O.V

Hello, dear friend!

You have successfully completed one test work. Let me remind you that after completing all the tests, you will receive a geographical portrait of our planet Earth. Today you have to amazing trip in "The World of Stone".
Lithosphere(from Greek lithos– stone) - the outer rocky, hard shell of the Earth, consisting of earth's crust, thickness maximum up to 70 km And the most upper layers mantle .
Let's take a trip to the center of the Earth. We'll start it with top shell, which has been studied best by man, - earth's crust. This upper part lithosphere - the hard shell of our planet. The structure and thickness of the earth's crust under continents and oceans varies, but in general it is no more than 70-75 km. But this is only 1.2% of the radius of the Earth!
The lithosphere is replaced mantle occupies more than 80% volume of the Earth. The mantle extends to depths up to 2900 km. In its upper part, pockets of magma are formed, which sometimes breaks through to the surface in the form volcanic lava or freezes at depth, in the thickness of the lithosphere, never finding its way to the surface. Many mineral deposits, including diamonds, are associated with such igneous rocks. At high pressures and mantle temperatures, mineral compounds change structure - crystal lattice. Most shining example This mineral is ordinary graphite, familiar to us from the lead in pencils. In mantle conditions, it becomes a super-strong diamond.
In the upper mantle there is a layer thick 200-250 km, where the wave speed changes sharply. This layer is named asthenosphere . The substance of the asthenosphere is characterized by increased plasticity. Plates - rigid sections of the lithosphere - move along it.
In the lower mantle (deeper than 400 km) the density of matter is much greater than in the upper; there is no data on its composition.
At the center of the planet is located core. It contains the heaviest chemical elements, such as iron. Like the mantle, the core is heterogeneous: the inner one is very heavy and solid, the outer one is more liquid. The core temperature reaches 10,000°C.

Mohorovic surface

Internal structure of the Earth

Mineral (fr. Min e ral, from late lat. Minera- ore) - a natural body with a certain chemical composition And crystal structure, formed as a result of natural physical and chemical processes and having certain properties. It is an integral part of the earth's crust, rocks, ores, meteorites. Science studies minerals mineralogy .

Minerals

		quartz

Set of irregularities earth's surface(various in size, age and origin) is called relief (from the French - relief, coming from Latin relevo- I pick it up).

Processes shaping the Earth's topography - internal (endogenous) - processes inside the Earth, in the mantle, core - manifest themselves on and near the Earth’s surface and how destructive, and how creative in the form volcanic processes, earthquakes , compression and stretching of the earth's crust. The earth's crust is in constant movement. The speed of such movements can be very small, noticeable only to ultra-precise instruments. The most active movements of the earth's crust occur near huge tectonic faults, peculiar cracks on a planetary scale through which mantle material enters the surface. In these zones there are active and extinct volcanoes earthquakes occur.
Science studies earthquakes seismology (from Greek Seismos- hesitation, logos- teaching). The most earthquake-prone areas of the planet, where earthquakes most often occur, usually coincide with the boundaries of lithospheric plates.
Seismic activity different Pacific fire ring volcanoes , which includes Kamchatka, Sakhalin, Kuril and Japanese Islands, Philippines, Indonesia, California coast, Chile . It is in these places that not only volcanic eruptions regularly occur, but also strongest earthquakes. Residents of the Japanese islands live under the constant threat of tremors. Even the structures and foundations of buildings have their own characteristics here: when tremors they are able to shift, but not collapse. Another dangerous area - Eurasian belt , which includes peninsula Asia Minor, regions of the Hindu Kush, Tien Shan and Pamir, Himalayas (Find objects on physical map atlas).

The activity of endogenous (internal) forces.

External (exogenous) – processes are caused by energy entering the Earth solar radiation . And they manifest themselves on the earth’s surface both as destructive and creative. For example, destructive processes: destruction of rocks due to temperature difference, wind action, erosion by water flows, moving glaciers, as well as human activity. Creative: accumulation of particles carried by water and wind in depressions of land, at the bottom of reservoirs.

Activity of exogenous (external) forces

Endogenous processes create, first of all, large irregularities determine the distribution of land and sea, the height of mountains, and the sharpness of outlines. Exogenous processes vice versa, smooth out unevenness, level surfaces, fill depressions with deposits.
The science that studies the causes of relief formation is called geomorphology .
To show all the variety of relief on a flat map, use lines connecting points with the same height. So, for example, a mountain will be depicted on the map in the form of closed lines nested inside each other different shapes. Lines connecting points on the map with the same height are called horizontals or isohypses (from Greek Izos- equal, hypsos- height – approx. From geoglobus.ru), and the map compiled in this way is hypsometric.
To show the altitudinal contrast of this mountain and the surrounding plain, color is used. Rich shades of brown mean high place, and the transition from beige and green colors is a decrease. The darkest green areas on the map represent places on land that lie below sea level.
For relief ocean floor there is the same principle for constructing maps, but it does not give the height of underwater landforms, but their depth, that is, the distance from them to sea level. Lines connecting sections of the bottom with equal depth are isobaths. The depth scale varies from thick blue in the deepest places - deep-sea trenches to light blue in shallow waters and shelves - the underwater margins of continents.

Color and image of relief on the map

Your journey to the “World of Stone” has ended, now you have to act as a researcher and complete a test. The following sources will help you:

1.Geographical atlas.
2.Geography: a reference book for high school students and those entering universities. – M.:Ast-Press, 2001..
3. Parmuzin Yu.P. Dictionary by physical geography/ Yu.P. Parmuzin, G.V. Karpov - M.: Education, 1994.

4.Geography textbook

5.I explore the world: Det. Encyclopedia: Geography /V. A. Markin - M.: LLC “Firm Publishing House AST”, 1999
6. Internet resources:
http://students.russianplanet.ru
http://www.geoglobus.ru
http://ru.wikipedia.org
http://geography.kz

You can also use any sources of information and seek help from your parents and geography teacher at school. Good luck!

The largest landforms on Earth are continental protrusions and oceanic depressions. Their presence is explained by differences in the structure of the earth's crust. There are two types of crust: continental and oceanic. Continental crust differs in the greater thickness, number and composition of rock layers. As most scientists believe, the earth was first formed bark oceanic type , then under the influence internal processes it folded into folds, mountainous areas formed, the thickness of the crust increased, and continental protrusions formed. Story further development The earth's crust is fraught with many mysteries. There are many hypotheses and theories. One of them is the theory of the structure of the earth's crust, based on the idea of ​​lithospheric plates.

Lithosphere plates. According to the theory of lithospheric plates, the earth's crust, together with part of the upper mantle, is not a monolithic shell of our planet, but consists of several very large blocks (plates) with a thickness of 60 to 100 km. The boundaries between plates run along mid-ocean ridges and deep-sea trenches, and on land along mountain belts and giant cracks - grabens.

Scientists identify 7-9 huge slabs and dozens of smaller slabs. Most plates include both continental and oceanic crust. Huge plates are lighter than the mantle and move along the relatively soft, plastic layer of the upper mantle. The forces that cause plate motion arise when matter moves in the upper mantle. The consequences of plate movement are such phenomena and processes as the formation of young oceanic crust V deep faults rift valleys mid-ocean ridges, the formation of deep-sea trenches, where one of the plates descends into the mantle, the emergence mining structures at plate boundaries.

In the boundary areas between lithospheric plates, called seismic belts, most of them are located active volcanoes. Data on the structure of the earth's crust, lithospheric plates, and processes occurring in the earth's crust are reflected on a special thematic (tectonic) map "Structure of the earth's crust." (Tectonics is the science of the structure and development of the earth’s crust.)

Relief is a set of irregularities on the earth's surface that vary in size, origin and age. The relief of our planet is very diverse and is due to the interaction of internal and external processes. Energy internal parts The earth is manifested in the processes of movement of the earth's crust, the introduction of mantle matter into it or its outpouring onto the surface. At the same time, rock layers move and the relief changes. There are slow vertical movements and horizontal movements occurring everywhere.

External processes of relief formation act-:-:? on the surface of the planet. They receive their energy from the Sun, as well as from gravity and the vital activity of organisms. This is weathering, the work of flowing waters, wind, groundwater, glaciers, sea surf and human activity, which is currently becoming a kind of geological force.

Internal and external relief-forming processes operate simultaneously. In this case, internal processes create mainly large relief forms, while external ones destroy them and create small relief forms (hills, ravines, river valleys, screes, alluvial cones, rocks of bizarre shapes). Changes in the Earth's topography i almost invisible to humans) occurs continuously and quite intensely.

The ocean floor is in no way inferior to the land surface in terms of the variety of relief forms; its main feature is a single system of mid-ocean ridges, total length of which there are over 60 thousand km.

In the placement of large relief forms on the surface of the Earth, certain patterns: continental protrusions correspond to the continental crust; in areas where the oceanic crust is distributed, there are depressions filled with ocean water. Vast plains on land correspond to ancient sections of lithospheric plates - platforms. Mountain folded areas, deep-sea trenches on the ocean floor are located at the boundaries of lithospheric plates.

1. Federal Law of January 10, 2002 N 7-FZ “On the Protection environment"(as amended on August 22, December 29, 2004, May 9, December 31, 2005, December 18, 2006, February 5, June 26, 2007, June 24, July 14, 23, December 30, 2008 ., March 14, December 27, 2009, December 29, 2010)

2. Abanina E.N., Zenyukova O.V., Sukhova E.A. Comment to Federal law dated January 10, 2002 N 7-FZ "On Environmental Protection", 2nd edition, revised and expanded. - System GARANT, 2007.

3. Brinchuk M.M. Environmental law. Textbook for higher educational institutions. - System GARANT, 2010

4. Gate N.A. Environmental law: course of lectures. - "TK Welby", "Prospekt Publishing House", 2009.

5. Commentary on the Federal Law of January 10, 2002 N 7-FZ “On Environmental Protection” (edited by O.L. Dubovik). - System GARANT, 2010

6. Scientific and practical commentary on the Federal Law “On Environmental Protection” (article-by-article) (edited by Doctor of Legal Sciences Anisimov A.P.). - "Business Yard", 2010

7. Tikhomirova L.A. Constitutional basis for the delimitation of jurisdiction and powers Russian Federation and its subjects in the field of environmental protection: scientific and practical research. - System GARANT, 2010.

Lithosphere- this stone shell of the Earth. Together with the atmosphere, hydrosphere and biosphere, the lithosphere is included in geographical envelope. It includes the earth's crust and the underlying mantle layer, down to the asthenosphere, located at a depth of 100-150 km. Due to its plasticity, the asthenosphere acts as a substrate along which they can move. lithospheric plates. The asthenosphere is a source of volcanism, since it contains pockets of molten magma, which can penetrate into the earth's crust or pour out onto the surface of the Earth.

The upper solid shell of the Earth is called earth's crust. Its thickness ranges from 30 to 75 km on continents, and from 5 to 15 km under the oceans. Based on their structure, they are divided into continental (continental) and oceanic crust.

Continental crust under the plains it has a thickness of 25-30 km, and under the mountains - up to 75 km. On average it is 33-35 km. Under the mountains, there is a thickening of the earth's crust, that is, its protrusions deeper into the interior - the “roots of the mountains.” Especially large thickness the crust reaches under the Pamirs and Hindu Kush - more than 60 km. The Himalayas (about 75 km) and the Andes (75 km). Thus, the highest mountains have the deepest “roots” in the bowels of the earth.

During seismic sounding of the continental crust, three main layers are distinguished:

1. The upper one is called sedimentary layer. This is the least dense layer thickness: from 2-3 km on platforms to 20-30 km in moving areas. This layer is represented by sedimentary rocks, that is, clays, sands, sandstones, limestones and marls. The soil cover lies on it.

2. The second, thickest layer of the continental crust is called granite layer. He has higher density and is composed of crystalline rocks, that is, granites and gneisses. This layer comes to the surface in places. For example, on Kola Peninsula; V central parts mountain ranges of the Caucasus, Tien Shan, Altai, Alps, Carpathians, etc. In most cases, the granite layer is covered with sedimentary rocks, the thickness of which reaches 10-20 km.

3. The third layer of crust is called the basalt layer. It consists of the heaviest rocks - basalts, gabbros, etc., its thickness is 15-25 km.

The oceanic crust is thinner than the continental crust and consists of two layers - sedimentary and basaltic. The thickness of the sedimentary layer varies and varies from a few meters at mid-ocean ridges to 3 km at the rest of the ocean floor. Most This layer is represented by limestone silts formed by the remains of living organisms.

The thickness of the basalt layer varies from 3 to 12 km. Between these two main layers there is a layer with a lower density than basalts: its thickness is from 1 to 2 km. It is believed to be composed of lavas and volcanic tuffs.

Thus, the total thickness of the oceanic crust is 5-15 km, increasing to 20 km near continents, under oceanic islands and underwater ridges. In the central part Pacific Ocean The thickness of the crust is about 5-8 km.

Relief of the Earth. The surface of the lithosphere is a collection of irregularities. This is the relief of the Earth. The word "relief" is of French origin and means "convexity, protrusion." Relief- this is a property of the lithosphere that arose as a result of its interaction with the external and internal shells of the Earth.

Science deals with the study of relief geomorphology, whose tasks include knowledge of the laws of relief development and their use in human economic activity. The relief consists of elementary forms, or relief elements.

Geometrically, these are: faces, or surfaces, edges and faceted angles. The relief clearly distinguishes surfaces that have different slopes and sizes.

1. According to the magnitude of the slope to horizontal plane distinguish: subhorizontal surfaces with an inclination angle of less than 2°; inclined surfaces - with an inclination angle of more than 2°;

2. Surfaces can be: smooth; concave(sinkhole); convex(volcanic cones);

3. There are forms: closed(hill); open(beam);

4. In relation to the conditional level there are: positive landforms; negative relief forms.

Relief elements, combining on a certain territory, form type of relief. So, type of relief- is a set or complex of relief forms in a certain territory, united by a unity of origin. For example, mountainous type of relief, flat type of relief.

Landforms can be simple and complex: 1- Simple- consist only of the same type of relief elements. Example: ravine. 2. Complex- include several simple shapes. Example: river valley.

Thus, the relief is characterized by a wide variety of properties, which, however, are combined into three groups:

1. Morphological properties;

2. Genetic properties;

3. Age of the relief.

Morphological properties of the relief characterized by: a) Morphological characteristics(i.e. qualitatively); for example, a flat intermountain valley; b) Morphometric characteristics(i.e. qualitatively); for example, the hill has a height of 210 m, the slope of the slopes is 5°, etc.

Genetic properties determined by the origin of the relief. For example: landforms associated with volcanic activity, water activity, etc.

Relief age maybe: a) absolute, that is, determined on a geochronological or historical scale; b) relative, that is, the formation of a relief is determined earlier or later than some other form or surface. The concept of relative age was introduced into science at the beginning of the 20th century by the American geomorphologist W. Davis.

Taking into account the properties of the relief, several classifications:

1. Morphological classification, taking into account the magnitude of relief forms

Table 1 Landforms of the Earth

The surface area of ​​the Earth is 510 million km 2. The share of the World Ocean is 70.8%, or 361.06 million km 2, the share of land is 29.2%, or 149.02 million km 2.

Water and land are distributed unevenly on Earth. Land is concentrated mainly in the Northern Hemisphere; here it occupies 39% of the total surface, while in the Southern Hemisphere land occupies only 19% of the surface.

The largest planetary forms relief – continents (6) and ocean (5). Since 1996, by decision of the Commission on Geographical Names, Southern Ocean(its boundaries vary from 37° S to 48° S on different meridians). S. V. Kalesnik identified seven continents (separately Europe and Asia). The area of ​​the oceans is given in the “hydrosphere” section. The continent is an isostatically balanced massif of the continental earth's crust, which has a structural core in the form of an ancient platform, to which younger folded structures are adjacent.

MainlandArea, million km2

Eurasia................................................. ...... 53.45

Africa................................................. ....... 30.30 -

North America................................... 24.25

South America................................... 18.28

Antarctica................................................. 13.97

Australia (without Oceania) ........................7.70

If continents include their underwater part (shelf), with its typical continental structure, then the area of ​​the continents will increase significantly. The above areas of the continents, therefore, are the parts of the continents that rise above sea level, i.e. modern land. In addition to the concept of “continent” in literature, there is the concept of “part of the world” that emerged in the process of cultural and historical development. There are also six parts of the world. On the continent of Eurasia there are two parts of the world - Europe and Asia. The two continents of the New World - North America and South America - form one part of the world.

Fig. 1Hypsographic curve of land and bathymetric curve of ocean floor

The generalized profile of the earth's surface is shown using a hypsographic curve (Fig. 1). The part of it related to the ocean is called the bathygraphic curve. The hypsographic curve shows the predominance of heights of less than 1000 m on land, and in the ocean - depths from 3000 to 6000 m. High mountains and trenches occupy very little space on Earth. Average height sushi is 875 m. Average depth ocean 3790 m. Level of the leveled surface of the earth's crust, i.e. solid surface without ocean, would be located 2430 m below ocean level. If you place all the water of the World Ocean on top of this, its level will be 250 m higher than today. This level is taken as intermediate level physical surface of the Earth.

On the surface of the Earth, the continents form two rows: equatorial - Africa, Australia, South America, and northern - North America, Eurasia. Antarctica remains outside the ranks. The position of the continents reflects the history of the development of the lithosphere and explains the geological relationship of the continents.

The southern continents are parts of a single Paleozoic megacontinent, Gondwana. The northern continents at that time were united into another continent - Laurasia. Between them in the Paleozoic and Mesozoic there was a system of vast sea basins called the Tethys Ocean. It extended from North Africa through Europe, Western Asia, the Himalayas to Indochina. In the Neogene, an Alpine fold belt arose in place of this ocean. The first split of Gondwana occurred on the border of the Triassic and Jurassic, at which time Afro-America separated, and a little later South America moved away from Africa. At the boundary of the Cretaceous and Paleogene periods, the Hindustan block approached Asia, and Antarctica moved away from Australia. The split of Laurasia into two continents - Eurasia and North America - occurred in the middle of the Mesozoic.

The study of the planetary topography of the Earth leads to the conclusion about a natural relationship between the areas of continents (oceans), their average height (depth), the thickness of the earth's crust and the energy of tectogenesis. The larger the area of ​​the continent, the higher it is, the more powerful the crust. The larger the ocean, the deeper it is and the thinner the crust underneath. The energy of tectogenesis is determined by the range of heights and increases in proportion to the area of ​​the continent. The earth's crust reaches its maximum thickness under the mountains (60–70 km), and its minimum thickness under the ocean (5–10 km). The observed pattern is explained by isostasy - the tendency of the earth's crust to balance. The destruction of mountains and the accumulation of sediments upset the balance. Under destroyed mountains, the mantle rocks rise closer to the surface; under areas that have received additional load, they sink. For example, Antarctica, under the weight of ice, dropped by 700 m. Scandinavia, after the melting of the glacier, rises by 1 cm per year. An interesting pattern is observed in the structure of continents and oceans: in the middle of the continent there are plains, along the periphery - high mountains, while in the middle of the ocean there is the largest system of mid-ocean ridges, and on the periphery there are oceanic basins.

When considering the planetary topography of the Earth, it should be remembered that this is the topography of a rotating body. Tidal friction slows down the rotation of the planets, so the Earth's oblateness decreases. Consequently, in low latitudes, water should predominate, in high latitudes - land. On Earth, indeed, the ocean occupies a large area at the equator. In temperate latitudes Northern Hemisphere there is a ring of land (maximum at 62° N), which caused compensatory subsidence in the northern polar region. In temperate latitudes Southern Hemisphere a continuous ring of water dominates (maximum at 62° S), and in the south polar region there is a compensatory uplift. As a result of the unequal slowdown in the rotation of the hemispheres, the southern continents shift eastward relative to the northern ones.

The following patterns are observed in the location and structure of continents. The continents are located in pairs in relation to each other: North and South America, Africa and Europe, Asia and Australia. Only Antarctica does not have a pair and is located near the South Pole. Moreover, as noted above, the southern continents are shifted to the east relative to the northern ones. On the western shores of the continents there are large bays; in the east the continents have a bulge.

The continents are located in such a way that each of them, at the opposite end of the Earth's diameter, certainly has a corresponding ocean. This pattern is called antipodality. The most striking example is Antarctica, which corresponds to the Arctic Ocean.

Almost all continents are shaped like wedges or triangles, with their sharp peaks facing south. The wedge shape is observed in South America and Africa, the triangular shape is characteristic of most of the peninsulas of Eurasia and Australia.

U northern continents the shelf area is significant - the underwater continuation of their low-lying surface, especially in the Arctic and Atlantic oceans. The southern continents are practically devoid of shelves. The coastline of the southern continents is relatively straight, with few peninsulas and islands. The northern continents are characterized by an extremely rugged coastline, an abundance of peninsulas, and many islands along the coast. From total area islands and peninsulas account for 32% in Eurasia, in North America 25%, in Africa 2.1%, in South America 1.1%, in Australia (excluding Oceania) 1.1 %.

Most of southern continents make up on ancient platforms. In the northern continents, ancient platforms occupy smaller areas, most of them in areas formed by Paleozoic and Mesozoic structures.

Main tectonic structures continents are platforms and orogenic belts (geosynclines). Each continent, except Eurasia, is based on one platform; Eurasia is based on five. Platforms are tectonically stable sections of the earth's crust. The structure of the platforms has two floors: a folded foundation lies below, and on the surface it is covered by a sedimentary cover - horizontally lying rocks. In some places the folded foundation comes to the surface; these areas are called shields. The Russian platform forms two shields: Baltic and Ukrainian. Most of the platforms were formed in the Archean and Proterozoic, they are called ancient (Fig. 2). The ancient platforms are located in two latitudinal rows. The first row serves as the basis of the northern continents - North American, Russian, Siberian, Chinese. The second row consists of blocks of Gondwana - South American, African, Arabian, Indian, Australian. The Antarctic platform remains outside the ranks. Some platforms were formed later - in the Paleozoic, they are called young. At the heart of the West Siberian Plain is a platform of Hercynian age. Platforms occupy 57 % area of ​​continents (including shelf).

An orogenic belt (geosyncline) is a tectonically mobile and sharply dissected folded belt of the earth's crust. It is characterized by increased speed and a large range of vertical movements, intense folding, magmatism, volcanism. In the Lower Paleozoic, a folded mountain formation occurred, called the Caledonian, which covered vast areas.

Rice. 2. Precambrian platforms:

1-North American, 2-Russian, 3-Siberian, 4-South American; 5-African and Arabian,

6 - Hindustan, 7, 8 - Chinese, 9 - Australian, 10 - Antarctic

Caledonian structures formed in the Silurian are preserved in Scotland, Greenland, and Transbaikalia. In the Upper Paleozoic (Carboniferous and Permian), the Hercynian orogeny occurred. During this era, mountains were formed - the predecessors of the Urals, partly the Tien Shan, Altai, and Sayans. During the Mesozoic, Paleozoic structures became peneplains. During the Mesozoic phase of orogenesis, the mountains of Northeast Asia and the Cordillera ranges were formed. The Alpine mountains were formed later than all others; the Alpine folding includes the Alpine-Himalayan mountain system and the mountains of the periphery of the Pacific Ocean. Paleozoic structures occupy 20 % area of ​​the continents, the areas of Meso-Cenozoic folding account for 23 % area.

In mobile belts, as a rule, the most significant stresses are in the earth's crust, where energy is released in the form of sharp displacements of rigid blocks that cause seismic tremors. However, slow or secular movements of the earth’s crust, so imperceptible at first glance, are much more powerful and have more significant consequences. Their speed may seem insignificant, but they act unidirectionally for hundreds of thousands and millions of years. It is these slow movements that shape the face of the Earth, creating its main features in the form of mountains, plains, and ocean basins. Internal, or endogenous, processes act, as it were, as the architect of the planet, which operate with enormous tectonic structures. Scientists propose to call the largest ones formed by them.

The forces acting in the outer shells of the planet give rise to various exogenous processes. External forces usually move fine particles rocks or mineral substance in a dissolved state. Their impact can be compared to the work of a sculptor who decorates a building erected by an architect with details. So, flowing waters form a dense network of river valleys, glaciers sharpen peaks and plow out deep basins, winds form rocks in deserts and create hills and ridges from sand - barchans and dunes. Areas where it is common permafrost, literally dotted with cracks, mounds, rounded dips and stone ruins.

IN lately People are increasingly entering the arena of relief formation. He is engaged in redevelopment of the area, preparing construction sites, digging out quarries, mining, making embankments and excavations, laying roads. Moreover, economic activity changes the natural course of processes; it happens that a person awakens them without meaning to. Erosion begins in plowed fields, landslides appear after deforestation, and on the banks of reservoirs waves destroy the newly created banks.

Formation of the Earth's relief

Features of the Earth's relief