Oceans and Continents Class 6 Notes

Oceans and Continents Class 6 Notes

Oceans and Continents Class 6 Notes

Understanding Earth’s Surface and Land Coverage

1. The Earth’s surface is mostly covered by water, making it the ‘blue planet’.
2. Oceans are the largest water bodies on the globe.
3. Land covers about one-fourth of the globe, a colour brown.
4. Landmasses and continents are large bodies of land.
5. Both oceans and continents shape the Earth’s climate and affect all aspects of life.
6. Their impact is evident in history, culture, and daily life.

The Distribution of Water and Land on the Earth

Ocean and Continental Distribution

1. Oceans and continents are not evenly distributed between the Northern and Southern Hemispheres.
2. Oceans hold most available water, but seawater is salty and unsuitable for human consumption.
3. Freshwater, found in glaciers, rivers, lakes, atmosphere, and underground, makes up a small proportion of the planet’s water resources.

Oceans

1. Five oceans : Pacific, Atlantic, India, Arctic, and Southern.
2. Oceans are not separate; natural boundaries are conventions.
3. Seawater flows across oceans, sustaining marine life.
4. Marine flora includes algae and seaweeds.
5. Marine fauna includes fish, dolphins, whales, and deep-sea creatures.
6. Each ocean has its own diverse life forms.
7. Pacific Ocean is the largest, followed by Atlantic.
8. Indian Ocean is the third largest, Southern Ocean is the fourth.
9. Arctic Ocean is the smallest.

Oceans and Disasters

1. Large clouds in the oceans bring rain to continents, such as monsoon rains in India.
2. Oceans often produce violent storms, such as cyclones, causing widespread damage to coastal regions.
3. Tsunamis, caused by strong earthquakes or volcanic eruptions, are another natural disaster originating from the ocean.
4. Tsunamis can travel thousands of kilometers and submerge coastal areas, causing widespread damage.

Continents

1. Continents are visible on ocean maps.
2. Continents can be counted in multiple ways, ranging from four to seven.
3. North America and South America are generally considered two separate continents, but can also be seen as one.
4. Europe and Asia are generally considered two separate continents, but geologists often regard them as a single continent called ‘Eurasia’.
5. Africa and Eurasia are generally considered two separate continents, but sometimes one.

Islands

1. Continents do not include all landmass.
2. Smaller land pieces, surrounded by water, are called islands.
3. Continents are also surrounded by water, but not considered islands.
4. There are lakhs of islands of varying sizes worldwide.

Oceans and Life

1. Oceans and continents are important to the Earth’s water cycle, supplying rain to the continents.
2. Over half of the world’s oxygen is produced by ocean flora, making them ‘the planet’s lungs’.
3. Oceans regulate climate and sustain life on Earth.
4. They have influenced human migration, trade, military campaigns, and food sources.
5. They have nourished coastal cultures worldwide, with tales and legends about the sea, sea gods, sea monsters, and treasures.

IMPORTANT TERMS AND DEFINITIONS

1. Oceans : The largest water .bodies on the Earth are called oceans.

2. Landmass : A large body of land is called a landmass.

3. Continents : A large continuous expanse of land is called continent.

4. Marine : Related to or found various plants and animals species in the oceans and seas.

5. Marine flora : The tiny plant algae and all kinds of seaweeds occurring in a particular region.

6. Marine fauna: The animal life of a particular region consists of thousands of species of colourful fish, dolphins, whales and countless mysterious deep-sea creatures.

7. Groundwater : Water found beneath Earth’s surface is called groundwater. 

8. Sea : A large body of salt water that is smaller than a ocean and partly or completely surrounded by land.

9. Gulf: A part of the sea nearly surrounded with land.

10. Bay : A broad inlet of the sea where the land curves inwards.