Class 6 geography chapter 5-6

Chapter 5 

major domains of the Earth

Earth's surface is a complex in which three main components Overlap and interact
Lithosphere Solid person portion
Atmosphere Gaseous layers Surround Earth
Hydrosphere Comprises water in all its forms
Biosphere Narrow Zone where we find land Water and Air together which contain all forms of life.

Lithosphere
Rocks of the Earth's crust and thin layers of the soil

Two main division
Of Earth's surface Large land masses Continents
Huge water bodies ocean basins
Level of seawater remains same everywhere.

Elevation of land is measured from level of sea which is taken as zero.

Highest mountain peak
Mount Everest(8,848 meters)

Greatest depth 11,022 metres Mariana Trench in the Pacific Ocean

Continents

Seven major continents-
Asia, Europe, Africa, North America, South America, Australia and Antarctica

Greater part in northern hemisphere

Asia
largest continent One third of total area(In the eastern hemisphere)
Tropic of Cancer passes through this continent
Separated from Europe by Ural Mountains On west
Combined landmass of Europe and Asia is called Eurasia.

Europe
Much smaller than Asia. West of Asia Arctic Circle passes through
Bounded by water bodies on three sides

Africa
Second largest continent
Equator 0 degree
Middle of the continent
Large party northern hemisphere
Only continent through which Tropic of Cancer Equator and Tropic of Capricorn pass.
Sahara Desert World's largest hot desert
Bound on all sides by oceans and seas World's longest river Nile flows through Africa

North America
third largest continent
Link to South America by a very narrow strip of land called isthmus of Panama.

Completely in northern and western hemisphere
Three oceans around this continent -
North Pacific, North Atlantic And Arctic Ocean

South America
Mostly in southern hemisphere
Two oceans around it- South Pacific and South Atlantic

The andes- World's longest mountain range
Worlds largest river the Amazon

Australia
Smallest continent
Entirely in southern hemisphere Surrounded on all sides by oceans and seas Called an island continent

Antarctica
completely in southern hemisphere
Huge continent
South Pole lies almost at the center.
Covered with thick ice sheets
No permanent human settlement
Research stations-
India's Maitri and dakshin gangotri

Hydrosphere
Earth surface- 71 percent covered with water 29% land
In different forms-
Oceans, rivers, lakes, ice in glaciers underground water, water vapor in atmosphere
97% of Earth's water found in oceans

Rest In form of ice sheets and Glaciers Or under the ground.
Very small percentage is available as freshwater 0.03%

Oceans Major part of hydrosphere All interconnected

Always moving
Three Chief movements-
Waves, Tides and ocean currents

Five major oceans are-
Pacific Ocean, Atlantic Ocean, Indian Ocean, Southern Ocean, And the Arctic Ocean

Pacific Ocean
Largest
Spread over one-third of the Earth.
Mariana Trench Lies in specific ocean
Almost circular in shape
Asia Australia North and South America's around it.

Atlantic Ocean
second-largest s-shaped
Flanked by North and South America's on western side Europe and Africa on Eastern side.
Coastline of Atlantic Ocean is highly indented.
Provides ideal location for natural harbors And ports
Busiest ocean
Indian oceans Only ocean named after a country
Shape is almost triangular.
Northbound by Asia West by Africa East by Australia Southern Ocean
Encircles the continent of Antarctica and extends northward to 60 degrees south latitude.

Arctic ocean
Within the Arctic Circle Surrounds North Pole
Connected with Pacific Ocean by a narrow stretch of shallow water known as Bering Strait.

Atmosphere 

Surrounded by a layer of gas called atmosphere
Provide us air we breathe and protects us from harmful effects of sun rays.
Extends up to a height of about 1600 kilometer.
Divided into five layers -
Based on composition temperature and other properties.

Troposphere, Stratosphere, mesosphere thermosphere and exosphere

Atmosphere composed mainly of nitrogen and oxygen Make up 99% (Nitrogen 78 percent oxygen 21 percent)

And other gases like carbon dioxide argon and others comprise 1%

Carbon dioxide in minute amount is important as it absorbs heat radiated by the Earth. Thereby keeping the planet warm.
It is also essential for growth of plants.

Density of atmosphere varies with height

Maximum at sea level and decreases rapidly as we go up.
Climbers experience problem in breathing
Temperature also decreases
The atmosphere exerts pressure on the Earth varies from place to place

Air moves from high pressure to low pressure
moving air is known as wind.

Biosphere

Narrow zone of contact between land, Water and Air

Organisms in the biosphere broadly divided into plant kingdom and Animal Kingdom

Chapter 6

Major landforms of the Earth

Result of two processes -

Internal process leads to upliftment and sinking of the Earth's surface at several places.

External process- Continuous wearing down and rebuilding of the land surface.

Erosion wearing away of the Earth's surface
Deposition- Rebuild the surface

Different landforms
Depending on elevation and slope- Mountains, plateaus and plains

Mountains

Natural elevation of the Earth's surface

Glaciers- Permanently frozen rivers of ice

Mountains arranged in line known as range

Three types of mountains mountains -

Fold mountains
Block mountains
And volcanic mountains

Fold mountains

Himalayan And Alps are young fold mountains(Rugged relief And conical Peaks)
Aravali range- oldest fold mountain in the world
Appalachians In North Africa America
Ural mountains In Russia(Rounded features and low elevation)
Old fold mountains

Block mountains

Created when Large areas are broken and displaced vertically.
Uplifted blocks horsts
Lowered blocks Grabbin

The Rhine Valley and vosges Mountain In Europe

Volcanic mountains

Due to volcanic activity.
Mount Kilimanjaro In Africa
Mount Fujiyama In Japan

Mountains are Storehouse of water. Many rivers have their source In glaciers in the mountains

Plateaus

Elevated flat land
Standing above the surrounding area
Have one or more sides with steep slopes.
Maybe young or old.
Deccan Plateau Oldest plateau
East African plateau in Kenya, Tanzania and Uganda
And Western plateau of Australia.
Tibetan Plateau highest plateau(Height of 4000 to 6000 meter)

Retain mineral deposits
African Plateau famous for gold and diamond
In India Iron Coal and manganese are found in Chota nagpur plateau.

Plateau area several waterfalls
Hundru falls in Chota nagpur on river subernekha
and Jog Falls in Karnataka

Plains
Large stretches of Flatland
Not more than 200 meters above mean sea level.
Rivers flow down the slopes of mountain and erode them, carry forward eroded material deposit them
These deposits That plains are formed.

Plains are very fertile
Construction of Transport network is easy.
Very thickly populated region
Highly productive for cultivation

Indo-gangetic Plains most densely populated region of the country.