Major Domains of the Earth
Overview
Everything above Earth can be divided into four domains: land (lithosphere), water (hydrosphere), air (atmosphere), and the zone where all three meet and support life (biosphere). This chapter takes you on a tour of the continents and oceans.
Typed Notes
Four Domains — All Connected to Each Other
Earth has four major domains, and they are all connected to one another: rivers are formed from land (lithosphere → hydrosphere), water evaporates into the air (hydrosphere → atmosphere), wind and clouds bring rainfall (atmosphere → everything else). And where all three meet, there is life — the biosphere. A change in one domain affects the others: cutting forests reduces rainfall, and reduced rainfall causes rivers to dry up.
Lithosphere and the Seven Continents
The lithosphere is the solid, rocky surface of Earth. It has two kinds of landmasses: continents (large, solid landmasses) and islands (smaller pieces of land surrounded by water on all sides). There are 7 continents in total: Asia — the largest (India is located here; it also has the largest share of the world's population); Europe — located next to Asia, with the Ural Mountains separating the two; Africa — home to the Sahara, the world's largest desert; North America and South America — separated from each other by the Panama Canal; Antarctica — the coldest continent, covered in ice, with no permanent human residents, only scientists (India has research centres here: Maitri and Himadri); Australia — the smallest continent, known as the island continent.
Hydrosphere and the Five Oceans
The hydrosphere includes all the water on Earth — oceans, rivers, lakes, ice, and water vapour. About 71% of Earth is covered by water, and the largest portion of it is held in five oceans: Pacific — the largest (covers about one-third of Earth's surface); Atlantic — the second largest, S-shaped, lying between the two Americas; Indian — the only ocean named after a country (India); Southern — surrounding Antarctica on all sides; Arctic — the smallest, covered by ice throughout the year. Ocean water is salty and cannot be drunk — fresh, drinkable water is very limited, so it is important to conserve it.
Atmosphere and Biosphere
The atmosphere is the blanket of air that surrounds Earth — made up of nitrogen (78%), oxygen (21%), and CO2 along with other gases (1%). It protects us from the Sun's harmful rays, keeps the temperature balanced, and provides the oxygen we breathe. The biosphere is the zone where the lithosphere, hydrosphere, and atmosphere come together to provide a home for life — plants, animals, humans, and micro-organisms. It is the smallest domain, but the most special — because life exists only here.
Key Concepts
Revision ke liye ek nazar — exam se pehle yahi padhna hai.
- 01Lithosphere: The solid, rocky outer surface of Earth — the land. Mountains, plains, and plateaus are all part of it, and it is where we live.
- 02Hydrosphere: All the water on Earth — oceans, rivers, lakes, and ice. About 71% of Earth is covered by water; the largest water body is the Pacific Ocean.
- 03Atmosphere: The blanket of air surrounding Earth — made up of nitrogen (78%), oxygen (21%), and other gases (1%). It protects us from the Sun's harmful rays.
- 04Biosphere: The zone where the lithosphere, hydrosphere, and atmosphere meet and where life exists — small but very special. Plants, animals, and humans — all are part of the biosphere.
- 057 Continents: Asia (the largest, India is located here), Africa, North America, South America, Antarctica (the land of ice), Europe, Australia (the island continent and the smallest).
Questions & Solutions
Pehle khud try karo — phir solution kholo. Yahi tariqa topper banata hai.
What are the four major domains of Earth?
Which is the largest continent and which is the largest ocean?
State two facts about Antarctica.
Why is the atmosphere essential for us?
Why is the Indian Ocean called the ocean named after India?
What is the difference between continents and islands?
Earth has 4 domains: lithosphere (land), hydrosphere (water), atmosphere (air), and biosphere (life). There are 7 continents — Asia is the largest; and 5 oceans — the Pacific is the largest. Antarctica is a continent of only ice and scientists.
Chapter-end quiz
4 MCQsOption tap karo — turant pata chalega sahi ya galat, explanation ke saath.
Q1.Which is the largest ocean?
Q2.What is the solid, rocky surface of Earth called?
Q3.Which continent is known as the island continent?
Q4.Which gas is present in the highest amount in the atmosphere?
Mark karo — dashboard par progress dikhega.