8th Standard Social (Lithosphere)

 Class 8 Lithosphere

I. Fill In The Blanks:

1. The continental crust is also called SIAL.

2. Vast basin shaped volcanic mouth is Caldera.

3. The most destructive earthquake waves are Surface waves.

4. Stalactites and stalagmites are most common in Australia.

5. The beaches are formed bv work Sea wave work.

II. Answer The Following Questions in 1 or 2 Sentences Each.

1. Mention the three major layers of the interior of the Earth.
Ans: The three major layers of the interior of the Earth are The Crust, The Mantle, and The Core.

 

2. Name the types of volcanoes on the basis of the frequency of eruption.
Ans: On the basis of the frequency of eruption, volcanoes are classified into three types. They are

a) Active volcanoes

b) Dormant volcanoes

c) Extinct volcanoes.

 

3. Mention the important earthquake zones of the world.
Ans: a) The circum – pacific belt-Regions around the Pacific ocean.

b) The Mediterranean belt-Regions around the Mediterranean sea.

c) The Himalayan belt-The Siwalik regions of India.

 

4. What is weathering? Name the three main types of weathering.
Ans: Weathering is the wearing away or breaking down or gradual disintegration of rocks by agents present in the atmosphere.

The three types of weathering are:

a) Mechanical weathering.

b) Chemical weathering.

c) Biological weathering.

 

III. Match The Following

 

A	B
SIMA	(c) Oceanic crust
Sandstone	(d) Sedimentary rock
Epicenter	(a) Earthquake
Geyser	(e) Underground
Loess	(b) Yellow soil

 

IV. Define The Following :

1. Aqueous rocks :
Ans: Sandstone rocks arc called aqueous rocks.

 

2. ‘Pacific ring of fire’:
Ans: Coastal margins or the Pacific Ocean consisting of the Philippines, Japan, USA, Central America, South America, etc.

 

3. Mechanical weathering:
Ans: When the rock is broken and disintegrated without any chemical alteration, the process is called Physical weathering or Mechanical weathering.

 

4. Carbonaceous rocks:
Ans: Organic sediments are those derived by the accumulation of remains of organisms.

 

5. Tsunami:
Ans: A tsunami is a large sea wave occasionally experienced along the coasts of Japan.

 

6. Continental glacier:
Ans: Continental glaciers are extensive ice sheets found in polar regions.

 

7. Hot spring:
Ans: Whenever warm or hot water comes out naturally it is called a hot spring or thermal spring.