2. What is Earth Science?
This learning area is designed to provide a general background for the
understanding of Earth Science and Biology
It discusses the Earth's structure, composition, the processes that
occur beneath and on the Earth's surface, as well as issues,
concerns, and problems pertaining to natural hazards are also
included.
It also deals with the basic principles and processes in the study of
biology
3. ^ ^ /
Learning
Competencies:
01 Characteristics of Earth that are necessary
(S11ES-Ia-b-3)
02 Four subsystems of Earth
(S11ES-Ib-4)
03 Rock-forming minerals
(S11ES-Ib-5)
4. “We do not inherit the Earth from our ancestors;
we borrow it from our children.”
7. What are the unique characteristics of
Earth that allow the existence of Life?
Liquid Water Heat Source Atmosphere
Energy
Right Distance from Sun Strong Magnetic
Field Nutrients
It is protected by the plate tectonics from
the very hot temperature of the core
9. Liquid Water
H20
This matter dissolves and
transports materials in and out
of the cell. Only Earth has the
right chemical materials like
liquid water that could support
life.
Water makes up about 71 % of
the Earth's surface, while the
other 29% consists of
continents and islands
"Universal Solvent"
10. Heat Source
The heat that drives the different systems necessary to support life on Earth comes
from two sources: Internal Heating of the Earth and External Heating from the
Sun.
Internal
Heat coming from Earth is caused by radiogenic
heat from radioactive decay of materials in the core and
mantle, and extruded via active tectonic activities, such as
volcanism and plate movement
radiation which enters Earth. As sunlight strikes Earth,
some of the heat is trapped by a layer of gasses called
Atmosphere.
238^ 235U 232Th 40K
External
Heat provide by the sun is in the form of
11. Atmosphere
The atmosphere of Earth is composed of nitrogen (about 78%),
oxygen (about 21%), argon (about 0.9%), carbon dioxide (0.04%)
an
other gases in trace amounts.
Examples of greenhouse gases are
water vapor, methane, and carbon
dioxide.
Without the greenhouse effect, Earth would be frozen, more than 60° F
colder. As mentioned above, the atmosphere is capable of trapping heat
because of greenhouse gases.
12. TROPOSPHERE
The troposphere is the lowest layer of Earth’s atmosphere and s
ather on Earth. It is bonded on the top by a layer of air called the tropopau
eparates the troposphere from the stratosphere, and on bottom by the surfa
Earth.
STRATOSPHERE
The stratosphere is a layer of Earth’s atmosphere. It is the second layer of the
atmosphere as you go upward. The troposphere, the lowest layer, is right below the
stratosphere. The next higher layer above the stratosphere is the mesosphere.
MESOSPHERE
The mesosphere is a layer of Earth’s atmosphere. The mesosphere is directly
above the stratosphere and below the thermosphere. It extends from about 50 to 85
km (31 to 53 miles) above our planet. Temperature decreases with height throughout
the mesosphere.
13. THERMOSPHERE
The thermosphere is the layer in the Earth’s atmosphere directly abov
mesosphere and below the exosphere. Within this layer of the atmosphere, ultra'
diation causes photoionization/photodissociation of molecules, creating n
the thermosphere thus constitutes the larger part of the ionosphere.
EXOSPHERE
The exosphere is the uppermost region of Earth’s atmosphere as it gradually
fades into the vacuum of space. Air in the exosphere is extremely thin - in many ways it
is almost the same as the airless void of outer space.
14. Energy
Living things use light or chemical energy to run essential life processes.
With the availability of sufficient energy, organisms can perform different
metabolic reactions through the cells. The inner planets such as Earth, ge
too much sunlight for life. The outer planets get too little.
Photosynthesis
The Earth orbits in the so-called Goldilocks zone, where the planet
receives enough energy to allow water to exist as a liquid on its surface.
Too far, and the water would freeze. Too close, and the water would
rapidly
evaporate into the atmosphere.
15. Strong Magnetic Field
It shields us from the electromagnetic radiation
coming from the Sun. The magnetic field
deflects the radiation that may destroy the
ozone layer.
Earth's magnetic field (and the surface
magnetic field) is approximately a magnetic
dipole, with the magnetic field S pole near the
Earth’s geographic north pole and the other
magnetic field N pole near the Earth’s
geographic south pole.
16. Mt Ds Rg Uub Uut UuqUup
These are materials that build
and maintain an organism's
body. The inner planets
including Earth and moons
have the same general
chemical components which
makes nutrients easily
available in the environment.
Essential for humans
Suggested to be essential for humans
Nonessential for humans
Na Mg
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G
d
Ge
Sb
Mo
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Ta W Re
10* I0»
Db Sg Bh
1!«
Rf
Ra Ac Hs
There are various biogeochemical cycles and geologic processes that facilitat
the transport and replenishment of the chemicals and nutrients required by th
biotic factors. Examples include water cycle and volcanism. The presence of
volcanoes, cycle of water and atmosphere, contribute to the flow of nutrients
within earth's systems.
Nutrients
17. Tectonic Plates
• The earth's core causes the convection currents in
the mantle causing the overlaying lithosphere to
— move. However, the surface is protected from heat
from the core by the lithospheric plates.
• A tectonic plate (also called lithospheric plate) is a
massive, irregularly shaped slab of solid rock,
generally composed of both continental and oceanic
lithosphere. Plate size can vary greatly, from a few
hundred to thousands of kilometers across; the
Pacific and Antarctic Plates are among the largest.
Thermosphere
Mesosphere
Stratosphere
Crust
Outer Core
Upper Mantle
Mant e
Inner Core
To scale
18. Summary
Factors that make a Planet
Habitable
Just Right Situation in the Solar System
Temperature
Influences how quickly atoms and
molecules move.
Life seems to be limited to a
temperature range of -150C to
1150C. In this range, liquid water
can still exist under certain
conditions.
Surface: Only the Earth’s surface is
in this temperature range.
Subsurface: the interior of the solid
planets and moons may be in this
temperature range.
Water
Dissolves and transports
chemicals within and to from a cell
Water is regularly available. Life
can go dormant between wet
periods, but, eventually, water
needs to be available.
Surface: Only Earth’s surface has
water, though Mars once had
surface water and still has water
ice in its polar ice caps. Saturn’s
moon, Titan, seems to be
covered with liquid methane.
Sub-surface: Mars and some
moons have deposits of
underground ice, which might
melt to produce water. Europa,
has a vast ocean beneath its
outer shell in ice.
19. Atmosphere
Traps heat, shield the surface from
harmful radiation, and provide
chemicals needed for life, such as
nitrogen and carbon dioxide.
Earth & Venus are the right size to
hold a sufficient-sized atmosphere.
Earth’s atmosphere is about 100
miles thick. It keeps the surface
warm & protects it from radiation &
small- to medium sized meteorites.
Of the solid planets and Moons, only
Earth, Venus, & Titan have significant
atmospheres. Mars’ atmosphere is
about 1/100th that of Earth’s, too small
for significant insulation or shielding.
Energy
Organisms use light or chemical
energy to run their life processes.
With a steady input of either light or
chemical energy, cells can run the
chemical reactions necessary for
life.
Surface: The inner planets get too
much sunlight for life. The outer
planets get too little. Sub-surface: Most
solid planets & moons have energy-
rich chemicals.
Nutrients
Used to build and maintain an
organism’s body.
All solid planets & moons have the
same general chemical makeup, so
nutrients are present. Those with a
water cycle or volcanic activity can
transport and replenish the
chemicals required by living
organisms.
Surface: Earth has water cycle, an
atmosphere, and volcanoes to
circulate nutrients. Venus, Titan, Io,
and Mars have nutrients and ways to
circulate them to organisms.
Subsurface: Any planet or moon with
sub-surface water or molten rock can
circulate and replenish nutrients for
organisms
