Know about environment and its different layers. Are they helpful to us or not?

3. Only after the last tree has been cut
down,
Only after the last river has been
poisoned,
Only after the last fish has been
caught,
Only then will you find that money
cannot be eaten.
NATIVE AMERICAN PROPHECY

4. Environment is the sum total of all the
external forces, influences and conditions,
which affect the life,
nature, behaviour and the growth,
development and maturation of living
organisms.

6. Environment includes water, air and land,
and their inter-relationships with human
beings, other living creatures, plants and
microorganisms.
Environment provides basic services
essential to humanity such as supporting
life, supplying materials, energy and
absorbing waste products.

7. The four major components of
environment include lithosphere,
hydrosphere, atmosphere and biosphere,
corresponding to rocks, water, air and
life respectively.

8. It is the outermost layer of earth called crust, which is
made of different minerals.
Rocky portion of the environment which includes the
study of rock, soil and landforms.
Soil consists of sand, silt, clay and humus that helps in
degrading organic matter.
Its depth can reach up to 100 kilometres and is found
on both land (terrestrial crust) and oceans (oceanic
crust). The main component of lithosphere is earth’s
tectonic plates.

9. SOIL
COMPOSITION:-
OXYGEN- 46.6%
SILICON- 27.7% IRON- 5%
CALCIUM- 6.6%
ALLUMINIUM-
8.3%
SODIUM- 2.83%
POTTASIUM-
2.5%
MAGNESIUM-
0.0%

10. The Hydrosphere comprises all types of water resources oceans,
seas, lakes, rivers, streams, reservoir, polar icecaps, glaciers, and
ground water.
 (i) Nature 97% of the earth’s water supply is in the oceans,
 (ii) About 2% of the water resources is locked in the polar
icecaps and glaciers.
 (iii)Only about 1% is available as fresh surface water-rivers,
lakes streams, and ground water fit to be used for human
consumption and other uses.

12. Pacific Ocean covers
1/3rd of the earth
surface and is the
deepest and the largest
of all the oceans.
Atlantic Ocean is half of
the sixe of the Pacific
ocean and covers 1/6th
of the earth surface.
Indian Ocean is smaller
than Atlantic Ocean.
Arctic Ocean is the
smallest of all four
oceans.
DOMINANT
OCEANS

13. The atmosphere implies the protective blanket of gases,
surrounding the earth:
(a) It sustains life on the earth.
(b) It saves it from the hostile environment of outer space.
(c) It absorbs most of the cosmic rays from outer space and a major portion of the
electromagnetic radiation from the sun.
(d) It transmits only here ultraviolet, visible, near infrared radiation (300 to 2500
nm) and radio waves. (0.14 to 40 m) while filtering out tissue-damaging ultraviolet
waves below about 300 nm.
The atmosphere is composed of nitrogen and oxygen. Besides,
argon, carbon dioxide,
and trace gases.

14. NITROGEN:78
.08%
OXYGEN:
20.95%
ARGON:0.
93%
CO2:0.034
%

15. Lapse Rate: It’s the change in temperature
with respect to the change in height.
POSITIVE LAPSE
RATE
NEGATIVE LAPSE
RATE
As the height
increases, the
temperature tends to
decrease.
As the height
decreases, the
temperature tends to
increase.

16. The atmosphere can be divided
into layers based on its
temperature, as shown in the
figure below. These layers are
the troposphere,
the stratosphere,
the mesosphere and
the thermosphere.

18. • It’s the fourth and last
layer, with negative lapse
rate, height : width =
500:415 km, contains
maximum temt. of more
than 1200*C, with the
lowest of pressure and
density.
• It’s the third layer, with
positive lapse rate, height :
width = 85:35 km,
dissociates gaseous
molecules and is the
coldest region of the
atmosphere (100*C).
• It’s the second layer, with
negative lapse rate, height :
width = 50:37.5 km, without
any dust, humidity or any
weather phenomenon. This
layer is important for radio
comm. And flight of jet
planes. Ozone is present in
this layer.
• It’s the first layer, with
positive lapse rate average
height : width is 12.5 km
with 80% of air mass and
all the weather
phenomenon occurs in
this very layer.
TROPOSPHRE STRATOSPHERE
THERMOSPHEREMESOSPHERE

19. Biosphere indicates the realm of living
organisms and their
interactions with environment, viz
atmosphere, hydrosphere and
lithosphere.