How rivers change the relief of the earth's surface. Why does land relief change? The main form of relief

The relief of our planet amazes with its diversity and unshakable greatness. Wide plains, deep river valleys and pointed spiers of the highest peaks - all this seemingly decorated and will decorate our world always. But it is not at all. In fact, the relief of the Earth changes.

But to notice these changes, not enough and several thousand years. What to say about the life of an ordinary person. The development of the earth's surface is a complex and multifaceted process that lasts now for several billion years. So why and how does the land relief change in time? And what underlies these changes?

Relief is ...

This scientific term comes from the Latin word RELEVO, which means "raising up". In geomorphology, under it implies a combination of all existing irregularities of the earth's surface.

Three are among key elements of the relief: a point (for example, a mountain peak), a line (for example, a watershed) and a surface (for example, a plateau). This gradation is very similar to the separation of the main figures in geometry.

The relief can be different: mountain, flat or hilly. It is represented by a variety of forms that may differ from each other not only by its appearance, but also origin, age. In the geographic shell of our planet, the relief plays an extremely important role. First of all, it is the basis of any natural-territorial complex, like the foundation of a residential building. In addition, he is directly involved in the redistribution of moisture on the surface of the Earth, and also participates in climate formation.

How does land relief change? And what are his forms known to modern scientists? This will be discussed further.

Earth relief: the main forms and age of embossed forms

The form of relief is a fundamental unit in geomorphological science. If we speak simple words, this is a specific irregularity of the earth's surface, which can be a simple or complex, positive or negative, convex, or concave.

The main facilities include the following forms of earth relief: mountain, brand, hollow, ridge, saddle, ravine, canyon, plateau, valley and others. According to its genesis (origin), they may be tectonic, erosion, eologic, karst, anthropogenic, etc. on the scale, it is customary to allocate planetary, mega-macro, meso, micro- and relief nanoforms. The planetary (largest) includes continents and oceanic beds, geosyncline and mid-oceanic ridges.

One of the main tasks of geomorphologist scientists is to determine the age of certain form of relief. Moreover, this age can be both absolute and relative. In the first case, it is determined using a special geochronological scale. In the second case, it is established regarding the age of any other surface (it is appropriate to apply the words "younger" or "ancient").

The famous relief researcher V. Davis compared the process of its formation with human life. Accordingly, he highlighted four stages of development of any form of relief:

childhood;
youth;
maturity;
decrepitude.

How and why the relief of the Earth varies in time?

In our world, nothing is forever and not static. Similarly, the relief of the Earth varies over time. But it is almost impossible to notice these changes, because they last hundreds of thousands of years. True, they manifest themselves in earthquakes, volcanic activities and other earthly events that we used to call cataclysms.

The main root causes of relief formation (as, however, and any other processes on our planet) are the energy of the Sun, Earth, as well as space. Changing the relief of the earth is going on constantly. And the basis of any such changes is only two processes: denudation and accumulation. These processes are very closely interrelated, like the well-known principle of "Yin-Yan" in ancient Chinese philosophy.

Accumulation is the process of accumulating loose geological material on land or bottom of reservoirs. In turn, denudation is the process of destruction and transfer of the destroyed fragments of rocks into other parts of the earth's surface. And if the accumulation seeks to accumulate geological material, then the denunciation tries to destroy it.

The main factors relief formation

The drawing of the earth's surface is formed due to the continuous interaction of endogenous (internal) and exogenous (external) forces of the Earth. If you compare the process of relief formation with the construction of the building, then endogenous forces can be called "builders", and exogenous forces are "sculptors" of earth relief.

The internal (endogenous) forces of the Earth include volcanism, earthquakes and the movement of the earth's crust. The external (exogenous) is the work of wind, fluid water, glaciers, etc. The latter forces are engaged in a peculiar design of relief forms, sometimes giving them bizarre outlines.

In general, geomorphologists allocate only four relief factors:

internal energy of the Earth;
worldwide strength;
solar energy;
cosmos energy.

So far, we have considered internal relief factors, such as the movements of the earth's crust, folding formation, etc. These processes are due to the effect of the internal energy of the Earth. As a result, large form of relief are created, such as mountains and plains. At the lesson, you will learn how the relief was formed and continues to form under the influence of external geological processes.

Other strengths work on the destruction of rocks chemical. Leaking on cracks, water gradually dissolves rocks (See Fig. 3).

Fig. 3. Dissolving rocks

The dissolving capacity of water increases with the content of various gases in it. Some breeds (granite, sandstone) are not dissolved, others (limestone, gypsum) dissolve quite intensively. If water penetrates along cracks into the soluble rock layers, then these cracks are expanding. In those places where water-soluble rocks are close to the surface, it observes numerous failures, funnels and basins. it karst form relief(See Fig. 4).

Fig. 4. Karst Forms Relief

Karst - This is the process of dissolving rocks.

Karst form relief are developed on the Eastern European Plain, the priestly, the Urals and the Caucasus.

Mountain breeds can be collapped and as a result of the vital activity of living organisms (plants of stone and dr.). it biological weathering.

Simultaneously with the processes of destruction, the transfer of destruction products into low sections is, thus, the relief is smoothed.

Consider how a quaternary glaciation formed a modern relief of our country. Glaciers have been preserved to date only on the Arctic Islands and on the highest tops of Russia (See Fig. 5).

Fig. 5. Glaciers in the mountains of the Caucasus ()

Going along steep slopes, the glaciers form a special, ice Relief. Such a relief is common in Russia and where there are no modern glaciers, in the northern parts of the Eastern European and West Siberian plains. This is the result of an ancient glaciation, which arose in a quaternary era due to climate cooling (See Fig. 6).

Fig. 6. Territory of the ancient glaciers

The largest centers of glaciation at the time were the Scandinavian Mountains, Polar Urals, New Earth Islands, Mountains of the Taimyr Peninsula. The thickness of the ice on the Scandinavian and Kola Peninsula reached 3 kilometers.

The glaciation arose more than once. It was posted on the territory of our plains with several waves. Scientists believe that it was about 3-4 glaciations that were replaced by interledstial epochs. The last glacial period ended about 10 thousand years ago. The most significant was the glaciation on the Eastern European Plain, where the southern region of the glacier reached 48º-50º s. sh.

By the south, the amount of precipitation decreased, so in Western Siberia, the glaciation reached only 60º s. sh., and east of Yenisei because of a small amount of snow was even less.

In the centers of glaciation, from where the ancient glaciers moved, traces of activity in the form of special shapes of the relief - lambs were widespread. These are braids of rocks with scratches and scars on the surface (the slopes facing the movement of the glacier, gentle, and the opposite - cool) (See Fig. 7).

Fig. 7. Bariums Lob

Under the action of its own weight, the glaciers spread far from the center of their formation. On the path of their following, they smoothed the relief. A characteristic glacial relief is observed in Russia in the territory of the Kola Peninsula, Timan Kryaga, the Republic of Karelia. The moving glacier scraped the surface of soft loose rocks and even large, solid debris. Clear clay and hard rocks for ice mOREN (deposits of thresholds of rocks formed by glaciers when they move and melting). These breeds were postponed in more southern regions where the glacier melted. As a result, sea hills were formed and even whole naval plains - Valdai, Smolensko-Moscow.

Fig. 8. Education Moraine

When the climate has not changed for a long time, the glacier stopped in place and along its edge accumulated single moraine. In the relief, they are represented by curved rows of tens or sometimes even hundreds of kilometers, such as Northern Horses in the Eastern European Plain (See Fig. 8).

During the melting of glaciers, the flows of melt waters were formed, which were twisted by Morane, so in the areas of the spread of glacial hills and a variety, and especially along the edge of the glacier accumulated water-glacial injuries. Sand flat plains arising from the outstanding glacier, are called - zandrovy(from him. "Zunder" - Sand). Examples of Zandrovy Plains are Meshcherskaya Lowland, Vytnevolzhskaya, Vyatsko-Kamskaya Nizin (See Fig. 9).

Fig. 9. Education of Zandrovy Plains

Among the flat-lower hills are widespread water-glacial facilities, obs(from Swedish. "OZ" - Rud). These are narrow ridges, up to 30 meters high and a length of up to several tens of kilometers, in shape resembling railway mounds. They were formed as a result of settlement on the surface of loose nans formed on the surface of glaciers rivers (See Fig. 10).

Fig. 10. Education of Oz

All water flowing on land, under the action of gravity, also forms relief. Permanent watercourses - rivers - form river valleys. With temporary watercourses formed after heavy rains, the formation of ravines (See Fig. 11).

Fig. 11. Orag.

Ingust, ravine turns into beam. The most developed beam-oxide network has slopes of hills (Midnoesertskaya, Volga, etc.). Well-designed river valleys are characteristic of rivers flowing outside the boundaries of the last glaciation. Current waters not only destroy rock rocks, but also accumulate river seizures - pebbles, gravel, sand and illum (See Fig. 12).

Fig. 12. Accumulation of river applications

Of these, river floats, stretching strips along the river bed (See Fig. 13).

Fig. 13. The structure of the river valley

Sometimes the latitude of floodplains ranges from 1.5 to 60 km (for example, the Volga) and depends on the size of the rivers (see Fig. 14).

Fig. 14. Volga width in different areas

Along the river valleys, traditional places of settlement of people are located and a special type of economic activity is formed - animal husbandry on floodplain meadows.

On lowlands experiencing slow tectonic lowerings, extensive spills of rivers and wandering of their beds occur. As a result, plains built by river nanos are formed. The most common is such a relief in the south of Western Siberia (See Fig. 15).

Fig. 15. Western Siberia

There are two types of erosion - side and bottom. The deep erosion is aimed at cutting streams into depth and prevails at the mountain rivers and plane rivers, which is why deep river valleys are formed here with steep slopes. Side erosion is aimed at blurring the shores and is characteristic of plain rivers. Speaking about the effects of water on the relief, the exposure to the sea can be considered. At the occurrence of the seas on the flooded land, sedimentary rocks accumulate horizontal layers. The surface of the plains, from which the sea retreated a long time ago, is strongly changed by flowing waters, wind, glaciers (See Fig. 16).

Fig. 16. Reception of the sea

Plains, relatively recently abandoned by the sea, have a relatively flat relief. In Russia, this is the Caspian lowland, as well as many plain areas along the coast of the Northern Ocean, part of the lowland plains of the Precocalism.

Wind activity also creates certain form of relief, which were called eoloic. The eoloid form of relief is formed on open spaces. In such conditions, the wind transfers a large amount of sand and dust. Often, a small bush is a sufficient obstacle, the wind speed is reduced, and the sand falls to the ground. So it is formed at first small, and then the large sandy hills - verakhans and dunes. In Plan, Barhahan has the shape of a crescent, and with its convex side, he addressed the wind. With a change in the direction of the wind, the orientation of the vehana is changing. Relief shapes associated with wind are distributed mainly on the Caspian lowland (vegana), on the Baltic coast (dunes) (See Fig. 17).

Fig. 17. Education of Barhana

Many small fragments and sand wind blows off the bare mountain peaks. Many grains endowed with them again hit the rocks and contribute to their destruction. You can observe bizarre weathered figures - ostasy(See Fig. 18).

Fig. 18. Rests - Fancy Forms of Relief

The formation of special breeds is connected with the wind activity - Lesov. - This is loose, porous, dust breed (See Fig. 19).

Fig. 19. Les

The forest is covered with large areas in the southern parts of the Eastern European and West Siberian plains, as well as in the Lena River basin, where there were no ancient glaciers (See Fig. 20).

Fig. 20. The territories of Russia covered with Loeos (shown in yellow)

It is believed that the formation of Loeza is associated with the vowing of dust and strong winds. The most fertile soils are formed on LOE, but it is easily blurred by water and the deepest ravines appear in it.

The formation of the relief occurs under the influence of both external and internal forces.
Internal forces create large form of relief, and the external forces destroy them, transforming into smaller.
Under the action of external forces is carried out both destructive and creative work.

Bibliography

Geography of Russia. Nature. Population. 1 half. Grade 8 / V.P. Dronov, I.I. Barinova, V.Ya Rom, A.A. Lobzhanidze.
VB Fifteenth, E.A. Customs. Geography of Russia. Nature. Population. 8th grade.
Atlas. Geography of Russia. Population and economy. - M.: Drop, 2012.
V.P. Dronov, L.E Savelyev. UMC (educational and methodical kit) "spheres". Tutorial "Russia: Nature, population, economy. 8th grade". Atlas.

The effect of internal and external processes on the formation of relief ().
External forces, changing relief. Weathering. ().
Weathered ().
Alession in Russia ().
Physics of vegans, or how sandy waves are formed ().

Homework

Is the statement true: "Weathered is the process of destruction of rocks under the influence of wind"?
Under the influence of what forces (external or internal) vertices of the Caucasian Mountains and Altai acquired a pointed form?

From the very beginning of the discussion of the problem of the formation of the globe, precisely the mountains embarrassed scientists. Because if we assume that first the earth was a fiery, molten ball, then its surface after cooling should remain more or less smooth ... well, it may be slightly rough. And where did the high mountain ranges and the deepest depressions in the oceans come from?

In the 19th century, the predominant idea was the idea that from time to time for some reason, a hot magma from within the attack goes to a stone shell and then the mountains are swept away and the ridges rose. Rise? But why then on the surface so many districts, where the ridges go parallel folds one beetroot? In the swelling, each mining area should have the form of the dome or bubble ... to explain the occurrence of folded mountains by the action of the vertical forces coming from the subsoil, failed. Folds demanded horizontal efforts.

Now take an apple in your hand. Let it be a small, slightly tested apple. Scroll it in your hands. See how the skin wrinkled, it was covered with small folds. And imagine that the apple is the size of the ground. Folding will grow and turn into the high mountain ranges ... What power could be so surviving the land so that it covered with folds?

You know that every red-hot body is compressed when cooled. Maybe this mechanism is suitable for explaining the folded mountains on the globe? Imagine - the molten land cooled and covered with a crust. Cork or bark, like a stone dress, turned out to be "stitched" to a certain size. But the planet is cooled further. And it cools, it is compressed. No wonder that over time, the stone shirt turned out to be great, began to swell, go folds.

Such a process suggested to explain the formation of the surface of the Earth, the French scientist Eli de Bomon. He called his contraction hypothesis from the word "contract", which translated from Latin just indicated - compression. One Swiss geologist tried to calculate what the sizes of the globe were, if smooth out all the folded mountains. It turned out a very impressive value. The radius of our planet would increase almost sixty kilometers!

The new hypothesis acquired many supporters. The most famous scientists supported it. They were deepened and developed separate sections, turning the assumption of the French geologist into a single science on the development, movement and deformation of the earth's crust. In 1860, this science, which became the most important section of the complex of the earth science, was offered to be called geotectonic. We will also come further to call this important section as well.

The hypothesis of contracts or compression of the Earth and wrinkling its bark was particularly strengthened when large "heads" opened in the Alps and Appalach. This term geologists indicate gaps in the occurring rocks, when some of them are as if driven to others. Specialists triumphed, the new hypothesis explained everything!

True, a small question arose: why the folds of the folds were located not all over the entire surface of the earth evenly, as on a wrinkled, having fun apple, but were going to the mountain belt? And why did these belts be located only according to certain parallels and meridians? The question is trifling, but cunning. Because the contract hypothesis could not answer him.

Deep roots mountains

In about the middle of the XIX century, or rather in 1855, the English scientist D. Pratt led the geodesic work on the territory of the "Pearl of the British Crown", that is, in India. He worked near the Himalayas. Every day, waking up in the morning, the Englishman admired the majestic spectacle of the Grand Mountain Area and unwittingly thought: how much can this colossal mountain range weigh? His mass must certainly have a noticeable force of attraction. How to find out? Stop, but if so, then the impressive mass should reject the light weight on the thread from the vertical. The vertical is the direction of gravity of the Earth, and the deviation is the direction of the attraction of Himalayas ...

Pratt immediately figured the total mass of the mountain range. It turned out really a decent value. According to it, using Newton's law, he calculated the expected deviation. Then, not far from the slopes of the mountains suspended the load on the thread and with the help of astronomical observations, its true deviation was measured. What was the disappointment of a scientist when, when comparing the results it turned out that the theory differs from practice more than five times. The calculated angle turned out to be more measured.

Pratt could not be in a sense, what is his mistake. He turned to the hypothesis, which was once launched by Leonardo da Vinci. The great Italian scientist and engineer suggested that the earth's crust and melted subcortex layer were almost everywhere in equilibrium. That is, the bark blocks float on a heavy melt like ice floes on the water. And since, at the same time, part of the "icemines" -lines is immersed in the melt, then in general blocks are easier than taken when calculating. After all, who does not know that the iceberg has only a smaller part protrudes over the water, and large - immersed ...

Pratta J. Erie's compatriot added their considerations to his arguments. "The density of rocks is about the same, he said. - But higher and powerful mountains stand, plunging deeper into the mantle. Less high mountains are smaller. " It turned out that the mountains would be root. Moreover, the root part turned out to be folded from less dense rocks, compared with the density of the mantle.

A good hypothesis turned out. For a long time, they used it scientists when measuring gravity in different parts of the Earth. Until then, the artificial satellites of the earth did not fly over the planet - the most faithful signs and field recorders of the attraction. But they are still ahead.

At the end of the last century, the American geologist Dutton expressed the idea that the highest and powerful blocks of the earth's crust are blurred with rains and flowing waters stronger than low, and therefore they should become easier and gradually "pop up". Meanwhile, sediments are applied to lighter and low blocks from top neighbors, and they are heavy. And if you are heavy, then they are immersed. Is this the process of one of the possible causes of earthquakes in the mountains and new skills? ..

A lot of interesting hypotheses nominated scientists of the end of the last century. But hardly the most fruitful of them was the creation of teachings on geosynclinal and platforms.

Geosyncline specialists call rather extensive stretched sections of the earth's crust, where earthquakes and volcanic eruptions are particularly often observed. The relief in these places is usually such that, as they say, "the hell himself will leak" - a fold on the fold.

Back in 1859, the American geologist J. Hall noticed that in the mining and folded areas of the precipitation is much thicker than in those places where breeds are calm horizontal formations. Why is that? Maybe under the severity of accumulated sediments, washed off from neighboring mountains, the land of the Earth flashed? ..

The expectation entertained. And a few years later, the colleague Hall James Dana developed the views of his predecessor. He called the elongated crops of the bark caused by side compression (then the hypothesis of contracts had already dominated), geosynclinal. A difficult term occurred from the association of three Greek words: "GE" - Earth, "Sin" - together and "Klin" - to tilt.

James Dana imagined this process as follows: First, the compressed area begins. Then the layers are frozen and extinguished in the form of a mountain fold.

Not all geologists immediately agreed with the opinion of the American specialist. Other paintings of geosynklinal development were also offered. The dispute about them does not subscribe for more than a hundred years. Some believe that a preheated subcortical substance is divided into heavy and light fractions. Heavy "drown", squeezing the upstairs lighter. They rise, "pop up" and plowed, tear the lithosphere. Then the wreckage of heavy slabs sculp and froze sediment layers ...

Others offer a different mechanism. They believe that there are slow flows in the declined subcortical substance. They are delayed, seminate sediments. And being in depth, these breeds are integrated under the action of pressures and high temperatures.

There are other concepts. According to one of them, for example, geosynclinal folds arise along the edges of continental platforms floating as ice floes in the ocean, on a plastic subcortical substance. Unfortunately, so far, none of the existing proposals on this account fully satisfies the naturalities observed in nature. And therefore the dispute seems to be far from its completion.

An outstanding Russian and Soviet geologist, a public figure Alexander Petrovich Karpinsky was born in 1846, in the village of Trician mines in the Verkhtursky county in the Urals. Now it is a city that has been his name. His father was mountainous / and an engineer, and therefore it was not surprising that the young man at the end of the gymnasium entered the famous St. Petersburg Mountain Institute.

At thirty-one, Alexander Petrovich became a professor of geology. And in nine years he was elected by a member of the Imperial Academy of Sciences.

He explores the structure and mineral resources of the Urals and constitutes consolidated geological maps of the European part of Russia. Starting from petrography - science on the composition and origin of rocks, Karpinsky concerns all literally sections of the science of land and everywhere leaves a noticeable trace. He explores fossil organisms. Writes outstanding work on the tectonics and the geological past of the Earth - on Paleogeography.

The doctrine of geosyncline, despite the progressive ideas in its basis, experienced many difficulties at the first stage. And at that time, Alexander Petrovich came to the study of the "calm areas" of the earth's surface. Subsequently, they were called "platforms". In these works, Karpinsky summarized a huge material on the geology of Russia, accumulated by generations of Russian geologists. He showed how the outlines of the ancient seas changed, filled these areas at different times. And brought two kinds of "wave-like-oscillatory movements" of the earth's crust. One, more ambitious, forms oceanic depressions and mainland raising. Another, not so majestic on scale, ensures the appearance of depressions and convexities within the platform itself. For example, the local fluctuations of the Russian platform, according to Karpinsky, took place in parallel to the Ural ridge in the meridional direction and in parallel to the Caucasus - by parallel.

Lithosphere and dangerous phenomena of nature

The life and health of the person is largely related to those processes that occur in the lithosphere. The economic activity of people depends on them. A significant part of these processes occurs under the influence of the forces of nature and is spontaneous

Natural processes and phenomena of nature are divided into two groups:

Earthquakes and volcanism caused by the internal energy of the Earth;
Owls, villages, landslides, screaming, which are a consequence of the forces of earthly attraction.

Earthquake belong to the most dangerous and unpredictable natural phenomenon. Within Russia, strong and frequent earthquakes are characteristic of Kamchatka, Sakhalin Islands, Kuril Islands. The last on the island of Sakhalin the destructive earthquake occurred at $ 1995. The tragic result of the earthquake was the death of $ 2000 $ inhabitants and the destroyed village of Oilnikov - Neftegorsk. Such mountain areas of Russia as the Caucasus, Altai, Sayan, Mountains of Baikalia and Transbaikalia are also dangerous from the point of view of the occurrence of earthquakes. Seismic in Russia is considered $ 40 $% of the territory, including $ 20 $% of mountain areas.

Volcanic activity No less large-scale on its manifestations. All volcanoes of the country are concentrated on Kamchatka and Kuril Islands. Of the $ 160 $ \u200b\u200bof volcanoes of Russia, $ 40 $ volcanoes are located on the Kuril Islands. The acting volcanoes of Kamchatka-Kuril Ridge are Karamskaya Natka, Klyuchevskaya Natka, Mutnovsky volcano, Volcano Shivech, Volcanoes Kizenimen, Unnamed, Berg, Sarychev. The gases and volcanic dust pillars rise to the atmosphere of $ 10 $ - $ 20 $ km and gradually settle on the surrounding area.

With the distribution areas of volcanoes are associated with hot sources and geysers. Hot underground water can be used for the heating of residential buildings and to generate electrical energy. For example, an experimental geothermal power plant is operating in Kamchatka - Pozhetskaya.

Scree and ribs Associated with mountain areas where the relief is very crossed. Destroyed rocks under the action of gravity are falling down, while moving exciting new debris. Most often, their cause is the activity of fluid water or underground shocks. In mountainous areas often arise seli.. This is a mixture of dirt, clay, stone formed during the period of protracted rains and soaked loose material of the mountains of the mountains, rapidly descends down. Sel moves with a speed of several meters per second and on its way can demolish the dam, the bridge, village. They destroy the crops and destroy the roads. Caucasus and Altai more often than other mountain areas are found with these phenomena.

Such a phenomenon is known as landslide. It is formed under the condition of alternating aquifer and waterproof rocks. In this case, the upper layers slide down the slippery waterproof, forming a landslide. The landslides are found on the Volga and in general on the steep shores of the banks, lakes, seas.

Direct impact of man on relief

Relief area form not only external and internal factors, but also the economic activity of man. As a result of this activity, anthropogenic forms are formed.

Definition 1.

Anthropogenic Relief is the form of relief modified or newly created people's activities.

The most influence on the relief has such activities as mining of minerals, launching roads, construction of underground structures and communications, the development of rural and forestry. As a result, there is a violation of the integrity of rocks and sedimentation of the earth's surface and, as a result, the destruction of buildings and industrial structures. In some places, anthropogenic earthquakes appear - this is usually associated with the extraction of a large amount of minerals from the bowels. Such earthquakes can be observed in the priestly and in the south of Western Siberia. Mining mining leads to the appearance of quarries, mines, hotcocks.

Definition 2.

Tercons - These are dumps from spent rocks that resemble low mountains.

Many exhaust industrial dumps are dangerous to health people. Most of all, such land falls on the Kuznetsky coal pool, a number of districts of the Far East, Southern Siberia are those areas where mining is in the open way. Anthropogenic form of relief occurs during the fence of artesian waters and under the underground work. They may have failed funnels quite large depth and diameter. Such funnels are celebrated in Moscow, their depth comes to $ 4 $-m, and a diameter of $ 40 $ m. Similar funnels in Kuzbass reach depth of $ 70 $ M. Overview and soil erosion are an example of improper agriculture, when the territory is intensive Natural vegetation is reduced.

Note 1.

Human economic activity, therefore, takes an active part and strongly changes the relief. Along with the natural shapes of the relief today there are artificial ones - these are structures, buildings, dams, bridges, tunnels. Formed multi-kilometer zones of solid settlement. Created by man artificial forms change the surface of the earth, influence the climate and surface flow of water.

Indirect human influence on relief

Impace the formation of the relief person can also indirectly. It is in intentional or unplanned change in the conditions of morphogenesis, strengthening or slowing down the natural processes of denudation and accumulation. The result is reinforced soil erosion, anthropogenic oral formation. Drainage of the marshes leads to a change in the relief of their surface. Unlimited grazing of livestock, and road degression enhance deflation and revitalize the dynamics of the accumulative sandy eolic forms of relief. In the areas of military operations, specific forms of microrelief and meso-relief are arising - these are trenches and trenches, defensive shafts, bomb funnels.

Conscious and unconscious actions are accepted in conditions of some uncertainty, and any particular situation leads to risk in one form or another. The human action carried out on the border of the stability of a natural or natural-anthropogenic geomorphological system leads to geomorphological risk. The risk is generated by the presence and feeling of danger, which comes from a geomorphological object and is associated with the active actions and operation of the danger entity - by a person. To this end, environmental geomorphology develops a system of principles and methods that allow you to identify dangerous geomorphological processes and objects, make a forecast for their development in order to reduce the degree and cost of risk.

Natural natural natural processes are often technologically predefined. For example, cutting down forests in mountainous areas activates the processes of formation of landslides and the villages. Recently, there is a strengthening of fluivinal-glycial and gravitational processes, which are formed as a result of the development of high-mountain meadows. The frequency of snowy avalanches in the high mountains increases, inflicting considerable damage. Mountain roads, bridges, buildings, etc. are usually dangerous from an ecological point of view, they suddenly occur. Experts, exploring their emergence and development, identified a number of important indicators factors, which make it possible to make a forecast for the further course of their development. Their connection is not viewed not so much with natural or anthropogenic factors, as with the simultaneous influence and activities of the population in places that are subject to these phenomena.

Note 2.

To predict the development of exogenous processes, remote sensing methods are most effective, which increase the objectivity of the geographical forecast and improve the quality of the material obtained. And this already makes it possible to judge the nature and strength of exogenous processes in the near future.

Geography is a science that studies the geographical shell of the Earth, as well as this science of earthly relief. The relief is this constantly changing shape of the earth's surface or a set of irregularities of the earth's surface, differing in origin, size and age. For millions of years, the history of the Earth under the influence of different forces where the mountains stood, the plains appeared, and where there were plains, there were high active volcanoes.

There is a direct relationship between the relief of the Earth and the structure of the lithosphere. So mountains were formed at the joints of lithospheric plates, and in the centers of plains.

Forms of relief or morphostructure

There are such large and small form of relief, as

continents - the largest forms; Scientists believe that once only one mainland was, the gradual separation of which led to the modern type of land;
oceanic depressions - also the large form of the earth relief, which is formed due to the movement of lithospheric plates; It is believed that once the oceans on Earth were less, and after hundreds of thousands of years the situation will change again, perhaps some parts of the sushi will be flooded with water;
the mountains - the most ambitious forms of earthly relief, reaching a grand height, mountains can form the chains of the mountains;
highlands - Separate mountains and ridge systems, such as Pamir or Tien Shan;
shelf - Sushi plots, completely hidden under water;
plains - The maximum flat ground surface, the best place for a person's life.

Figure 1. Earth relief

Such forms have a definite name - morphostructure. Scientists distinguish such types of morphostructures as planetary and regional, which appeared later. Tectonic movements participated in their development, and on their background there were movements of the top horizons of the lithosphere.

Causes of the transformation of the earth's surface

Changes in land relief occurs for various reasons. Transformation can be used as internal and external forces.

External forces affect the earthly relief not as much as internal.

Domestic powers

Age of relief

The time passed since the formation of the modern appearance of the Earth is called the age of relief. It may be years, hundreds, thousands, millions of years. The age of large embossed forms can withdraw from 200 to 90 million years. In addition to age, there are also numerical characteristics of the surface of the relief.

What did we know?

Earth relief is distinguished by a large variety, complexity and incredible morphostructures. Why land relief is very diverse? There are large and small irregularities that occur under the influence of internal and external forces. Transformation and changes occur slowly, gradually, one human life is not enough to notice all the changes that have happened. The earth's surface seems to be breathing, it is lowered, it rises, and sometimes it simply bursts from the stress arising. Thus, the development of land relief occurs at the present time.

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Process	Example	Manifestation in relief	Essence of the process
Weathering	Figure 2. Weathered	formation of fuse
Wind power	Figure 3. Wind power	education of vegans and dunes	transfer rocks and loose deposits
Power of water	Figure 4. Power of water	destruction of rocks	transfer and blurring rocks
Melting glaciers	Figure 5. Melting of glaciers	changes in the outline of the mainland	increased water volume in the World Ocean