• Lowland - a plain that rises no higher than 200 m above sea level.
• Uplands are flat land areas with a height of 200 to 500 meters above sea level.
• A plateau is a plain with a flat or slightly wavy surface, raised above sea level by more than 500 meters.

Accumulation

Raising the seabed

Alteration of plains by water flows

Just like the mountains, the plains are gradually changing. They do a lot of work water streams, both permanent (rivers) and temporary, which form on the slopes after heavy rains or during the spring melting of snow.

Each tributary of the river pulls out a valley for itself, along which it flows, each tributary erodes the banks, deepens, albeit slowly, its channel. The erosion process is especially fast on the hills and plateaus, since the rivers originating from them have a more rapid flow.

The water flowing down the surface washes away the upper, arable layer of the soil from the fields, along with the nutrients that plants need so much. The washout occurs especially quickly on steep slopes not covered with vegetation; that's why steep slopes are not plowed up. Slopes with a slight slope should be plowed only across. When plowing a slope laterally, the flowing water is trapped by furrows, absorbed into the ground and does not wash away the soil. Thus, millions of hectares of fertile soil are saved from erosion. Material from the site

Plains change under the influence of wind

Winds sweeping over the plains do a lot of destructive work. It so happens that hurricane force winds blow over the plains for several days in a row, without ceasing. A dust storm begins. In one such storm, the wind can blow away a layer of soil up to 25 cm thick, and previously fertile lands turn into barren wastelands.

Grass strips that form at regular intervals in the fields, as well as forest strips, reduce soil blowing.

Particularly great work is done by the wind on plains covered with loose sands, not fastened by plant roots - dunes and dunes. The open space of sand is never even.

Question 1. How are the irregularities of the earth's surface indicated on a geographical map?

To indicate absolute heights on plans and maps, horizontals are used - conditional lines connecting points with the same absolute height. The direction of the slope decline is shown by short dashes - bergstrokes. The absolute heights of the tops of hills or mountains are shown on plans and maps as a number with a dot. On physical geographic maps, for greater clarity, colors of intervals between contours are used to indicate heights and depths. For the heights of land use shades of green, yellow and brown, for the depths of the ocean - shades of blue. The colors that denote depths and heights are placed next to the map frame and called the scale of heights and depths.

Question 2. What is absolute height?

Absolute height - the height of any point on the earth's surface above ocean level.

Question 3. What forces are involved in the formation of the roughness of the earth's surface?

The formation and development of landforms is actively influenced by two groups of forces: one is the internal forces of the Earth, the main reason for the emergence of which is due to the deep processes of our planet, the other is external forces arising under the influence of the thermal energy of the Sun.

Question 4. Are all the irregularities of the earth's surface landforms?

Yes. Landforms are specific irregularities of the earth's surface, which are a surface that encloses a three-dimensional volumetric body and consists of relief elements or simpler relief forms. Landforms can be simple and complex, positive and negative, open and closed.

Question 5. What is relief?

Relief is all the irregularities of the earth's surface that have different sizes, shapes, origins and are formed as a result of the simultaneous action of internal and external forces. Irregularities in the earth's surface are called landforms.

Question 6. Give definitions to the following concepts: mountains, plains, lowlands, hills, plateaus.

Mountains are highly elevated landforms, within which significant differences in altitude are observed. Plains are called vast areas of the Earth's surface with small elevation differences (less than 200 m), that is, equal. They can vary in surface nature, that is, be flat and hilly. The lowest plains are called lowlands. The higher plains are called highlands. Their height above sea level ranges from 200 to 500 m. The most elevated plains are called plateaus.

Question 7. Which mountains are the tallest on Earth?

The highest mountains on the planet are the Himalayas, located north of the Indian subcontinent. In this huge mountain range, 13 peaks are more than 8 km high.

Question 8. What are mid-ocean ridges?

Mid-ocean ridges are huge and very complex mountain ranges stretching for tens of thousands of kilometers.

Question 9. How do internal and external forces influence the formation of the relief of our planet?

Internal and external forces are slowly but constantly transforming the relief of the planet. Thanks to them, mountains, plains, lowlands, hills, plateaus are formed.

Question 10. How are mountains different from plains?

Mountains are huge, highly rugged areas of the earth's surface that are elevated above the surrounding area. Plains are huge, fairly flat areas of the earth's surface, which are characterized by a slight fluctuation in relative heights.

Question 11. Why does the topography of the ocean floor differ from the topography of the land surface?

Because the ocean floor is less exposed to external forces, its topography is mainly influenced by only deep forces.

Question 12. How is the mid-ocean ridge different from the mountains of the land?

In the mountain ranges of the land there are no rift valleys, as in the oceanic ones, since they were formed mainly as a result of the collision of plates, and not their separation. In such a collision, the sedimentary layers are compressed and in the form of huge folds bulge up or sag down, forming mountains and valleys. For the same reason, the mountain ranges of the land are not cut by transform faults, like the ridges of the ocean.

Question 13. Using a physical map of the world, write down the names of landforms by filling out the table.

Plain is one of the main forms of terrestrial relief. On the physical world map, the plains are indicated in three colors: green, yellow, and light brown. They occupy about 60% of the entire surface of our planet. The most extensive plains are confined to plates and platforms.

Characteristics of the plains

A plain is an area of \u200b\u200bland or the seabed with a slight fluctuation in heights (up to 200 m) and a slight slope (up to 5º). They meet at different heights, including at the bottom of the oceans.

A distinctive feature of the plains is a clear, open horizon line, straight or wavy, depending on the surface relief.

Another feature is that it is the plains that are the main territories inhabited by people.

Natural areas of the plains

Since the plains occupy a vast territory, there are practically all natural zones. For example, tundra, taiga, mixed and deciduous forests, steppes and semi-deserts are represented on the East European Plain. Most The Amazonian lowlands are occupied by selva, and the plains of Australia are semi-deserts and savannahs.

Plains

In geography, the plains are divided according to several criteria.

1. By absolute height distinguish between:

... vile ... The height above sea level does not exceed 200m. A striking example is the West Siberian Plain.

... Exalted - with a difference in height from 200 to 500 m above sea level. For example, the Central Russian Plain.

... High plains , whose level is measured by marks over 500 m. For example, the Iranian Highlands.

... Depressions - the highest point is below sea level. Example - Caspian lowland.

Separately, underwater plains are distinguished, which include the bottom of depressions, shelves and abyssal areas.

2. By origin plains are:

... Accumulative (sea, river and mainland) - formed as a result of the impact of rivers, ebb and flow. Their surface is covered with alluvial sediments, and in the sea - marine, river and glacial sediments. From the sea can be cited as an example the West Siberian Lowland, and from the river - the Amazon. Among the mainland, the accumulative plains include the marginal lowlands, which have a slight slope to the sea.

... Abrasive - formed as a result of the impact of surf on land. In areas dominated by strong winds, sea waves are frequent, and the coastline is formed of weak rocks, more often this type of plains is formed.

... Structural - the most difficult in origin. Mountains once stood in the place of such plains. As a result of volcanic activity and earthquakes, the mountains were destroyed. Magma flowing from cracks and splits bound the land surface, like armor, hiding all the unevenness of the relief.

... Lakes - are formed in the place of dried up lakes. Such plains are usually small in area and are often bordered by coastal ramparts and ledges. An example of a lake plain is Jalanash and Kegen in Kazakhstan.

3. By the type of relief distinguish between plains:

... flat or horizontal - The Great Chinese and West Siberian Plains.

... wavy - are formed under the influence of water and water-glacial flows. For example, the Central Russian Upland

... hilly - in the relief there are individual hills, hills, ravines. An example is the East European Plain.

... stepped - formed under the influence internal forces Earth. Example - Central Siberian Plateau

... concave - they include the plains of intermontane depressions. For example, the Tsaidam Basin.

Ridge and ridge plains are also distinguished. But in nature, the mixed type is most often found. For example, the Pribelskaya rolling-undulating plain in Bashkortostan.

Plains climate

The climate of the plains is formed depending on its geographical location, the proximity of the ocean, the area of \u200b\u200bthe plain itself, its length from north to south, as well as climatic zone... Free movement of cyclones provides a clear change of seasons. The plains are often rich in rivers and lakes, which contribute to the formation of climatic conditions.

The largest plains in the world

Plains are common on all continents, with the exception of Antarctica. In Eurasia, the largest are the East European, West Siberian, Turan, and East Chinese plains. In Africa - the East African Plateau, In North America - the Mississippi, Great, Mexican, in South America - The Amazonian lowland (the largest in the world, its area is over 5 million square kilometers) and the Guiana Plateau.

section: Lithosphere Final test

1. The shell of the Earth, including the earth's crust and upper mantle, is called:

a) thermosphere;

b) the asthenosphere;

c) lithosphere .

2. It consists of solid materials and rocks:

a) mantle;

c) the earth's crust .

3. Igneous rocks were formed as a result of:

b) lava solidification;

c) destruction of solid rocks;

^ 4. On the Earth's surface above the earthquake source is located:

a) volcano;

b) a geyser;

c) crater;

d) epicenter.

5. Plains located at an altitude of 200 to 500 m above sea level are called ...

A) lowlands

B) hills

B) plateaus

^ 6. Rocks that have undergone changes under the influence of high pressure and high temperature during the subsidence of parts of the earth's crust are called ...

a) metamorphic rocks

b) igneous rocks

c) clastic rocks

d) organic rocks

^ 7. Tremors with oscillatory movements arising from sudden displacements and ruptures in the earth's crust and mantle are called

a) volcanoes

b) earthquakes

c) tsunami

^ 8. Indicate the number in the figure indicating the magma chamber.

9. A fountain of hot water and steam is called

a) a spring

B) lava

B) a geyser

d) key

^ 10. Establish the correspondence of concepts and their definitions.

^ 11. The inner shell of the Earth is called:

A) the core;

B) the asthenosphere;

C) the lithosphere.

12. Thickness of the earth's crust under the ocean:

B) 15-100 km;

B) 10-60 km.

^ 13. Sedimentary rocks were formed as a result of:

A) the accumulation of animal residues;

B) lava solidification;

C) destruction of solid rocks;

D) pressure increase and high temperatures at great depths.

^ 14. The section of the earth's crust, along which magma rises:

A) volcano;

B) mouth;

B) crater;

D) epicenter .

15. Read and make the correct conclusion.

“The road went up and down. On the sides of the road, streams ran merrily in numerous ravines. "
This road passed ...

A) on a mountainous country b) flat plain

C) hilly plain d) the bottom of the gorge

^ 16. An elevated plain with a special relief, with an absolute height exceeding 500 m, is called ...

A) lowland b) plateau

B) upland

^ 17. What color are the mountains painted on the physical map:

A) blue;

B) green;

B) brown.

18. Volcanoes that erupt more or less regularly are called ... ..

A) sleeping

B) acting

C) extinct

^ 19. The igneous rocks include:

A) hard coal; c) marble;

B) granite; d) sandstone.

20. Metamorphic rocks include:

B) quartz;

B) basalt;

D) clay.

21. The epicenter of an earthquake is:

A) the area of \u200b\u200bthe earthquake;

B) the focus of the earthquake;

C) a point on the surface of the Earth located
over the source of the earthquake.

22. ^ The crossing of several mountain ranges is called

A) mountain knot

B) mountainous country

B) mountain range

23... Mountains with heights from 1000 to 2000 m are called

A) low

B) medium

B) high

24. ^ The change in rocks under the influence of external forces is called

A) erosion

B) earthquake

C) weathering

25.Earthquake recorder

A) seismologist

B) seismograph

C) seismology

Answers