Thursday, April 9, 2009

Relief (unedited)


Q1. which two forces are responsible for shaping the present landform features of India?

Ans. Divergence and convergence cause two continental plates to fracture and fold. The movements of these crustal plates have changed the position and size of the continents over millions of years.
the present landform features or relief of India isa part of this process.

Q2. What are tetonic plates?

Ans. Radioactive decay in the interior of the earth produces heat which escapes towards surface producing convection currents in the molten rocks. Rising currents tear the crust apart, dividing it into large fragments called tectonic plates or lithospheric plates.

Q3. Which continents of today were part of the Gondwanaland?

Ans. South America,Africa, Australia and Antartica were a part of Gondwanaland.

Q4. What is the Bhabar?

Ans. A narrow belt covered with pebbles lies along the foot of the Shivaliks from the Indus to the Tista. They are laid down by the numerous streams descending down the hills. The pebbled beds are parallel to the slope of the river bed. This belt is about 8 to 16 km in width and is known as the Bhabar.

Q5. Name the three major divisions of the Himalayas from north to south?

Ans. The three major divisions of the Himalayas are the Himadri, the Himachal and the Shiwaliks.

Q6. How was the Arabian sea formed?

Ans. When the Himalayas were being formed an extensive volcanic eruption took place in the north western part of the plateau. Besides, the western part of the plateau subsided. The Indian Ocean advanced to occupy this depression and thus the Arabian sea was formed.

Q7. Why are Shiwaliks prone to landslides?

Ans. The Shivaliks are made up of unconsolidated sediments and hence are prone to landslides.

Q8. Name two passes of the Eastern Himalayas?

Ans. Some of the passesof the Himalayas are Shipkila, Nathula and Bomdila.

Q9. Which plateau lies between the Aravalli and the Vindhyan ranges?

Ans. The Malwa Plateau lies between the Aravalli and the Vindhyan Ranges.

Q10. Name the island group of India having coral origin.

Ans. Lakshadweep island group of India is having coral origin.

Q 11. Name the Physiographic divisions of J & K State.

Ans. The physiographic divisions of J & K State are Jammu(Sub-Himalayan), Kashmir(Himalayan) and Ladakh ( Trans Himalayan).

Q 12. What is LOO?

Ans. Hot wind blowing from

Q 13. Name the range of mountain where K2 is located?

Ans. K2 is locatedin the Great Himalaya range or the Himadri.

Q14. Name the famous glaciers of Karakoram range?

Ans. The famous glaciers of the Karakoram range are Baltoro and Saichin.

Q 15. Which areas a part of the outer plains of J & K State?

Ans. The outer plain is an extension of Great Indian Plain and is alluvial in nature. It stretches from river Ravi to River Chenab. Akhnoor, Ranbirsinghpora, Samba and Kathua are the main areas of outer plains. Itis locally known as Anderwah and Bajwat.

Q2. Distinguish between

a) Converging and diverging tectonic plates.

When two plates are pushed together they are converging

When two plates are moving away from each other is called diverging.

Convergence can cause the land form to fold to form mountain range

Divergence can cause the land form to fracture.

When they converge, they can collide and crumble and may slide under other.

When they diverge they can also move horizontally past each other.

b) A delta and a estuary.
When the river joins the large water body, it deposits sediments at the mouth causing small islands called the Delta
When the river rushes to join the large water bodies, the sediments are not deposited at the mouth and no small islands are formed is called a estuary.
The islands that are formed at the Delta are rich in sediments and alluvial soil
The sediments are spread over a large area in the largewater body.

c) A tributary and a distributary.
A tributary is sometimes a small river which joins the main river
A distributary is when the river distributes itself to make way for itself when sediments form islands on its path.
A tributary mainly joins the river through its course
A distributary mainly is formed at the mouth when the river joins the larger water bodies.

d) Khadar and the Bhangar
The younger alluviam of the flood plains is known as the khadar
The older alluviam is known as the Bhangar
The Khadar gives one harvest after the floods i.e. rice
The Bhangar gives more than one harvest and needs constant manuring.

e) Western Ghats and the Eastern Ghats
The western ghats spread uninterruptedly along the Arabian Coast.
The Eastern Ghats are discontinuous hill ranges
The western ghats are higher with a altitude of 900 – 1100 meters
The eastern ghats are hill ranges with the maximum altitude of 900 meters.

f) A Plateau and a Karewa
A Plateau is a table land
The Karewas are lacustrine deposits and are the unique features of the kashmir valley.
The plateau has a general elevation of 600-900 meters
The Karewas occupy about 50% of the valley floor.

Q3. Describe how the Himalayas were formed?
Ans. Millions of years ago India was a part of an ancient super continent called the Gondwanaland. This was located in the southern hemisphere. The convection currents of the mantle fractured it into a number of pieces. The Indo – Australian plate after getting seperated from the Gondwanaland drifted slowly towards the north. It collided with the much larger Eurasian plate in the northern hemisphere approximately five crores of years ago. The northern edge of the Indo-Austrialian plate was pushed under the Eurasian plate. Under the impact of this collision, the sedimentary rocks of the enclosed ocean were folded to form the mountain system of central Asia including the Himalayas.

Q4. Which are the main physiogaphic division of India? Contrast the relief of the Himalayan region with that of the Peninsular Plateau.
Ans. The Physiographic divisions of India are
1) The Great Mountains of the North.
2) The North Indian Plain.
3) The Peninsular Plateau
4) The Coastal Plains
5) The Islands
The land of India is characterised by a great diversity in its relief or physical features. In the north, there is a vast expanse of rugged terrain made of sedimentary rocks and metamorphic rocks. Series of mountain chains with lofty peaks, enclosed plateaus, and narrow and deep valleys are the characteristic features of this part. In contrast, the North Indian Plain, drained by the Indus, the Ganga,and the Bramhaputra is made up of the alluvium. It is an area of low relief and level or featureless surface. In south, the peninsular plateau is made of igneous and metamorphic rocks which contain valuable minerals. It is the oldest landmass of the country. It has remnants of the old mountain ranges and dissected plateaus. In some areas, the plateau rises in the form of staircase. It is bordered by coastal plains to its east and west.

Q5. Give an account of the northern plains of India.
Ans. When the Himalayas rose in the north, plains were formed soon after the rising land. The rivers that took birth in the glaciers started depositing rich alluvium into the plains. The rivers being perrinial had water alround the year and thus the northern plains are one of the richest plains of the world. These plains extend between the mouths of the Indus and the Gangal-Brahmaputra covering a distance of about 3200 KM. These plains are broadly divided into the Indus river system in the west and the GangaBrahmaputra river system in the east. The Indus and its tributaries flow westward after taking birth in the Himalayas and flow through Pakistan and reach Arabian sea. This plain is fed by 5 rivers and hence is called Panch+ab meaning Punjab. The Ganga flows eastward and the Brahmaputra enters India from Arunachal pradesh and joins the Ganges in Bangladesh and both flow south under the name Meghna and join the Bay of Bengal and form one of the world’s largest and fastest growing deltas of the world.

Q6. Write Short Notes on
a) The middle Himalayas. They are also called Himachal and lie south of Himadri. They consist of Pir Panjal, the Dhaoladhar and the Mahabarat ranges. Some of the important hill stations of north India arefound in these ranges namely Dharmshala, Dalhousie, Shimla, Mussorie and Darjeeling.
b) The Central Highlands. The northern part of the plateau consists ofa number of plateaus, denuded mountain ranges and low hills. They are made up of igneous rocks. The Aravalli hills which border the plateau