (water plays the role of a buffer in thermal processes on the planet).

The great importance of the world ocean lies in the fact that it produces almost half of the total oxygen in the atmosphere with its phytoplankton, i.e. is a kind of "lung" of the planet. At the same time, plants and microorganisms of the ocean in the process of photosynthesis assimilate annually significantly most carbon dioxide than plants on land absorb.

living organisms in the ocean – hydrobionates - are divided into three main ecological groups: plankton, nekton and benthos. Plankton - a set of passively floating and portable sea ​​currents plants (phytoplankton), living organisms (zooplankton) and bacteria (bacterioplankton). Nekton - this is a group of actively swimming living organisms moving over considerable distances (fish, cetaceans, seals, sea snakes and turtles, octopus squids, etc.). Benthos - these are organisms that live on the seabed: sessile (corals, algae, sponges); burrowing (worms, mollusks); crawling (crustaceans, echinoderms); floating freely at the bottom. The coastal areas of the oceans and seas are the richest in benthos.

The oceans are a source of huge mineral resources. Already, oil, gas, 90% bromine, 60% magnesium, 30% salt, etc. are being extracted from it. The ocean has huge reserves of gold, platinum, phosphorites, oxides of iron and manganese, and other minerals. The level of mining in the ocean is constantly growing.

Pollution of the hydrosphere. In many regions of the world, the state of water bodies is of great concern. Pollution water resources not without reason is now regarded as the most serious threat to the environment. The river network actually functions as the natural sewer system of modern civilization.

The most polluted are inland seas. They have a longer coastline and are therefore more prone to pollution. The accumulated experience of the struggle for the purity of the seas shows that this is an incomparably more difficult task than the protection of rivers and lakes.

The processes of water pollution are caused by various factors. The main ones are: 1) discharge of untreated wastewater into water bodies; 2) flushing of pesticides with heavy rainfall; 3) gas and smoke emissions; 4) leakage of oil and oil products.

The greatest harm to water bodies is caused by the release of untreated wastewater into them - industrial, domestic, collector and drainage, etc. Industrial wastewater pollutes ecosystems with various components, depending on the specifics of industries.

Pollution level Russian seas(with the exception of White Sea), according to the State report “On the state of the environment Russian Federation", in 1998. exceeded the MPC for hydrocarbon content, heavy metals, mercury; surfactants (surfactants) on average 3-5 times.

The ingress of pollution to the ocean floor has a serious impact on the nature of biochemical processes. In this regard, the assessment of environmental safety in the planned extraction of minerals from the ocean floor, primarily iron-manganese nodules containing manganese, copper, cobalt and other valuable metals, is of particular importance. In the process of raking the bottom, the very possibility of life on the ocean floor will be destroyed for a long period, and the ingress of substances extracted from the bottom to the surface can adversely affect the air atmosphere of the region.

The huge volume of the World Ocean testifies to the inexhaustibility of the planet's natural resources. In addition, the oceans are a collector river waters land, annually taking about 39 thousand km 3 of water. The emerging pollution of the World Ocean threatens to disrupt the natural process of moisture circulation in its most critical link - evaporation from the surface of the ocean.

In the Water Code of the Russian Federation, the concept " water resources ” is defined as “reserves of surface and groundwater located in water bodies that are used or can be used. Water is the most important component of the environment, a renewable, limited and vulnerable natural resource, used and protected in the Russian Federation as the basis of life and activity of the peoples living on its territory, ensures the economic, social, environmental well-being of the population, the existence of flora and fauna.

Any body of water or water source is associated with its external environment. It is influenced by the conditions for the formation of surface or underground water runoff, various natural phenomena, industry, industrial and municipal construction, transport, economic and domestic human activities. The consequence of these influences is the introduction into aquatic environment new, unusual substances - pollutants that degrade water quality. Pollution entering the aquatic environment is classified in different ways, depending on the approaches, criteria and tasks. So, usually allocate chemical, physical and biological pollution. Chemical pollution is a change in the natural chemical properties of water due to an increase in the content of harmful impurities both inorganic (mineral salts, acids, alkalis, clay particles) and organic nature(oil and oil products, organic residues, surfactants, pesticides) .

Despite the huge funds spent on the construction of treatment facilities, many rivers are still dirty, especially in urban areas. Pollution processes have even touched the oceans. And this does not seem surprising, since all caught in the rivers pollutants eventually rush to the ocean and reach it if they are difficult to decompose.

The environmental consequences of pollution of marine ecosystems are expressed in the following processes and phenomena:

violation of the stability of ecosystems;

progressive eutrophication;

the appearance of "red tides";

accumulation of chemical toxicants in biota;

decrease in biological productivity;

the occurrence of mutagenesis and carcinogenesis in the marine environment;

microbiological pollution of the coastal regions of the world.

Protecting the aquatic ecosystem is a complex and very important issue. To this end, the following environmental protection measures:

– development of waste-free and water-free technologies; introduction of water recycling systems;

– wastewater treatment (industrial, municipal, etc.);

– injection of sewage into deep aquifers;

- cleaning and disinfection surface water used for water supply and other purposes .

The main pollutant of surface waters is wastewater, therefore, the development and implementation of effective wastewater treatment methods is a very urgent and environmentally important task. The most effective way to protect surface waters from pollution by sewage is the development and implementation of an anhydrous and waste-free production technology, the initial stage of which is the creation of a circulating water supply.

When organizing a recycling water supply system, it includes a number of treatment facilities and installations, which makes it possible to create a closed cycle for the use of industrial and domestic wastewater. With this method of water treatment, wastewater is always in circulation and their entry into surface water bodies is completely excluded.

Due to the huge variety of composition of wastewater, there are various ways their purification: mechanical, physico-chemical, chemical, biological, etc. Depending on the degree of harmfulness and nature of pollution, wastewater treatment can be carried out by any one method or a set of methods (combined method). The treatment process involves the treatment of sludge (or excess biomass) and the disinfection of wastewater before being discharged into a reservoir.

In recent years, new effective methods have been actively developed that contribute to the environmental friendliness of wastewater treatment processes:

– electrochemical methods based on the processes of anodic oxidation and cathodic reduction, electrocoagulation and electroflotation;

– membrane purification processes (ultrafilters, electrodialysis, and others);

– magnetic treatment, which improves the flotation of suspended particles;

– radiation purification of water, which makes it possible to subject pollutants to oxidation, coagulation and decomposition in the shortest possible time;

- ozonation, in which wastewater does not form substances that adversely affect natural biochemical processes;

- introduction of new selective types for the selective separation of useful components from wastewater for the purpose of recycling, and others.

It is known that pesticides and fertilizers washed off by surface runoff from agricultural land play a role in the contamination of water bodies. To prevent the ingress of polluting effluents into water bodies, a set of measures is required, including:

compliance with the norms and terms of applying fertilizers and pesticides;

focal and tape treatment with pesticides instead of continuous;

application of fertilizers in the form of granules and, if possible, together with irrigation water;

replacement of pesticides by biological methods of plant protection.

Measures for the protection of waters and seas and the World Ocean are to eliminate the causes of deterioration in the quality and pollution of waters. Special measures to prevent pollution of sea water should be envisaged in the exploration and development of oil and gas fields on the continental shelves. There should be a ban on burial toxic substances in the ocean, maintain a moratorium on nuclear weapons testing.

Atmosphere - the air environment around the Earth, its mass is about 5.15 * 10 18 kg. It has a layered structure and consists of several spheres, between which there are transitional layers - pauses. In the spheres, the amount of air and temperature change.

Depending on the distribution of temperature, the atmosphere is divided into:

– troposphere (its length in height in the middle latitudes is 10-12 km above sea level, at the poles - 7-10, above the equator - 16-18 km, more than 4/5 of the mass of the earth's atmosphere is concentrated here; due to the uneven heating of the earth's surface in powerful vertical air currents are formed in the troposphere, instability of temperature, relative humidity, pressure is noted, the air temperature in the troposphere decreases in height by 0.6 ° C for every 100 m and ranges from +40 to -50 ° C);

– stratosphere (has a length of about 40 km, the air in it is rarefied, the humidity is low, the air temperature is from -50 to 0 ° C at altitudes of about 50 km; in the stratosphere, under the influence of cosmic radiation and the short-wave part of the ultraviolet radiation of the sun, air molecules are ionized, resulting in the formation ozone layer located at an altitude of 25-40 km);

– mesosphere (from 0 to -90 o C at altitudes of 50-55 km);

– thermosphere (it is characterized by a continuous increase in temperature with increasing altitude - at an altitude of 200 km 500 ° C, and at an altitude of 500-600 km it exceeds 1500 ° C; in the thermosphere, gases are very rarefied, their molecules move at high speed, but rarely collide with each other and therefore cannot cause even a slight heating of the body located here);

– exosphere (from several hundred km).

Uneven heating contributes to the general circulation of the atmosphere, which affects the weather and climate of the Earth.

The gas composition of the atmosphere is as follows: nitrogen (79.09%), oxygen (20.95%), argon (0.93%), carbon dioxide (0.03%) and a small amount of inert gases (helium, neon, krypton, xenon ), ammonia, methane, hydrogen, etc. . The lower layers of the atmosphere (20 km) contain water vapor, the amount of which decreases rapidly with height. At an altitude of 110-120 km, almost all oxygen becomes atomic. It is assumed that above 400-500 km and nitrogen is in the atomic state. The oxygen-nitrogen composition persists approximately up to an altitude of 400-600 km. The ozone layer, which protects living organisms from harmful short-wave radiation, is located at an altitude of 20-25 km. Above 100 km, the proportion of light gases increases, and at very high altitudes, helium and hydrogen predominate; part of the gas molecules break down into atoms and ions, forming ionosphere . Air pressure and density decrease with height.

Air pollution. The atmosphere has a huge impact on biological processes on land and in water bodies. The oxygen contained in it is used in the process of respiration of organisms and during the mineralization of organic matter, carbon dioxide is consumed during photosynthesis by autotrophic plants, and ozone reduces the ultraviolet radiation of the sun harmful to organisms. In addition, the atmosphere contributes to the preservation of the Earth's heat, regulates the climate, perceives gaseous metabolic products, transports water vapor around the planet, etc. Without an atmosphere, the existence of any complex organisms is impossible. Therefore, the issues of preventing air pollution have always been and remain relevant.

To assess the composition and pollution of the atmosphere, the concept of concentration (C, mg/m 3) is used.

Pure natural air has the following composition (in % vol): nitrogen 78.8%; oxygen 20.95%; argon 0.93%; CO 2 0.03%; other gases 0.01%. It is believed that such a composition should correspond to air at a height of 1 m above the ocean surface away from the coast.

As for all other components of the biosphere, there are two main sources of pollution for the atmosphere: natural and anthropogenic (artificial). The entire classification of pollution sources can be represented according to the above structural diagram: industry, transport, energy are the main sources of air pollution. According to the nature of the impact on the biosphere, atmospheric pollutants can be divided into 3 groups: 1) affecting global climate warming; 2) destroying biota; 3) destroying the ozone layer.

Let us note the brief characteristics of some atmospheric pollutants.

To pollutants first group should include CO 2, nitrous oxide, methane, freons. Into the creation greenhouse effect » The main contributor is carbon dioxide, which is increasing by 0.4% annually (for more on the greenhouse effect, see chapter 3.3). Compared with the middle of the XIX century, the content of CO 2 increased by 25%, nitrous oxide by 19%.

Freons – chemical compounds, unusual for the atmosphere, used as refrigerants - are responsible for 25% of the greenhouse effect in the 90s. Calculations show that, despite the Montreal Agreement of 1987. on limiting the use of freons, by 2040. the concentration of the main freons will increase significantly (chlorofluorocarbon from 11 to 77%, chlorofluorocarbon - from 12 to 66%), which will lead to an increase in the greenhouse effect by 20%. The increase in the content of methane in the atmosphere was insignificant, but the specific contribution of this gas is about 25 times higher than that of carbon dioxide. If you do not stop the flow of "greenhouse" gases into the atmosphere, the average annual temperatures on Earth by the end of the 21st century will rise by an average of 2.5-5 ° C. It is necessary: ​​to reduce the burning of hydrocarbon fuels and deforestation. The latter is dangerous, in addition to leading to an increase in carbon in the atmosphere, it will also cause a decrease in the assimilating capacity of the biosphere.

To pollutants second group should include sulfur dioxide, suspended solids, ozone, carbon monoxide, nitric oxide, hydrocarbons. Of these substances in the gaseous state, sulfur dioxide and nitrogen oxides cause the greatest damage to the biosphere, which in the process chemical reactions are converted into small crystals of salts of sulfuric and nitric acid. The most acute problem is air pollution with sulfur-containing substances. Sulfur dioxide is harmful to plants. Entering the leaf during respiration, SO 2 inhibits the vital activity of cells. In this case, the leaves of the plants are first covered with brown spots, and then dry up.

Sulfur dioxide and its other compounds irritate the mucous membranes of the eyes and the respiratory tract. Long lasting low concentrations of SO 2 leads to chronic gastritis, hepatopathy, bronchitis, laryngitis and other diseases. There is evidence of a relationship between the content of SO 2 in the air and the death rate from lung cancer.

In the atmosphere, SO 2 is oxidized to SO 3. Oxidation occurs catalytically under the influence of trace metals, mainly manganese. In addition, SO 2 gaseous and dissolved in water can be oxidized with ozone or hydrogen peroxide. Combining with water, SO 3 forms sulfuric acid, which forms sulfates with the metals present in the atmosphere. The biological effect of acid sulfates at equal concentrations is more pronounced compared to SO 2 . Sulfur dioxide exists in the atmosphere from several hours to several days, depending on humidity and other conditions.

In general, aerosols of salts and acids penetrate into sensitive tissues of the lungs, devastate forests and lakes, reduce crops, destroy buildings, architectural and archaeological monuments. Suspended particulate matter poses a public health hazard that outweighs that of acid aerosols. Basically, this is the danger of big cities. Particularly harmful solids are found in the exhaust gases of diesel engines and two-stroke gasoline engines. Most of the particulate matter in the air is of industrial origin. developed countries successfully captured by various technical means.

Ozone in the surface layer appears as a result of the interaction of hydrocarbons formed during the incomplete combustion of fuel in automobile engines and released during many production processes, with nitrogen oxides. It is one of the most dangerous pollutants affecting the respiratory system. It is most intense in hot weather.

Carbon monoxide, nitrogen oxides and hydrocarbons mainly enter the atmosphere with vehicle exhaust gases. All of these chemical compounds have a devastating effect on ecosystems at concentrations even lower than those permissible for humans, namely: they acidify water basins, killing living organisms in them, destroy forests, and reduce crop yields (ozone is especially dangerous). Studies in the United States have shown that current concentrations of ozone reduce the yield of sorghum and corn by 1%, cotton and soybeans by 7%, and alfalfa by more than 30%.

Of the pollutants that destroy the stratospheric ozone layer, freons, nitrogen compounds, exhausts of supersonic aircraft and rockets should be noted.

Fluorochlorohydrocarbons, which are widely used as refrigerants, are considered the main source of chlorine in the atmosphere. They are used not only in refrigeration units, but also in numerous household aerosol cans with paints, varnishes, insecticides. Freon molecules are resistant and can be transported almost unchanged with atmospheric masses over great distances. At altitudes of 15–25 km (the zone of maximum ozone content), they are exposed to ultraviolet rays and decompose to form atomic chlorine.

It has been established that over the past decade, the loss of the ozone layer amounted to 12–15% in the polar and 4–8% in the middle latitudes. In 1992, stunning results were established: areas with a loss of the ozone layer up to 45% were found at the latitude of Moscow. Already now, due to increased ultraviolet insolation, there is a decrease in yields in Australia and New Zealand, an increase in skin cancer.

Technogenic substances of the biosphere that have a harmful effect on biota are classified as follows (a general classification is given that is valid not only for gaseous substances) . According to the degree of danger, all harmful substances are divided into four classes (Table 2):

I - extremely dangerous substances;

II - highly hazardous substances;

III - moderately hazardous substances;

IV - low-hazard substances.

The assignment of a harmful substance to a hazard class is carried out according to the indicator, the value of which corresponds to the highest hazard class.

Here: A) is a concentration that, during daily (except weekends) work for 8 hours, or another duration, but not more than 41 hours a week, during the entire working experience cannot cause diseases or deviations in the state of health detected by modern research methods in the process of work or in the remote periods of life of the present and subsequent generations;

B) - the dose of a substance that causes the death of 50% of animals with a single injection into the stomach;

C) - dose of a substance that causes the death of 50% of animals with a single application to the skin;

D) - the concentration of a substance in the air, causing the death of 50% of animals with a 2-4 hour inhalation exposure;

E) - the ratio of the maximum allowable concentration of a harmful substance in the air at 20 ° C to the average lethal concentration for mice;

E) - the ratio of the average lethal concentration of a harmful substance to the minimum (threshold) concentration that causes a change in biological indicators at the level of the whole organism, beyond the limits of adaptive physiological reactions;

G) - The ratio of the minimum (threshold) concentration that causes a change in biological parameters at the level of the whole organism, beyond the limits of adaptive physiological reactions, to the minimum (threshold) concentration that causes a harmful effect in a chronic experiment for 4 hours, 5 times a week for at least 4 -x months.

Table 2 Classification of harmful substances

Indicator	Norm for hazard class
(A) Maximum permissible concentration (MPC) of harmful substances in the air of the working area, mg / m 3
(B) Mean lethal dose when injected into the stomach (MAD), mg/kg				over 5000
(B) Mean lethal dose when applied to the skin (MTD), mg/kg				over 2500
(D) Mean lethal concentration in air (TLC), mg/m 3				more than 50000
(E) Inhalation Poisoning Possibility Ratio (POI)
(E) Acute action zone (ZAZ)
(G) Chronic zone (ZZhA)	over 10.0

The danger of atmospheric pollutants for human health depends not only on their content in the air, but also on the hazard class. For a comparative assessment of the atmosphere of cities, regions, taking into account the hazard class of pollutants, the air pollution index is used.

Single and complex indices of air pollution can be calculated for different time intervals - for a month, a year. At the same time, the average monthly and average annual concentrations of pollutants are used in the calculations.

For those pollutants for which MPCs have not been established ( maximum allowable concentration ), is set estimated safe exposure levels (SHEETS). As a rule, this is explained by the fact that there is no experience gained in their use, sufficient to judge the long-term consequences of their impact on the population. If in technological processes substances are released and enter the air environment for which there are no approved MPCs or SHELs, enterprises are required to apply to the territorial bodies of the Ministry of Natural Resources to establish temporary standards. In addition, for some substances that pollute the air from time to time, only one-time MPCs have been established (for example, for formalin).

For some heavy metals, not only the average daily content in the atmospheric air (MPC ss) is normalized, but also the maximum allowable concentration during single measurements (MPC rz) in the air of the working area (for example, for lead - MPC ss = 0.0003 mg / m 3, and MPC pz \u003d 0.01 mg / m 3).

Permissible concentrations of dusts and pesticides in the atmospheric air are also standardized. So, for dust containing silicon dioxide, MPC depends on the content of free SiO 2 in it; when the content of SiO 2 changes from 70% to 10%, MPC changes from 1 mg/m 3 to 4.0 mg/m 3 .

Some substances have a unidirectional harmful effect, which is called the summation effect (for example, acetone, acrolein, phthalic anhydride - group 1).

Anthropogenic pollution of the atmosphere can be characterized by the duration of their presence in the atmosphere, by the rate of increase in their content, by the scale of influence, by the nature of the influence.

The duration of the presence of the same substances is different in the troposphere and stratosphere. So, CO 2 is present in the troposphere for 4 years, and in the stratosphere - 2 years, ozone - 30-40 days in the troposphere, and 2 years in the stratosphere, and nitric oxide - 150 years (both there and there).

The rate of accumulation of pollution in the atmosphere is different (probably related to the utilization capacity of the biosphere). So the content of CO 2 increases by 0.4% per year, and nitrogen oxides - by 0.2% per year.

Basic principles of hygienic regulation of atmospheric pollutants.

The hygienic standardization of atmospheric pollution is based on the following criteria for the harmfulness of atmospheric pollution :

1. Only such a concentration of a substance in the atmospheric air can be recognized as permissible, which does not have a direct or indirect harmful and unpleasant effect on a person, does not reduce his working capacity, does not affect his well-being and mood.

2. Addiction to harmful substances should be considered as an unfavorable moment and proof of the inadmissibility of the studied concentration.

3. Such concentrations of harmful substances that adversely affect the vegetation, the climate of the area, the transparency of the atmosphere and the living conditions of the population are unacceptable.

The solution of the issue of the permissible content of atmospheric pollution is based on the idea of ​​the presence of thresholds in the action of pollution.

When scientifically substantiating the MPC of harmful substances in the atmospheric air, the principle of a limiting indicator is used (rationing according to the most sensitive indicator). So, if the smell is felt at concentrations that do not have a harmful effect on the human body and the environment, the rationing is carried out taking into account the threshold of smell. If a substance has a harmful effect on the environment in lower concentrations, then in the course of hygienic regulation, the threshold of action of this substance on the environment is taken into account.

For substances polluting the atmospheric air, two standards have been established in Russia: one-time and average daily MPC.

The maximum one-time MPC is set to prevent reflex reactions in humans (sense of smell, changes in the bioelectrical activity of the brain, light sensitivity of the eyes, etc.) with short-term (up to 20 minutes) exposure to atmospheric pollution, and the average daily one is set to prevent their resorptive (general toxic, mutagenic, carcinogenic, etc.) influences.

Thus, all components of the biosphere experience a colossal technogenic influence of man. At present, there is every reason to speak of the technosphere as a "sphere of unreason".

Questions for self-control

1. Group classification of elements of the biosphere V.I. Vernadsky.

2. What factors determine soil fertility?

3. What is the "hydrosphere"? Distribution and role of water in nature.

4. In what forms are harmful impurities present in wastewater, and how does this affect the choice of wastewater treatment methods?

5. Distinctive features of different layers of the atmosphere.

6. The concept of a harmful substance. Hazard classes of harmful substances.

7. What is MPC? Units of measurement of MPC in air and in water. Where are MPCs of harmful substances controlled?

8. How are the sources of emission and emissions of harmful substances into the atmosphere divided?

3.3 Circulation of substances in the biosphere . Biospheric carbon cycle. Greenhouse effect: the mechanism of occurrence and possible consequences.

The processes of photosynthesis of organic substances continue for hundreds of millions of years. But since the Earth is a finite physical body, any chemical elements are also physically finite. Over millions of years, they should, it would seem, be exhausted. However, this does not happen. Moreover, man constantly intensifies this process, increasing the productivity of the ecosystems he has created.

All substances on our planet are in the process of biochemical circulation of substances. There are 2 main circuits large or geological and small or chemical.

big circuit lasts for millions of years. It lies in the fact that rocks are subject to destruction, the products of destruction are carried away by water flows into the oceans or partially return to land along with precipitation. The processes of subsidence of the continents and the uplift of the seabed for a long time lead to the return of these substances to land. And the process starts again.

Small circuit , being part of a larger one, occurs at the ecosystem level and lies in the fact that nutrients soils, water, carbon accumulate in the substance of plants, are spent on building the body and life processes. The decomposition products of the soil microflora decompose again to mineral components available to plants and are again involved in the flow of matter.

The circulation of chemicals from the inorganic environment through plants and animals back to the inorganic environment using solar energy of chemical reactions is called biochemical cycle .

The complex mechanism of evolution on Earth is determined by the chemical element "carbon". Carbon - an integral part of rocks and in the form of carbon dioxide is contained in part of the atmospheric air. Sources of CO2 are volcanoes, respiration, Forest fires, fuel combustion, industry, etc.

The atmosphere intensively exchanges carbon dioxide with the world's oceans, where it is 60 times more than in the atmosphere, because. CO 2 is highly soluble in water (the lower the temperature, the higher the solubility, i.e. it is more in low latitudes). The ocean acts like a giant pump: it absorbs CO 2 in cold areas and partially "blows it out" in the tropics.

Excess carbon monoxide in the ocean combines with water to form carbonic acid. Combining with calcium, potassium, sodium, it forms stable compounds in the form of carbonates, which settle to the bottom.

Phytoplankton in the ocean absorb carbon dioxide during photosynthesis. Dead organisms fall to the bottom and become part of the sedimentary rocks. This shows the interaction of large and small circulation of substances.

Carbon from the CO 2 molecule during photosynthesis is included in the composition of glucose, and then in the composition of more complex compounds from which plants are built. Subsequently, they are transferred along food chains and form the tissues of all other living organisms in the ecosystem and are returned to the environment as part of CO 2 .

Carbon is also present in oil and coal. By burning fuel, a person also completes the cycle of carbon contained in the fuel - this is how biotechnical carbon cycle.

The remaining mass of carbon is found in carbonate deposits of the ocean floor (1.3-10t), in crystalline rocks (1-10t), in coal and oil (3.4-10t). This carbon takes part in the ecological cycle. Life on Earth and the gas balance of the atmosphere is maintained by a relatively small amount of carbon (5-10 tons).

There is a widespread opinion that global warming and its consequences threaten us due to industrial heat generation. That is, all the energy consumed in everyday life, industry and transport heats the Earth and the atmosphere. However, the simplest calculations show that the heating of the Earth by the Sun is many orders of magnitude higher than the results of human activity.

Scientists also consider the increase in the concentration of carbon dioxide in the Earth's atmosphere to be the probable cause of global warming. It is he who causes the so-called « greenhouse effect ».

What is the greenhouse effect ? We encounter this phenomenon very often. It is well known that at the same daytime temperature, the nighttime temperature is different, depending on the cloudiness. Cloudiness covers the earth like a blanket, and a cloudy night is 5-10 degrees warmer than a cloudless one at the same daytime temperature. However, if clouds, which are the smallest droplets of water, do not allow heat to pass both outside and from the Sun to the Earth, then carbon dioxide works like a diode - heat from the Sun comes to the Earth, but not back.

Mankind spends a huge amount of natural resources, burns more and more fossil fuels, as a result of which the percentage of carbon dioxide in the atmosphere increases, and it does not release into space. infrared radiation from the heated surface of the Earth, creating " the greenhouse effect". The consequence of a further increase in the concentration of carbon dioxide in the atmosphere may be global warming and an increase in the temperature of the Earth, which, in turn, will lead to such consequences as the melting of glaciers and the rise in the level of the world ocean by tens or even hundreds of meters, many coastal cities of the world.

This is a possible scenario for the development of events and the consequences of global warming, the cause of which is the greenhouse effect. However, even if all the glaciers of Antarctica and Greenland melt, the level of the world ocean will rise by a maximum of 60 meters. But this is an extreme, hypothetical case, which can only occur with the sudden melting of the glaciers of Antarctica. And for this, a positive temperature must be established in Antarctica, which can only be a consequence of a catastrophe on a planetary scale (for example, a change in the inclination of the earth's axis).

Among the supporters of the "greenhouse catastrophe" there is no unanimity about its likely scale, and the most authoritative of them do not promise anything terrible. The marginal warming, in the case of doubling the concentration of carbon dioxide, can be a maximum of 4°C. In addition, it is likely that with global warming and rising temperatures, the level of the ocean will not change, or even, on the contrary, will decrease. After all, with an increase in temperature, precipitation will also intensify, and the melting of the margins of glaciers can be compensated by increased snowfall in their central parts.

Thus, the problem of the greenhouse effect and the global warming it causes, as well as their possible consequences, although it exists objectively, the scale of these phenomena is clearly exaggerated today. In any case, they require very thorough research and long-term observation.

An international congress of climatologists, held in October 1985, was devoted to the analysis of the possible climatic consequences of the greenhouse effect. in Villach (Austria). The congress participants came to the conclusion that even a slight warming of the climate will lead to a noticeable increase in evaporation from the surface of the World Ocean, resulting in an increase in the amount of summer and winter precipitation over the continents. This increase will not be uniform. It is calculated that a strip will stretch across the south of Europe from Spain to Ukraine, within which the amount of precipitation will remain the same as now, or even slightly decrease. To the north of 50 ° (this is the latitude of Kharkov) both in Europe and in America it will gradually increase with fluctuations, which we have been observing over the past decade. Consequently, the flow of the Volga will increase, and the Caspian Sea is not threatened by a decrease in the level. This was the main scientific argument, which finally made it possible to abandon the project of transferring part of the flow of northern rivers to the Volga.

The most accurate, convincing data on the possible consequences of the greenhouse effect are provided by paleogeographic reconstructions compiled by specialists studying the geological history of the Earth over the past million years. After all, during this “recent” time of geological history, the climate of the Earth was subjected to very sharp global changes. In epochs colder than today, continental ice, like those that now hold down Antarctica and Greenland, covered all of Canada and the whole of northern Europe, including the places where Moscow and Kyiv now stand. Herds of reindeer and shaggy mammoths roamed the Crimean tundra and North Caucasus, there now find the remains of their skeletons. And during the interglacial epochs, the Earth's climate was much warmer than the current one: continental ice in North America and Europe they melted, in Siberia the permafrost thawed many meters, sea ice disappeared off our northern coasts, forest vegetation, judging by the fossil spore-pollen spectra, spread to the territory of modern tundra. Powerful river streams flowed across the plains of Central Asia, filling the basin of the Aral Sea with water up to a mark of plus 72 meters, many of them carried water to the Caspian Sea. The Karakum desert in Turkmenistan is the scattered sand deposits of these ancient channels.

In general, the physical-geographical situation during the warm interglacial epochs throughout the entire territory of the former USSR was more favorable than now. It was the same in the Scandinavian countries and the countries of Central Europe.

Unfortunately, until now, geologists studying the geological history of the last million years of the evolution of our planet have not been involved in the discussion of the problem of the greenhouse effect. And geologists could make valuable additions to existing ideas. In particular, it is obvious that for a correct assessment of the possible consequences of the greenhouse effect, paleographic data on past epochs of significant global climate warming should be more widely used. An analysis of such data, known today, allows us to think that the greenhouse effect, contrary to popular belief, does not bring any disasters for the peoples of our planet. On the contrary, in many countries, including Russia, it will create more favorable climatic conditions than now.

Questions for self-control

1. The essence of the main biochemical circulations of substances.

2. What is the biochemical carbon cycle?

3. What is meant by the term "greenhouse effect" and what is it associated with? Your brief assessment of the problem.

4. Do you think there is a threat of global warming? Justify your answer

Autonomous educational institution of higher professional education

Leningradsky State University them. A. S. Pushkin

REPORT

on this topic:

Interaction of the lithosphere, hydrosphere and atmosphere.

Faculty of Philology, Course 1

Supervisor: doctor biological sciences,

Professor Feodor Efimovich Ilyin.

Saint Petersburg-Pushkin

1. Introduction.

2. Components of the biosphere.

3. Interaction of the atmosphere, lithosphere and hydrosphere.

4. Conclusion.

5. Sources.

Introduction.

Environment- a necessary condition for the life and activity of society. It serves as its habitat, the most important source of resources, and has a great influence on the spiritual world of people.

The natural environment has always been the source of human existence. However, the interaction between man and nature has changed in different historical eras, and the processes connecting the hydrosphere, atmosphere and lithosphere are constant.

V. V. Dokuchaev, who discovered the law of geographical zoning, noted that in nature six natural ingredients: the earth's crust of the lithosphere, the air of the atmosphere, the water of the hydrosphere, the flora and fauna of the biosphere, as well as the soil, constantly exchange matter and energy with each other.

The three components of the biosphere - the hydrosphere, the atmosphere and the lithosphere - are closely related to each other, making up a single functional system.

Components of the biosphere.

Biosphere(from the Greek bios - life; sphaire - ball) - the shell of the Earth, the composition, structure and energy of which are determined by the combined activity of living organisms.

The biosphere covers the upper part of the earth's crust (soil, parent rock), a set of water bodies (hydrosphere), lower part atmosphere (troposphere and partially stratosphere) (Fig. 1). The boundaries of the sphere of life are determined by the conditions necessary for the existence of organisms. The upper limit of life is limited by the intense concentration of ultraviolet rays, small atmospheric pressure and low temperature. In the zone of critical ecological conditions at an altitude of 20 km, only lower organisms- spores of bacteria and fungi. Heat the interior of the earth's crust (over 100 ° C) limits the lower limit of life. Anaerobic microorganisms are found at a depth of 3 km.

The biosphere includes parts of the hydrosphere, atmosphere and lithosphere.

Hydrosphere- one of the shells of the Earth. It unites all free waters (including the World Ocean, land waters (rivers, lakes, swamps, glaciers), underground waters), which can move under the influence of solar energy and gravitational forces, move from one state to another. The hydrosphere is closely connected with other shells of the Earth - the atmosphere and the lithosphere.

Almost the entire mass of hydrogen and oxygen is concentrated in the hydrosphere, as well as sodium, potassium, magnesium, boron, sulfur, chlorine and bromine, the compounds of which are highly soluble in natural waters; 88% of the total mass of carbon in the biosphere is dissolved in the waters of the hydrosphere. The presence of substances dissolved in water is one of the conditions for the existence of living things.

The area of ​​the hydrosphere is 70.8% of the surface area of ​​the globe. The proportion of surface water in the hydrosphere is very small, but they are extremely active (changing on average every 11 days), and this is the beginning of the formation of almost all sources of fresh water on land. The amount of fresh water is 2.5% of the total, while almost two-thirds of this water is contained in the glaciers of Antarctica, Greenland, polar islands, ice floes and icebergs, mountain peaks. Groundwater is at different depths (up to 200 m or more); deep underground aquifers are mineralized and sometimes saline. In addition to water in the hydrosphere itself, water vapor in the atmosphere, groundwater in soils and the earth's crust, there is biological water in living organisms. With a total mass of living matter in the biosphere of 1400 billion tons, the mass of biological water is 80% or 1120 billion tons.

The predominant part of the hydrospheric waters is concentrated in the World Ocean, which is the main closing link in the water cycle in nature. It releases most of the evaporating moisture into the atmosphere.

Earth's lithosphere consists of two layers: the earth's crust and part of the upper mantle. The earth's crust is the outermost solid shell of the earth. The crust is not a unique formation, inherent only to the Earth, because. found on most planets terrestrial group, the Earth's satellite - the Moon and the satellites of the giant planets: Jupiter, Saturn, Uranus and Neptune. However, only on Earth there are two types of crust: oceanic and continental.

oceanic crust consists of three layers: upper sedimentary, intermediate basalt and lower gabbro-serpentinite, which until recently was included in the composition of basalt. Its thickness ranges from 2 km in the zones of mid-ocean ridges to 130 km in subduction zones, where oceanic crust plunges into the mantle.

The sedimentary layer consists of sand, deposits of animal remains and precipitated minerals. At its base, thin metaliferous sediments, which are not consistent along strike, with a predominance of iron oxides, often occur.

The basalt layer in the upper part is composed of tholeiitic basaltic lavas, which are also called pillow lavas because of characteristic form. It is exposed in many places adjacent to the mid-ocean ridges.

The gabbro-serpentinite layer lies directly above the upper mantle.

continental crust, as the name implies, lies under the continents of the Earth and large islands. Like the oceanic continental crust, it consists of three layers: upper sedimentary, middle granitic and lower basalt. The thickness of this type of crust under young mountains reaches 75 km, under plains it is from 35 to 45 km, under island arcs it is reduced to 20-25 km.

The sedimentary layer of the continental crust is formed by: clay deposits and carbonates of shallow marine basins.

The granite layer of the earth's crust is formed as a result of the invasion of magma into cracks in the earth's crust. Composed of silica, aluminum and other minerals. At depths of 15-20 km, the Konrad boundary is often traced, which separates the granite and basalt layers.

The basalt layer is formed during the outpouring of basic (basalt) lavas onto the land surface in zones of intraplate magmatism. Basalt is heavier than granite and contains more iron, magnesium and calcium.

total weight the earth's crust is estimated at 2.8 × 1019 tons, which is only 0.473% of the mass of the entire planet Earth.

The layer under the earth's crust is called the mantle. From below, the earth's crust is separated from the upper mantle by the Mohorovic or Moho boundary, established in 1909 by the Croatian geophysicist and seismologist Andrei Mohorovic.

Mantle It is divided by the Golitsyn layer into upper and lower layers, the boundary between which runs at a depth of about 670 km. Within the upper mantle, the asthenosphere stands out - a lamellar layer, within which the velocities of seismic waves decrease.

The Earth's lithosphere is divided into platforms. Platforms- These are relatively stable areas of the earth's crust. They arise on the site of previously existing highly mobile folded structures, formed during the closure of geosynclinal systems, by their successive transformation into tectonically stable areas.

Lithospheric platforms experience vertical oscillatory movements: go up or down. Similar movements are associated with those that occurred repeatedly throughout the entire geological history Lands of transgression and regression of the sea.

In Central Asia, the formation of the mountain belts of Central Asia: Tien Shan, Altai, Sayan, etc. is associated with the latest tectonic movements of the platforms. Such mountains are called revived (epiplatforms or epiplatform orogenic belts or secondary orogens). They are formed during orrogenesis epochs in areas adjacent to geosynclinal belts.

Atmosphere- the gaseous shell surrounding the planet Earth, one of the geospheres. Its inner surface covers the hydrosphere and partially the earth's crust, while its outer surface borders on the near-Earth part of outer space. The atmosphere is considered to be that area around the Earth in which gaseous environment rotates together with the Earth as a whole; With this definition, the atmosphere passes into interplanetary space gradually; in the exosphere, which begins at an altitude of about 1000 km from the Earth's surface, the boundary of the atmosphere can also be conditionally drawn along an altitude of 1300 km.

The atmosphere of the Earth arose as a result of two processes: the evaporation of the substance of cosmic bodies during their fall to the Earth and the release of gases during volcanic eruptions (degassing of the earth's mantle). With the separation of the oceans and the emergence of the biosphere, the atmosphere changed due to gas exchange with water, plants, animals and their decomposition products in soils and swamps.

At present, the Earth's atmosphere consists mainly of gases and various impurities (dust, water drops, ice crystals, sea salts, combustion products). The concentration of gases that make up the atmosphere is almost constant, with the exception of water (H2O) and carbon dioxide (CO2).

Atmospheric layers: 1 Troposphere, 2 Tropopause, 3 Stratosphere, 4 Stratopause, 5 Mesosphere, 6 Mesopause, 7 Thermosphere, 8 Thermopause

The ozone layer is a part of the stratosphere at an altitude of 12 to 50 km (in tropical latitudes 25-30 km, in temperate latitudes 20-25, in polar 15-20), with the highest ozone content formed as a result of exposure to ultraviolet radiation Sun on molecular oxygen (O2). At the same time, with greatest intensity, precisely due to the processes of dissociation of oxygen, the atoms of which then form ozone (O3), the absorption of the near (to the visible light) part of the ultraviolet of the solar spectrum occurs. In addition, the dissociation of ozone under the influence of ultraviolet radiation leads to the absorption of its hardest part.