SST REVISION

SST REVISION

CONTINENTS AND OCEANS

You have already read that the earth's surface is covered by land and water. The large areas of land are known as continents. You will find that there are seven countries. These are Asia, Africa, North America, South America, Europe, Australia and Antarctica. India is a part of Asia.

LANDFORMS

The land on the earth's surface has different shapes and forms. These are called landforms or natural features. These are 'mountains', 'hills', 'valleys', 'plateaus', and 'plains'.

MOUNTAINS

The highest areas on earth are known as mountains. The top of a mountain is called its peak.

HILLS

High areas of land which are not as high as mountains are called hills. A line or a group of mountains or hills is called a range.

VALLEYS

The low land below two hills or two mountains is known as valley.

PLATEAUS.

Large areas of highland that are flat on the top are known as plateaus. They are also known as tablelands.

PLAINS

Plains are large stretches of almost flat land. They may have been formed from flowing lava or when hills and mountains were broken down by wind or rain. Plains are generally suitable for growing crops, so they are important for agriculture.

COASTAL PLAINS

The land near the sea or ocean is known as coast. Coastal plains are flat areas of land near the sea. These are generally sandy.

DESERTS

Deserts are those areas of land which receive very little rain and few plants or trees grow. Most deserts are very hot and dry, for instance, the Thar Desert in the western part of India. Some deserts can also be cold. Those areas which are covered by snow throughout the year are cold deserts, so nothing can grow there. Ladahk is a cold desert.

OCEANS

These large areas on the earth's surface covered by water. they are known as oceans. The smaller areas covered by water are known as seas. The water in oceans and seas is very salty. The five oceans are the Pacific Ocean, the Atlantic Ocean, the Indian Ocean, the Arctic Ocean and the Southern Ocean.

INDIAN OCEAN

It is found between Africa, Asia, Australia, and Antarctica.

ATLANTIC OCEAN

The Atlantic Ocean separates the American continents from Europe and Africa. It is the second largest ocean in the world.

PACIFIC OCEAN

It is the largest and deepest ocean in the world. The Mariana Trench is the deepest point on the earth. It is located in the Pacific Ocean. It covers one-tenth of the earth's surface.

ARCTIC OCEAN

It is the coldest ocean in the world. It is located in the North Polar region.

SOUTHERN OCEAN

It is also known as the Antarctic Ocean.

ISLANDS

The top of some underwater mountains rise above the water and become islands. An island is a piece of land surrounded by water. A group of islands that are close together in the sea is known as an archipelago. The Andaman and Nicobar Islands of India is an example of an archipelago.

PENINSULA

It is a piece of land that is surrounded by water on three sides. It is joined to a larger piece of land on one side. The southern part of India is a peninsula

The southern part of India is a peninsula.