Major Landforms of the Earth

Q38. What are Block Mountains? Give examples

Ans. Block Mountains are created when large areas are broken and displaced vertically. The uplifted blocks are termed as horsts and the lowered blocks are called graben. The Rhine valley and the Vosges Mountain in Europe are examples of such mountain systems.

Q39. How plains are useful?

Ans. Importance of plains

     1.   Plains are very fertile.

     2.   Construction of transport network is easy.

     3.   More flat land is available for building houses, as well as for cultivation.

Q40. Discuss the processes which lead to formation of landforms.

Ans. Landforms are a result of two processes. Within the earth, a continuous movement is taking place. The first or the internal process leads to the upliftment and sinking of the earth’s surface at several places. The second or the external process is the continuous wearing down and rebuilding of the land surface.

Q41. How are plains formed?

Ans. Most of the plains are formed by rivers and their tributaries. The rivers flow down the slopes of mountains and erode them. They carry forward the eroded material. Then they deposit their load consisting of stones, sand and silt along their courses and in their valleys. It is from these deposits that plains are formed.

Q42. Write some important features of plains?

Ans. Important features of plains

     1.   Plains are large stretches of flat land.

     2.   They are, generally, not more than 200 metres above mean sea level.

     3.   Most of the plains are formed by rivers and their tributaries.

     4.   Generally, plains are very fertile.

     5.   Construction of transport network is easy.

     6.   Plains are very thickly-populated.

Q43. How plateaus are useful to us?

Ans. Plateaus are very useful because they are rich in mineral deposits. African plateau is famous for gold and diamond mining. In India huge reserves of iron, coal and manganese are found in the Chhotanagpur plateau. In the plateau areas, there may be several waterfalls as the river falls from a great height. The lava plateaus are rich in black soils that are fertile and good for cultivation. Many plateaus have scenic spots and are of great attraction to tourists.

Q44. List some important features of plateaus?

Ans. Features of plateaus

     1.   A plateau is an elevated flat land.

     2.   It is a flat-topped table land standing above the surrounding area.

     3.   A plateau may have one or more sides with steep slopes.

     4.   The height of plateaus often varies from few hundred metres to several thousand metres.

     5.   Plateaus, like mountains may be young or old.

     6.   The Deccan plateau in India is one of the oldest plateaus.

     7.   The Tibet plateau the highest plateau in the world with a height of 4,000 to 6,000 metres above the mean sea level.

     8.   Plateaus are rich in mineral deposits.

Q45. How mountains are useful?

Ans. Importance of mountains

     1.   The mountains are a storehouse of water.

     2.   Many rivers have their source in the glaciers in the mountains.

     3.   Reservoirs are made and the water is harnessed for the use of people.

     4.   Water from the mountains is also used for irrigation and generation of hydro-electricity.

     5.   Mountains have a rich variety of flora and fauna.

     6.   The forests provide fuel, fodder, shelter and other products like gum, raisins, etc.

     7.   Mountains provide an idyllic site for tourists.

     8.   Several sports like paragliding, hang gliding, river rafting and skiing are popular in the mountains.

Q46. Write a short note on types of mountains.

Ans. There are three types of mountains- Fold Mountains, Block Mountains and the Volcanic Mountains.

Fold Mountains - The Himalayan Mountains and the Alps are young fold mountains with rugged relief and high conical peaks. The Aravali range in India is one of the oldest fold mountain systems in the world. The range has considerably worn down due to the processes of erosion. The Appalachians in North America and the Ural mountains in Russia have rounded features and low elevation. They are very old fold mountains.

Block Mountains - Block Mountains are created when large areas are broken and displaced vertically. The uplifted blocks are termed as horsts and the lowered blocks are called graben. The Rhine valley and the Vosges Mountain in Europe are examples of such mountain systems.

Volcanic Mountains - Volcanic Mountains are formed due to volcanic activity. Mt.Kilimanjaro in Africa and Mt.Fujiyama in Japan are examples of such mountains.

Q47. Explain the major landforms of India?

Ans. We can group different landforms depending on elevation and slope as mountains, plateaus and plains.

Mountains - A mountain is any natural elevation of the earth surface. The mountains may have a small summit and a broad base. It is considerably higher than the surrounding area. Some mountains are even higher than the clouds. In some mountains, there are permanently frozen rivers of ice. They are called glaciers. There are some mountains you cannot see as they are under the sea. Because of harsh climate, less people live in the mountain areas. Since the slopes are steep, less land is available for farming.

Plateau – A plateau is an elevated flat land. It is a flat-topped table land standing above the surrounding area. A plateau may have one or more sides with steep slopes. The height of plateaus often varies from few hundred metres to several thousand metres. Plateaus, like mountains may be young or old. The Deccan plateau in India is one of the oldest plateaus. The Tibet plateau is the highest plateau in the world with a height of 4,000 to 6,000 metres above the mean sea level. Plateaus are very useful because they are rich in mineral deposits.

Plains - Plains are large stretches of flat land. They are, generally, not more than 200 metres above mean sea level. Some plains are extremely level. Others may be slightly rolling and undulating. Most of the plains are formed by rivers and their tributaries. Generally, plains are very fertile. Construction of transport network is easy.Thus, these plains are very thickly-populated regions of the world.