Table of Contents
- What are the four major domains of the earth?
- Why is the Biosphere important for living organisms?
- Lithosphere
- Name the major continents of the earth?
- Isthmus
- Strait
- Hydrosphere
- Atmosphere
What are the four major domains of the earth?
The following of the major four domains of the earth:
- Lithosphere
- Hydrosphere
- Atmosphere
- Biosphere
Why is the Biosphere important for living organisms?
The biosphere is the narrow zone of the earth where three components of earth Solid Portion( Litho Sphere), Liquid portion( Hydrosphere), and Gaseous portion( Atmosphere) meet. Life enables because everything is available that any life form needs. All life forms of the earth exist only in the biosphere.
The organism in the biosphere:
- Plant Kingdom
- Animal Kingdom
What is Lithosphere?
The lithosphere is comprising of earth crust and the thin layer of soil where all nutrients elements are found.
Earth surface are in two types:
- Continents
- Ocean basins
Continents
The highest mountain peak is Mt. Everest having 8848 meters of height.Greatest depth in ocean recorded in the Pacific Ocean at Mariana trench having 11,022 meters of depth.
Name the major continents of the earth?
There are 7 (seven) major continents in the earth, the following are listed in the decreasing order of area:
- Asia
- Africa
- North America
- South America
- Antarctic
- Europe
- Australia
Africa Continents:
- It is only continents where tropic of cancer, equator, tropic of Capricorn passes
- The Sahara Desert, world largest hot desert is in Africa
- The Nile, world longest river is in Africa
What is Isthmus?
- The narrow strip of land which separates two large water bodies and connect to larger landmasses.
- For example, Isthmus of Panama connects North American and South America with a narrow strip of land and separate two water bodies that are Pacifica ocean and Atlantic sea.
What is Strait?
A narrow passage of water connecting two large water bodies.
- Ural mountain separate Asia and Europe.
- The Andes, the world largest mountain range is in South America
- Australia, the smallest continents in the world.
- Antarctica, permanently covered with thick ice sheets. No permanently human settlements are there.
India's two research stations in Antarctica:
- Maitri
- Dakshin Gangotri
Name the two continents that lie entirely in the Southern Hemisphere?
- Australia
- Antarctica
Why is the Northern Hemisphere called the Land Hemisphere?
Most of the continents or lands of the earth are in the northern hemisphere, hence it is also called a land hemisphere.
Hydrosphere
Why is the earth called the ‘blue planet’?Earth is called a blue planet as more than 71% of the earth's surface is covered by water.
Composition of the above 71 % water:
- Oceans: 97.2 %
- Ice Sheets & Groundwater: 2.77 %
- Freshwater in river, lakes: 0.03 %
Oceans: All Oceans are interconnected and water of oceans are moving by
- Waves
- Tides
- Ocean Currents
There are five major oceans decreasing order of their size:
- Pacific Ocean
- Atlantic ocean
- Indian Ocean
- Southern Ocean
- Arctic Ocean
Pacific Ocean:
- It is 1/3rd size of earth surface
- Mariana Trench, deepest place of earth located in the Pacific ocean
- It is the almost circular shape
Atlantic Ocean:
- It is "S" shaped
- It is the busiest ocean in terms of trade, as it, irregular and indented coastline provides an ideal condition of natural harbors and port.
Indian Ocean:
- It is only an ocean named after county name that is India.
- It is in triangular-shaped
Arctic Ocean:
- Separated by a narrow stretch of shallow water from Pacific ocean called Berring straits
Atmosphere
Earth is surrounded by air is called the atmosphere.Air is a mixture of many gases or substances:
- Water Vapour
- Oxygen, it supports burning
- Nitrogen does not support burning.
- Carbon dioxide, plants consume Co2 during the photosynthesis process, it is ani burning air.
- Dust and Smoke
Uses of the atmosphere:
- It provides air to breathe
- Protect us from harmful effects from the Sun.
Composition of atmosphere:
Composition of Atmosphere is listed in the below tables:
Attributes
|
% in the Atmosphere
|
Nitrogen (N2)
|
78.084 = ~ 78%
|
Oxygen (O2)
|
20.946 =~ 21%
|
Argon (Ar)
|
0.934=~1%
|
Carbon Dioxide (Co2)
|
0.037
|
Neon(Ne)
|
0.00182
|
Helium (He)
|
0.00052
|
Krypton (Kr)
|
0.000114
|
Hydrogen (H2)
|
0.00005
|
Xenon (Xe)
|
0.000009
|
Name the different layers of the atmosphere.?
There are five different layers of the atmosphere:- Troposphere
- Stratosphere
- Mesosphere
- Thermo or ionosphere
- Exosphere
 |
| Layers of atmosphere |
Troposphere:
The following are the characteristics of the troposphere:
- Height of troposphere decrease from the equator ( 18 km ) to poles( 11 km)
- All the weather phenomenons such as cloud formation, thundering, etc are found in this layer.
- Greenhouse gases found
- Air Pressure and temperature decrease when we go up from the earth in the troposphere
- Vertical movement of air due to heating
- 75% of the air of the atmosphere is found in this layer.
- 99% of water vapors are found in this layer.
- Tropo pause is found at the top of the troposphere.
Stratosphere:
The following are the characteristics of the stratosphere:
- This is the second layer from the earth and goes up to 50 km.
- The ozone layer is found at the bottom of the stratosphere.
- Temperature increases with height due to the absorption of U V rays by the ozone layer.
- Polar stratospheric clouds are found in this layer.
- Calm atmosphere.
- In the lower stratosphere, commercial planes and jets fly
Mesosphere:
The following are the characteristics of the Mesosphere:
- This is the third layer and goes up to 80 km.
- Most Meteor burn in this layer
- Temperature decrease with height
- -90-degree temperature is in menopause( topmost)
- Thermosphere or Ionosphere
Thermosphere:
The following are the characteristics:
It extends from 80 to 1000 km
- High energy such as X-Ray and UV radiation are absorbed and temperature increase with height
- Temperature riches up to 1500 degree but you will feel cold because of very low air molecules.
- Colorful Aurora Borealis and Aurora Australia can be seen here.
- The international space station is in this layer.
Exosphere:
- The exosphere is up to half distance from the earth to the moon.
- A very very low atmospheric molecule made of mostly Helium & Hydrogen
- It absorbed most of the harmful radiation
Exercises
Q1. What are the four major domains of the earth?
Answer.
The following are the four major domains of the earth:
Lithosphere
Hydrosphere
Atmosphere
Biosphere
Q2. Name the major continents of the earth.
Answer:
The following are the 7 major continents on the decreasing order of areas.
- Asia
- Africa
- North America
- South America
- Antarctica
- Europe
- Australia
Q3. Name the two continents that lie entirely in the Southern Hemisphere.
Answer.
The following are the two continents that lie entirely in Southern hemisphere:
- Antarctica
- Australia
Q4. Name the different layers of the atmosphere.
Answer:
The following are the different layer of the atmosphere from earth surface:
- Troposphere
- Stratosphere
- Mesosphere
- Ionosphere or Thermosphere
- Exosphere
Q5. Why is the earth called the ‘blue planet’?
Answer.
Earth appears blue from outer space because 2/3rd of the earth's surface is covered by water that why it is called the blue planet.
Q6. Why is the Northern Hemisphere called the Land Hemisphere?
Answer.
Most of the continents or landmass lie in the northern hemisphere that why it is called a land hemisphere.
Q7. Why is the Biosphere important for living organisms?
Answer.
All life form of earth is only found in the biosphere. Life enables because everything is available that any life form needs that are land, water, and air.
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