Chapter 9:
Earth
9.1 The System And Structure Of The Earth
The Earth system consists of four main components which are
interconnected :
Hydrosphere
Water zone that includes rivers, lakes
and seas.
Water trapped as ice, undereground
water and water vapour in the
atmosphere.
Atmosphere
Air zone covering the Earth’s surface /
the envelope of gases surrounding the
earth.
Geosphere
Rock and soil zone on the Earth’s
surface
Refers to the solid part of the Earth
Biosphere
Life zone consists of a variety of life
such as humans, animals, plants and
microorganism.
ATMOSPHERIC STRATIFICATION
(480 km and above) Contains light gases such as helium
and hydrogen.
Air become thinner towards space.
(80 – 480 km) Contains ions that can reflect radio waves.
Aurora, a stream of colourful lights resulting from
reactions of charged particles with Earth’s magnetic field
and atmospheric gases occurs here.
(50 – 80 km) Burning and destruction of meteoritis occur
in this layer.
(13 – 50 km) Contains ozone gas which absorb harmful
ultraviolet rays from sunlight is found here.
(0 – 13 km) The layer where living organism breathes,
wind blows and where clouds, rain and snow form.
OCEAN STRATIFICATION
The ocean can be divided into different zones :
Surface Zone
In this zone, the water is
very shallow and light can
penetrate.This makes the
zone suitable as a habitat
for plants.
Midnight Zone
This zone has a little or no
light.It is difficult for plants
to live at this depth but
this level of depth
becomes the habitat for
large marine animals, such
as giant squids and various
species of whales.
Dark Zone
This zone is very deep and
no light can reach
it.Therefore, most animals
in this zone have
shimmering bodies or are
able to glow in the dark.
DISTRIBUTION OF WATER ON EARTH
The water cycle process is continuous. The total amount of water contained in
Earth, on Earth’s surface and in Earth’s atmosphere is always constant.
EARTH’S LAYER
THREE MAIN LAYERS :
Crust
Mantle
Core
EARTH IS THE ONLY HOME FOR LIVING ORGANISMS
Earth’s temperature, which is not too hot
or too cold.
Due to the Earth’s position, which is not to
near or too far from the Sun.
The presence of water and oxygen on
earth also allow Earth to host all life.
LOVE OUR EARTH BY
TAKING GOOD CARE OF
THE ENVIRONMENT !
9.2 Composition of the Earth
Igneous rock Types of Sedimentary rock
Rocks
Igneous rock
Igneous rock Sedimentary rock Igneous rock
Formed the process of Formed by compression of Formed when igneous
cooling and freezing of deposited materials rocks or sedimentary rocks
magma or lava that flows carried by the rivers, are exposed to very high
out of the mantle. glaciers and wind. pressure and temperature.
Contains various Consists of many layers Usually harder than the
minerals. which are sometimes original rocks that formed
hollow and contain fossils. them.
THE PROCESS OF ROCK FORMATION
9.3 Main Processes of the Earth
Earth’s surface is formed by two processes, exogenic process and endogenic prosess.
Exogenic Process Process that occurs on Earth’s surface.
Examples: Weathering, erosion, mass and land
depletion, transport and sedimentation.
Endogenic Process Process that is caused by forces from within the Earth.
Forms and changes the Earth’s surface.
Examples: Mantle convection process, magma activity
and Earth’s crust movement (Plate tectonics).
EXOGENIC PROCESS
WEATHERING
It is a process of rock fragmentation and decomposition or
decay due to changes in temperature, rainwater, frosting and
microorganisms.
EROSION
It is a process of eroding of the Earth’s surface by moving
agents such as water, wind and waves.
TRANSPORT AND SEDIMENTATION
Weathered or corroded materials are moved by agents such
as running water, wind, waves and glaciers. The materials will
be sedimented when the velocity of the agents decrease.
MASS AND LAND DEPLETION
They involve soil movement from the top of a slope to below
as a result of gravitational force.
ENDOGENIC PROCESS Litosphere
MANTLE CONVECTION PROCESS
The high temperature in the mantle and the core of Earth
produces convection currents in the asthenosphere layer.
These currents are able to move Earth’s crust
PLATE TECTONICS
The Earth’s crust is divided into several pieces of plates. Plates
constantly move resulting in collision and divergence which
produce various landforms on Earth an continental drifts.
MAGMA ACTIVITY
Volcano allow molten and hot magma to flow out through it in
strong eruption. It will accumulate around the slope of the
vent and form volcanic cones.
9.4 Geohazard Phenomena
The consequences of the endogenic process are occurences of geohazard such as:
Tsunami
Volcanism
QUICKSAND
Can be found at riverbanks, marshes, lake
shorelines, beaches and areas near underground
springs.
ACID RAIN
Is a geohazard that usually occurs in the industrial
area.
SCIENCE AND TECHNOLOGY USED TO PREPARE FOR GEOHAZARDS
Landslide detector Earthquake detector
Tsunami Detector
9.5 Age of Earth
- The age of earth is
estimated to be 4.5 billion
years based on meteorites
obtained.
- Earth has gone through
various stage of periods,
which have changed or
shaped the Earth’s
landscape.
- Each era is divided into
several periods.
FOSSIL
Fossils are Earth’s materials such as plants, animals and insects which have been
submerged and burried for a very long period of time.
Fossil records can
provide information
about how animals
and plants species on
Earth have evolved
over million of years.
Also provide
information about
species that have gone
extinct.
Various organisms on Earth sice
5000 million years ago
Animal that have gone extinct :
9.6 Earth’s Resources and Applied geology
SURFACE WATER AND UNDERGROUND WATER
Found on the surface of Earth, Filss up the empty spaces between soil
example: seas, ponds and rivers. particles and the layers of permeable
rocks.
Can be polluted by waste materials
from industrial and housing areas. Can be polluted by domestic waste in
landfills.
ECONOMIC MINERALS
Earth consist of metallic minerals, non-metallic minerals and rare earth minerals.
Metallic minerals – iron Rare Earth minerals –
ore, tin and gold. consist of one or more
than one of 17 rare earth
Non-metallic minerals –
coal and petrolium. elements, unique
properties.
How petroleum and coal is formed?
How petroleum is formed.
Plants died naturally and the `
remains were burried under
layers of sediment and mud.
Under high pressure and heat,
fossil of plants turned into coal.
HYDROTHERMAL PROCESS
The advantages of the hydrothermal process in economic prospects
Tourist Attraction
Hot Spring in Sungai Klah, Perak
THE NEGATIVE EFFECTS OF UNPLANNED HUMAN ACTIVITIES
Deforestation Human Activities that are Erosion
Agriculture not well planned Flash Flood
Industrialisation Extinction of flora and fauna
Open Burning Water, air, therman and
sound pollution
Global warming