Oceans and Continents

Class 06 Social Science

Almost three-fourths of the Earth’s surface is covered with water. The largest water bodies are called oceans. The land 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.

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 (groundwater).

Oceans

Five oceans are:

  1. Pacific Ocean
  2. Atlantic Ocean
  3. Indian Ocean
  4. Arctic Ocean
  5. Southern or Antarctic Ocean

Oceans are not really separate. Seawater 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.

Pacific Ocean is the largest of all oceans, followed by the Atlantic Ocean. The Indian Ocean is the third largest, while the Southern Ocean is the fourth. The smallest one is the Arctic Ocean.

Oceans and Disasters

Oceans often give rise to storms - violent events with extreme rainfall or very strong winds, such as cyclones, which can cause widespread damage to coastal regions of the world.

A tsunami is another natural disaster that originates in the ocean. It is a huge and powerful wave generally caused by a strong earthquake or a volcanic eruption at the bottom of the ocean.

Continents

North America and South America are generally considered to be two continents, but if seen as a single landmass, they can also be considered as one.

Europe and Asia are generally considered as two continents, although they form a single landmass. For historical and cultural reasons, Europe’s evolution has been very different from Asia's, which is why they can be seen as two continents. Geologists often regard them as a single continent called Eurasia.

Africa and Eurasia are generally regarded as two continents, but sometimes as one.

Seven continents:

  1. Africa
  2. Antarctica
  3. Asia
  4. Australia,
  5. Europe
  6. North America
  7. South America

Islands

The continents do not include all landmass. Some smaller pieces of land surrounded by water on all sides, are called islands.

Greenland is the largest island in the world.

Oceans and Life

Oceans and continents are vital parts of the environment and affect most aspects of our lives.

  1. Oceans send rain to the continents. This is part of the Earth’s water cycle.
  2. More than half of the world’s oxygen is produced by the oceans’ flora, which is why they are called ‘the planet’s lungs’.

The oceans play a crucial role in regulating the climate and sustaining life on Earth.

Oceans have deeply impacted humanity in many other ways. From early times, people have used oceans and seas to migrate to other regions, to trade in all kinds of goods, to conduct military campaigns, and as a source of food through fishing.

Oceans have also nourished the cultures of coastal people all over the world. Almost all of them have tales and legends about the sea, sea gods and goddesses, sea monsters and treasures from the sea - the oceans’ dangers and blessings.