Class 6 Social Science Chapter 2 : Oceans and Continents Notes & Summary in English for CBSE students
CBSE Class 6 Social Science Chapter 2 Notes & Summary in English for “Oceans and Continents” (based on NCERT Social studies textbook Exploring Society: India and Beyond).
Chapter 2 – Oceans and Continents Complete Notes
Class 6 Social Science – Exploring Society: India and Beyond
Theme A — India and the World: Land and the People
Chapter 2: Oceans and Continents
(Complete Notes + Concept-wise Explanation + Summary CBSE Class 6 Social Science – Exploring Society: India and Beyond (sst) Book)
Chapter 2: Oceans and Continents – Notes & Summary
Introduction
When we look at the Earth from space, the most dominant colour visible is blue. This blue colour represents water, which covers almost three-fourths (seven-tenths) of the Earth’s surface. Because of this, the Earth is often called the “Blue Planet.”
The remaining surface, which appears brown or green, represents land. Both water and land are essential for life on Earth. Large water bodies are called oceans, and large continuous land areas are called continents. Together, oceans and continents shape Earth’s climate, environment, history, and human life.
Big Questions of the Chapter
- What are oceans and continents? What are their names and distribution?
- How do oceans and continents affect life on Earth, including human life?
Oceans and Water on Earth
Extent of Water on Earth
• Nearly 75% of Earth’s surface is covered with water
• Oceans contain most of the Earth’s water
• Ocean water is salty and cannot be consumed by humans
Freshwater on Earth
Freshwater makes up only a small fraction of Earth’s water and is found in:
• Glaciers and ice caps
• Rivers and lakes
• Underground (groundwater)
• The atmosphere
Despite the abundance of water, water scarcity occurs due to:
• Unequal distribution
• Pollution
• Overuse and wastage
• Climate change
Distribution of Water and Land
The Earth is divided into:
• Northern Hemisphere
• Southern Hemisphere
The distribution of land and water is unequal:
• The Northern Hemisphere has more land
• The Southern Hemisphere has more water
Maps viewed from the North Pole and South Pole show circular lines (latitudes) and radiating lines (longitudes), which help us understand Earth’s structure and distribution.
Oceans of the World
There are five oceans on Earth:
- Pacific Ocean – Largest ocean
- Atlantic Ocean – Second largest
- Indian Ocean – Third largest
- Southern (Antarctic) Ocean – Fourth largest
- Arctic Ocean – Smallest ocean
Important Features
• Oceans are interconnected
• Boundaries shown on maps are conventional, not natural
• Water, marine life, and currents flow freely between oceans
Indian Ocean
• Bounded by Asia (north), Africa (west), Australia (east)
• Southern side merges with the Southern Ocean
• Two important parts:
– Arabian Sea (west of India)
– Bay of Bengal (east of India)
Marine Life
Marine Flora
• Algae
• Seaweeds
• Phytoplankton
Marine Fauna
• Fish
• Dolphins
• Whales
• Sharks
• Penguins
• Turtles
• Deep-sea creatures
Each ocean zone, from surface to deep sea, supports different life forms.
Oceans and Climate
Oceans play a major role in:
• Regulating Earth’s climate
• Producing more than half of the world’s oxygen
• Supporting the water cycle
• Sending rain to continents (monsoon winds)
Without oceans:
• No rainfall
• Earth would become a desert
• Life would not survive
Because of this, oceans are called “the lungs of the planet.”
Oceans and Natural Disasters
Cyclones
• Originate over warm oceans
• Bring strong winds and heavy rainfall
• Affect coastal regions
Tsunamis
• Caused by underwater earthquakes or volcanic eruptions
• Extremely powerful waves
• Travel long distances
• Cause massive destruction along coasts
2004 Indian Ocean Tsunami
• Occurred on 26 December 2004
• Affected India and 13 other countries
• Caused over two lakh deaths
• Severely affected Andaman & Nicobar Islands, Tamil Nadu and Kerala
Disaster Management
• Early warning systems help reduce damage
• India participates in the Indian Ocean Tsunami Warning System
• India has a National Disaster Management Authority (NDMA)
Continents
What is a Continent?
A continent is a large continuous landmass.
Counting Continents
Continents can be counted in different ways:
• 4 continents
• 5 continents
• 6 continents
• 7 continents
Most Widely Accepted List – Seven Continents
- Asia
- Africa
- North America
- South America
- Europe
- Australia
- Antarctica
Special Cases
• Europe and Asia together form Eurasia
• North and South America can be considered one landmass
• Africa and Eurasia may be combined in some classifications
Sizes of Continents
• Largest continent – Asia
• Smallest continent – Australia
• Coldest continent – Antarctica
Islands
What is an Island?
An island is a piece of land surrounded by water on all sides, smaller than a continent.
Important Facts
• There are lakhs of islands on Earth
• Greenland is the largest island
• India has over 1,300 islands
Major Indian Island Groups
• Andaman and Nicobar Islands – Bay of Bengal
• Lakshadweep Islands – Arabian Sea
India and Antarctica
• India has been part of the Indian Antarctica Programme since 1981
• First research station: Dakshin Gangotri (1983)
• Indian scientists study climate and environmental changes
• Antarctica has extremely harsh and cold conditions
Oceans and Human Life
Oceans have helped humans:
• Travel and migrate
• Trade goods
• Fish for food
• Conduct military campaigns
• Develop coastal cultures
Many cultures have myths, legends, gods, and stories related to the sea.
Threats to Oceans
Oceans are under serious threat due to:
• Plastic pollution
• Chemical waste
• Oil spills
• Overfishing
• Climate change
Millions of tonnes of plastic enter oceans every year, harming marine life.
World Oceans Day
• Celebrated on June 8
• Highlights the importance of oceans
• Encourages protection of marine ecosystems
Chapter Summary
• Oceans cover most of the Earth and are interconnected
• Continents are large landmasses; seven continents are commonly accepted
• The Northern Hemisphere has more land than the Southern Hemisphere
• Oceans regulate climate, support life, and provide oxygen
• Human activities are threatening oceans
• Protecting oceans is essential for the future of life on Earth