NCERT Textbook: Oceans and Continents | Geography for UPSC CSE PDF Download

 Page 1


27
2 – Oceans and Continents
Oceans and Continents
CHAPTER
2
The ocean is everything. It covers seven-tenths of the 
terrestrial globe. Its breath is pure and healthy. It is an 
immense desert, where man is never lonely, for he feels life 
stirring all around. ... The ocean is the vast reservoir of 
Nature. The globe began with the ocean, so to speak, and 
who knows if it will not end with it. …
— Jules Verne (1870)
1. What are oceans 
and continents? 
What are their 
names and their 
distribution?
2. In what ways 
do oceans and 
continents 
impact life on 
Earth, including 
human life?
The Big 
Questions
Fig. 2.1 The Earth seen from space (photograph by the Lunar 
Reconnaissance Orbiter). The view is centred on the Pacific 
Ocean, with Africa to the left, India and part of Asia at the 
top, Australia to the right, and Antarctica at the bottom.
2_100724_v7.indd   27 2_100724_v7.indd   27 11-Jul-24   4:20:56 PM 11-Jul-24   4:20:56 PM
Page 2


27
2 – Oceans and Continents
Oceans and Continents
CHAPTER
2
The ocean is everything. It covers seven-tenths of the 
terrestrial globe. Its breath is pure and healthy. It is an 
immense desert, where man is never lonely, for he feels life 
stirring all around. ... The ocean is the vast reservoir of 
Nature. The globe began with the ocean, so to speak, and 
who knows if it will not end with it. …
— Jules Verne (1870)
1. What are oceans 
and continents? 
What are their 
names and their 
distribution?
2. In what ways 
do oceans and 
continents 
impact life on 
Earth, including 
human life?
The Big 
Questions
Fig. 2.1 The Earth seen from space (photograph by the Lunar 
Reconnaissance Orbiter). The view is centred on the Pacific 
Ocean, with Africa to the left, India and part of Asia at the 
top, Australia to the right, and Antarctica at the bottom.
2_100724_v7.indd   27 2_100724_v7.indd   27 11-Jul-24   4:20:56 PM 11-Jul-24   4:20:56 PM
28
Exploring Society: India and Beyond 
India and the World: Land and the People
Let us return to our globe and rotate it gently. Or look at 
the picture of the Earth seen from the Moon. What is the 
most widespread colour you see? Blue, obviously, but what 
does it represent? You must have guessed the answer — it 
is ‘water’. This means that most of the Earth’s surface is 
actually covered with water — almost three-fourths of the 
surface, in fact. That is why, when seen from outer space, 
the Earth appears mostly blue. Indeed, early astronauts 
lovingly called the Earth the ‘blue planet’.
The largest water bodies we see on the globe are called 
‘oceans’. 
But in the picture of the Earth (Fig. 2.1), you can see at least 
one other colour, brown. This colour is that of land, which 
covers a little over one-fourth of the globe. A large body of 
land is called a ‘landmass’, and a large continuous expanse 
of land is called a ‘continent’. 
Both oceans and continents play a vital role in shaping the 
climate of the Earth. They affect all aspects of life, including 
all plants and animals, and therefore, human life too. We 
see their impact throughout our history and culture, and in 
our daily lives. 
The emblem of the Indian Navy 
contains the motto Sam noh Varunah 
(pronounced ‘Sham no Varu?ah’), which 
means, “Be auspicious to us, O Varuna.” 
This is an invocation to Varu?a, a Vedic 
deity associated with the oceans, the 
sky, and water in general. 
   DON’T MISS OUT
2_100724_v7.indd   28 2_100724_v7.indd   28 11-Jul-24   4:20:57 PM 11-Jul-24   4:20:57 PM
Page 3


27
2 – Oceans and Continents
Oceans and Continents
CHAPTER
2
The ocean is everything. It covers seven-tenths of the 
terrestrial globe. Its breath is pure and healthy. It is an 
immense desert, where man is never lonely, for he feels life 
stirring all around. ... The ocean is the vast reservoir of 
Nature. The globe began with the ocean, so to speak, and 
who knows if it will not end with it. …
— Jules Verne (1870)
1. What are oceans 
and continents? 
What are their 
names and their 
distribution?
2. In what ways 
do oceans and 
continents 
impact life on 
Earth, including 
human life?
The Big 
Questions
Fig. 2.1 The Earth seen from space (photograph by the Lunar 
Reconnaissance Orbiter). The view is centred on the Pacific 
Ocean, with Africa to the left, India and part of Asia at the 
top, Australia to the right, and Antarctica at the bottom.
2_100724_v7.indd   27 2_100724_v7.indd   27 11-Jul-24   4:20:56 PM 11-Jul-24   4:20:56 PM
28
Exploring Society: India and Beyond 
India and the World: Land and the People
Let us return to our globe and rotate it gently. Or look at 
the picture of the Earth seen from the Moon. What is the 
most widespread colour you see? Blue, obviously, but what 
does it represent? You must have guessed the answer — it 
is ‘water’. This means that most of the Earth’s surface is 
actually covered with water — almost three-fourths of the 
surface, in fact. That is why, when seen from outer space, 
the Earth appears mostly blue. Indeed, early astronauts 
lovingly called the Earth the ‘blue planet’.
The largest water bodies we see on the globe are called 
‘oceans’. 
But in the picture of the Earth (Fig. 2.1), you can see at least 
one other colour, brown. This colour is that of land, which 
covers a little over one-fourth of the globe. A large body of 
land is called a ‘landmass’, and a large continuous expanse 
of land is called a ‘continent’. 
Both oceans and continents play a vital role in shaping the 
climate of the Earth. They affect all aspects of life, including 
all plants and animals, and therefore, human life too. We 
see their impact throughout our history and culture, and in 
our daily lives. 
The emblem of the Indian Navy 
contains the motto Sam noh Varunah 
(pronounced ‘Sham no Varu?ah’), which 
means, “Be auspicious to us, O Varuna.” 
This is an invocation to Varu?a, a Vedic 
deity associated with the oceans, the 
sky, and water in general. 
   DON’T MISS OUT
2_100724_v7.indd   28 2_100724_v7.indd   28 11-Jul-24   4:20:57 PM 11-Jul-24   4:20:57 PM
29
2 – Oceans and Continents
The Distribution of Water and  
Land on the Earth
As it happens, oceans and continents are not distributed 
equally between the Northern and Southern Hemispheres. 
Fig. 2.2. Maps of the Earth as seen from above the North Pole (left) and above 
the South Pole (right).
Let us examine the two maps in Fig. 2.2. Here too, the blue 
areas consist of oceans, along with their smaller extensions, 
which have various names — ‘sea’, ‘bay’, ‘gulf’, etc.
 LET’S EXPLORE
 Æ What are the circular lines in each map called? And do 
you know what the lines radiating out of the two poles are 
called? (Hint: you studied them in the previous chapter, but 
here they are presented differently.)
 Æ Which hemisphere holds more water? 
 Æ What do you think could be the approximate proportion 
of water to land in the Northern Hemisphere? And in the 
Southern Hemisphere? Discuss in groups.
 Æ Are all the oceans connected with one another, or are there 
separations between them?
Definitions 
for these 
terms are in 
the Glossary 
at the end of 
this textbook.
2_100724_v7.indd   29 2_100724_v7.indd   29 11-Jul-24   4:20:57 PM 11-Jul-24   4:20:57 PM
Page 4


27
2 – Oceans and Continents
Oceans and Continents
CHAPTER
2
The ocean is everything. It covers seven-tenths of the 
terrestrial globe. Its breath is pure and healthy. It is an 
immense desert, where man is never lonely, for he feels life 
stirring all around. ... The ocean is the vast reservoir of 
Nature. The globe began with the ocean, so to speak, and 
who knows if it will not end with it. …
— Jules Verne (1870)
1. What are oceans 
and continents? 
What are their 
names and their 
distribution?
2. In what ways 
do oceans and 
continents 
impact life on 
Earth, including 
human life?
The Big 
Questions
Fig. 2.1 The Earth seen from space (photograph by the Lunar 
Reconnaissance Orbiter). The view is centred on the Pacific 
Ocean, with Africa to the left, India and part of Asia at the 
top, Australia to the right, and Antarctica at the bottom.
2_100724_v7.indd   27 2_100724_v7.indd   27 11-Jul-24   4:20:56 PM 11-Jul-24   4:20:56 PM
28
Exploring Society: India and Beyond 
India and the World: Land and the People
Let us return to our globe and rotate it gently. Or look at 
the picture of the Earth seen from the Moon. What is the 
most widespread colour you see? Blue, obviously, but what 
does it represent? You must have guessed the answer — it 
is ‘water’. This means that most of the Earth’s surface is 
actually covered with water — almost three-fourths of the 
surface, in fact. That is why, when seen from outer space, 
the Earth appears mostly blue. Indeed, early astronauts 
lovingly called the Earth the ‘blue planet’.
The largest water bodies we see on the globe are called 
‘oceans’. 
But in the picture of the Earth (Fig. 2.1), you can see at least 
one other colour, brown. This colour is that of land, which 
covers a little over one-fourth of the globe. A large body of 
land is called a ‘landmass’, and a large continuous expanse 
of land is called a ‘continent’. 
Both oceans and continents play a vital role in shaping the 
climate of the Earth. They affect all aspects of life, including 
all plants and animals, and therefore, human life too. We 
see their impact throughout our history and culture, and in 
our daily lives. 
The emblem of the Indian Navy 
contains the motto Sam noh Varunah 
(pronounced ‘Sham no Varu?ah’), which 
means, “Be auspicious to us, O Varuna.” 
This is an invocation to Varu?a, a Vedic 
deity associated with the oceans, the 
sky, and water in general. 
   DON’T MISS OUT
2_100724_v7.indd   28 2_100724_v7.indd   28 11-Jul-24   4:20:57 PM 11-Jul-24   4:20:57 PM
29
2 – Oceans and Continents
The Distribution of Water and  
Land on the Earth
As it happens, oceans and continents are not distributed 
equally between the Northern and Southern Hemispheres. 
Fig. 2.2. Maps of the Earth as seen from above the North Pole (left) and above 
the South Pole (right).
Let us examine the two maps in Fig. 2.2. Here too, the blue 
areas consist of oceans, along with their smaller extensions, 
which have various names — ‘sea’, ‘bay’, ‘gulf’, etc.
 LET’S EXPLORE
 Æ What are the circular lines in each map called? And do 
you know what the lines radiating out of the two poles are 
called? (Hint: you studied them in the previous chapter, but 
here they are presented differently.)
 Æ Which hemisphere holds more water? 
 Æ What do you think could be the approximate proportion 
of water to land in the Northern Hemisphere? And in the 
Southern Hemisphere? Discuss in groups.
 Æ Are all the oceans connected with one another, or are there 
separations between them?
Definitions 
for these 
terms are in 
the Glossary 
at the end of 
this textbook.
2_100724_v7.indd   29 2_100724_v7.indd   29 11-Jul-24   4:20:57 PM 11-Jul-24   4:20:57 PM
30
Exploring Society: India and Beyond 
India and the World: Land and the People
Ocean 
Life
   Emperor penguins Bonaire sea turtle Algae
Coral reef 
  A star fish on a sea anemone
Sperm whale, mother and baby Shark 
Dolphins  
Shallow coral reef with colourful tropical fish
2_100724_v7.indd   30 2_100724_v7.indd   30 11-Jul-24   4:21:03 PM 11-Jul-24   4:21:03 PM
Page 5


27
2 – Oceans and Continents
Oceans and Continents
CHAPTER
2
The ocean is everything. It covers seven-tenths of the 
terrestrial globe. Its breath is pure and healthy. It is an 
immense desert, where man is never lonely, for he feels life 
stirring all around. ... The ocean is the vast reservoir of 
Nature. The globe began with the ocean, so to speak, and 
who knows if it will not end with it. …
— Jules Verne (1870)
1. What are oceans 
and continents? 
What are their 
names and their 
distribution?
2. In what ways 
do oceans and 
continents 
impact life on 
Earth, including 
human life?
The Big 
Questions
Fig. 2.1 The Earth seen from space (photograph by the Lunar 
Reconnaissance Orbiter). The view is centred on the Pacific 
Ocean, with Africa to the left, India and part of Asia at the 
top, Australia to the right, and Antarctica at the bottom.
2_100724_v7.indd   27 2_100724_v7.indd   27 11-Jul-24   4:20:56 PM 11-Jul-24   4:20:56 PM
28
Exploring Society: India and Beyond 
India and the World: Land and the People
Let us return to our globe and rotate it gently. Or look at 
the picture of the Earth seen from the Moon. What is the 
most widespread colour you see? Blue, obviously, but what 
does it represent? You must have guessed the answer — it 
is ‘water’. This means that most of the Earth’s surface is 
actually covered with water — almost three-fourths of the 
surface, in fact. That is why, when seen from outer space, 
the Earth appears mostly blue. Indeed, early astronauts 
lovingly called the Earth the ‘blue planet’.
The largest water bodies we see on the globe are called 
‘oceans’. 
But in the picture of the Earth (Fig. 2.1), you can see at least 
one other colour, brown. This colour is that of land, which 
covers a little over one-fourth of the globe. A large body of 
land is called a ‘landmass’, and a large continuous expanse 
of land is called a ‘continent’. 
Both oceans and continents play a vital role in shaping the 
climate of the Earth. They affect all aspects of life, including 
all plants and animals, and therefore, human life too. We 
see their impact throughout our history and culture, and in 
our daily lives. 
The emblem of the Indian Navy 
contains the motto Sam noh Varunah 
(pronounced ‘Sham no Varu?ah’), which 
means, “Be auspicious to us, O Varuna.” 
This is an invocation to Varu?a, a Vedic 
deity associated with the oceans, the 
sky, and water in general. 
   DON’T MISS OUT
2_100724_v7.indd   28 2_100724_v7.indd   28 11-Jul-24   4:20:57 PM 11-Jul-24   4:20:57 PM
29
2 – Oceans and Continents
The Distribution of Water and  
Land on the Earth
As it happens, oceans and continents are not distributed 
equally between the Northern and Southern Hemispheres. 
Fig. 2.2. Maps of the Earth as seen from above the North Pole (left) and above 
the South Pole (right).
Let us examine the two maps in Fig. 2.2. Here too, the blue 
areas consist of oceans, along with their smaller extensions, 
which have various names — ‘sea’, ‘bay’, ‘gulf’, etc.
 LET’S EXPLORE
 Æ What are the circular lines in each map called? And do 
you know what the lines radiating out of the two poles are 
called? (Hint: you studied them in the previous chapter, but 
here they are presented differently.)
 Æ Which hemisphere holds more water? 
 Æ What do you think could be the approximate proportion 
of water to land in the Northern Hemisphere? And in the 
Southern Hemisphere? Discuss in groups.
 Æ Are all the oceans connected with one another, or are there 
separations between them?
Definitions 
for these 
terms are in 
the Glossary 
at the end of 
this textbook.
2_100724_v7.indd   29 2_100724_v7.indd   29 11-Jul-24   4:20:57 PM 11-Jul-24   4:20:57 PM
30
Exploring Society: India and Beyond 
India and the World: Land and the People
Ocean 
Life
   Emperor penguins Bonaire sea turtle Algae
Coral reef 
  A star fish on a sea anemone
Sperm whale, mother and baby Shark 
Dolphins  
Shallow coral reef with colourful tropical fish
2_100724_v7.indd   30 2_100724_v7.indd   30 11-Jul-24   4:21:03 PM 11-Jul-24   4:21:03 PM
31
2 – Oceans and Continents
The oceans together hold most of the water available on the 
planet. But this seawater is salty and unfit for consumption 
by most land animals, including humans. On the other 
hand, freshwater makes up a very small proportion of the 
planet’s water resources; it is found in glaciers, rivers, lakes, 
in the atmosphere and also underground (the last is called 
‘groundwater’).
THINK ABOUT IT
 ? If there is such abundance of water on the planet, why is 
there so much talk of ‘water scarcity’ or a ‘water crisis’?
 ? What ways of saving water are you aware of? Which 
ones have you seen practised at home, at your school, 
and in your village, town or city?
Oceans
On the world map in Fig. 2.3 on page 32, we can observe  
five oceans — the Pacific Ocean, the Atlantic Ocean, the 
Indian Ocean, the Arctic Ocean and the Southern (or 
Antarctic) Ocean.
Although we have listed five oceans, it is clear from the 
map that they are not really separate. The lines that divide 
them on the map are no more than conventions — the 
natural world does not follow such boundaries. Seawater, 
for example, constantly flows across different oceans, 
sustaining a rich diversity of marine life. Many plant and 
animal species can be found across multiple oceans. 
The marine flora includes tiny plants called algae and all 
kinds of seaweeds; the marine fauna consists of thousands 
of species of colourful fish, dolphins, whales, and countless 
mysterious deep-sea creatures. Each part of the ocean, from 
the sun-lit surface to the dark depths, has its own diverse 
life forms.  
Marine:  
Related to 
or found in 
the oceans 
and seas.
Flora: 
The plant 
life of a 
particular 
region or 
period of 
time.
Fauna:  
The animal 
life of a 
particular 
region or 
period of 
time.
2_100724_v7.indd   31 2_100724_v7.indd   31 11-Jul-24   4:21:04 PM 11-Jul-24   4:21:04 PM