The geographic envelope is an integral continuous near-surface part of the Earth, within which there is an intense interaction of four components: the lithosphere, hydrosphere, atmosphere and biosphere (living matter). This is the most complex and varied material system our planet, which includes the entire hydrosphere, the lower layer of the atmosphere (troposphere), the upper part of the lithosphere and the living organisms inhabiting them. Spatial structure geographical envelope three-dimensional and spherical. This is the zone active interaction natural ingredients, in which the greatest manifestation of physical geographical processes and phenomena.Geographic envelope boundaries fuzzy. Up and down from the earth's surface, the interaction of the components gradually weakens, and then completely disappears. Therefore, scientists draw the boundaries of the geographical shell in different ways. The upper boundary is often taken to be the ozone layer located at an altitude of 25 km, where most of ultraviolet rays that are detrimental to living organisms. However, some researchers conduct it along the upper boundary of the troposphere, which most actively interacts with the earth's surface. The base of the weathering crust up to 1 km thick is usually taken as the lower boundary on land, and the ocean floor in the ocean.The idea of ​​a geographical shell as a special natural formation was formulated at the beginning of the 20th century. A.A. Grigoriev and S.V. Kalesnik. They revealed the main features of the geographic envelope: 1) the complexity of the composition and the diversity of the state of matter; 2) the flow of all physical and geographical processes due to solar (cosmic) and internal (telluric) energy; 3) transformation and partial conservation of all types of energy entering it; 4) the concentration of life and the presence of human society; 5) the presence of a substance in three states of aggregation.The geographical envelope consists of structural parts - components. These are rocks, water, air, plants, animals and soils. They differ in physical condition(solid, liquid, gaseous), level of organization (non-living, living, bio-inert), chemical composition, activity (inert - rocks, soil, mobile - water, air, active - living matter).The geographical envelope has vertical structure consisting of separate spheres. The lower tier is composed of dense matter of the lithosphere, while the upper ones are represented by lighter matter of the hydrosphere and atmosphere. Such a structure is the result of matter differentiation with the release of dense matter in the center of the Earth, and lighter matter along the periphery. The vertical differentiation of the geographic shell served as the basis for F.N. Milkov to single out a landscape sphere inside it - a thin layer (up to 300 m), where the earth's crust, atmosphere and hydrosphere come into contact and actively interact.The geographical envelope in the horizontal direction is divided into separate natural complexes, which is determined by the uneven distribution of heat in different parts of the earth's surface and its heterogeneity. I call natural complexes formed on land territorial, and in the ocean or other body of water - aquatic. The geographic envelope is a natural complex of the highest, planetary rank. On land, it includes smaller natural complexes: continents and oceans, natural areas and such natural formations as the East European Plain, the Sahara Desert, the Amazonian Lowland, etc. The smallest natural-territorial complex, in the structure of which all the main components participate, is considered a physical-geographical region. It is a block of the earth's crust, connected with all other components of the complex, that is, with water, air, vegetation and wildlife. This block should be sufficiently isolated from neighboring blocks and have its own morphological structure, that is, include parts of the landscape, which are facies, tracts and areas.

Introduction

This research in the field of geography was very relevant at all times. This topic has not lost its significance even now. The biospheric layer is the outer shell of the solid part of the Earth, and its study is necessary to understand all the geographical processes taking place on the Earth.

The solution of this problem has both theoretical and practical significance. By studying the biospheric tier of the geographic envelope, we can learn how the evolution of the biospheric tier took place, and how a stable dynamic balance was formed along its length, which was determined by the consumer-recovery function, i.e. the consumed natural resources were constantly and timely recreated. With each stage of a significant increase in the population, an imbalance in the biosphere became tangible. This is due to the growth natural resources, which was first pointed out by T. Malthus in 1798. The superpowerful technogenic activity of mankind significantly changes the Earth's biosphere, which, according to V.I. Vernadsky turned into a noosphere, i.e. sphere smart life. IN AND. Vernadsky made a particularly significant contribution to the doctrine of the noosphere. By modern ideas, noosphere is a sphere conscious activity human on a global scale, the interaction of society and nature, within which the intelligent human activity becomes the main, decisive factor development. The practical significance of this problem lies in the fact that this knowledge can be used in economic activity human, as well as in the protection of his work and health.

The object of research is the geographic envelope. The subject of our study is the biospheric stage. The purpose of studying this issue is to study the biospheric tier of the geographic envelope and its evolution. The method of studying this work is theoretical, namely the study of various literary sources geographic information. The study of this topic was carried out by V.I. Vernadsky, E. Suess, F.N. Milkov, and other scientists. In my work, I asked several questions: What is a geographic envelope? What role does the biospheric layer play in it? What was its evolution? And what disturbances can human activity bring to the Earth's biosphere? Over time, the biosphere becomes more and more unstable. There are several premature changes in the state of the biosphere that are tragic for mankind, some of them are associated with the activities of mankind.

Geographic envelope

The concept and composition of the geographical shell

Most common object study geographical science is the geographical envelope. The term "geographical shell" was proposed by the famous geographer A.A. Grigoriev in 1932

The geographic envelope is the largest natural complex on Earth, in which the lithosphere, hydrosphere, atmosphere and biosphere, intertwining intricately, interact with each other, penetrate each other, exchange matter and energy. Each component of the complex has its own chemical composition, differs only in its properties. Within the shell, as it were, lying on the border of the planet and space, both cosmic and internal forces act. One of the most important properties of the geographic envelope is the presence of substances (primarily water) simultaneously in liquid, solid and gaseous states. They may have their own organization of matter, patterns of development, may be organic or inorganic.

The processes occurring in the geographic envelope are diverse, closely interconnected and can be easily disturbed. They are still insufficiently studied and their importance is extremely important for the preservation of the Earth and the survival of man. The geographic envelope is unique primarily in that they act in it, intertwining with each other, mutually complementing each other or colliding as opposite, different forms energy: part - terrestrial, part - cosmic. An abundance of energy generates various processes- geological, biological, physical and chemical. We are talking about the fact that on the earth's surface there is a confrontation between external and internal forces. And some of them seek to establish a balance. For example: the force of gravity, which is associated with both the leveling of the relief and the runoff of water from its depression. Ebb and flow are connected with the forces of attraction of the Moon and the Sun. Among internal sources energy comes first radioactive substances, which is associated with the formation of mountains and movement lithospheric plates, earthquakes and volcanic eruptions, the activity of geysers, hot springs. All these processes are accompanied by dehydration and degassing of the subsoil, i.e. removal of water and gases to earth's surface. a significant role also plays the fact that the Earth, as a common magnet, forms a magnetic field, which affects not only the processes of attraction, but also the behavior electric charges in the atmosphere. Cosmic energy reaches the Earth's surface in the form of various radiations, of which solar dominates. She does a lot. significant portion solar energy reflected back into space. Two are connected in solar energy critical process, which create a unique shell on Earth. This is the water cycle and the development of life. The boundaries of the geographic shell are not clearly expressed and are drawn by different scientists in different ways, since the basis for its division is different. But more often than not, everyone draws the following boundaries.

Rice. one.

The geographic envelope includes the layer of the atmosphere in which the presence of dust, mainly of volcanic origin, water vapor is noted, and organisms can exist. The height of this layer reaches 25-30 km; The geographic envelope includes the troposphere and the lower layers of the stratosphere. In the lithosphere, only a part of the earth's crust, which extends from the Earth's surface to a depth of several hundred meters, sometimes up to 4-5 km, belongs to the geographical shell. It is up to this depth that the influence of the atmosphere and hydrosphere on the lithosphere can be traced. The composition of the geographic envelope includes almost the entire hydrosphere, with the exception of its insignificant part, which is located at great depths. The largest part of the geographic shell - the biosphere - is one of the shells of the Earth, the composition, properties and processes of which are determined by the activity of living organisms. That is, the basis of the allocation of the boundaries of the biosphere is the activity of living organisms, and the basis of the geographical shell is the presence of the interaction of the main parts (spheres). Therefore, the main parameters of the biosphere and geosphere may not coincide. There is no consensus regarding the relationship between the biosphere and the geographic envelope of the Earth. If we take the presence or absence of bacteria as a basis, then the habitat of the latter goes beyond the boundaries of the geographic envelope, since bacterial spores are found much higher than the troposphere, and in the oil-bearing layers of the lithosphere, bacteria are found at depths of up to several kilometers. Within the boundaries of the land of the geographic envelope, individual scientists single out the landscape sphere. This is a thin layer (from 5-10 m in the tundra to 100-150 m in the tropics), which includes the upper part of the weathering crust, soil, vegetation, animal world, surface layer of air, surface and ground waters.

Stages of formation of the geographical shell

In the life of the Earth, changes in the development of the earth's crust, climate, organic world, as well as the entire geographic envelope. In the process of development, it constantly became more complicated. In its development, the geographic envelope went through three stages.

The beginning of the first - inorganic - can be considered the appearance of the atmosphere. Then only the simplest organisms existed, and they took little part in the formation of the geographical envelope. The atmosphere was characterized by a poor composition of free oxygen and a high content of carbon dioxide.

At the second stage of the geographic envelope, the biosphere was formed, which transformed all the processes that had taken place in it before. In the core of the geographic shell, in the zone of active interaction between the lithosphere, hydrosphere and atmosphere, organic life was born, the presence of which is the second unique feature of not only one of the shells, but also the Earth as a planet as a whole. Organic life in its various manifestations, characteristic of the entire hydrosphere, extends several kilometers deep into the lithosphere, is carried by air currents through the troposphere. Zone organic life forms one of the specific shells of the Earth - the biosphere. Its thin horizon with the highest concentration of living matter on the surface of the land, ocean, and ocean floor was called the biostrome (living cover).

At the third stage, in the geographical envelope appeared human society. Man began to actively transform the geographic shell. His distinguishing feature in that a person begins to actively influence the development of the geographical envelope. It depends on the person whether the geographical shell will exist, whether it will remain so beautiful.

geographical shell biosphere noosphere

14.1 Geographic envelope- an integral material system formed by the interaction and interpenetration of the atmosphere, hydrosphere, lithosphere, living matter.

Many geographers wrote that geography studies the special shell of the Earth. A. Humboldt in his work "Cosmos" "sought to embrace the phenomena of the outside world in their general connection, nature as a whole, moved and animated by internal forces. His “life sphere” is similar in content to the biosphere; in the final lines he speaks of the “sphere of reason”. The clearest idea of ​​the outer shell of the Earth was set forth in the works of P. I. Brounov. In 1910, in the preface to the "Course of Physical Geography", he wrote that physical geography studies "the modern appearance of the Earth, in other words, the modern structure of the outer shell, which is the arena of organic life ... The outer shell of the Earth consists of several concentric spherical shells, and namely: solid, or lithosphere, liquid, or hydrosphere, and gaseous, or atmosphere, to which the fourth, the biosphere, also joins. All these shells to a large extent penetrate one another and, by their interaction, determine both the external appearance of the Earth and all phenomena on the Earth. The term "geographical shell" was proposed in 1932 by A. A. Grigoriev ("Subject and tasks of physical geography"). He believed that “the earth's surface is a qualitatively special vertical physical-geographical zone, or shell, characterized by deep interpenetration and active interaction of the lithosphere, atmosphere and hydrosphere, the emergence and development of organic life in it, the presence in it of a complex but unified physical-geographical process."

The shell was called differently: landscape shell (S.V. Kalesnik), landscape sphere (Yu.K. Efremov). A.I. Isachenko suggested calling the geographic shell the epigeo-sphere, emphasizing that this is precisely the outer earthly shell. I.M. Zabelin believed that the term geographic shell should be replaced by the term biogenosphere. He wrote that the term emphasizes the most important feature - the origin of life.

In geographical literature, the term "geographical environment" is often used. Some scientists put an equal sign between the terms geographic environment and geographic shell. In their opinion, these terms complement each other. However, in the term “geographical environment”, a person, human society, is put in the first place; the boundaries of the environment change along with the development of human society. The term "geographical envelope" is more literate from the point of view of geographers: in the geographical envelope, all components are given the same meaning.

The position of the upper and lower boundaries is estimated differently by different authors. AAGrigoriev draws the upper boundary of the geographic envelope in the stratosphere at a height of 20 - 25 km, below the ozone concentration layer. The lower boundary, in his opinion, is slightly below the Moho boundary. On the continents, the lower boundary runs at a depth of 30 - 40 km, under the oceans 5 - 8 km. According to A.A.Grigoriev, the thickness of the geographical envelope is 75 km on the continents and 45 km on the ocean.

Within the boundaries close to those indicated by A.A. Grigoriev, A. M. Ryabchikov considers the geographical shell. However, he drew the lower boundary at the level of the earth's crust. SV Kalesnik made the upper boundary at the level of the tropopause. It limits the lower boundary to the sedimentary layer of the earth's crust (4 - 5 km). A. G. Isachenko includes the troposphere, hydrosphere and sedimentary layer earth's crust. I.M. Zabelin connects the lower limit with the lower limit of the distribution of organic life and water in liquid state. F.N. Milkov, D.L. Armand the upper boundary is drawn along the tropopause, the lower one - along the boundary of the earth's crust. In the Geographical Encyclopedic Dictionary and the book "The World of Geography", the authors draw the lower boundary along the hypergenesis zone, the upper one - along the tropopause ("World of Geography"), at an altitude of 25 km (Geographical Encyclopedic Dictionary).

The boundaries of the geographical envelope, obviously, should be drawn along the border of the most active interaction of all components and the manifestation of geographical patterns, features of geographical zonality. Consequently, the upper limit is located at the level of the ozone screen - 22 - 25 km; since in this layer of the atmosphere, as a result of interaction, air masses, living matter can exist up to this limit. The lower boundary should be drawn along the boundary of the hypergenesis zone (500-800 m), in this zone zonal weathering crusts have formed, and the cycles of matter and energy are taking place. The geographic envelope includes the entire hydrosphere. In this case, the thickness of the geographic envelope is 23 - 26 km.

A number of scientists proposed to replace the term "geographical envelope" with the term "biosphere". They believe that the biosphere, in the understanding of V. I. Vernadsky, in terms of power and meaning invested in the concept, coincides with the geographical shell. Moreover, the term "biosphere" has received wide use in scientific and popular literature and understandable to all the inhabitants of the planet. However, in traditional understanding in the term "biosphere" the central place is assigned to living matter, the remaining components form its environment, which is not entirely correct. In addition, the geographic envelope exists more long time than the biosphere. The biospheric stage is the stage of development of the geographic envelope.

14.2 Geographical space. Developing ideas geographic space and time” were studied by many scientists, such as Yu.K. Efremov, D.L. Armand, K.K. Makarov, N.M. Svatkov, V.S. "There are many real-life forms of space and time, we can talk about chemical, biological, geographical space and time." Space is the mutual arrangement of the components of the system, time is the alternation of states of a given self-developing system. The Geographical Encyclopedic Dictionary gives the following definition of geographic space: “geographical space is a form of existence of geographical objects and phenomena within the geographic shell; a set of relationships between geographical objects located in a particular territory and developing over time.

A broader interpretation of "geographical space" is given by K.V. Pashkang. He believes that the geographic shell is closely connected with the outer space surrounding it and with the inner parts of the Earth. Solar energy coming from the Sun to the Earth is the source of all geographical processes. The gravitational force of the Sun keeps the Earth in orbit around the Sun, the gravitational force of the Moon causes the formation of tides. Meteorites fall on the Earth's surface. Endogenous energy comes from the bowels of the Earth, which determines the formation of the largest forms of the earth's surface. The upper boundary of the geographic space is located at a height of 10 Earth radii, on the upper boundary of the magnetosphere; the lower one is on the Moho surface. Geographic space is divided into four parts.

1. Near space. The lower boundary runs along the upper boundary of the atmosphere at an altitude of 2000 km above the Earth. Here there is an interaction of cosmic factors with magnetic and gravitational fields. The corpuscular radiation of the Sun is delayed in the magnetosphere.

2. High atmosphere. From below, it is limited to the stratopause. This is where cosmic rays are slowed down, converted, and ozone is formed.

3. Geographic cover.

4. Underlying bark. The lower boundary is the Moho surface. This is an area of ​​manifestation of endogenous processes that form geotectures and morphostructures of the planet.

14.3. Components, structural levels of the geographic shell.Components geographic shells are homogeneous material formations. These include natural water, air, rocks, plants, animals, soils.

Components are distinguished by state of aggregation- solid, liquid and gaseous. Now a fourth state is being isolated - water in capillaries: it does not freeze at zero degrees, but becomes viscous.

Components can have different levels of organization: living, inert (abiotic), bio-inert (organo-mineral). Living components include plants, animals; to bioinert - soils; to inert - air, water, rocks.

According to the degree of activity, the components are divided into stable ones - rocks, soils; mobile - water, air; active - plants, animals. Some scholars classify the components into primary - water, air, rocks, plants, animals; and derivatives - soils, ice, frozen rocks (K. I. Gerenchuk, V. A. Bokov, I. G. Chervanev). Sometimes relief, climate (A.A. Polovinkin, K.K. Markov, A.G. Isachenko, V.S. Zhekulin), or lithosphere, atmosphere, are sometimes referred to as components of the geographical shell. However, not the entire lithosphere and atmosphere are included in the composition of the geographic shell, and the relief and climate are not components, but properties rocks and air.

There are three structural level geographical envelope. First level - geocomponent. This is the easiest level, the individual components are studied by the natural sciences - geology, botany, geochemistry and geophysics.

The second level is called geospheric.Geospheres are shells occupied predominantly by one component. Geospheres determine the vertical structure of the geographic shell, they are arranged in tiers and distributed according to their specific gravity. Upper - the atmosphere formed by the lightest gases. The hydrosphere and lithosphere lie below. These shells form heavier chemical elements.

The shell has the most complex structure at the contact of the spheres: atmosphere and lithosphere (Earth surface), hydrosphere and lithosphere (ocean floor), atmosphere and hydrosphere (ocean surface), atmosphere, hydrosphere and atmosphere (in the coastal zone of the ocean).

Third level - geosystemic.Geosystems - complexes formed by the interaction of all components. Geosystems form a horizontal structure of the geographic envelope. The differentiation of the geographic shell into geosystems is due to the uneven distribution of heat and moisture, the heterogeneity of the earth's surface.

The geographical shell has a qualitative originality and differs from the primary geospheres that form it:

The geographic shell is the most complex shell of the planet, characterized by a variety of material composition;

Within the geographic envelope, the substance is in three states of aggregation, has a wide range of physical characteristics;

The shell contains different kinds energy, solar energy is converted into energy chemical bonds, thermal and mechanical;

Within the geographic envelope, there is a close interaction of its constituent components, which leads to the formation of qualitatively new formations - natural complexes;

Within the geographic shell, life arose, there is a human society.

14.4. Stages of development of the geographical shell. There are several stages in the life of the geographic shell. The earliest is the pre-biospheric, then the biospheric stage of development. At present, more and more often, scientists began to say that a new stage begins in the life of the geographical shell - the noo-spheral one. The development followed the path of complication of the structure, in the process of interaction new components and complexes were formed. Each new stage is characterized by the emergence of new cycles of matter and energy.

pre-biospheric (geological) stage of development lasted from 4.5 billion years to 570 million years. At this time, the formation of continents and oceanic depressions took place, the atmosphere and hydrosphere were formed. At the pre-biospheric stage, the atmosphere, hydrosphere, and lithosphere interacted. Living matter existed, but did not have a continuous distribution. At this time, the integrity of the shell was maintained by the cycles of water and chemical elements. As a result of the interaction of the primary components - water, air, rocks - the components of the geographical envelope were formed. Natural water and air were formed, i.e. components carry the results of shell interaction. natural air- it is no longer only gases of the atmosphere, it contains water of the hydrosphere and solid particles of the lithosphere. AT natural water there are salts and gases. Sedimentary rocks have formed. At the pre-biospheric stage, the upper boundary of the geographic shell was probably located at an altitude of 80 km (in this layer there are noctilucent clouds consisting of frozen gases and ice, i.e., water vapor was carried to this height during gyres). In addition, the boundary of the homosphere passes at this height. The lower boundary ran along the boundary of the sedimentary layer: sedimentary rocks are the result of the impact on rocks of water and air, in addition, it is here that groundwater horizons are located.

On the second, biospheric, stage, living matter is included in the interaction (from 570 million years to 40 thousand years). A biogenic one is added to the cycles: inorganic elements in the world are converted into organic matter due to the reaction of photosynthesis, and transpiration is added to evaporation. The components of the geographic envelope become more complex; living matter is involved in their transformation. Natural water acquires a specific gas and salt composition, which is the result of the vital activity of organisms. Weathering crusts and soils are formed, their formation is also associated with the activity of living matter. The gases of the atmosphere have passed through biological cycles. Vegetation and animals are added to the components. Obviously, the components become biogenic. However, mother-of-pearl clouds and sedimentary rocks are outside the zone of active circulation. The upper boundary of the geographic envelope descends to the ozone screen (zonal air masses are formed here), the lower boundary outlines the zone of hypergenesis.

At the third stage, the geographical envelope enters into noospheric stage of development. Under noosphere(the sphere of reason) understand the sphere of interaction between nature and society, in which the rational activity of man becomes the determining factor in development. At the noospheric stage, the anthropogenic circulation of matter and energy is added to the cycles. Anthropogenic components begin to form, they carry the results of the impact of human activity. The boundaries of the geographic shell of the noospheric stage, obviously, should expand, in the future, humanity will master the entire solar system. A detailed description of the noosphere is given in a separate chapter.

14.5. The cycle of matter. The migration of matter in GO has the form of cycles of various scales. The circles are not closed. gaseous and liquid substances as very dynamic penetrate into the solid lithosphere through pores, cracks. Water forms underground aquifers. A lot of water is in a bound state. Water dissolves rocks and transports dissolved substances over long distances, complex interaction processes occur, as a result of which not only new substances are formed, but also various structural formations. In its turn, solids penetrate into the air aquatic environment. The movement of matter is called its circulation. Especially significant are the results of the circulation of substances over geological periods of time.

In the history of Z., large stages of the predominance of mountain building are known, alternating with relatively calm geological stages, when the processes of leveling the relief prevailed, which was and is accompanied by a redistribution of huge volumes of matter. As a result, loose surface rocks found themselves at great depths, underwent the action of great pressures and high temperatures, turning, for example, into metamorphic rocks. Or, conversely, the bottom sediments of the sea can compose mountain ranges. Movement amplitudes reach tens of kilometers. The ratio of land and sea changed many times.

The water cycle in nature is well known from the school course. It is accompanied by the exchange of matter between land and sea. As already noted, 577 thousand km 3 of water enters the atmosphere from the earth's surface annually due to evaporation and transpiration by plants, and the same amount returns to the earth's surface in the form of precipitation. The main links of the water cycle: evaporation, the transfer of water vapor or cloud formations by air currents, precipitation. There is a general, or large cycle, in which the Ocean, land and atmosphere participate, as well as small ones - intracontinental and intraoceanic.

The circulation of matter between land and sea, associated with the water cycle, is also distinguished. Not only pure water participates in the cycle, but also salts, suspensions, solutions. Due to the so-called solid runoff carried away from the land, terrigenous bottom sediments of the Ocean are formed. The intensity of the solid runoff is determined by the tectonic setting, which also determines the ratio of the land to the sea, the slopes of the earth's surface, its dissection, etc.

14.6. Energy cycle. All types of energy are connected by the law of equivalence and gradually turn into heat, therefore they are measured in calories. The energy of the Earth has 2 sources: the internal energy of the Earth and the energy of the S. and Cosmos. The internal energy of the earth is 50 erg/cm 2 per second, or 3x10 17 kcal/year for the entire surface of the earth. This is predominantly radioactive heat. External energy: Space -1.4 X 10 13 kcal / year. The main solar energy is 1.4 X 10 21 kcal/year.

An insignificant part of the energy is accumulated in the biomass of green plants in the form of chemical energy capable of further transformations. In finished form, this energy is then used by all heterotrophic organisms. Total energy accumulated by the living matter of the biosphere is about 10 19 kcal/year. The annual production of biomass in terms of energy is about 8x10 17 kcal. After the death of organisms, chemical energy is converted into thermal energy as a result of oxidation, part of it is accumulated by the humus shell, which, in the end, also turns into thermal energy. Thus, the Earth, how much energy it receives, gives away as much (partially accumulating).

In the processes of the circulation of matter and energy, the connection of particular geographical shells and the unity of GO are expressed.

14.7. Landscape structure of the geographical shell, natural-territorial complexes. GO - huge, covering the entire Earth, natural (geographical complex). Its components: the substance of the lithosphere (rocks), hydrosphere (water), atmosphere (air), organisms. Their combination can be observed anywhere on the earth's surface, because the GO is continuous. Solid, but not everywhere the same. The development of civil defense led to the formation of the so-called NTC (natural-territorial complexes), geographical landscapes. Each NTC is a relatively homogeneous area of ​​the earth's surface, which differs from neighboring ones in the nature of the interaction between the components, the main of which are 1) relief with the rocks that form it, 2) soils with weathering crust, 3) water, 4) atmospheric air, 5) living organisms . Examples of PTC are the landscape of a river floodplain, the landscape of a moraine hill, etc. When classifying the simplest element of the PTC, facies is considered (sometimes identified with the concept of biogeocenosis). Facies form PTC more high order. The study of NTC, both unchanged and modified by human activities, is the branch of physical geography, called by most geographers landscape science. , where the PTC hierarchy will also be considered.

By landscape, all geographers understand a natural complex, but some extend this concept to any natural complex, regardless of its size and complexity (landscape = natural complex). Others call a landscape only a natural complex of a certain rank, distinguished by individuality, uniqueness in space and time, and take it as the main unit in physical and geographical zoning. In this case, natural complexes that are more complex than landscapes are combinations of landscapes, and less complex ones are parts of the landscape.

PTC on a planetary scale - geographic zones and natural areas . The PTCs of land and Ocean are not the same. On land, a huge variety of PTCs has been identified. To be convinced of this, it is enough to travel along the meridian from one pole to another. In this case, such NTCs as polar deserts, steppes of temperate latitudes, tropical forests, etc. will be encountered. The location of NTCs is subject to a certain pattern, which is called latitudinal (horizontal) zonality. Zonality is one of the main patterns of GO, which also include its azonal, wholeness, rhythmicity, sectorality, and regionality.

14.8. The law of zonality and geographical zonation of the nature of the earth's surface expresses regular changes in all GO components in the direction from the equator to the poles. These changes are a consequence of the spherical shape of the Earth, the surface of which, in the process of daily and annual movement in a stream of parallel sunlight, receives a different amount of heat and light, depending on latitude.

The inclination of the earth's axis causes a change in the influx of solar energy over time for each latitude, and, consequently, changes in natural processes and phenomena within a year.

The zoning fades up and down from the earth's surface, which is caused by a decrease in solar radiation (energy), therefore, within the GO, they emit landscape area, adjacent to the earth's surface. Zoning is not clearly seen at the upper and lower boundaries of the GO.

The largest zonal structures of GO are natural (geographical) belts (GB). If we compare maps of climatic and natural zoning the globe, it can be seen that the boundaries of the MS coincide with the boundaries climatic zones Moreover, they have the same names: equatorial, 2 subequatorial, 2 tropical, 2 subtropical, 2 temperate, 2 subpolar, 2 polar(Arctic and Antarctic).

The relative homogeneity of temperature conditions within the climatic (and, consequently, the HP) is due to the dominance of homogeneous types of air masses, or their regular change. As you know, there are 4 types of air masses: equatorial, tropical, temperate and arctic (antarctic) . The properties of air masses are determined in critical the conditions of heating and cooling of the underlying surface at certain latitudes, and, consequently, of the air, as well as other factors. Accordingly, there are 7 major climate zones – 1 equatorial, 2 tropical, 2 temperate (polar), arctic and antarctic. Within these belts, one air mass dominates throughout the year. In addition, allocated 6 transitional climatic zones , 3 in each hemisphere. Their names begin with the prefix "sub-" ("almost"): subarctic, subantarctic, 2 subtropical, 2 subequatorial.

The identification of transitional belts is associated with the peculiarities of the formation of climatic conditions during seasonal change air masses. The change in air masses is caused by the relative movement of the zenithal position of the Sun during the year. At the time of the summer solstice of the northern hemisphere (June 22), the boundaries of the distribution of air masses are shifted following the zenithal ray of the Sun and occupy the extreme northern position. On the contrary, on the day of the summer solstice of the southern hemisphere, the air masses shift southward and their borders occupy the extreme southern position. Within the limits of transitional climatic zones, thus, during the year, weather and climate are formed by two air masses (air masses of the main belts located either to the north or south): in the subarctic summer there is air of temperate latitudes, and in winter - arctic, in subtropical summer - tropical, in winter - temperate (aka polar air), in subequatorial summer - equatorial, in winter - tropical.

In total, 13 climatic zones have been identified, where the conditions for the formation of climate determine the properties and mode of change of these air masses.

We emphasize once again that the decisive factor in dividing GO into HP is temperature differences determined by the value of the temperature balance, i.e. difference between heat input and output. The zonal distribution of solar energy largely determines the zoning of cloudiness and moisture, atmospheric circulation, and so on.

GPs include both parts of the continents and land. Zonal differences in the Ocean can be traced at depths up to 2 thousand meters.

Within the land areas of the GP, natural zones are distinguished. Natural zones are clearly distinguished by the predominant type of vegetation cover. For example, the terms "tundra zone", "forest zone", "desert zone", "steppe zone", "subtropical forest zone", "zone equatorial forests» and others. In total, about 50 natural zones have been identified.

The main criterion for determining the boundaries of natural zones is the ratio of heat and moisture. Quantitative indicators of this ratio are moisture coefficients, dryness indices, hydrothermal coefficients, which are used by researchers who deal with issues of landscape (physico-geographical) zoning.

Moisture coefficient (N.N. Ivanova) - the ratio of the amount of precipitation falling over a certain period ( R) to the evaporation value ( E) for the same period, i.e.k= R: E, expressed as a percentage. For example, the moisture coefficient for RMS according to this formula is calculated as the ratio of the layer of precipitation (350 mm per year) to the layer of water that can evaporate from the given territory in a year with the existing influx of solar energy (about 750 mm), i.e. 350mm:750mm x 100% = 47%.

Radiation Dryness Index (according to M.I. Budyko) - the ratio of the annual radiation balance of the underlying surface ( R) to the amount of heat (lr), needed to evaporate the annual rainfall (r) on the same area (L – latent heat of vaporization), i.e. R : lr. For example, for SCO, this indicator can be calculated as follows:

30 kcal / cm 2 per year: (600 cal / g x 35 g) \u003d 1.4, where 30 kcal / cm 2 per year is the annual radiation balance of the underlying surface of the SOC, 600 cal / g is the latent heat of evaporation, 35g is the volume in grams a layer of water falling on 1 cm 2 of the surface per year.

Selyaninov hydrothermal coefficient - value K = (Rx 10): sumt, whereR – the sum of precipitation in mm for the period with temperatures above 10 0 , sumt – sum of temperatures in degrees for the same time. The hydrothermal coefficient is a characteristic of the moisture content of the territory (moisture supply). It is assumed that the moisture consumption for evaporation in the warm months of the year is approximately equal to the sum of temperatures reduced by 10 times. According to calculations, the northern border of the steppe belt of the European part of Russia coincides with the isoline K = 1, and the northern border of the semi-desert with the isoline K = 0,., For SKO

K varies from 1.1 in the north to 0.7 in the south of the region.

Since the availability of moisture depends not only on the latitude of the place, but also on many other factors (atmospheric circulation, topography, distance from the ocean, etc.), the configuration of natural zones is different and depends on a complex of regional reasons. Natural zones have both latitudinal and meridional strike, they can have isometric forms.

14.9 Vertical zonality. The influence of the relief on the ratio of heat and moisture, which determines the formation of natural complexes, is especially great. It is the influence of the relief that explains the presence of vertical zonality in mountainous countries. As one rises upwards, the amount of heat (radiation balance) decreases, humidity changes with a complex ruggedness of the relief (the surface is crushed into mountain folds). All taken together leads to the formation of natural complexes in the mountains, which have features that are not characteristic of lowland countries.

The mountains of each GP have their own combinations of altitudinal belts, changing sequentially from the foot to the top. The foot belt corresponds to the horizontal zone, the place where the slope of the mountain system is located. The completeness of the spectrum of zones of altitudinal zonation, therefore, depends on the position of the mountainous country and the height. Of great importance in the formation of vertical zones is the exposure of slopes (windward or leeward slope, etc.), which again ultimately determine the ratio of heat and moisture.

Altitude zones can be replaced, dropped out, changed places, etc.

14.10. Asymmetry (azonality) of the geographic shell. Along with the practically symmetrical location of HPs (their frequency in the northern and southern hemispheres relative to the equator), the presence of asymmetry has long been noticed in GO. The latter is not expressed in the full manifestation of zonal symmetry and in many other manifestations of the properties of the planet. According to the generalization of Academician K.K. Markov, manifestations of asymmetry include:

asymmetry of the figure of the Earth;

uneven distribution of land and sea (19 and 39% of land, respectively, in the southern and northern hemispheres);

state of the atmosphere (pressure, circulation);

differences in temperature (in the northern hemisphere 15.2 0 , in the southern hemisphere 13.3 0 С);

temperature amplitudes are less in southern hemisphere, compared with the north;

the state of modern glaciation (differences in age, dynamics, etc.);

the "Western drift" current exists only in the southern hemisphere;

not all natural zones are repeated in each of the hemispheres (in the southern there are no zones of tundra, forest-tundra, taiga, mixed forests).

14.11. The integrity of the geographic envelope - due to the fact that it is a complex natural complex, natural system, all components of which are in mutual relations and dependencies. A change in one component causes a chain of reactions, up to destruction. AT recent times more and more influence is exerted by a person on the development of existing relationships in natural complexes. For example, D.L. Armand writes in his book “To Us and Our Grandchildren”: “In American literature, a case is described when herbicides improved the herbage of meadows, but at the same time killed the willows that served as food for beavers. The beavers left the river high level which was supported by dams. The dams gradually collapsed, the river became shallow, and the trout and other fish that lived in it died. Then the level of groundwater dropped throughout the area and rich floodplain meadows, for which herbicides were used, dried up and lost their value. The intended event did not work, because people tried to influence only one link in the complex interweaving of causes and effects.

14.12. Rhythm geographic shell - repeatability of similar processes and phenomena in time. We have already considered daily, seasonal, annual rhythms, 11-year cycles of solar activity, mentioned the recurrence of the galactic year with a period of 180-200 million years. The recurrence of these phenomena is known, although we do not always know about their consequences, about how they act when superimposed on each other. We probably do not know the reasons for the recurrence of some other processes and phenomena. For example, the reasons for the periodicity of glaciations and interglacials of the Quaternary, changes in the polarity of the Earth's magnetic field in the geological past, changes in climate and the levels of inland water bodies associated with it, etc.

14.13. Sector geographical envelope- Longitudinal change of landscapes. On the continents, western coastal sectors, sectors of the central parts of the continents, eastern coastal territories with their specific features associated with the influence of the oceans, ocean currents, the direction of prevailing winds, remoteness from the sea, etc. are distinguished.

14.14. Regionality of the geographic shell - the presence of regional features within natural zones. For example, within the coniferous forests of the temperate zone, regions are distinguished with a predominance of cedar, or European spruce, Siberian spruce, etc.

14.15. The system nature - population - society. At the initial stages of the development of modern GO, the formation of its inorganic part - the lithosphere, hydrosphere, and atmosphere - took place. This process went along the line of differentiation of the corresponding part of the planet's matter, the complication of its structure and each geosphere included in it. In the course of development, the prerequisites for the emergence of life were created.

The emergence of living matter marked the onset of a qualitatively new stage in the development of the system. Living matter, as it develops and becomes more complex, becomes a powerful geological force, which led to a significant change in the composition of the atmosphere, lithosphere, the appearance of a soil cover, and the emergence of new processes (biogeochemical, etc.). A complex unity of inorganic and biological components was formed - the biosphere.

Finally, the emergence of human society meant the final formation of an extremely complex system of interaction between three forms of the movement of matter - planetary inorganic, biological and social - modern GO. A new state of the biosphere as a result of the gigantic work of mankind V.I. Vernadsky named noosphere (the realm of the mind). However, the conclusion that far from everything in it is reasonable is becoming more and more obvious.

Let us briefly consider some aspects of the interaction between nature and man (society) - the most burning problem of our time.

The stability of the natural system, its elasticity, its ability and desire for natural balance are amazing. In the history of the Earth, geological and climatic perturbations took place - transgressions, orogenies, glaciations, but they, in the final analysis, served nature, at least living nature - only for the benefit. After such a "compression" nature-"spring" again "spread out". Creating difficulties for existence, great changes led to the destruction of weak genera and gave birth to others, more adapted to the opening of new ecological niches, more enduring and resourceful.

Obviously, human pressure would also have an effect if it continued for a long geological time and slowly. But it is too short for the creation of new species, it has developed and is developing rapidly, although for some time the influence of human society in intensity and content did not differ from the influence of the animal world. People were collecting. major milestone in the matter of changing the natural environment - the transition from gathering to farming. With the development of cattle breeding, and especially agriculture (slash-and-burn at first), the impact of man on nature has increased dramatically. The forests were particularly affected. Previously, all forests began to be destroyed in Western Europe. Ancient Europeans were surrounded by a green ocean. For 3 thousand years, forests were reduced in Europe on an area of ​​​​about 600 million hectares. Practically Europe is deforested (natural forests are preserved only in Eastern Europe, in Scandinavia and in the mountains).

At present, the forests of Western Europe are also suffering, but already due to "sulphurous rains". Such rains occur when atmospheric moisture combines with sulfur dioxide, a product of combustion. From the combustion of 10 tons of coal, 1 ton of sulfur dioxide is formed. With a high concentration of industrial enterprises, a huge amount of sulfur dioxide is formed, and acid rain destroy forests, all living things in rivers, lakes. Created in West Germany Political Party the Greens, which advocates for the protection of the environment; and one of the slogans of this party: "First the forest will die, then we will die."

But the fate of the North American forests is especially indicative and deplorable, where the colonists entered the virgin land with energy and enthusiasm. Such a change in the surface of the Earth began, the like of which history has not yet known. ... The white inhabitants of this new country in their conquest of the 'desert' and 'the conquest of the west' set a stunning record of devastation and destruction." Millions of hectares of slopes, once covered with majestic forests, were bare by flat washout; endless ravines crossed the once richest lands. For 100 years in Sev. America was cut down 540 million hectares of forests. The consequence is catastrophic water and wind erosion, sandstorms, floods, and summer droughts. Now the United States covers only 60% of the cost of oxygen consumed by their industry, Switzerland - only 25%. Because forests are the lungs of the planet. These are one of the many sad examples of the violation of the existing equilibria in natural systems, which have huge negative consequences.

The area of ​​tropical and equatorial forests has also been significantly reduced. The World Conservation Strategy states that they are retreating at a rate of 44 hectares per minute. If the retreat of the forests proceeds at an increasing rate, as it has been until now, then in the current century it will be necessary to grow forests "for oxygen".

In the following decades, the problem of air pollution becomes very acute.

Anthropogenic pollution is currently being produced more than their volcanoes supply. Especially a lot: 1) cars (60% of all air pollution in the USA); 2) industrial enterprises (sulphurous gas has already been mentioned, but besides it, others harmful emissions- smoke, soot, CO 2, etc.; dust of rubbing parts - ¼ of the metal produced per year turns into dust (in cities, the soil contains 10 times more metal dust than in rural areas). One machine per year produces 10 kg of rubber dust, it is estimated that in 1970. almost 40 billion tons of various products of production were emitted into the atmosphere, and by 2000 this figure will increase to 100 billion tons.

The problem of soil conservation is also ominously acute. Arable land currently makes up 10% of the land (1450 million hectares); this means that there are 0.5 ha per capita in the world. In the territory former USSR for each inhabitant, on average, 0.8-0.9 ha, in the USA - 1.0 ha, in Canada - 2.0 ha. To satisfy all human needs with the current crop yield per person, 1 hectare of arable land is required, however, the yield depends on the quality of the soil, on climatic features, etc. Therefore, a person is trying to improve the quality of soils, increase fertility: proper cultivation, fertilizers, drainage, watering, irrigation, erosion protection - all this has a positive effect. At the same time, the reverse process also takes place: erosion, pollution with chemicals, salinization, waterlogging, diversion for buildings, reservoirs, quarries, dumps, communication facilities, etc.

Especially dangerous chemical pollution- 30 thousand chemical substances are produced annually - detergents, chemical fertilizers, herbicides, pesticides, etc. Environmental pollution is dangerous because many harmful substances are involved in the biological cycle, toxic substances, and by food chains they enter the human body. And this is fraught with many undesirable consequences. Radiation pollution is also dangerous: on the island of Bikini in the early 50s, nuclear weapon There is still no life on the island.

The damage from negative processes has taken on alarming proportions: the decrease in the area of ​​soils is 1000 times faster than their formation. Lost about 20 million km 2 of soil. No less acute is the problem of fresh water. The main problem is the pollution of land surface waters (about 40% of the river runoff is polluted) and its lack in many industrial and agricultural regions.

The facts of irretrievable, irreplaceable losses in the animal and plant world are well known. 105 species of plants and animals (bison, sea cow, etc.) disappeared; 600 species are currently close to extinction; some of them are being restored, especially protected.

Up to a certain period of burden, the biosphere could be considered for mankind an unlimited environment of life, not placing any restrictions on its economic development. Resources seemed inexhaustible and natural environment unshakable. But already in the 2nd half of the 19th century, the global impact of mankind on nature was realized (a great merit in this was Academician V.I. Vernadsky). However, it took a whole century for the truth about the reverse effect of nature changed by people on man, on his economy, to be deeply and universally understood. So that the extent of the danger that has arisen due to the imbalance in the “nature-man-society” system has loomed quite clearly in the minds of people.

The main contradictions that have arisen between modern society and nature are as follows:

nature is a source of raw materials for material production and, at the same time, a habitat; by increasing production, a person worsens the quality of the environment for himself;

For the development of the economy, more and more volumes are needed natural materials, but than faster pace, the worse the habitat;

Scientific and technological progress is a powerful factor of pressure on nature, but at the same time it is a lever for constructive actions to protect the environment.

To positive impact should include the breeding of a huge number of new breeds of animals, plant varieties, and their cultivation, soil enrichment with organo-mineral fertilizers that increase fertility, drainage of swamps, irrigation of arid territories, the destruction of pathogens, the search and production of new materials that reduce the withdrawal of natural resources, new resource-saving, little - about waste-free technologies, etc.

14.16 The problem of the use of natural resources. At present, mankind has realized the exhaustibility of natural resources, facing the fact of their growing deficit. One of the main problems was the provision of raw materials and energy resources. A wide awareness of the problem of resources occurred in the 70s of the last century, when energy, raw materials, environmental crises. Why? Problems should be divided into regional and global ones.

Regional: different countries have different availability of mineral resources depending on the geological structure and distribution of minerals (oil and gas and ore belts, provinces, zones, etc.).

Global: repeated increase in volumes of withdrawn natural materials. If in ancient times 19 chemical elements were used, at the beginning of the 20th century - 60, now - all those found in nature, and hundreds of thousands of artificial substances. If in 1913, on average, 4.9 tons were mined per person, in 1940 - 7.4 tons, in 1985 - 28 tons, then in 2000 - 35-40 tons. Over the last 30-35 lei, about the same amount of raw materials was used , how much for the entire previous history. 1000 billion tons are withdrawn annually, while 1-2% of the useful component (final product) is received (98-99% is waste).

Natural resources are divided into exhaustible and inexhaustible (solar radiation, river flow, wind). The former are subdivided into renewable (soil fertility, vegetation, fauna, atmospheric components) and non-renewable (mineral raw materials - ores, oil, gas, coal, etc.).

Exhaustibility depends on reserves (explored and undiscovered) and on the rate of production. As non-renewable resources are depleted, the technological complexity and energy intensity of production increase. The use of available and rich in useful components deposits is a thing of the past. Society is forced to switch to the use of poor ores, to mine them in remote and hard-to-reach places.

Judging by the rate of production, in a few decades the reserves of diamonds, ores of copper, lead, mercury, cadmium, tin, zinc (Table 1), tungsten, gold, silver will be exhausted. Uranium reserves are limited. Scientific and technological progress makes it possible to penetrate deeper and deeper into the subsoil: oil is already extracted from a depth of about 8 km, the depth of mines reaches 4 km, quarries - 800 m.

Perhaps there will be technologies for the extraction of iron-manganese nodules from the bottom of the Ocean (Cu, Ni, Co, Fe, Mn), the reserves of which are estimated at 100 billion tons only at the bottom of the Pacific Ocean. In the future, it is possible to extract useful components from sea ​​water(iodine, U, NaCl, etc.), as well as by processing granite. 100 tons of granite contains uranium and thorium equivalent to 5 thousand tons. coal, in addition, - about 8 tons of aluminum, 5 tons of iron, 0.5 tons of titanium, 80 kg of manganese, 30 kg of chromium, 17 kg of nickel, etc.

An acute shortage of minerals is felt in Japan, England, France, Germany, Italy, Holland, Belgium, etc.

The number of years that the world reserves of some ores will last in the production of metals at the level of 1992; R-explored, P-forecast reserves

Table 1

Production and exploration of oil in the North Sea is 15-17 times more expensive than in the Middle East. The reserves of the shelf of Antarctica are estimated to be 6 billion tons of oil and 11.5 trillion. m cu. gas, but it is very difficult and expensive to extract them.

Environmental problems are exacerbated by disproportions in the distribution of both resources and consumption of manufactured products. About 30 years ago, the United Nations World Commission on environment and development under the leadership of Gro Harlem Brundtland, the report "Our Common Future" was produced, which preceded the Rio 92 World Forum. This report reached a clear conclusion: poverty is main reason and a consequence of global environmental problems. It is therefore hopeless to attempt to address them without a broader consideration of the factors causing world poverty and international inequality. The main share of the world's products is consumed by only a quarter of the world's population (the "golden billion"). "Overconsumption" by this part of the population, according to the commission, is the main cause of resource depletion and environmental pollution.

Distribution of world consumption, on average for 1980-1982, in %

The geographic shell is the shell of the Earth, within which they mutually penetrate each other and are located in close cooperation the lower layers of the atmosphere, the upper parts of the lithosphere, the entire hydrosphere and biosphere (Fig. 1).

The concept of the geographic shell as the "outer sphere of the earth" was introduced by the Russian meteorologist and geographer P. I. Brounov (1852-1927) back in 1910, and modern concept developed by the famous geographer, academician of the USSR Academy of Sciences A. A. Grigoriev.

The troposphere, the earth's crust, the hydrosphere, the biosphere are the structural parts geographical envelope, and the substance contained in them is its Components.

Rice. 1. Scheme of the structure of the geographic shell

Despite the significant differences in the structural parts of the geographic shell, they have one common, very significant feature - continuous process movement of matter. However, the rate of intracomponent movement of matter in different structural parts of the geographic envelope is not the same. The highest rate is noted in the troposphere. Even when there is no wind, absolutely motionless surface air does not exist. Conditionally as average speed the displacement of matter in the troposphere can be taken as 500-700 cm/s.

in the hydrosphere due to greater density water, the speed of movement of matter is lower, and here, in contrast to the troposphere, there is a general regular decrease in the speed of movement of water with depth. In general, the average water transfer rates in the World Ocean are (cm / s): on the surface - 1.38, at a depth of 100 m - 0.62, 200 m - 0.54, 500 m - 0.44, 1000 m - 0 .37, 2000 m - 0.30, 5000 m -0.25.

AT earth's crust the process of substance transfer is so slow that special studies are required to establish it. The speed of movement of matter in the earth's crust is measured by several centimeters or even millimeters per year. Thus, the rate of expansion of the mid-ocean ridge varies from 1 cm/year in the Northern Arctic Ocean up to 6 cm/year in the equatorial part Pacific Ocean. The average rate of expansion of the oceanic crust is approximately 1.3 cm/year. Installed vertical speed of modern tectonic movements on land of the same order.

In all structural parts of the geographic envelope, the intracomponent movement of matter proceeds in two directions: horizontal and vertical. These two directions do not oppose each other, but represent different sides the same process.

Between structural parts geographic shell, an active and continuous exchange of matter and energy is carried out (Fig. 2). For example, water enters the atmosphere as a result of evaporation from the surface of the ocean and land, solid particles enter the air shell during volcanic eruptions or with the help of wind. Air and water, penetrating through cracks and pores deep into the rock pores, enter the lithosphere. Gases from the atmosphere constantly enter the reservoirs, as well as various solid particles that are carried away by water flows. The upper layers of the atmosphere are heated from the Earth's surface. Plants absorb from the atmosphere carbon dioxide and release oxygen into it, necessary for the respiration of all living beings. Living organisms, dying, form the soil.

Rice. 2. Scheme of connections in the system of geographic envelope

The vertical boundaries of the geographic shell are not clearly expressed, so scientists define them in different ways. A. A. Grigoriev, like most scientists, drew the upper boundary of the geographic shell in the stratosphere at an altitude of 20-25 km, below the layer of maximum ozone concentration, which delays ultraviolet radiation Sun. Below this layer, air movements are observed associated with the interaction of the atmosphere with land and the ocean; above, atmospheric movements of this nature come to naught. The greatest controversy among scientists is the lower boundary of the geographic shell.

Most often, it is carried out along the sole of the earth's crust, i.e., at a depth of 8-10 km under the oceans and 40-70 km under the continents. Thus, the total thickness of the geographical envelope is about 30 km. Compared to the size of the Earth, this is a thin film.

Life on our planet originated due to a combination of many factors. The earth is on favorable distance from the Sun - it does not heat up too much during the day and does not get supercooled at night. The earth has a solid surface and liquid water exists on it. air shell, surrounding the earth, protects it from hard cosmic radiation and "bombardment" by meteorites. Our planet has unique features - its surface is encircled, interacting with each other, by several shells: solid, air and water.

Air shell - the atmosphere extends above the Earth to a height of 2-3 thousand km, but most of its mass is concentrated at the surface of the planet. The atmosphere is held together by the Earth's gravity, so its density decreases with altitude. The atmosphere contains oxygen, necessary for the respiration of living organisms. The atmosphere contains a layer of ozone, the so-called protective shield, which absorbs some of the sun's ultraviolet radiation and protects the Earth from excess ultraviolet rays. Not all planets solar system there is a solid shell: for example, the surfaces of the giant planets - Jupiter, Saturn, Uranus and Neptune consist of gases that are in liquid or solid state due to high pressure and low temperatures. The solid shell of the Earth, or the lithosphere, is a huge mass of rocks on land and at the bottom of the ocean. Under the oceans and continents, it has a different thickness - from 70 to 250 km. The lithosphere is divided into large blocks - lithospheric plates.

water shell of our planet - the hydrosphere includes all the water of the planet - in solid, liquid and gaseous state. The hydrosphere is the seas and oceans, rivers and lakes, The groundwater, swamps, glaciers, water vapor in the air and water in living organisms. The water shell redistributes the heat coming from the Sun. Slowly heating up, the water masses of the World Ocean accumulate heat, and then transfer it to the atmosphere, which softens the climate on the continents during cold periods. Involved in the world cycle, water is constantly moving: evaporating from the surfaces of the seas, oceans, lakes or rivers, it is transferred to land by clouds and falls in the form of rain or snow.

The shell of the Earth, in which life exists in all its manifestations, is called the biosphere. It includes the uppermost part of the lithosphere, the hydrosphere and the surface part of the atmosphere. The lower boundary of the biosphere is located in the earth's crust of the continents at a depth of 4-5 km, and in air shell the sphere of life extends to the ozone layer.

All shells of the Earth influence each other. The main object of study of geography is the geographical shell - the planetary sphere, where intertwined and closely interact Bottom part atmosphere, hydrosphere, biosphere and top part lithosphere. The geographical envelope develops according to daily and annual rhythms, it is influenced by eleven year cycles solar activity, so characteristic feature geographical shell is the rhythm of ongoing processes.

The geographic envelope changes from the equator to the poles and from the foothills to the tops of the mountains, it is characterized by the main patterns: integrity, unity of all components, continuity and heterogeneity.

The rapid development of human civilization has led to the appearance of a shell in which man actively influences nature. This shell is called the noosphere, or the sphere of the mind. Sometimes people change the surface of the planet even more actively than some natural natural processes. Gross intervention in nature, neglect of its laws can lead to the fact that over time the conditions on our planet will become unacceptable for life.