Oceans and Continents

Why This Matters

Look at a photo of the Earth taken from space. What colour do you see most? Blue.

That blue is water. Lots and lots of water. In fact, almost three out of every four parts of the Earth’s surface are water. That is why early space travellers lovingly called the Earth the “blue planet”.

The rest is land — the brown and green bits where we live, grow food, and build our towns.

So our home, the Earth, is really made of two things: huge bodies of water, and huge pieces of land. In this chapter, we will give them their names. We will learn the continents (the big lands) and the oceans (the big waters). We will also find out exactly where India sits.

Why care? Because knowing this is like learning your home address — but for the whole planet. Once you can read a world map, you can find any place on Earth.

The Big Idea

The Earth’s surface is made of two main things: water and land. The very large bodies of water are called oceans — there are five of them. The very large pieces of land are called continents — there are seven of them. Oceans cover much more of the Earth than land does. We can show all of them together on a flat picture called a map, or on a round ball called a globe. Once you know the names and places of the continents and oceans, you can find any country — including India — on a world map.

Let’s Break It Down

Land and water on Earth

Let us start with the two big words.

An ocean is a very large body of salty water. “Body of water” just means a large amount of water in one place — like how a pond, a lake, or the sea are all bodies of water. An ocean is the biggest kind.

A continent is a very large, unbroken piece of land. “Unbroken” means it joins up — you could (in theory) walk across it without crossing the sea. India, China, and Saudi Arabia are all on one continent, because the land joins them up.

Now, here is the key fact. Water covers much more of the Earth than land does. Look at Figure 2.1 below. It shows how the blue (water) is far more than the brown (land).

The picture below makes this easy to see at a glance.

Tap to zoom

So remember: water wins. Most of the Earth is ocean. Land is the smaller part.

Now let us name the seven continents.

The seven continents

There are seven continents on Earth. Here they are, with a one-line note on each.

• Asia — the biggest continent. India is part of Asia. It is also the continent with the most people.
• Africa — the second biggest. It sits just below Europe and to the west (left) of Asia.
• North America — the third biggest. It is in the top-left part of the world map.
• South America — joined to the bottom of North America. It is shaped a bit like a long triangle.
• Antarctica — the continent at the very bottom of the Earth. It is covered in thick ice and is freezing cold.
• Europe — a small continent. It is joined to Asia on its left side.
• Australia — the smallest continent. It sits down on the right side, all on its own.

A quick memory tip: think of the two pairs. There are two “Americas” (North and South). And Europe and Asia are joined together like neighbours.

Now look at Figure 2.2. Each continent is in its own colour, so you can tell them apart. This is a simple, stylised map — the shapes are not exact, but each continent is in the right place compared to the others.

The map below shows all seven continents together.

Tap to zoom

You can see from the map that Europe and Asia are really joined into one big land. We still count them as two continents for historical reasons — their history and ways of life grew differently. But the land itself is connected.

How big is each continent?

Knowing the names is good. But which is biggest? Which is smallest? This matters for reading maps and for comparing places.

The order from biggest to smallest is: Asia, Africa, North America, South America, Antarctica, Europe, Australia.

A picture makes this much clearer than a list. In Figure 2.3, each continent is a bar. The longer the bar, the bigger the continent.

The chart below lines them up by size.

Tap to zoom

Here is the same idea in a table you can keep handy.

The answer: because their history, peoples, and ways of life grew very differently over time. So we split them by culture, not by a gap in the land.

The oceans

Now for the water. There are five oceans on Earth. Here they are, biggest first.

• Pacific Ocean — the biggest ocean. It is so huge it touches both sides of a world map.
• Atlantic Ocean — the second biggest. It sits between the Americas on one side and Europe and Africa on the other.
• Indian Ocean — the third biggest. It is below Asia and is the one closest to us. India gave it its name.
• Southern Ocean — also called the Antarctic Ocean. It rings the icy land of Antarctica at the bottom of the Earth.
• Arctic Ocean — the smallest ocean. It sits at the very top of the Earth and is often frozen.

Here is something important. On a map, lines seem to split the oceans into five. But in real life, the oceans are all joined together. Water flows freely from one to the next. The lines are just made by people to help us name and talk about them. The sea does not really stop and start.

Look at Figure 2.4. The land shapes are shown in faint grey, so the oceans stand out clearly.

The map below labels each of the five oceans around the continents.

Tap to zoom

Let us compare the two groups side by side, so the difference is crisp.

Where India is

Now the most important place for us — India.

India is a country. It is part of the continent of Asia. On the world map, India sticks out from the bottom of Asia, pointing down towards the water.

Three bodies of water touch India:

• To the west (left) is the Arabian Sea.
• To the east (right) is the Bay of Bengal.
• To the south (below) is the big Indian Ocean itself.

A “sea” is like a smaller part of an ocean, closer to land. So the Arabian Sea and the Bay of Bengal are both parts of the Indian Ocean, hugging India on its two sides.

Figure 2.5 shows all of this clearly.

The map below highlights India and the waters around it.

Tap to zoom

Reading a world map

A map is a flat drawing of the Earth, or a part of it. A globe is a round model of the Earth, shaped like a ball. The globe shows shapes more truly because the Earth is round. But a flat map is easier to carry and to print in a book.

To read any world map, use three simple steps:

1. Find the directions. Top is north, bottom is south, left is west, right is east.
2. Find the big things first — the continents and oceans you now know.
3. Then zoom in to the place you want, using the big things as guides.

Let us practise with a real example.

The answer is north. The top of a map is always north, and the bottom is south.

Common Mistakes

Let us clear up some ideas that often confuse students.

Quick Check

Time for a few quick questions to test what you have learnt.

Practice Problems

Try each one yourself first. Then tap to check your answer.

Easy

Medium

Challenge

Summary

• The Earth’s surface is mostly water (about three-fourths) and partly land (about one-fourth). That is why it is called the “blue planet”.
• A continent is a very large piece of land. There are seven: Asia, Africa, North America, South America, Antarctica, Europe, and Australia.
• Asia is the largest continent, and Australia is the smallest.
• An ocean is a very large body of salty water. There are five: Pacific, Atlantic, Indian, Southern, and Arctic.
• The Pacific is the largest ocean, and the Arctic is the smallest.
• The five oceans are all joined together — the dividing lines are just names, not real walls.
• India is a country in the continent of Asia, with the Arabian Sea to its west, the Bay of Bengal to its east, and the Indian Ocean to its south.
• To read a world map: top is north, bottom is south, left is west, right is east — then find the big continents and oceans first.

What’s Next

You now know the big shapes of our planet — the seven lands and the five waters. But land is not all flat. Some of it rises into tall mountains, some spreads into wide plains, and some sinks into deep valleys.

In the next chapter, Landforms and Life, we will zoom in on the land itself. We will see the different shapes the land takes, and how those shapes change the way people live, farm, and travel.