7. Lithosphere - is the rigid outermost
shell of a rocky planet.
It comprises the crust and the
portion of the upper mantle that
behaves elastically on time scales
of thousands of years or greater.
The Surface of the earth consists of
soil & rocks.
This surface layer of the earth is
called the CRUST or the
The crust includes both oceans &
the land masses.
8. Lithosphere is of great significance.
This layer provides all the MINERALS
including metallic minerals such as iron,
copper, gold, etc., to us.
Coal, natural gas & mineral fuels provide us
energy. It also provides us non-metallic
minerals such as limestone and gypsum.
This layer has soil on which all plants grow.
A fertile layer of soil is essential for good
agricultural output to support human
10. Hydrosphere - in physical geography
describes the combined mass of water
found on, under, and over the surface of
Hydrosphere includes the vast oceans,
seas, lakes, glaciers & polar ice sheet
that cover 71 per cent of the earth’s
surface, giving it the blue color. It
includes saline as well as fresh water.
The oceans contain 97 per cent of the
total water present on the planet.
Oceans provide us with various minerals
such as salt, manganese, bromine, etc.
11. Fish & other organisms are rich source of
Oceans & rivers also provide a medium
for transport by ships, boats etc.
Water on the earth is constantly in
motion. It keeps changing from one form
to other in a cyclical manner. It is called
Water cycle or Hydrological cycle.
Water evaporates from the water bodies
such as the oceans, lakes, ponds, etc.
THE HYDROLOGICAL CYCLE
12. The water vapor rises to reach the
upper layers of the atmosphere
where it condenses due to cooling
in the upper layers.
The CONDENSATION finally results
in PRECIPITATION. This water
seeps into the soil or flows down as
rivers, finally joining back the
oceans & seas.
The balance of water on earth thus
remains constant over time through
this cyclical process.
14. Atmosphere surrounds the earth like an
envelop of various gases. It is held
together by the gravitational force of the
Though the atmosphere extends beyond
1500 km above the earth, 97 per cent of
it lies within 25 km from the earth’s
surface. It is thus densest in the lower
15. The composition of the atmosphere :
NITROGEN is most abundant gas in the
atmosphere. It comprises 78 per cent of the total
volume of the air.
OXYGEN forms 21 per cent of the atmosphere. It is
vital for the survival of the living beings on the
The remaining 1 per cent consists of minute
quantities of gases such as argon, carbon dioxide,
etc. The atmosphere also contains dust particles
and water vapor.
The atmosphere acts like a blanket protecting the
earth from harmful rays of the sun especially the
ozone layer. It maintains the optimum temperature
which is essential for our survival on earth.
17. The Bioshere is the global sum of all
ecosystems. It can also be termed the
zone of life on Earth, a closed system
(apart from solar & cosmic radiation &
heat from the interior of the Earth) and
largely self regulating.
The biosphere includes the parts of the
atmosphere, lithosphere & hydrosphere
in which living organisms exist. It
contains organisms from tiny ones such
as algae, fungi to higher organisms such
as human beings.
18. It involves close relationship & interdependence of
all the other realms namely hydrosphere,
atmosphere & lithosphere. All the requisites for life
such as heat, water, air, food, habitat, etc., are
found in this realm. It is thus called the “Realm of
Biosphere is made of biotic or living environment
and abiotic or non-living environment. These two
interact with each other creating a balanced life
supporting environment called an ecosystem.