ECOLOGY AND ENVIRONMENT
The biosphere is the area of Earth
where living things exist. The
biosphere is divided into regions
known as biomes. In general,
biomes are areas with a particular
type of climate and similar plant
and animal species.
Biomes can be further subdivided into
dynamic, interrelated systems of
plants and animals, nonliving matter,
and the energy of the system. These
are called ecosystems.
Ecosystems vary in size. They can be as
small as a puddle or as large as Earth
itself. Any group of living and nonliving
things interacting with each other can
be considered as an ecosystem.
Within each ecosystem, there
are habitats which may also vary in size.
A habitat is a place where plants and
animals normally live. Some habitats
have lots of plants and animals, some
do not. Some habitats are near water,
some are on top of mountains. Each
habitat has a different mixture
of species living there. A habitat is the
place where a population lives.
HOW ENVIRONMENT SHAPES
ORGANISM?
•Environment decides
the colour of skin, hair
and overall shape of the
body
•Environment decides
the type of agriculture
and mining.
•Environment gives an
organism food and also
shapes all the features.
Human beings also play a key role in shaping the
environment!
Australian Bushfire
SYDNEY, JANUARY 03, 2020 04:40 IST
• At the peak of the summer holiday period, tens of
thousands of holidaymakers have been urged to leave
national parks and tourist areas on the NSW south coast
and eastern areas of Victoria before a return of
temperatures above 40C (104 F) and hot winds on Saturday.
• Yet with all roads blocked, sea transport is the only way out
of the stricken town and each round trip could take a day or
more. Forecasters are warning that temperatures will soar
above 40 degrees Celsius (104 Fahrenheit) on Saturday,
bringing a return of wild winds.
• Bushfires so far this season have scorched more than 4
million hectares (10 million acres) of bush land and
destroyed over 1,000 homes, including 381 homes
destroyed on the south coast just this week.
JANUARY 06, 2020 22:35 IST
• Australian Prime Minister Scott Morrison has called up
about 3,000 reservists as the threat of wildfires escalated
Saturday in at least three states.
• The fire broke containment lines Friday and was described
as “virtually unstoppable” as it destroyed buildings and
burned through more than 14,000 hectares (35,000 acres)
of Flinders Chase National Park. While the warning level for
the fire was reduced Saturday, the Country Fire Service said
it was still a risk to lives and property.
• Rural Fire Service Commissioner Shane Fizsimmons said the
264,000-hectare (652,000-acre) Green Wattle Creek fire in
a national park west of Sydney had the potential to spread
into Sydney’s western suburbs
• A total of 50 fires were burning across almost 320,000
hectares (791,000 acres) in Victoria state and conditions are
expected to worsen with a southerly wind change.
MELBOURNE, JANUARY 04, 2020 13:39 IST
• Authorities warn Australian bushfires developing their
own weather systems.
• The weather conditions are the results of the
formation of pyrocumulonimbus clouds which may
become a more frequent occurrence for Australians.
• The bushfires ravaging Australia are generating so
much heat that they are creating their own weather
systems including dry lighting storms
and fire tornadoes.
• A fire-generated thunderstorm has formed over the
Currowan fire on the northern edge of the fire near
Nowra. This is a very dangerous situation.
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Cumulus Clouds
• Cumulus clouds are puffy clouds that sometimes
look like pieces of floating cotton.
• The base of each cloud is often flat and may be
only 1000 meters (3300 feet) above the ground.
The top of the cloud has rounded towers.
• When the top of the cumulus resembles the
head of a cauliflower, it is called cumulus
congestus or towering cumulus.
• These clouds grow upward, and they can develop
into a giant cumulonimbus, which is a
thunderstorm cloud.
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Cumulonimbus clouds
• Cumulonimbus clouds are thunderstorm clouds that
form if cumulus congestus clouds continue to grow
vertically.
• Their dark bases may be no more than 300 m (1000 ft)
above the Earth's surface. Their tops may extend
upward to over 12,000 m (39,000 ft).
• Tremendous amounts of energy are released by the
condensation of water vapor within a cumulonimbus.
Lightning, thunder, and even violent tornadoes are
associated with the cumulonimbus.
INTERESTING FACTS
• They are formed beneath 20,000 ft. and are
relatively close to the ground.
• These clouds often produce lightning in their
heart. This is caused by ionized droplets in the
clouds rubbing against each other.
• Cumulonimbus clouds need warm and humid
conditions to form. This gives them the moist
warm updrafts needed to produce themThe
static charge built up create lightning.
DOMAINS OF ENVIRONMENT
LITHOSPHERE
• Lithosphere is the solid crust or the hard top
layer of the earth.
• It is made up of rocks and minerals and
covered by a thin layer of soil.
• It is an irregular surface with various
landforms such as mountains, plateaus,
plains,valleys, etc. Landforms are found over
the continents and also on the ocean floors.
INTERIOR OF THE EARTH
CRUST
The
uppermost layer over
the earth’s surface is
called the crust.
It is the
thinnest of all the
layers.
It is about 35 km.
on the continental
masses and only 5 km.
on the ocean floors.
• The main mineral constituents of the
continental mass are silica and alumina. It is
thus called sial (si-silica and al-alumina).
• The oceanic crust mainly consists of silica and
magnesium; it is therefore called sima (si-silica
and ma-magnesium)
• Just beneath the crust is the mantle which
extends up to a depth of 2900 km.
• The innermost layer is the core with a radius
of about 3500 km. It is mainly made up of
nickel and iron and is called nife.
What is the Mohorovičić
Discontinuity?
•
The Mohorovicic Discontinuity, or "Moho," is the
boundary between the crust and the mantle.
• In geology the word "discontinuity" is used for a
surface at which seismic waves change velocity.
• One of these surfaces exists at an average depth of
8 kilometers beneath the ocean basin and at an
average depth of about 32 kilometers beneath the
continents. At this discontinuity, seismic waves
accelerate.
When the molten magma cools, it becomes solid.
Rocks thus formed are called igneous rocks.
They are also called primary rocks.
There are two types of igneous rocks:
intrusive rocks
extrusive rocks.
Lava is actually fiery red molten magma coming out from
the interior of the earth on its surface. When this molten
lava comes on the earth’s surface, it rapidly cools down
and becomes solid. Rocks formed in such a way on the
crust are called extrusive igneous rocks. They have a
very fine grained structure. For example, basalt. The
Deccan plateau is made up of basalt rocks.
Sometimes the molten magma cools down deep
inside the earth's crust. Solid rocks so formed
are called intrusive igneous rocks. Since they
cool down slowly they form large grains.
Granite is an example of such a rock.
Sedimentary rocks.
• Sediments are transported and deposited by
wind, water, etc.
• Loose sediments are compressed and
hardened to form layers of rocks.
• These rocks may also contain fossils of plants,
animals and other microorganisms that once
lived on them.
Evolution of Landforms
• The earth movements are divided on the basis
of the forces which cause them.
• The forces which act in the interior of the
earth are called as Endogenic forces and the
forces that work on the surface of the earth
are called as Exogenic forces
Lithospheric plates
• The earth’s crust consists of several
large and some small, rigid,
irregularly shaped plates (slabs)
which carry continents and the
ocean floor.
Lithospheric plates.