Samacheer Class 7 Social Science - Landforms

weathering
2. The place where the river joins a lake or a sea is known as ………………………….
River mouth
3. Inselbergs are found in the …………………………. desert in South Africa.
Kalahari
4. A cirque is known as ………………………….in Germany.
Kar

5. The longest beach in the world is ………………………….
Miami Beach in the U.S.A

mountain, hill

2. The raised river banks are called ………………..
Levees
3. An active agent of erosion and deposition in the deserts is ………………..
wind
4. An isolated residual hill, stand like a pillar with rounded tops are ………………..
Inselbergs
5. Northern China loess deposits are brought from the ……………….. Desert.
Gobi
6. A part of land adjoining near the sea is called ………………..
sea coast

7. The boundary of the sea coast, where land meets water is ………………..
coastline
8. ………………..are steep rockfaces formed when the sea waves dash against them.
sea cliffs
9. The wall-like feature in the sea is ………………..
stacks
10. The second largest beach in the world is the ……………….. beach in Chennai.
Marina
11. Moraines are ………………..deposition.
glacial
12. ……………….is a stream or river that flow into and joins the main river.
Tributary

13. The collection of sediments from all the months of river forms ………………..
Delta
14. ………………..is the armchair shaped depression formed by glacial erosion.
Cirque
15. The process of leveling of highlands is called ………………..
Gradation

1. A. Glacier
2. B. Barchans
3. C. Lagoon
4. D. Weathering

1. Breaking and crumbling of rocks
d) Weathering
2. Abandoned meander loops
e) Oxbow lake
3. Large body of moving ice
a) Glacier
4. Crescent-shaped sand dunes
b) Barchan
5.Vembanad lake
c) Lagoon

‘V’ Shaped Valley
formed by the river erosion.
The landscape creates a steep-sided valley like the letter ‘V’ is ‘V’ shaped valley.

‘U’Shaped Valley:
formed by Glacier erosion.
The landscape deepened and widened by the lateral and vertical erosion is like a letter TJ’ is TJ1 shaped valley.

Continental Glacier:
The Glacier covering vast areas of a continent with thick ice sheets.
Ex: Antarctica, Greenland
Mountain Glacier:
Mountain Glacier is a stream of ice flowing along a valley and bounded by steep sides.
Ex: The Himalayas and the Alps

As the river floods, it deposits layers of fine soil and other materials called sediments along its banks.
This leads to the formation of a flat fertile flood plain. So the flood plains are very fertile.

As the cavities of sea caves become bigger, only the roof of the caves remains to form sea Arches. When erosion further breaks the roof, only walls are left, thus forming stacks.

The running water in the river erodes the landscape and formed different kinds of land. They are:
’V’Shaped Valley: The river erosion creates a steep-sided valley like the letter ‘V’ is known as ‘V’ Shaped Valley.
Waterfall: When the soft rocks are removed by river erosion formed a waterfall. E.g: Courtallam falls
Plunge Pool: It is a hollow feature at the base of a waterfall which is formed by cavitation.
Oxbow lake: Due to continuous erosion along the sides of the meander, the loop cuts off from the river and forms a cutoff lake is called Oxbow lake.

By the wind, erosion, and deposition the different types of land formed.
Mushroom Rocks:
In deserts, the rocks in the shape of Mushroom commonly called Mushroom Rocks.
Inselbergs:
The eroded hill standing like a pillar with rounded tops are called Inselbergs.
Sand Dunes:
As the wind blows the sand transformed and deposited in low hill like structures called sand Dunes.
Barchans.
The crescent-shaped sand dunes are called Barchans.
Loess:
Very fine and light sand is deposited in large areas is called Loess.

When two adjacent cirques erode towards each other, the previously rounded landscape is transformed into narrow rocky, steep-sided ridges called Aretes.
Thus by the erosion of Glacier, the Aretes are formed.

S.No
Natural Agents
Landforms
Erosion
Deposition
1.
River
V-Shaped Valley
Alluvial Fan
2.
Glacier
Arete
Moraine
3.
Wind
nselberg
Barchan
4.
Sea wave
Cliff
Lagoon
[Barchan, ‘V’ Shaped valley, Cliff, Arete, Inselberg, Moraine, Alluvial fan, Lagon]

Hill – The rocks, mountains are known as hills. The rivers originate from hills.
Waterfall – The falling of water over a vertical step in the river bed is called a waterfall.
River (or) stream – The water flowing in a definite course is called a river or stream.
Beach – The sea waves deposit sediments of sand and gravel along shores forming beaches.