Geographical shell of the earth composition features. What influence does man have on the shells of the Earth? The structure of the geographical shell

As a result of mastering the content of chapter 14, the student must:

know

Concepts " geographical envelope”, “natural-territorial complex”, regularities and features of the geographical shell;

be able to

to distinguish PTC by level, to explain the cause-and-effect relationships between all components of the PTC;
adapt knowledge and skills for their use in professional activities;

own

The skill of searching and selecting information when using information and communication tools.

The concept of a geographical shell

The geographic envelope is a complex natural-anthropogenic system of our planet. This is a continuous continuous outer shell Earth, within which all geospheres touch and interact: the lithosphere, atmosphere, hydrosphere and biosphere (Fig. 14.1).

For the first time, the concept of this shell was introduced into science at the beginning of the 20th century, but modern concept about the geographical shell was developed only in the 1930s. Academician L. A. Grigoriev.

There are three stages in the development of the geographic envelope. At the first stage, the earth's crust, continents and oceans were formed. Chemotrophic bacteria arose, and later - photosynthetic organisms. The second stage (Paleozoic, Mesozoic, Cenozoic) is significant for the formation of the ozone screen, the formation of the hydrosphere and atmosphere in modern form. There was a qualitative and quantitative leap in the development of living matter, soils were formed. The third stage is associated with the emergence of Homo sapiens and continues to the present. The main difference of this stage is the human impact on the natural environment.

The present stage of development of the geographic envelope is characterized by the formation of natural-anthropogenic systems.

Rice. 14.1.

Until now, the issue of the boundaries of the geographic envelope (GO) is debatable. The upper limit is considered to be ozone layer, and the bottom - the sole of the weathering crust. Many scientists adhere to the point of view that the boundaries of the distribution of living matter in it can be considered the boundary of the geographical shell. It includes the lower layer of the atmosphere, the hydrosphere, the upper part of the lithosphere, living organisms and the layer within which human economic activity is manifested.

All earthly shells in the near-surface part of the Earth mutually penetrate each other, touching and interacting. So, as a result of a long interaction, a continuous shell was formed - geographical envelope.

The geographic envelope has the following features.

1. A substance exists in three states of aggregation.
2. The geographic envelope receives different kinds energy, due to which various processes take place. Part of the energy is conserved in the bowels of the Earth (combustible

fossils), some goes into outer space. The radiant energy of the Sun is converted into thermal energy.

3. The substance in the geographic envelope has a wide range physical characteristics and chemical composition.
4. The geographical envelope was the place of origin and spread of life.
5. Geographical shell - the place of human activity.

The geographic shell is a natural complex on a planetary scale, its integrity is determined by the continuous exchange of matter and energy between its different parts. The structural parts of the geographic envelope are components and natural complexes.

The components of the geographic envelope are: rocks, water and air, plants and animals and a special formation - soil. They are involved in the formation of both natural and anthropogenic landscapes.

Components differ in physical state, in chemical composition. There are also differences in the level of organization: living (plants and animals), non-living (rocks, air, water), bio-inert (soil). According to the degree of activity, the components are also divided into stable (rocks and soil), mobile (water and air), active (living organisms).

The most complex structure in the geographic shell is distinguished by thin layers of direct contact and active interaction of parts of the lithosphere, atmosphere and hydrosphere. These include, firstly, the land surface ( upper layer lithosphere), the surface layer of the atmosphere, surface and The groundwater. Secondly, the upper layer of the World Ocean, thirdly, the ocean floor. V. I. Vernadsky called these contact zones “films of life”, because it is here that the highest concentration of living matter is observed.

The geographical envelope has patterns: integrity, circulation of matter, rhythm, zoning.

Let us consider the essence of these regularities.

1. Integrity means the unity of the geographical shell, which is due to the circulation of matter and energy between the components. The geographical envelope develops as a whole.

Integrity means that all components of the geographic envelope are interconnected, and a change in one component invariably entails a change in all the others. Economic activity a person also has an impact on the components of the geographic envelope. Therefore, when man interferes with nature, it is necessary to take into account such a property of the geographical envelope as integrity.

2. The circulation of matter in nature is another important regularity of the geographic shell, due to which energy is exchanged in it. There is a water cycle (large and small), a cycle of rocks, nitrogen, circulation of the atmosphere and ocean currents. (The process of the water cycle in the geographic envelope is discussed in Chapter 4.) However, there is also a water cycle in the ocean. Sea currents form rings of oceanic circulation. Large currents arise between the equatorial regions and the fortieth latitudes. Under the influence of the Coriolis force, the currents deviate to the right, moving clockwise in the Northern Hemisphere. A similar picture is emerging in the Pacific Ocean. The cycle, circulation of water in the ocean is supported by compensatory currents. The movements of water in the ocean reflect the circulation of the atmosphere, in which, therefore, cycles of matter (air) are also observed. The circulation of the atmosphere at equatorial and temperate latitudes was considered in more detail in Chapter 5. We should not forget about the circulation solid, rocks. Magma, entering the Earth's surface, turns into effusive, i.e. igneous rocks. Under the influence of external forces, they change, collapse, are transported by water, wind or ice to other places and are deposited in the form of sedimentary deposits. Gradually, in the process of metamorphization, they turn into metamorphic rocks, and later they can again turn into igneous, etc.
3. Rhythm - another pattern of GO, which implies the repetition of phenomena in time. There are daily, annual, intra-secular rhythms, etc.

The daily rhythm in nature is determined by the axial rotation of the Earth, therefore, by the change of day and night, when the light regime changes (the illuminated and unlit part of the day). Inanimate and Live nature(daily course of air temperature, absolute and relative humidity, photosynthesis processes, vital activity of plants and animals).

The annual rhythm in the geographical envelope is due to the annual (orbital) movement of the Earth, the change of seasons. In temperate latitudes, the seasonal rhythm is pronounced. It affects air and water temperatures, atmospheric circulation, and animal migration.

There are also intra-century rhythms. The most noticeable for the geographic envelope are 11-year rhythms, which are associated with periodic changes solar activity. 30-35-year cycles are also noted, they are considered as three-fold 11-year cycles. The epochs of mountain building, according to the widespread point of view, manifested themselves as a consequence of the rhythm of the 26,000-year cycle associated with a change in the angle of inclination of the earth's axis to the plane of the orbit.

Zoning can be considered an important regularity of the geographical envelope - a regular change in natural components and natural complexes from the equator to the poles. Geographical zonality as a law was established by V. V. Dokuchaev.

Zoning is explained by the fact that during the year the Earth occupies a different position in relation to the Sun, therefore, it is illuminated and heated differently. The angle of incidence of the sun's rays on the earth's surface is different, due to the figure of the Earth. At the same time, geographical zonality is distinguished as component (for example, temperature, wind, climate) and complex (geographic).

Along with zonality, the main features of the nature of a particular region are determined by azonal factors (azonality). This concept means the spread of any geographical object or phenomenon out of connection with the zonal features of the territory, in “violation” of zoning. The most striking example is currents, for example, cold ones. They, passing along the coast, contribute to lowering the air temperature, reducing the amount precipitation and, consequently, the formation of coastal deserts. Altitude zonality is observed in mountainous countries - a regular change of natural components and natural complexes from the foot of the mountains to the peaks, which is mainly determined by a decrease in air temperature with height and a change in the amount of precipitation. The concept of "vertical zoning" is somewhat broader, since it implies a change in natural complexes not only with height, but also with depth (reduction in the amount of heat and sunlight).

The largest complex zonal subdivisions of the geographic envelope are called geographic belts. They encircle the globe in the latitudinal direction. Their isolation occurs due to approximately the same amount of solar radiation. Therefore, each belt is distinguished by its radiation balance, atmospheric circulation, the rate of circulation of energy and matter, rhythms in nature, etc. The following belts are distinguished: equatorial, two subequatorial, two tropical, two subtropical, two temperate, subarctic and subantarctic, arctic and antarctic.

Within geographic zones, there are natural areas. The geographical envelope consists of natural complexes of different rank and size.

biosphere noosphere technogenesis

The most general object of study of 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 in its inherent 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, first of all, in that they act in it, intertwining with each other, mutually complementing each other or colliding as opposite, different forms of energy: part of it is earthly, part is cosmic. The abundance of energy gives rise to 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 the internal energy sources, the first place is occupied by the decay of 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, that is, the removal of water and gases to the earth's surface. A significant role is also played by 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. Much of the solar energy is reflected back into space. In solar energy, two most important processes are connected, 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 held by different scientists in different ways, since the bases for its division are different. But more often than not, everyone draws the following boundaries.

Fig.1

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 geographic shell belongs to earth's crust, which extends from the surface of the Earth to a depth of several hundred meters, sometimes up to 4-5 km. 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 geographical 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 shell, 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.

21.1. The concept of a geographical shell

The geographic shell is an integral continuous near-surface part of the Earth, within which the lithosphere, hydrosphere, atmosphere and living matter come into contact and interact. This is the most complex and diverse material system of our planet. The geographic shell includes the entire hydrosphere, the lower layer of the atmosphere, the upper part of the lithosphere and the biosphere, which are its structural parts.

The geographical shell does not have clear boundaries, so scientists conduct them in different ways. Usually, the ozone screen, located at an altitude of about 25–30 km, is taken as the upper limit, where most of the ultraviolet solar radiation, which has a detrimental effect on living organisms, is retained. At the same time, the main processes that determine the weather and climate, and hence the formation of landscapes, occur in the troposphere, the height of which varies in latitudes from 16–18 km near the equator to 8 km above the poles. The base of the weathering crust is most often considered the lower boundary on land. This part of the earth's surface is subject to the strongest changes under the influence of the atmosphere, hydrosphere and living organisms. Its maximum power is about one kilometer. Thus, the total thickness of the geographic envelope on land is about 30 km. In the ocean, the bottom of the geographic shell is considered to be its bottom.

However, it should be noted that there are the greatest differences among scientists regarding the position of the lower boundary of the geographic envelope. We can give five or six points of view on this issue with appropriate justifications. At the same time, the boundary is drawn at depths from several hundred meters to tens and even hundreds of kilometers, and in different ways within the continents and oceans, as well as various parts of the continents.

There is no unity in regard to the name of the geographic shell. The following terms have been proposed for its designation: landscape shell or sphere, geographic sphere or environment, biogenosphere, epigeosphere, and a number of others. However, at present, most geographers adhere to the names and boundaries of the geographic shell that we have given.

The idea of a geographical shell as a special natural formation was formulated in science in the 20th century. The main merit in the development of this idea belongs to Academician A. A. Grigoriev. He also revealed the main features of the geographical shell, which are as follows:

Compared to the bowels of the Earth and the rest of the atmosphere, the geographic envelope is characterized by a greater variety of material composition, as well as the energy entering non-human forms and the forms of their transformation.

The substance in the geographic envelope is in three states of aggregation (outside it, one state of matter prevails).

All processes here proceed due to both solar and internal earthly sources energy (outside the geographic envelope - mainly due to one of them), with solar energy absolutely predominating.

A substance in a geographic envelope has a wide range of physical characteristics (density, thermal conductivity, heat capacity, etc.). Only here is life. The geographical envelope is the arena of human life and activity.

5. The general process that connects the spheres that make up the geographical envelope is the movement of matter and energy, which takes place in the form of cycles of matter and in changes in the components of energy balances. All cycles of matter occur at different speeds and at different levels of substance organization (macro level, micro levels of phase transitions and chemical transformations). Part of the energy entering the geographic shell is conserved in it, the other part in the process of the circulation of substances leaves the planet, having previously experienced a number of transformations.

The geographical envelope consists of components. These are certain material formations: rocks, water, air, plants, animals, soils. Components differ in physical state (solid, liquid, gaseous), level of organization (non-living, living, bio-inert - a combination of living and non-living, which includes the soil), chemical composition, and also by the degree of activity. According to the last criterion, the components are divided into stable (inert) - rocks and soils, mobile - water and air, and active - living matter.

Sometimes partial shells are considered as components of the geographic shell - the lithosphere, atmosphere, hydrosphere and biosphere. This is not a completely correct idea, because not all of the lithosphere and atmosphere are part of the geographic shell, and the biosphere does not form a spatially isolated shell: it is the area of distribution of living matter within a part of other shells.

Geographical shell geographically and in volume almost coincides with the biosphere. However, there is no single point of view regarding the relationship between the biosphere and the geographic envelope. Some scientists believe that the concepts of "biosphere" and "geographical envelope" are very close or even identical. In this regard, proposals were made to replace the term "geographical envelope" with the term "biosphere" as more common and familiar to the general public. Other geographers consider the biosphere as a certain stage in the development of the geographical envelope (three main stages are distinguished in its history: geological, biogenic and modern anthropogenic). According to others, the terms "biosphere" and "geographical shell" are not identical, since the concept of "biosphere" focuses on the active role of living matter in the development of this shell, and this term has a special biocentric orientation. Apparently, one should agree with the latter approach.

The geographical shell is now considered as a system, and the system is complex (consisting of many material bodies), dynamic (continuously changing), self-regulating (having a certain

stable stability) and open (continuously exchanging with environment matter, energy and information).

The geographic envelope is heterogeneous. It has a tiered vertical structure, consisting of individual spheres. The substance is distributed in it by density: the higher the density of the substance, the lower it is located. At the same time, the geographic shell has the most complex structure at the contact of the spheres: the atmosphere and the lithosphere (the land surface), the atmosphere and the hydrosphere (the surface layers of the World Ocean), the hydrosphere and the lithosphere (the bottom of the World Ocean), as well as in the coastal strip of the ocean, where the hydrosphere is in contact, lithosphere and atmosphere. With distance from these contact zones, the structure of the geographic envelope becomes simpler.

The vertical differentiation of the geographic shell served as the basis for the well-known geographer F.N. Milkov to single out a landscape sphere inside this shell - a thin layer of direct contact and active interaction of the earth's crust, atmosphere and water shell. The landscape sphere is the biological focus of the geographic shell. Its thickness varies from several tens of meters to 200-300 m. ). The most common of them is water-surface. It includes a 200-meter surface layer of water and a layer of air 50 m high. The composition of the terrestrial version of the landscape sphere, better studied than others, includes a surface layer of air 30–50 m high, vegetation with the animal world inhabiting it, soil and modern weathering crust . Thus, the landscape sphere is the active core of the geographic shell.

The geographic envelope is heterogeneous not only in the vertical but also in the horizontal direction. In this regard, it is divided into separate natural complexes. The differentiation of the geographic envelope into natural complexes is due to the uneven distribution of heat in its various parts and the heterogeneity of the earth's surface (the presence of continents and oceanic depressions, mountains, plains, elevations, etc.). The largest natural complex is the geographical envelope itself. Geographical complexes also include continents and oceans, natural zones (tundra, forests, steppes, etc.), as well as regional natural formations, such as the East European Plain, the Sahara Desert, the Amazonian Lowland, etc. Small natural complexes are confined to individual hills, their slopes, river valleys and their separate sections(channel, floodplain, terraces above the floodplain) and other meso- and microforms of relief. The smaller the natural complex, the more homogeneous the natural conditions within it. Thus, the entire geographic envelope has a complex mosaic structure; it consists of natural complexes of different ranks.

The geographical shell has gone through a long and complex history of development, which can be divided into several stages. It is assumed that the primary cold Earth was formed, like other planets, from interstellar dust and gases about 5 billion years ago. In the pregeological period of the Earth's development, which ended 4.5 billion years ago, its accretion took place, the surface was bombarded by meteorites and experienced powerful tidal fluctuations from the nearby Moon. The geographic envelope as a complex of spheres did not exist then.

The first one is the geological stage of the development of the geographic envelope, which began along with the early geological stage development of the Earth (4.6 billion years ago) and captured its entire pre-Cambrian history, continuing until the beginning of the Phanerozoic (570 million years ago). This was the period of the formation of the hydrosphere and atmosphere during degassing of the mantle. The concentration of heavy elements (iron, nickel) in the center of the Earth and its rapid rotation led to the emergence of a powerful magnetic field protecting the earth's surface from cosmic radiation. Thick strata of the continental crust arose along with the primary oceanic, and by the end of the stage, the continental crust began to split into plates and, together with the resulting young oceanic crust, began to drift through the viscous asthenosphere.

At this stage, 3.6–3.8 billion years ago, the first signs of life appeared in the aquatic environment, which, by the end of the geological stage, conquered the oceanic spaces of the Earth. At that time, organic matter did not yet play an important role in the development of the geographic envelope, as it does now.

The second stage in the development of the geographic envelope (from 570 million to 40 thousand years ago) includes the Paleozoic, Mesozoic, and almost the entire Cenozoic. This stage is characterized by the formation of an ozone screen, the formation of the modern atmosphere and hydrosphere, a sharp qualitative and quantitative leap in the development of the organic world, and the beginning of soil formation. Moreover, as in the previous stage, periods of evolutionary development alternated with periods that had a catastrophic character. This applies to both inorganic and organic nature. Thus, periods of calm evolution of living organisms (homeostasis) were replaced by periods of mass extinction of plants and animals (four such periods were recorded during the stage under consideration).

The third stage (40 thousand years ago - our time) begins with the appearance of modern Homo sapiens, more precisely, with the beginning of a noticeable and ever-increasing impact of man on his natural environment 1 .

In conclusion, it should be said that the development of the geographical shell proceeded along the line of complication of its structure, accompanied by processes and phenomena that were still far from known by man. As one of the geographers successfully noted in this regard, the geographic shell is a single unique object with a mysterious past and an unpredictable future.

21.2. The main regularities of the geographical shell

The geographic envelope has a number of general patterns. These include: integrity, rhythm of development, horizontal zonality, azonality, polar asymmetry.

Integrity is the unity of the geographical shell, due to the close relationship of its constituent components. Moreover, the geographic envelope is not a mechanical sum of components, but a qualitatively new formation that has its own characteristics and develops as a whole. As a result of the interaction of components in natural complexes, the production of living matter is carried out and soil is formed. A change within the natural complex of one of the components leads to a change in the others and the natural complex as a whole.

Many examples can be cited to support this. The most striking of them for the geographic envelope is the example of the appearance of the El Niño current in the equatorial Pacific Ocean.

Usually trade winds blow here and sea currents move from the coast of America to Asia. However, with an interval of 4-7 years, the situation changes. The winds, for unknown reasons, change their direction to the opposite, heading towards the shores of South America. Under their influence, a warm El Niño current arises, pushing the cold waters of the Peruvian Current, rich in plankton, from the coast of the mainland. This current appears off the coast of Ecuador in the band 5 - 7 ° S. sh., washes the coast of Peru and the northern part of Chile, penetrating up to 15 ° S. sh., and sometimes to the south. This usually happens at the end of the year (the name of the current, which usually occurs around Christmas, means “baby” in Spanish and comes from the baby Christ), lasts 12-15 months and is accompanied by catastrophic consequences for South America: heavy rainfall in in the form of showers, floods, the development of mudflows, landslides, erosion, the reproduction of harmful insects, the departure of fish from the coast due to the arrival of warm waters, etc. To date, a relationship has been revealed weather conditions in many regions of our planet from the El Niño current: unusually heavy rainfall in Japan, severe droughts in South Africa, droughts and forest fires in Australia, violent floods in England, heavy winter precipitation in the Eastern Mediterranean. Its occurrence also affects the economy of many countries, primarily the production of agricultural crops (coffee, cocoa beans, tea, sugar cane, etc.) and fishing. The most intense in the last century was El Niño in 1982–1983. It is estimated that during this time the current caused the world economy material damage in the amount of about $ 14 billion and led to the death of 20 thousand people.

Other examples of the manifestation of the integrity of the geographic envelope are shown in Scheme 3.

The integrity of the geographic shell is achieved by the circulation of energy and matter. Energy cycles are expressed by balances. For the geographic envelope, radiation and heat balances are most typical. As for the cycles of matter, the matter of all spheres of the geographic envelope is involved in them.

Cycles in the geographic envelope are different in their complexity. Some of them, for example, the circulation of the atmosphere, the system of sea currents or the movement of masses in the bowels of the Earth, are mechanical movements, others (the water cycle) are accompanied by a change in the aggregate state of matter, and others (biological circulation and changes in matter in the lithosphere) are chemical transformations.

As a result of the cycles in the geographic shell, there is an interaction between the private shells, during which they exchange matter and energy. It is sometimes argued that the atmosphere, hydrosphere and lithosphere penetrate each other. In fact, this is not so: it is not the geospheres that penetrate each other, but their components. Thus, solid particles of the lithosphere enter the atmosphere and hydrosphere, air penetrates the lithosphere and hydrosphere, etc. Particles of matter that have fallen from one sphere to another become an integral part of the latter. Water and solid particles of the atmosphere are its constituent parts, just like gases and solid particles in water bodies belong to the hydrosphere. The presence of substances that have fallen from one shell into another form, to one degree or another, the properties of this shell.

A typical example of a cycle that connects all the structural parts of a geographic envelope is the water cycle. The general, global and private cycles are known: ocean - atmosphere, continent - atmosphere, intra-oceanic, intra-atmospheric, intra-terrestrial, etc. All water cycles occur due to the mechanical movement of huge masses of water, but many of them - between different spheres, are accompanied by phase transitions water or occur with the participation of some specific forces, such as surface tension. The global water cycle, covering all spheres, is accompanied, in addition, by the chemical transformations of water - the entry of its molecules into minerals, into organisms. The complete (global) water cycle with all its particular components is well represented in the scheme of L. S. Abramov (Fig. 146). In total, there are 23 cycles of moisture circulation.

Integrity is the most important geographical regularity, on the knowledge of which the theory and practice of rational nature management is based. Accounting for this regularity makes it possible to foresee possible changes in nature, to give a geographical forecast of the results of human impact on nature, to carry out a geographical examination of projects related to the economic development of certain territories.

rice. 146. Complete and partial water cycles in nature

The geographical shell is characterized by the rhythm of development - the repetition in time of certain phenomena. There are two forms of rhythm: periodic and cyclic. Under the periods understand the rhythms of the same duration, under the cycles - a variable duration. In nature, there are rhythms of different duration - daily, intra-secular, centuries-old and super-secular, having different origins. Manifesting at the same time, rhythms are superimposed one on another, in some cases strengthening, in others - weakening each other.

The daily rhythm, due to the rotation of the Earth around its axis, manifests itself in changes in temperature, pressure, air humidity, cloudiness, wind strength, in the phenomena of ebbs and flows, the circulation of breezes, in the functioning of living organisms and in a number of other phenomena. The daily rhythm at different latitudes has its own specifics. This is due to the duration of illumination and the height of the Sun above the horizon.

The annual rhythm is manifested in the change of seasons, in the formation of monsoons, in the change in the intensity of exogenous processes, as well as in the processes of soil formation and destruction of rocks, seasonality in human economic activity. in different natural regions different number of seasons are distinguished. So, in the equatorial zone there is only one season of the year - hot and humid, in the savannahs there are two seasons: dry and wet. In temperate latitudes, climatologists even suggest distinguishing six seasons of the year: in addition to the well-known four, two more - pre-winter and pre-spring. Pre-winter is the period from the moment the average daily temperature passes through 0 ° C in autumn until the establishment of a stable snow cover. Prespring begins with the beginning of the melting of the snow cover until its complete disappearance. As can be seen, the annual rhythm is best expressed in the temperate zone and very weakly in the equatorial zone. The seasons of the year in different regions may have different names. It is hardly legitimate to single out the winter season at low latitudes. It should be borne in mind that the reasons for the annual rhythm are different in different natural regions. So, in subpolar latitudes, it is determined by the light regime, in temperate latitudes - by the course of temperatures, in subequatorial latitudes - by the moisture regime.

Of the intrasecular rhythms, the 11-year rhythms associated with changes in solar activity are most clearly expressed. It has a great influence on the Earth's magnetic field and ionosphere and, through them, on many processes in the geographic envelope. This leads to periodic changes in atmospheric processes, in particular, to deepening of cyclones and strengthening of anticyclones, fluctuations in river flow, and changes in the intensity of sedimentation in lakes. The rhythms of solar activity affect growth woody plants, which is reflected in the thickness of their growth rings, contribute to periodic outbreaks of epidemic diseases, as well as the mass reproduction of pests of forests and crops, including locusts. As the famous heliobiologist A.L. Chizhevsky, 11-year rhythms affect not only the development of many natural processes but also on the organism of animals and man, as well as on his life and activity. It is interesting to note that some geologists now associate tectonic activity with solar activity. A sensational statement on this subject was made at the International Geological Congress held in 1996 in Beijing. Employees of the Institute of Geology of China revealed the cyclicity of earthquakes in the eastern part of their country. Exactly every 22 years (doubled solar cycle) in this area there is a perturbation of the earth's crust. It is preceded by sunspot activity. Scientists have studied historical chronicles since 1888 and found complete confirmation of their conclusions regarding the 22-year cycles of earth's crust activity leading to earthquakes.

Centuries-old rhythms are manifested only in individual processes and phenomena. Among them, the rhythm lasting 1800–1900 years, established by A.V. Shnitnikov. Three phases are distinguished in it: transgressive (of a cool-humid climate), developing rapidly, but short (300–500 years); regressive (dry and warm climate), developing slowly (600 - 800 years); transitional (700–800 years). In the transgressive phase, glaciation on Earth intensifies, river flow increases, and the level of lakes rises. In the regressive phase, glaciers, on the contrary, retreat, rivers become shallow, and the water level in lakes decreases.

The rhythm under consideration is associated with a change in tide-forming forces. Approximately every 1800 years, the Sun, Moon and Earth are in the same plane and on the same straight line, and the distance between the Earth and the Sun becomes the smallest. Tidal forces reach their maximum value. In the World Ocean, the movement of water in the vertical direction increases to a maximum - deep cold waters come to the surface, which leads to cooling of the atmosphere and the formation of a transgressive phase. Over time, the “parade of the Moon, Earth and Sun” is disturbed and humidity returns to normal.

The supersecular cycles include three cycles associated with changes in the orbital characteristics of the Earth: precession (26 thousand years), a complete oscillation of the ecliptic plane relative to the earth's axis (42 thousand years), a complete change in the eccentricity of the orbit (92 - 94 thousand years).

The longest cycles in the development of our planet are tectonic cycles lasting about 200 million years, known to us as the Baikal, Caledonian, Hercynian and Mesozoic-Alpine epochs of folding. They are caused by cosmic causes, mainly by the onset of galactic summer in a galactic year. The galactic year is understood as the revolution of the solar system around the center of the galaxy, lasting the same number of years. When the system approaches the center of the Galaxy, in perigalactia, i.e., "galactic summer", gravity increases by 27% compared to apogalactia, which leads to an increase in tectonic activity on Earth.

There are also reversals of the Earth's magnetic field with a duration of 145–160 Ma.

Rhythmic phenomena do not completely repeat at the end of the rhythm the state of nature that was at its beginning. This is precisely what explains the directed development of natural processes, which, when rhythm is superimposed on progress, ultimately turns out to be going in a spiral.

The study of rhythmic phenomena is of great importance for the development of geographic forecasts.

The planetary geographical regularity, established by the great Russian scientist V.V. Dokuchaev, is zoning - a regular change in natural components and natural complexes in the direction from the equator to the poles. Zoning is due to the unequal amount of heat coming to different latitudes due to the spherical shape of the Earth. The distance of the Earth from the Sun is also important. The dimensions of the Earth are also important: its mass allows it to keep an air shell around it, without which there would be no zoning. Finally, zoning is complicated by a certain inclination of the earth's axis to the plane of the ecliptic.

On Earth, the climate, land and ocean waters, weathering processes, some landforms formed under the influence of external forces (surface waters, winds, glaciers), vegetation, soils, and wildlife are zonal. The zonality of components and structural parts predetermines the zonality of the entire geographic envelope, i.e., geographic or landscape zonality. Geographers distinguish between component (climate, vegetation, soil, etc.) and complex (geographical or landscape) zonality. The concept of component zoning has developed since ancient times. Complex zoning was discovered by V.V. Dokuchaev.

The largest zonal subdivisions of the geographic shell are geographic belts. They differ from each other in temperature conditions, general features of the circulation of the atmosphere. On land, the following geographical zones are distinguished: equatorial and in each hemisphere - subequatorial, tropical, subtropical, temperate, as well as in the northern hemisphere - subarctic and arctic, and in the southern - subantarctic and antarctic. In total, thus, 13 natural belts are distinguished on land. Each of them has its own characteristics for human life and economic activity. These conditions are most favorable in three zones: subtropical, temperate and subequatorial (by the way, all three have a well-defined seasonal rhythm of nature development). They are more intensively mastered by man than others.

Belts similar in name (with the exception of subequatorial ones) have also been identified in the World Ocean. The zonality of the World Ocean is expressed in sublatitudinal changes in temperature, salinity, density, gas composition of water, in the dynamics of the upper water column, as well as in the organic world. D.V. Bogdanov distinguishes natural oceanic belts - "vast water spaces covering the surface of the ocean and the adjacent upper layers to a depth of several hundred meters, in which the features of the nature of the oceans (temperature and salinity of water, currents, ice conditions, biological and some hydrochemical indicators) are clearly visible, directly or indirectly due to the influence of the latitude of the place ”(Fig. 147). The boundaries of the belts were drawn by him along oceanological fronts - the boundaries of the distribution and interaction of waters with different properties. Oceanic belts are very well combined with physical and geographical zones on land; the exception is the subequatorial belt of land, which does not have its own oceanic counterpart.

Within the belts on land, according to the ratio of heat and moisture, natural zones are distinguished, the names of which are determined by the type of vegetation prevailing in them. So, for example, in the subarctic zone there are zones of tundra and forest-tundra, in the temperate zone there are zones of forests, forest-steppes, steppes, semi-deserts and deserts, in the tropical zone there are zones of evergreen forests, semi-deserts and deserts.

Rice. 147. Geographical zonation of the World Ocean (in conjunction with the geographical zones of land) (according to D.V. Bogdanov)

Geographical zones are subdivided into subzones according to the degree of manifestation of zonal features. Theoretically, in each zone, three subzones can be distinguished: the central one, with the most typical features for the zone, and

marginal, bearing some features characteristic of adjacent zones. An example is the forest zone of the temperate zone, in which subzones of the northern, middle and southern taiga, as well as subtaiga (coniferous-deciduous) and broad-leaved forests, are distinguished.

Due to the heterogeneity of the earth's surface, and consequently, the conditions of moisture in various parts continents zones and subzones do not always have a latitudinal strike. Sometimes they stretch almost in a meridional direction, as, for example, in the southern half of North America or in eastern Asia. Therefore, it is more correct to call zonality not latitudinal, but horizontal. In addition, many zones are not distributed around the globe like belts; some of them are found only in the west of the continents, in the east or in their center. This is explained by the fact that the zones were formed as a result of hydrothermal, and not radiation, differentiation of the geographic envelope, i.e., due to the different ratio of heat and moisture. In this case, only the distribution of heat is zonal; the distribution of moisture depends on the distance of the territory from sources of moisture, i.e., from the oceans.

In 1956 A.A. Grigoriev and M.I. Budyko formulated the so-called periodic law geographic zoning, where each natural zone is characterized by its quantitative ratios of heat and moisture. Heat is estimated in this law by the radiation balance, and the degree of moisture is estimated by the radiation dryness index K B (or RIS) = B / (Z x r), where B is the annual radiation balance, r is the annual amount of precipitation, L is the latent heat of vaporization.

The radiation dryness index shows what proportion of the radiation balance is spent on the evaporation of precipitation: if the evaporation of precipitation requires more heat than it comes from the Sun, and part of the precipitation remains on Earth, then the humidification of such a territory is sufficient or excessive. If more heat comes in than is spent on evaporation, then the excess heat heats the earth's surface, which at the same time experiences a lack of moisture: K B< 0,45 – климат избыточно влажный, К Б = 0,45-Н,0 – влажный, К Б = 1,0-^3,0 – недостаточно влажный, К Б >3.0 - dry.

It turned out that, although zoning is based on the increase in the radiation balance from high latitudes to low latitudes, the landscape appearance of the natural zone is most of all determined by moistening conditions. This indicator determines the type of zone (forest, steppe, desert, etc.), and the radiation balance determines its specific appearance (temperate latitudes, subtropical, tropical, etc.). Therefore, in each geographical zone, depending on the degree of moisture, their own humid and arid natural zones have formed, which can be replaced at the same latitude, depending on the degree of moisture. It is characteristic that in all belts the optimal conditions for the development of vegetation are created when the radiation index of dryness is close to one.

Rice. 148. Periodic law of geographical zonality. K B is the radiation index of dryness. (The diameters of the circles are proportional to the biological productivity of landscapes)

The periodic law of geographic zoning is written in the form of a matrix table, in which the radiation dryness index is calculated horizontally, and the annual radiation balance values \u200b\u200bare vertically (Fig. 148).

Speaking of zoning as a general pattern, it should be borne in mind that it is not equally expressed everywhere. It manifests itself most clearly in the polar, equatorial and equatorial latitudes, as well as in the inland: flat conditions of temperate and subtropical latitudes. The latter include, first of all, the largest East European and West Siberian Plain. Apparently, this helped V.V. Dokuchaev to identify the pattern under consideration, since he studied it on the East European Plain. The fact that V.V. Dokuchaev was a soil scientist played a role in determining the complex zonality, and the soil, as you know, is an integral indicator natural conditions territory.

Some scientists (O. K. Leontiev, A. P. Lisitsyn) trace natural zones in the thickness and at the bottom of the oceans. However, the natural complexes identified by them here cannot be called physico-geographical zones in the conventional sense, i.e., their isolation is not affected by the zonal distribution of radiation, which is the main cause of zoning on the Earth's surface. Here we can talk about the zonal properties of water masses and bottom sediments of flora and fauna acquired indirectly through water exchange with the near-surface water mass, redeposition of zonal terrigenous and biogenic sediments, and trophic dependence of bottom fauna on dead organic residues coming from above.

The zoning of the geographic envelope as a planetary phenomenon is violated by the opposite property - azonality.

The azonality of a geographic envelope is understood as the distribution of some object or phenomenon out of connection with the zonal features of a given territory. The reason for the azonality is the heterogeneity of the earth's surface: the presence of continents and oceans, mountains and plains on the continents, the peculiarity of moistening conditions and other properties of the geographical envelope. There are two main forms of manifestation of azonality - sectoral geographic zones and altitudinal zonality.

Sectorization, or longitudinal differentiation, of geographic zones is determined by moisture (in contrast to latitudinal zones, where not only moisture, but also heat supply play an important role). Sectorism is manifested primarily in the formation of three sectors within the belts - the continental and two oceanic. However, they are not expressed equally everywhere, which depends on the geographic location of the continent, its size and configuration, as well as on the nature of atmospheric circulation.

Geographic sectoring is most fully expressed on the largest continent of the Earth - in Eurasia, from the Arctic to the equatorial belt inclusive. Longitudinal differentiation is most pronounced here in the temperate and subtropical zones, where all three sectors are clearly expressed. There are two sectors in the tropical zone. Longitudinal differentiation is weakly expressed in the equatorial and subpolar belts.

Another reason for the azonality of the geographic envelope, which violates zoning and sectoring, is the location of mountain systems, which can prevent the penetration of air masses carrying moisture and heat into the depths of the continents. This is especially true for those ridges of the temperate zone, which are located submeridionally on the path of cyclones following from the west.

The azonal nature of landscapes is often determined by the features of the rocks that compose them. Thus, the occurrence of soluble rocks close to the surface leads to the formation of peculiar karst landscapes, which differ significantly from the surrounding zonal natural complexes. In the areas of distribution of water-glacial sands, landscapes of the Polissya type are formed. Figure 149 shows the location of geographic zones and sectors within them on a hypothetical flat continent, built on the basis of the actual distribution of land on the globe at different latitudes. The same figure clearly illustrates the asymmetry of the geographic envelope.

In conclusion, we note that azonality, as well as zoning, is a general pattern. Each area of the earth's surface, due to its heterogeneity, reacts in its own way to the incoming solar energy and, therefore, acquires specific features that are formed against the general zonal background. In essence, azonation is a specific form of manifestation of zoning. Therefore, any part of the earth's surface is simultaneously zonal and azonal.

Altitudinal zonality is a natural change of natural components and natural complexes with an ascent to the mountains from their foot to the peaks. It is due to climate change with height: temperature decrease and precipitation increase up to a certain height (up to 2-3 km) on the windward slopes.

Altitudinal zonality has much in common with horizontal zonality: when ascending mountains, the change of belts occurs in the same sequence as on the plains, when moving from the equator to the poles. However, the natural belts in the mountains are changing much faster than the natural zones in the plains. In the northern hemisphere, in the direction from the equator to the poles, the temperature decreases by about 0.5 ° C for every degree of latitude (111 km), while in the mountains it drops by an average of 0.6 ° C for every 100 m.

Rice. 149. Scheme of geographical zones and main zonal types of landscapes on a hypothetical mainland (the size of the depicted mainland corresponds to half the land area the globe in scale 1: 90,000,000), configuration - its location in latitudes, surface - a low plain (according to A. M. Ryabchikov et al.)

There are other differences: in the mountains in all belts with enough warmth and moisture, there is a special belt of subalpine and alpine meadows, which is not found on the plains. Moreover, each belt of mountains, similar in name to the plain, differs significantly from it, because they receive solar radiation of different composition and have different lighting conditions.

The altitudinal zonality in the mountains is formed not only under the influence of changes in altitude, but also in the features of the relief of the mountains. In this case, the exposure of slopes, both insolation and circulation, plays an important role. Under certain conditions, an inversion of altitudinal zonality is observed in the mountains: when cold air stagnates in intermountain basins, the belt of coniferous forests, for example, can occupy a lower position compared to the belt of broad-leaved forests. On the whole, the altitudinal zonality is much more diverse than the horizontal zonality and, moreover, manifests itself at close distances.

However, there is a close relationship between horizontal zonality and altitudinal zonality. Altitudinal zonality begins in the mountains with an analog of the horizontal zone within which the mountains are located. So, in the mountains located in steppe zone, the lower belt is mountain-steppe, in the forest - mountain-forest, etc. Horizontal zonality determines the type of altitudinal zonality. In each horizontal zone, mountains have their own range (set) of altitudinal belts. The number of altitudinal belts depends on the height of the mountains and their location. The higher the mountains and the closer to the equator they are located, the richer their spectrum of belts.

The nature of the altitudinal zonality is also affected by the sector nature of the geographic envelope: the composition of the vertical belts differs depending on which particular sector a particular mountain range is located in. The generalized structure of the altitudinal zonality of landscapes in different geographical zones (at different latitudes) and in various sectors is shown in Figure 150. Similarly to the altitudinal zonality in mountains on land, one can speak of deep zonality in the ocean.

One of the main (and according to Academician K.K. Markov, the main) regularities of the geographic envelope should be considered polar asymmetry. The reason for this pattern is primarily the asymmetry of the figure of the Earth. As you know, the northern semi-axis of the Earth is 30 m longer than the southern one, so that the Earth is more flattened at South Pole. The location of continental and oceanic masses on the Earth is asymmetrical. In the northern hemisphere, land occupies 39% of the area, and in the southern hemisphere - only 19%. Around the North Pole is the ocean, around the South - the mainland of Antarctica. On the southern continents platforms occupy from 70 to 95% of their area, on the northern ones - 30 - 50%. In the northern hemisphere there is a belt of young folded structures (Alpine-Himalayan), stretching in a latitudinal direction. It has no analogue in the southern hemisphere. In the northern hemisphere, between 50 and 70 °, the most geostructurally elevated land areas are located (Canadian, Baltic, Anabar. Aldan shields). In the southern hemisphere at these latitudes there is a chain of oceanic depressions. In the northern hemisphere there is a continental ring framing the polar ocean, in the southern hemisphere there is an oceanic ring that borders the polar continent.

The asymmetry of land and sea entails the asymmetry of other components of the geographic envelope. Thus, in the oceanosphere, the systems of sea currents in the northern and southern hemispheres do not repeat each other; Furthermore, warm currents in the northern hemisphere they spread up to arctic latitudes, while in the southern hemisphere they spread only up to a latitude of 35°. The water temperature in the northern hemisphere is 3° higher than in the southern.

The climate of the northern hemisphere is more continental than that of the southern one (the annual air temperature amplitude is 14 and 6 °C, respectively). In the northern hemisphere, there is weak continental glaciation, strong sea glaciation, and a large area of permafrost. In the southern hemisphere, these figures are directly opposite. In the northern hemisphere, the taiga zone occupies a huge area, in the southern hemisphere it has no analogue. Moreover, at latitudes where broad-leaved and mixed forests dominate in the northern hemisphere (~50°), arctic deserts are located on islands in the southern hemisphere. The fauna of the hemispheres is also different. In the southern hemisphere, there are no zones of tundra, forest-tundra, forest-steppe, and deserts of the temperate zone. The fauna of the hemispheres is also different. There are no bactrian camels, walruses, polar bears and many other animals in the southern, but there are, for example, penguins, marsupials and some other animals that are not in the northern hemisphere. In general, differences in the species composition of plants and animals between the hemispheres are very significant.

These are the basic laws of the geographic shell, some of them are sometimes called laws. However, as D. L. Armand convincingly proved, physical geography does not deal with laws, but with regularities - steadily repeating relationships between phenomena in nature, but having a lower rank than laws.

rice. 150. Generalized structure of altitudinal zonality of landscapes in different geographical zones (according to Ryabchikov A.A.)

Describing the geographic shell, it is necessary to emphasize once again that it is closely connected with the outer space surrounding it and with the internal parts of the Earth. First of all, it receives the energy it needs from the Cosmos. The forces of attraction keep the Earth in orbit around the Sun and cause periodic tidal disturbances in the body of the planet. Corpuscular streams (“solar wind”), X-rays and ultraviolet rays, radio waves and visible radiant energy are directed towards the Earth from the Sun. Cosmic rays are directed from the depths of the Universe towards the Earth. The streams of these rays and particles cause the formation of magnetic storms, auroras, air ionization and other phenomena near the Earth. The mass of the Earth is constantly increasing due to the fall of meteorites and cosmic dust. But the Earth perceives the impact of the Cosmos non-passively. Around the Earth as a planet with a magnetic field and radiation belts, a specific natural system is being created, which is called geographic space. It extends from the magnetopause - the upper boundary of the Earth's magnetic field, which is located at a height of at least 10 Earth radii, to the lower boundary of the Earth's crust - the so-called Mohorovichich (Moho) surface. Geographical space is divided into four parts (from top to bottom):

Near space. Its lower boundary runs along the upper boundary of the atmosphere at an altitude of 1500 - 2000 km above the Earth. Here the main interaction of cosmic factors with the magnetic and gravitational fields of the Earth takes place. Here the corpuscular radiation of the Cosmos, which is detrimental to living organisms, is retained.

High atmosphere. From below, it is limited by the stratopause, which in this case is also taken as the upper boundary of the geographic envelope. Here, primary cosmic rays slow down, they are transformed, and the thermosphere is heated.

Geographic cover. Its lower boundary is the base of the weathering crust in the lithosphere.

Underlying bark. The lower boundary is the Moho surface. This is the area of manifestation of endogenous factors that form the primary relief of the planet.

The concept of geographical space specifies the position of the geographic envelope of our planet.

In conclusion, we note that a person in the course of his economic activity currently has a great influence on the geographical envelope.

The shell of the Earth, within which the lower layers of the atmosphere, the upper parts of the lithosphere, the entire hydrosphere and biosphere mutually penetrate each other and interact, is called geographical envelope(earth shell) All components of the geographic shell interact with each other.

The geographic envelope does not have sharp boundaries. Many scientists believe that its thickness is on average 55 km. The geographic envelope is sometimes referred to as the natural environment or simply nature.

Geographic envelope properties.

Only in the geographical envelope are there substances in the solid, liquid and gaseous state, which is of great importance for all processes occurring in the geographical envelope, and above all for the emergence of life. Only here, near the solid surface of the Earth, first life arose, and then man and human society, for the existence and development of which there are all conditions: air, water, rocks and minerals, solar heat and light, soils, vegetation, bacterial and animal life.

All processes in the geographic envelope occur under the influence of solar energy and, to a lesser extent, internal terrestrial energy sources. In this way, geographic envelope properties : integrity, rhythm, zoning .

Civil defense integrity It manifests itself in the fact that a change in one component of nature inevitably causes a change in all the others. These changes can evenly cover the entire geographic envelope and appear in some of its separate parts, influencing other parts.

Rhythm natural phenomena is the repetition of similar phenomena in time. Examples of rhythm: daily and annual periods of the Earth's rotation; long periods of mountain building and climate change on Earth; periods of change in solar activity. The study of rhythms is important for forecasting the processes and phenomena occurring in the geographic envelope.

Zoning – regular change of all GO components from the equator to the poles. It is caused by the rotation of the spherical Earth with a certain inclination of the axis of rotation around the Sun. Depending on the geographical latitude solar radiation is distributed zonally and causes a change in climates, soils, vegetation and other components of the geographic envelope. The world law of zonality of the geographical shell is manifested in its division into geographical zones and natural zones. On its basis, the physical-geographical zoning of the Earth and its individual sections is carried out.

Simultaneously with the zonal, there are also azonal factors associated with the internal energy of the Earth (relief, height, configuration of the continents). They violate the zonal distribution of GO components. In any part of the world, zonal and azonal factors act simultaneously.

Circulation of matter and energy

The circulation of matter and energy is essential mechanism natural processes of the geographical shell. There are various cycles of matter and energy: air cycles in the atmosphere, the earth's crust, water cycles, etc.

For the geographical envelope, it is of great importance The water cycle, which is carried out due to the movement of air masses. There can be no life without water.

A huge role in the life of the geographical shell belongs to biological cycle. In green plants, as is known, organic substances are formed from carbon dioxide and water in the light, which serve as food for animals. After death, animals and plants are decomposed by bacteria and fungi to minerals, which are then reabsorbed by green plants.

The leading role in all cycles belongs to air cycle in the troposphere, which includes the entire system of winds and the vertical movement of air. The movement of air in the troposphere draws the hydrosphere into the global circulation, forming the world water cycle.

Each subsequent cycle is different from the previous ones. It does not form a vicious circle. Plants, for example, take nutrients from the soil, and when they die, they give them much more, since organic matter plants is created mainly due to atmospheric carbon dioxide, and not due to substances coming from the soil.

The role of living organisms in the formation of nature.

Life makes our planet unique. Life processes consist of three main stages: the creation of primary products as a result of photosynthesis of organic matter; transformation of primary (plant) products into secondary (animal); destruction of primary and secondary biological products by bacteria, fungi. Without these processes, life is impossible. Living organisms include: plants, animals, bacteria and fungi. Each group (kingdom) of living organisms plays a certain role in the development of nature.

Under the influence of living organisms, there was more oxygen in the air and the content of carbon dioxide decreased. Green plants are the main source of atmospheric oxygen. Another was the composition of the oceans. Rocks of organic origin appeared in the lithosphere. Deposits of coal and oil, most limestone deposits are the result of the activity of living organisms.

Geography is the science of the internal and external structure of the Earth, studying the nature of all continents and oceans. The main object of study are various geospheres and geosystems.

Introduction

The geographic shell or GO is one of the basic concepts of geography as a science, introduced into circulation at the beginning of the 20th century. It denotes the shell of the entire Earth, a special natural system. The geographic shell of the Earth is called an integral and continuous shell, consisting of several parts that interact with each other, penetrate each other, constantly exchange substances and energy with each other.

Fig 1. Geographical shell of the Earth

There are similar terms, with narrow meanings, used in the writings of European scientists. But they don't mean natural system, only a set of natural and social phenomena.

Stages of development

The geographic shell of the earth has gone through a number of specific stages in its development and formation:

geological (prebiogenic)– the first stage of formation, which began about 4.5 billion years ago (lasted about 3 billion years);
biological– the second stage, which began about 600 million years ago;
anthropogenic (modern)- a stage that continues to this day, which began about 40 thousand years ago, when humanity began to exert a noticeable influence on nature.

The composition of the geographic shell of the Earth

Geographic envelope- this is a system of the planet, which, as you know, has the shape of a ball, flattened on both sides by the caps of the poles, with a long equator of more than 40 tons km. GO has a certain structure. It consists of interconnected environments.

Upper and lower bounds

In the entire structure of the geographic envelope and geographic environments, a clear zoning can be traced.

The law of geographical zoning provides not only for the division of the entire shell into spheres and environments, but also for the division into natural zones of land and oceans. It is interesting that such a division naturally repeats itself in both hemispheres.

Zoning is due to the nature of the distribution of solar energy over latitudes and the intensity of moisture (different in different hemispheres, continents).

Naturally, it is possible to determine the upper boundary of the geographic envelope and the lower one. Upper bound located at an altitude of 25 km, and bottom line The geographic envelope runs at a level of 6 km under the oceans and at a level of 30-50 km on the continents. Although, it should be noted that the lower limit is conditional and there are still disputes over its setting.

Even if we take the upper boundary in the region of 25 km, and the lower one in the region of 50 km, then, in comparison with overall dimensions Earth, it turns out something like very thin film that covers the planet and protects it.

Basic laws and properties of the geographical shell

Within these boundaries of the geographical envelope, the basic laws and properties that characterize and determine it operate.

Interpenetration of components or intra-component movement- the main property (there are two types of intra-component movement of substances - horizontal and vertical; they do not contradict and do not interfere with each other, although in different structural parts of GO the speed of movement of components is different).
Geographic zonation- the basic Law.
Rhythm- the frequency of all natural phenomena (daily, annual).
The unity of all parts of the geographical shell due to their close relationship.

Characteristics of the Earth's shells included in the GO

Atmosphere

The atmosphere is important for keeping warm, and therefore life on the planet. It also protects all living things from ultraviolet radiation, affects soil formation and climate.

The size of this shell is from 8 km to 1 t km (or more) in height. It consists of:

gases (nitrogen, oxygen, argon, carbon dioxide, ozone, helium, hydrogen, inert gases);
dust;
water vapor.

The atmosphere, in turn, is divided into several interconnected layers. Their characteristics are presented in the table.

All shells of the earth are similar. For example, they contain all types aggregate states substances: solid, liquid, gaseous.

Fig 2. The structure of the atmosphere

Lithosphere

The hard shell of the earth, the earth's crust. It has several layers, which are characterized by different power, thickness, density, composition:

upper lithospheric layer;
sigmatic sheath;
semi-metallic or ore shell.

The maximum depth of the lithosphere is 2900 km.

What is the lithosphere made of? From solids: basalt, magnesium, cobalt, iron and others.

Hydrosphere

The hydrosphere is made up of all the waters of the Earth (oceans, seas, rivers, lakes, swamps, glaciers and even groundwater). It is located on the surface of the Earth and occupies more than 70% of the space. Interestingly, there is a theory according to which large reserves of water are contained in the thickness of the earth's crust.

There are two types of water: salt and fresh. As a result of interaction with the atmosphere, during condensate, the salt evaporates, thereby providing the land with fresh water.

Fig 3. Earth's hydrosphere (view of the oceans from space)

Biosphere

The biosphere is the most "living" shell of the earth. It includes the entire hydrosphere, the lower atmosphere, the land surface and the upper lithospheric layer. It is interesting that living organisms inhabiting the biosphere are responsible for the accumulation and distribution of solar energy, for migration processes. chemical substances in the soil, for gas exchange, for redox reactions. We can say that the atmosphere exists only thanks to living organisms.

Fig 4. Components of the Earth's biosphere

Examples of the interaction of media (shells) of the Earth

There are many examples of media interaction.

During the evaporation of water from the surface of rivers, lakes, seas and oceans, water enters the atmosphere.
Air and water, penetrating through the soil into the depths of the lithosphere, makes it possible for vegetation to rise.
Vegetation provides photosynthesis by enriching the atmosphere with oxygen and absorbing carbon dioxide.
From the surface of the earth and oceans, the upper layers of the atmosphere are heated, forming a climate that provides life.
Living organisms, dying, form the soil.

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