The relief of the earth's surface is the main forms of relief. Basic landforms

Relief. Basic landforms.

relief called a set of irregularities of the land, the bottom of the oceans and seas, diverse in shape, size, origin, age of the history of development.

The main landforms are

Mountain - it's towering over surrounding area cone-shaped relief. Its highest point is called the top. The top can be sharp - a peak or in the form of a platform - a plateau. Side surface consists of slopes. The line of slopes with the surrounding terrain is called the sole or base of the mountain.

Basin - landform opposite to the mountain, which is a closed depression. The most low point her bottom. The side surface consists of slopes; line of their confluence with environment locality is called a brow.

Ridge - it is a hill, elongated and constantly lowering in any direction. The ridge has two slopes; in the upper part of the ridge they merge, forming a watershed line, or watershed.

Hollow - a relief form opposite to a ridge and representing a constantly lowering recess elongated in some direction and open at one end. Two slopes of the hollow, merging with each other in the lowest part of it, form a spillway or thalweg, along which water flows down, falling on the slopes. The varieties of the hollow are the valley and the ravine.

saddle - this is a place that is formed by the confluence of the slopes of two neighboring mountains. Sometimes a saddle is the confluence of the watersheds of two ranges. Two hollows originate from the saddle, spreading in opposite directions. In mountainous areas, roads or hiking trails usually run through saddles, so saddles in the mountains are called passes.

Representation of relief on plans and maps.

For solutions engineering tasks the image of the relief should provide: firstly, a quick determination with the required accuracy of the heights of the points of the terrain, the direction of the steepness of the slopes and the slopes of the lines; secondly, a visual display of the actual landscape of the area.

The terrain on the plans and maps depict different ways(hatching, dotted line, colored plastic), but most often with the help of horizontal lines (isohypses), numerical marks and conventional signs.

A curved line connecting all points of the terrain with equal marks is called horizontal.

When solving a number of engineering problems, it is necessary to know the properties of contour lines:

1. All points of the terrain lying on the horizontal have equal marks.

2. Contours cannot intersect on the plan because they lie at different heights. Exceptions are possible in mountainous areas, when an overhanging cliff is depicted as contour lines.

3. Contours are continuous lines. Contours interrupted at the frame of the plan are closed outside the plan.

4. The distance between horizontal cutting planes is called relief section height and is marked with the letter h.

5. The distance between adjacent contour lines on a plan or map is called slope laying or slope.

Another characteristic of the steepness is the slope i. The slope of the terrain line is the ratio of elevation to horizontal distance. The slope is a dimensionless quantity.

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Lesson questions:

1. Types and forms of terrain. The essence of the image of the relief on the maps by contour lines. Types of horizontals. Image by contour lines of typical landforms.

1.1 Types and forms of terrain.
In military affairs terrain understand the area of the earth's surface on which to conduct hostilities. The unevenness of the earth's surface is called terrain, and all objects located on it, created by nature or human labor (rivers, settlements, roads, etc.) - local items.
The relief and local objects are the main topographical elements of the terrain that affect the organization and conduct of combat, the use of military equipment in combat, the conditions for observation, firing, orientation, camouflage and maneuverability, i.e., determining its tactical properties.
A topographic map is an accurate display of all the most tactically important elements of the terrain, plotted in a mutually exact location relative to each other. It makes it possible to explore any territory in a relatively short time. Preliminary study of the terrain and decision-making for the performance of a particular combat mission by a subunit (unit, formation) is usually carried out on a map, and then refined on the ground.
The terrain, influencing combat operations, in one case can contribute to the success of the troops, and in the other have a negative effect. Combat practice convincingly shows that one and the same terrain can give more advantages to those who study it better and use it more skillfully.
According to the nature of the relief, the area is divided into flat, hilly and mountainous.
flat terrain characterized by small (up to 25 m) relative elevations and a relatively small (up to 2 °) steepness of slopes. Absolute heights are usually small (up to 300 m) (Fig. 1).

The tactical properties of flat terrain depend mainly on the soil and vegetation cover and on the degree of ruggedness. Clayey, loamy, sandy loamy, peaty soils allow the unhindered movement of military equipment in dry weather and significantly impede movement during the rainy season, spring and autumn thaws. It can be indented by riverbeds, ravines and gullies, have many lakes and marshes, which significantly limit the ability to maneuver troops and reduce the rate of advance (Fig. 2).
Flat terrain is usually more favorable for the organization and conduct of an offensive and less favorable for defense.

hilly area characterized by a wavy nature of the earth's surface, forming irregularities (hills) with absolute heights up to 500 m, relative elevations of 25 - 200 m and a prevailing steepness of 2-3 ° (Fig. 3, 4). The hills are usually composed of hard rocks, their tops and slopes are covered with a thick layer of loose rocks. The depressions between the hills are wide, flat or closed basins.

Hilly terrain provides movement and deployment of troops hidden from enemy ground observation, facilitates the choice of places for firing positions missile troops and artillery, provides good conditions for the concentration of troops and military equipment. In general, it is favorable both for the offensive and for defense.
Mountain landscape represents areas of the earth's surface that are significantly elevated above the surrounding area (having absolute heights of 500 m or more) (Fig. 5). It is distinguished by a complex and varied relief, specific natural conditions. The main landforms are mountains and mountain ranges with steep slopes, often turning into rocks and rocky cliffs, as well as hollows and gorges located between mountain ranges. The mountainous area is characterized by a sharp ruggedness of the relief, the presence of hard-to-reach areas, a sparse network of roads, a limited number of settlements, rapid flow of rivers with sharp fluctuations in water levels, a variety climatic conditions, the predominance of rocky soils.
fighting in mountainous areas are considered as actions in special conditions. Troops often have to use mountain passes; observation and firing, orientation and target designation are difficult, at the same time it contributes to the secrecy of the location and movement of troops, facilitates the setting up of ambushes and engineering barriers, and the organization of camouflage.

1.2 The essence of the image of the relief on maps by contour lines.
The relief is essential element terrain that determines its tactical properties.
Relief image on topographic maps gives a complete and sufficiently detailed idea of the irregularities of the earth's surface, the shape and relative position, elevations and absolute heights of terrain points, the prevailing steepness and length of slopes.

1.3 Types of contour lines.
Horizontal- a closed curved line on the map, which corresponds to a contour on the ground, all points of which are located at the same height above sea level.
There are the following horizontal lines:

main(solid) - relief section corresponding to the height;
thickened - every fifth main horizontal; stands out for ease of reading the relief;
additional horizontals(semi-horizontals) - are drawn by a broken line at the height of the relief section equal to half of the main one;
auxiliary - shown as short dashed lines. thin lines, at an arbitrary height.

Distance between two adjacent main contour lines in height are called the height of the relief section. The height of the relief section is signed on each sheet of the map under its scale. For example: "Solid contours are drawn through 10 meters."
To facilitate the calculation of contour lines when determining the heights of points on the map, all solid contour lines corresponding to the fifth multiple of the height of the section are drawn thickened and a number indicating the height above sea level is put on it.
In order to quickly determine the nature of surface irregularities on maps when reading a map, special slope direction indicators are used - berghashes- in the form of short dashes placed on the horizontals (perpendicular to them) in the direction of the slopes. They are placed on the bends of contours in the most characteristic places, mainly at the tops of saddles or at the bottom of basins.
Additional contours(semi-horizontal) are used to display characteristic forms and details of the relief (bends of slopes, peaks, saddles, etc.), if they are not expressed by the main contours. In addition, they are used to depict flat areas, when the laying between the main contours is very large (more than 3 - 4 cm on the map).
Auxiliary horizontals used to depict individual details of the relief (saucers in the steppe regions, depressions, individual hillocks on flat terrain), which are not transmitted by the main or additional horizontals.

1.4 Image by contour lines standard forms relief.
Relief on topographic maps is represented by curves closed lines, connecting the points of the terrain, having the same height above the level surface, taken as the origin of the heights. Such lines are called horizontal lines. The image of the relief with contour lines is supplemented by labels of absolute heights, characteristic points of the terrain, some contour lines, as well as numerical characteristics relief details - height, depth or width (Fig. 7).

Some typical forms of terrain on the maps are displayed not only by the main, but also by additional and auxiliary contour lines (Fig. 8).


Rice. 8. Image of typical landforms

2. Determination on the map of absolute heights and relative elevations of terrain points, ascents and descents, steepness of slopes.

2.1. Determination on the map of absolute heights and relative elevations of terrain points

2.2. Definition on the map of ascents and descents on the route.

Rice. ten. Definition on the map of ascents and descents on the route of movement (route profile).

Rice. eleven. Determination on the map of the steepness of the slopes

Profile- a drawing depicting a section of the terrain with a vertical plane.
For greater expressiveness of the terrain, the vertical scale of the profile is taken 10 or more times larger than the horizontal one.
In this regard, the profile, transmitting the mutual excess of points, distorts (increases) the steepness of the slopes.
To build a profile, you need(Fig. 10) :

draw a profile line (travel route) on the map, attach a sheet of graphed (millimetric) paper to it, transfer to its edge with short lines the places of contour lines, the inflection points of the slopes and local objects that the profile line cuts, and sign their heights;
sign on a sheet of graphed paper at the horizontal lines the heights corresponding to the heights of the contour lines on the map, conventionally taking the gaps between these lines as the height of the section (set the vertical scale);
from all dashes denoting intersections profile line with elevation marks of contour lines, inflection points of slopes and local objects, lower the perpendiculars until they intersect with the corresponding marks parallel lines and mark the resulting intersection points;
connect the intersection points of a smooth curve, which will depict the terrain profile (ascents and descents on the route of movement).

2.3. Determination on the map of the steepness of the slopes.
The steepness of the slope on the map is determined by the location - the distance between two adjacent main or thickened contour lines; the smaller the laying, the steeper the slope \.
To determine the steepness of the slope, it is necessary to measure the distance between the horizontals with a compass, find the corresponding segment on the laying chart and read the number of degrees (Fig. 11).
On steep slopes, this distance is measured between thickened contours and the steepness of the slope is determined from the graph on the right.

3. Conventional signs of relief elements that are not expressed by contour lines.

	Ice cliffs (barriers) and outcrops of fossil ice (8 - height of the cliff in meters)

	Sod ledges (edges) that are not expressed by horizontal lines
	Shafts coastal, historical, etc., not expressed by contour lines (3 - height in meters)
	1) Dry channels in one line (less than 5 m wide); 2) Dry channels in two lines with a width of 5 to 15 m (0.5 mm on the map scale); 3) Dry channels more than 15 m wide (from 0.5 to 1.5 mm on a map scale); 4) Dry channels with a width of more than 1.5 mm on a map scale and basins of dry lakes
	Height marks
	Command Height Marks
	Landmark elevations
	Main passes, marks of their heights and duration
	Passes, marks of their heights and duration
	Karst and thermokarst sinkholes not expressed on the map scale
	Pits that are not expressed on the scale of the map
	Pits expressed in map scale
	Rocks-outliers that have a landmark value (10-height in meters)
	Rocks-outliers that do not have a landmark value
	Dikes and other narrow, steeply walled hard rock ridges (5 - height of the ridge in meters)
	Mud volcano craters
	Volcanic craters not expressed on the map scale
	Mounds and mounds that are not expressed on the scale of the map
	Mounds and mounds, expressed on the scale of the map (5 - height in meters)
	Clusters of stones
	Separately lying stones (3 - height in meters)
	Entrances to caves and grottoes

Abstracts

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The relief is made up of positive(convex) and negative(concave) shapes. The largest negative forms relief on Earth - the depressions of the oceans, positive - the continents. These are landforms of the first order. Landforms of the second order - mountains and plains (both on land and at the bottom of the oceans). The surface of mountains and plains has a complex relief, consisting of smaller forms.

Morphostructures- large elements of the land relief, the bottom of the oceans and seas, the leading role in the formation of which belongs to endogenous processes . The largest irregularities on the Earth's surface form protrusions of the continents and depressions of the oceans. The largest land relief elements are flat-platform and mountainous areas.

Plain-platform areas include flat parts of ancient and young platforms and occupy about 64% of the land area. Among the flat-platform areas there are low, with absolute heights of 100-300 m (East European, West Siberian, Turan, North American plains), and high raised latest movements crust to a height of 400-1000 m (Central Siberian Plateau, African-Arabian, Hindustan, significant parts of the Australian and South American plains).

mountainous areas occupy about 36% of the land area.

Underwater margin of the mainland(about 14% of the Earth's surface) includes a shallow flat strip as a whole offshore(shelf), continental slope and continental foot located at depths from 2500 to 6000 m. The continental slope and the continental foot separate the protrusions of the continents, formed by the combination of land and shelf, from the main part of the ocean floor, called the ocean floor.

Island arc zone- ocean bed transition zone . The actual ocean bed (about 40% of the Earth's surface) is mostly occupied by deep-sea (average depth 3-4 thousand m) plains, which correspond to oceanic platforms.

The relief of the bottom of the oceans

Zone	Characteristics
Shelf	The underwater margin of the continents, has in common with the coastal land geological structure, the total area is up to 10% of the area of the World Ocean. It is rich in minerals (oil, gas, diamonds, placers of metals).
continental slope	Distributed from the lower boundary of the shelf to a depth of 2000 m or more; within its limits, the granite layer decreases; has steep slopes, stepped, dissected by faults.
Ocean bed	It occupies 70% of the area of the World Ocean, is located at an average depth of 6000 m, the earth's crust ocean type, complex relief; ferromanganese nodules.
mid-ocean ridges	Volcanic origin; at the borders lithospheric plates; uplift of the ocean earth's crust, consisting of basalts; along the axis of the ridges - a deep fault - rift zone where magma erupts; characterized by earthquakes and volcanoes.

Morphosculptures- elements of the relief of the earth's surface, in the formation of which the leading role belongs to exogenous processes .

The work of rivers and temporary streams plays the greatest role in the formation of morphosculptures. They create widespread fluvial(erosive and accumulative) forms(river valleys, beams, ravines, etc.). Great distribution have glacial forms due to the activity of modern and ancient glaciers, especially the cover type (northern part of Eurasia and North America). They are represented by trough valleys, "ram's foreheads" and "curly" rocks, moraine ridges, eskers, etc. In the vast territories of Asia and North America, where permafrost rock strata are widespread, various forms of permafrost (cryogenic) relief are developed.

The most important forms relief

Most large forms relief - protrusions of the continents and depressions of the oceans. Their distribution depends on the presence of a granite layer in the earth's crust.

Continents and oceans the main landforms of the Earth. Their formation is due to tectonic, cosmic and planetary processes.

Mainland- This largest array the earth's crust, which has a three-layer structure. Most of its surface protrudes above the level of the oceans. In the modern geological era, there are 6 continents: Eurasia, Africa, North and South America, Australia and Antarctica. Their areas are 54, 30, 24, 18, 17, 9, 14 million km2, respectively.

World Ocean– continuous water shell Earth surrounding the continents and having a common salt composition. The world ocean is divided by continents into 4 oceans: Quiet, Atlantic, Indian and Arctic.

The Earth's surface is 510 million km2. The share of land accounts for only 29% of the Earth's area. Everything else is the World Ocean, i.e. 71%.

Mountains and plains, as well as continents and oceans, are the main landforms of the Earth, as well as the main landforms of the land. Mountains are formed as a result of tectonic uplifts, and plains as a result of the destruction of mountains.

Approximately 60% of the land is occupied plains- vast areas of the earth's surface with relatively small (up to 200 m) elevation fluctuations.

Plains - vast areas of the earth's surface with small fluctuations in height and slight slopes.

Plains- large areas with a relatively flat surface. By altitude Plains are divided into lowlands (height 0-200 m), highlands (200-500 m) and plateaus (above 500 m).

An example lowlands (from 0 to 200 m) can serve as Amazonian lowland- the largest on Earth, and also Indo-Ghana lowland. It happens that the lowlands are located below sea level - this is hollows . Caspian lowland located 28 meters below sea level. An example of a plain proper is the largest Eastern European plain.

At altitudes of 200-500 m above sea level, hills . For example, Central Russian, Volga, and above 500 m - plateaus and highlands . The largest of them are Central Siberian, Brazilian, Deccan, Guiana, East African, Great Basin, Arabian.

By the nature of the surface - flat, hilly, stepped.

Origin:

Alluvial (accumulative) formed as a result of deposition and accumulation of river sediments (Amazonian, La Plata).

Denudation formed as a result of long-term destruction of mountains (Kazakh uplands).

Marine formed along the coasts of the seas and oceans as a result of the retreat of the sea (Prichernomorskaya).

Continental accumulative formed at the foot of the mountains by the accumulation and deposition of destruction products rocks carried by streams of water.

Water-glacial formed as a result of the activity of the glacier (Meshchera,

Polissya).

Abrasive formed as a result of the destruction of the coast by the wave-cutting activity of the sea.

Reservoir formed on platforms and composed of layers of sedimentary cover (64% of all plains on the continents).

The mountains- elevations of the earth's surface (more than 200 m) with clearly defined slopes, soles, peaks. By appearance mountains are subdivided into mountain ranges, chains, ridges and mountainous countries.

The mountains(mountainous countries) - vast, highly elevated above the surrounding area, strongly and deeply dissected areas of the earth's crust with a folded or folded-block structure.

The mountains- areas of the earth's surface, significantly elevated above sea level to a height of more than 500 m and strongly dissected.

Mountains count low if their height is from 500 to 1000 m; average – from 1000 to 2000 m and high - over 2000 m. The highest mountain peak on Earth - mountain Chomolungma (Everest) in Himalayas has a height of 8848 m.

Separate mountains are rare, representing either volcanoes or the remains of ancient destroyed mountains. The morphological elements of mountains are: the base, or sole; slopes; peak or ridge (near ridges).

sole of the mountain- this is the border between its slopes and the surrounding area, and it is expressed quite clearly. With a gradual transition from the plains to the mountains, a strip is distinguished, which is called the foothills.

The slopes occupy most of the surface of the mountains and are extremely varied in appearance and steepness.

Vertex- the highest point of a mountain (mountain ranges), a pointed peak of a mountain - peak .

Mountain countries (mountain systems)- large mountain structures, which consist of mountain ranges - linearly elongated mountain rises intersecting with slopes. The points of connection and intersection of mountain ranges form mountain nodes. These are usually the highest parts of mountainous countries. The depression between two ridges is called a mountain valley.

uplands- sections of mountainous countries, consisting of heavily destroyed ridges and high plains covered with destruction products.

You can determine the height of mountains by physical map using the height scale.

Mountains are divided by absolute height into:

Low (low mountains)- up to 1000 m (Tien Shan, Middle Urals).

Medium-high - up to 2000 m (Khibiny, Carpathians).

High (highlands) - more than 2000 m (Pamir, Himalayas, Andes).

According to the structure, folded, folded-block and blocky mountains are distinguished.

By geomorphological age, young, rejuvenated and reborn mountains. On land, mountains of tectonic origin predominate, in the oceans - volcanic.

Mountains differ not only in height, but also in shape. A group of mountains - elongated by a chain, is called mountain range . Mountains have this shape. Caucasus. Is there some more mountain belts , For example, Alpine-Himalayan, and mountainous countries , For example, Pamir.

Mountains and plains are located both on the continents and in the oceans.

By origin, mountains are divided into tectonic and volcanic.

Tectonic, in turn, are divided into:

Folded:"young", formed during the Alpine folding ( separate sections in the Himalayas) - "primary".

Folded-blocky: during repeated tectonic movements on the site of the destroyed mountains - "reborn" (Tien Shan, Altai, Transbaikalia).

Blocky-folded: not completely destroyed mountains Mesozoic folding uplifted by the newest tectonic movements- "rejuvenated" (Rocky Mountains, highlands of Tibet, Verkhoyansk Range).

Volcanic rocks formed at fault lines or at the boundaries of lithospheric plates, composed of products of volcanic eruptions ( Klyuchevskaya Sopka, Elbrus).

The largest mountain systems

name of the mountains	Max height (m)
Eurasia
Altai	4506(Belukha)
Alps	4807 (Mont Blanc)
Himalayas	8848 (Chomolungma)
Greater Caucasus	5642 (Elbrus)
Carpathians	2655(Gerlachowski-Shtit)
Pamir	7495 (Communism Peak)
Tien Shan	7439 (Victory Peak)
Scandinavian	2469 (Galdhepiggen)
Africa
Atlassian	4165(Jebel Toubkal)
kilimanjaro	5895 (Kilimanjaro)
North and South America
Appalachians	2037 (Mitchell)
Andes (South Am.)	6990 (Aconcagua)
Cordillera	6193 (McKinley)
rocky	4399 (Elbert)
Australia
australia Alps	2230 (Kosciushko)
South Alps (N.Zel.)	3756 (Cook)

The sizes of landforms reflect the features of their origin. So, the largest landforms - tectonic - formed as a result of the prevailing influence internal forces Earth. Forms of small and medium scales were formed with the predominant participation external forces (erosional forms).

The relief of Russia is characterized by heterogeneity and contrast: high mountain ranges coexist with vast plains and lowlands. Almost 2/3 of the country's territory is occupied by endless plains various shapes and heights. The diversity of Russian landscapes is explained by the large occupied area and the peculiarities of geological development.

Features of the relief of Russia

The relief is a complex of all the irregularities of the earth's surface, which can be either convex or concave. Based on these features, the relief is conditionally divided into two large groups: mountains and plains.

Rice. 1. Relief map of Russia

Relief Russian Federation is of great variety. The country is dominated by flat land areas rich in minerals: oil, natural gas, coal, shale, iron ore, gold and many other mineral resources.

The plains alternate with the heights of the mountain ranges. The most high point not only in the country, but throughout Europe - the famous Mount Elbrus (5642 m.), Located in the Caucasus. There are also other five-thousander mountains here: Kazbek, Dykhtau, Shkhara, Pushkin Peak.

The Caucasus Mountains, located between the Caspian and Black Seas, are divided into two mountain systems: the Lesser Caucasus and the Greater Caucasus. All the highest peaks are located in the latter, where on high altitudes glaciers and eternal snows reign.

Fig.2. Caucasian mountains

The Caspian lowland is located 28 m below sea level. Such fluctuations in altitude - about 5700 m - on the territory of one state are very impressive.

The position of Russia relative to large landforms

The variety of landforms and their location is closely related to geological features territory. On the surface of young and ancient platforms of Russia at different heights lie large plains occupying the main part of the country's area:

Eastern European (another name is Russian);
West Siberian;
Central Siberian Plateau.

The central part of Russia is located on the East European Plain, which is considered one of the largest on the globe.

Russian and West Siberian Plain separated by ridges Ural mountains, total length which is more than 2.5 thousand km. In the southeast, the Russian Plain is bounded by the Altai mountain system.

The average altitude of the Central Siberian Plateau ranges from 500-700 m above the level of the World Ocean.

In the northeast of the Russian Federation, the Pacific Folding Belt is located, which includes Kamchatka, the Kuril Islands and Sakhalin Island.

All of the above islands are the peaks of ancient sea mountains, the growth of which does not stop to this day. It is for this reason that this region is characterized by frequent and intense earthquakes.

In the northwest, the territory of the country is located on the Baltic Crystalline Shield. This region is characterized by lake and sea plains, low mountains and marshy lowlands.

Mountain systems of the Russian Federation

Mountains in Russia occupy almost 1/3 of the entire territory.

On the border of Asia and European parts states located Ural Mountains - the oldest and longest. They don't differ great height and is now heavily damaged. On average, the height of the Ural Mountains does not exceed 400 m, and the highest point is Mount Narodnaya (1895 m).
In the south of the Russian Federation there is a young mountain system Greater Caucasus, which serves as a natural border between Georgia and Azerbaijan. Mount Elbrus (5642 m) is the highest point.
The Altai Mountains are located in the south of Siberia. They are relatively low, but their growth is still ongoing. The highest point is Mount Belukha (4506 m).
Kamchatka has high mountain ranges with volcanic peaks. This is where the world's largest active volcano- Klyuchevskaya Sopka (4850 m.).

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The main landforms of the Earth

Continents and oceans are the main landforms of the Earth. Their formation is due to tectonic, cosmic and planetary processes.

Mainland- this is the largest massif of the earth's crust, which has a three-layer structure. Most of its surface protrudes above the level of the oceans. In the modern geological era, there are 6 continents: Eurasia, Africa, North America, South America, Australia, Antarctica.

World Ocean- a continuous water shell of the Earth, surrounding the continents and having a common salt composition. The world ocean is divided by continents into 4 oceans: the Pacific, the Atlantic, the Indian Islands and the Arctic.

The surface of the Earth is 510 million km 2. The share of land accounts for only 29% of the Earth's area. Everything else is the World Ocean, that is, 71%.

Mountains and plains, as well as continents and oceans, are the main landforms of the Earth. Mountains are formed as a result of tectonic uplifts, and plains as a result of the destruction of mountains.

Plains- large areas with a relatively flat surface. They vary in height. An example lowlands(from 0 to 200 m above sea level) can serve as the Amazonian lowland - the largest on Earth, as well as the Indo-Gangetic lowland. It happens that the lowlands are located below sea level - this is hollows. The Caspian lowland is located 28 m below sea level. An example of a plain proper is the largest East European Plain.

At altitudes of 200–500 m above sea level, hills. For example, Central Russian, Volga, and above 500 m - plateaus and highlands. The largest of them are the Central Siberian,

Brazilian, Deccan, Guiana, East African, Great Basin, Arabian.

The mountains- areas of the earth's surface, significantly elevated above sea level to a height of more than 500 m and strongly dissected. Mountains are considered low if their height is from 500 to 1000 m; medium - from 1000 to 2000 m and high - over 2000 m. The highest mountain peak on Earth - Mount Chomolungma (Everest) in the Himalayas has a height of 8848 m. You can determine the height of the mountains on a physical map using the height scale.

The sizes of landforms reflect the features of their origin. So, the largest landforms - tectonic- formed as a result of the prevailing influence of the internal forces of the Earth. Forms of medium and small scales were formed with the predominant participation of external forces (erosive forms).

Mountains differ not only in height, but also in shape (Table 7.3). A group of mountains stretched out in a chain is called mountain range. For example, the mountains of the Caucasus have such a shape.