NCERT Book Class 6 Social Science Oceans and Continents PDF Download

Chapter 2: Oceans and Continents

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)

The Big Questions

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?

[Figure 2.1: The Earth seen from space (photograph by the Lunar Reconnaissance Orbiter). The view is centred on the Indian Ocean, with Africa to the left, India and part of Asia at the top, Australia to the right, and Antarctica at the bottom, See in your textbook]

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.

Teacher's Note

Remember that three-fourths of Earth's surface is water, not land. When you see the Earth from space, it looks mostly blue because of the oceans. On any map or globe, blue always represents water and brown or green represents land. This is the key to understanding why Earth is called the 'blue planet'.

Don't Miss Out

The emblem of the Indian Navy contains the motto Sam noh Varunah (pronounced 'Sham no Varunah'), which means, "Be auspicious to us, O Varuna." This is an invocation to Varunah, a Vedic deity associated with the oceans, the sky, and water in general.

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.

[Figure 2.2: Maps of the Earth as seen from above the North Pole (left) and above the South Pole (right), See in your textbook]

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

• 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.)
• Which hemisphere holds more water?
• 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.
• Are all the oceans connected with one another, or are there separations between them?

Teacher's Note

When comparing the two pole maps, look carefully at which one shows more blue (water) and which shows more brown (land). The Southern Hemisphere is dominated by water, while the Northern Hemisphere has more continents. This unequal distribution is important to understand because it affects climate and human settlement patterns across the globe.

Key Points

• Earth is called the 'blue planet' because about three-fourths of its surface is covered with water in the form of oceans.
• A landmass is a large body of land, and a continent is a large continuous expanse of land that covers a little over one-fourth of Earth's surface.
• Oceans and continents are not distributed equally between the Northern and Southern Hemispheres; the Southern Hemisphere has much more water.
• The largest water bodies are oceans, which have smaller extensions called seas, bays, and gulfs.
• Both oceans and continents play a vital role in shaping Earth's climate and affect all life, including plants, animals, and humans.

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