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1. THE EARTH’S
INTERIOR
Prepared by: Renlie Jane Pascua- Pedronan

2. Learning Competency
 The learners demonstrate an understanding
of geologic processes that occur within the
Earth.

3. Learning Competency
 The learners explain why the Earth’s interior
is hot (S11/12ES-IIb-c-23).

4. Learning Objectives
Objectives:
Describe the properties of the layers of
the Earth.
Tell the composition of the layers of the
Earth.

5. Studying the Earth’s Interior
 Scientists tried to explore and study the
interior of the Earth. Yet, until today, there are
no mechanical probes or actual explorations
done to totally discover the deepest region of
the Earth.

6. How did they know?
 The Earth is made up of three layers: the crust,
the mantle, and the core.
 The study of these layers is mostly done in the
Earth’s crust since mechanical probes are
impossible due to the tremendous heat and very
high pressure underneath the Earth’s surface.

7. The Solid Earth
 geology -the study of the structure, history, and activity
of the solid Earth, including its interactions with the
atmosphere, hydrosphere, cryosphere, and biosphere
 solid Earth contains four major zones: the core (which
is divided into inner and outer zones), the (upper and
lower) mantle, the asthenosphere, and the
lithosphere

8. Geology
Forces that wear away
mountains and every
other feature on the
Earth’s surface.
Forces that shape the
Earth’s surface by
building up mountains
and landmasses.
Constructive Forces Destructive Forces

9. OUR HOME PLANET, EARTH
 Our Earth is about average among the planets in the Solar
System, in many respects:
largest and most massive of the four terrestrial planets,
but smaller and less massive than the four giant, or
Jovian, planets
third in distance from the Sun among the four terrestrial
planets
has a moderately dense atmosphere; 90 times less dense
than that of Venus but 100 times denser than that of Mars

10. OUR HOME PLANET, EARTH
 Earth is also unique in many respects:
the only planet with liquid water on its surface.
the only one having a significant (21%) proportion of
molecular oxygen
to our best current knowledge, the only planet in the
solar system having living organisms
the only terrestrial planet having a moderately strong
magnetic field
the only terrestrial planet having a large satellite

11. OUR HOME PLANET, EARTH

12. The Solid Earth
 the outer zones is not uniform and fixed over the
surface of the Earth, but shows much variability with
position and time.
 The field of plate tectonics deals with this spatial and
temporal variability.
 Geological phenomena such as earthquakes,
volcanoes, and continental drift are accounted for by
plate tectonics.

13. Earth's Interior

15. Exploring the Earth’s Interior with a Hard-Boiled Egg

16. Bring the following: (Individual)
hardboiled egg/s
 bread knife
used paper/newspaper to work on

17. Activity 1C: Hard Boiled Earth
PROCEDURE:
1. Prepare the materials. (hardboiled egg, bread
knife, used paper to work on)
2. Place used paper or newspaper on your working
area. Cut the egg into halves using a knife or a
cutter.
3. Draw the appearance of the cut hard-boiled egg.

18. Procedure:
 Using qualitative observation, describe the parts of the egg
from the outermost to the innermost by completing the table.
Write your answer on a piece of paper/ short bond paper.
PARTS OF THE
EGG
DECSRIPTION
EQUIVALENT TO
THE EARTH’S
LAYER
DESCRIPTION

19. Guide Questions:
1. How many layers does a hard-boiled egg have?
2. Which is the largest part? The thinnest?
3. Compare the parts of the egg to the model of the
earth.
4. Aside from the hard-boiled egg, what other things
can you compare to the earth’s interior layers?

21. CRUST

22. What is the Earth's Crust?
The Earth's crust is the solid,
rocky outer layer, covering the
entire planet. It is relatively thin
compared to other layers.
The Earth's crust is where all life
forms exist, providing the
environment for plants, animals,
and humans.

23. The Crust
thinnest and the outermost layer of the
Earth that extends from the surface to
about 32 kilometers below
Continental
Oceanic

24. Types of Crust: Continental
and Oceanic
1 Continental Crust
 This type of crust is thicker and less
dense, forming the continents and
landmasses.
 It's predominantly made of granitic
rocks.

25. Continental
 mainly made up of silicon, oxygen, aluminum,
calcium, sodium, and potassium
 mostly 35-40 kilometers
 found under land masses
 made of less dense rocks such as granite

26. Types of Crust: Continental
and Oceanic
2 Oceanic Crust
 This crust is thinner and denser,
found beneath the oceans.
 It's composed mainly of basaltic
rocks and is younger than
continental crust.

27. Oceanic
 oceanic crust is around 7-10 kilometers thick which
its average thickness is 8 kilometers.
 found under the ocean floor
 made of dense rocks such as basalt
 heavier than the continental crust.

28. Elements in the Crust

29. Moho Discontinuity
 While studying the speed of earthquake
waves, Croatian geophysicist Andrija
Mohorovičić discovers a boundary
between Earth's crust and mantle, which
becomes known as the Mohorovičić, or
Moho, Discontinuity.

30. Subduction Zones
1 Oceanic-Continental
Denser oceanic plate
subducts beneath continental
plate.
2 Oceanic-Oceanic
Denser oceanic plate
subducts under another
oceanic plate.
3 Continental-Continental
Two continental plates
collide, resulting in mountain
ranges.

31. Continental Rift Zones
Continental
Separation
Continents split
apart due to
tectonic forces.
Volcanic Activity
Magma rises to the
surface, creating
volcanoes and
associated features.
Formation of New Ocean
Over time, the rift valley can widen
and fill with water, forming a new
ocean basin.

32. Geological Processes Shaping the Crust
1 Volcanism
Volcanic eruptions, a result of molten rock (magma) rising
to the surface, can create new landforms, like islands and
mountains.
2 Earthquakes
Sudden movements along fault lines release energy in
the form of seismic waves, causing the ground to shake.
3 Weathering and Erosion
These processes break down rocks and transport them,
shaping the Earth's surface over time.
4 Mountain Formation
The collision of tectonic plates can create mountains,
folds, and faults, shaping the landscape.

33. Geological Features of the Earth's Crust
Canyons
Deep, narrow gorges
carved by rivers over
millions of years.
Mountains
Elevated landforms
created by tectonic
forces or volcanic
activity.
Ocean Trenches
Deepest parts of the
ocean, formed at
convergent plate
boundaries where one
plate subducts beneath
another.

34. Significance and Importance
of the Earth's Crust
Home to Life
The Earth's crust
provides the
environment for all living
organisms, supporting
diverse ecosystems.
Natural Resources
The Earth's crust contains
valuable natural
resources, including
minerals, fuels, and
water.
Understanding Our Planet
Studying the Earth's crust
helps us understand
geological processes and
the history of our planet.
Protection
The Earth's crust
provides protection from
the harsh conditions of
space, creating a safe
environment for life.

35. The Earth's
Mantle

36. The Mantle
 Beneath the crust is the mantle
 extends to about 2900 kilometers from the Earth’s surface
 about 80% of the Earth’s total volume
 about 68% of its total mass
 mainly made up of silicate rocks
 and contrary to common belief, is solid, since both S-waves
and P-waves pass through it

37. The Mantle
 mostly made of the elements silicon, oxygen, iron and
magnesium
 lower part of the mantle consists of more iron than the upper
part
 lower mantle is denser than the upper portion
 temperature and the pressure increase with depth
 high temperature and pressure in the mantle allows the solid
rock to flow slowly

38. Upper Mantle
This layer, extending from the crust down to
around 410 km, is composed of peridotite, a
dense, dark-colored rock rich in magnesium
and iron.
Lower Mantle
The lower mantle, stretching from 410 km to
the core, is hotter and denser, with the mineral
composition shifting due to intense pressure.
Composition and Structure of the Mantle

39. Heat Transfer and Convection Currents
Heat Source
The Earth's core generates immense heat, primarily through
radioactive decay of elements.
Mantle Flow
This heat creates convection currents, where hot, less dense rock
rises and cooler, denser rock sinks, creating a circular flow.
Driving Force
These currents are a fundamental force driving plate tectonics,
shaping Earth's surface.

40. Mantle Plumes and Hotspot Volcanism
1 Upwelling Plumes
Mantle plumes are
narrow columns of
abnormally hot rock
that rise from deep
within the mantle.
2 Volcanic Activity
When these plumes
reach the surface,
they can create
hotspots, regions of
intense volcanic
activity, often
forming island
chains like Hawaii.
3 Geochemical Signatures
Volcanic eruptions
from hotspots often
produce unique
geochemical
signatures, helping
scientists
understand the
composition of the
deep mantle.

41. Plate Tectonics and the Role
of the Mantle
1 Mantle Convection
The mantle's convection currents
provide the driving force for plate
tectonics.
2 Plate Movement
The plates, riding on the moving
mantle, interact with each other,
causing earthquakes, volcanic
eruptions, and mountain formation.
3 Earth's Dynamics
The interplay between the mantle and
tectonic plates is responsible for the
Earth's dynamic surface, shaping
continents, oceans, and landscapes.

42. Mantle Mineralogy and Phase Changes
Pressure Effects
The immense
pressure within the
mantle causes
minerals to transform
into denser phases,
changing their crystal
structure.
Phase Transitions
These phase
transitions play a
crucial role in the
physical and chemical
properties of the
mantle, affecting its
flow and the behavior
of seismic waves.
Mineral Research
Studying mantle
minerals and their
phase changes helps
us understand the
evolution of the Earth
and its internal
processes.

43. Implications for Earth's Evolution and Future
Volcanic Activity
The mantle influences
volcanic eruptions,
which release gases and
minerals, impacting
Earth's atmosphere and
climate over time.
Earthquakes
The mantle's movement
drives plate tectonics,
causing earthquakes
that shape landscapes
and release energy
within the Earth.
Mountain Building
The collision of tectonic
plates, driven by mantle
convection, results in
the formation of
mountain ranges,
shaping Earth's
topography.

44. The Earth's Core

45. What is the Earth's Core?
Inner Core
The solid, innermost
part of the Earth,
primarily composed
of iron with a
temperature of
about 5,200°C
(9,392°F).
Outer Core
A liquid layer of iron
and nickel that
surrounds the inner
core, with
temperatures
ranging from
4,500°C to 5,500°C
(8,132°F to 9,932°F).

46. The Core
2000-5000o
C
core is subdivided into two
layers:
the inner
the outer core.

47. Core
Outer Core
The outer core is a
liquid layer
composed
primarily of iron
and nickel. It is
responsible for
generating Earth's
magnetic field.
Inner Core
The inner core is a
solid sphere of
iron and nickel,
despite the
extreme
temperatures. The
immense pressure
at the core causes
the iron to solidify.

48. Outer Core
 2900 kilometers below the Earth’s surface
 2250 kilometers thick
 made up of iron and nickel
 temperature reaches up to 2000o
C at this very high
temperature, iron and nickel melt

49. Outer Core
 Aside from seismic data analysis, the
Earth’s magnetic field strengthens the idea
that the Earth’s outer core is molten/liquid
 mainly made up of iron and nickel moving
around the solid inner core, creating Earth’s
magnetism

50. The Inner Core
 made up of solid iron and nickel and has a radius of 1300
kilometers
 about 5000o
C
 extreme temperature could have molten the iron and nickel but
it is believed to have solidified as a result of pressure
freezing, which is common to liquids subjected under
tremendous pressure

51. The Inner Core
 Aside from the fact that the Earth has a magnetic field and
that it must be iron or other materials which are magnetic in
nature, the inner core must have a density that is about 14
times that of water.
 Average crustal rocks with densities 2.8 times that of water
could not have the density calculated for the core.
 So iron, which is three times denser than crustal rocks,
meets the required density.

52. Clues that the inner core and the outer core
are made up of iron
 Iron and nickel are both dense and magnetic.
 overall density of the earth is much higher than
the density of the rocks in the crust
 suggests that the inside must be made up of
something denser than rocks

53. Clues that the inner core and the outer core are made
up of iron
 Meteorite analysis have revealed that the most common
type is chondrite.
 Chondrite contains iron, silicon, magnesium and
oxygen; some contains nickel.
 The whole earth and the meteorite roughly have the
same density, thus the Earth’s mantle rock and a
meteorite minus its iron, have the same density.

54. Structure of the Earth's Core
1 Inner Core
The inner core is solid due to immense pressure, despite its high
temperature.
2 Outer Core
The outer core is liquid, allowing for the flow of molten iron, which
generates Earth's magnetic field.

55. Composition of the Earth's Core
Element Percentage
Iron 88%
Nickel 5.5%
Sulfur 4.5%
Silicon 1%
Oxygen 0.5%

56. Importance of the Earth's
Core
1 Magnetic Field
The Earth's
magnetic field
protects us from
harmful solar
radiation,
allowing life to
thrive.
2 Plate Tectonics
The Earth's core
drives plate
tectonics, which
shapes
continents and
creates
mountains,
volcanoes, and
earthquakes.

57. How the Earth's Core Generates Magnetic Field
Convection Currents
Heat from the Earth's core
creates convection currents in
the liquid outer core.
Electric Currents
The movement of molten iron
generates electric currents,
which in turn create a
magnetic field.

58. Dynamics of the Earth's Core
Seismic Waves
Seismic waves travel through the
Earth's core, providing scientists
with valuable information about its
structure and composition.
Magnetic Reversals
The Earth's magnetic field
periodically reverses, with the
north and south poles switching
places.

59. Exploring the Earth's Core
Drilling
Scientists have drilled deep into the Earth's crust, but
reaching the core remains a significant technological
challenge.
Seismology
By studying seismic waves, scientists can infer the
structure and composition of the Earth's core.
Satellite Data
Satellites provide valuable data about the Earth's
magnetic field, which is generated by the core.

60. Did you know?
 The deepest mine in the world, the gold mine in
South Africa, reaches a depth of 3.8km.
But...
You would have to travel more than 1,600 times that
distance-over 6000km-to reach the earth’s center.

61. The Composition of the Earth’s Interior

63. DENSITY AND TEMPERATURE VARIATION IN DEPTH

64. Remember:
 The ability of the asthenosphere to flow slowly
is termed as plasticity.
 crust and the uppermost part of the mantle
form a relatively cool, outermost rigid shell
called lithosphere (Gk.lithos means “stone”)
and is about 50 to 100 kilometers thick

65. Remember:
 Beneath the lithosphere lies the soft, weak layer known as the
asthenosphere (Gk. asthenes means “weak”) made of hot
molten material, about 300 – 800o
C
 upper 150 kilometers has a temperature enough to facilitate a
small amount of melting, and make it capable to flow
 facilitates the movement of the lithospheric plates
 lithosphere, with the continents on top of it, is being carried by
the flowing asthenosphere.

66. Seismic Waves
 Seismic waves from earthquakes are used to
analyze the composition and internal structure
of the Earth.
What are seismic waves?
Wheel of Names | Random name picker

67. Seismic waves
 Earthquake is a vibration of the Earth
produced by the rapid release of energy.
 This energy radiates in all directions from the
focus in the form of waves called seismic
waves.

68. Earthquake: Seismic Wave
Wave
Direction
Fault
Epicenter
Focus
https://ds.iris.edu/seismon/swaves/index.php

69. Types of Seismic Wave
Surface waves
Body Waves

70. Surface Waves
 can only travel through the surface of the Earth
 arrive after the main P and S waves
 They are slower-moving than body waves but are
much larger and therefore more destructive.
 They travel only through solid media.

71. Types of Surface Waves

72. Types of Surface Waves

73. Rayleigh Waves
 named after John William Strutt, Lord
Rayleigh, who mathematically predicted the
existence of this kind of wave in 1885
 wave rolls along the ground just like a wave
rolls across a lake or an ocean
 up and down or side-to-side similar to the
direction of the wave’s movement
 shaking felt from an earthquake

74. Rayleigh Waves

75. Love Waves
 named after A.E.H. Love, a British
mathematician who worked out the
mathematical model for this kind of wave in
1911.
 faster than Rayleigh wave
 it moves the ground in a side-to-side
horizontal motion, like that of a snake’s
causing the ground to twist
 cause the most damage to structures during
an earthquake.

76. Love Waves

77. Body waves
can travel through the Earth’s inner
layers
they are used by scientists to study the
Earth’s interior
higher frequency than the surface
waves

78. Body waves
2 types
P-Waves (Primary waves)
S-waves (Secondary waves)

79. P-waves (Primary)
is a pulse energy that travels quickly
through the Earth and through liquids
travels faster than the S-wave
it reaches a detector first

80. P-waves (Primary)
 compressional waves, travel by particles
vibrating parallel to the direction the wave travel
 move backward and forward as they are
compressed and expanded
 they travel through solids, liquids and gases

81. S-waves (Secondary/Shear)
 pulse energy that travels slower than a P-wave
through Earth and solids
 Move as shear or transverse waves, and force
the ground to sway from side to side, in rolling
motion that shakes the ground back and forth
perpendicular to the direction of the waves

82. S-waves (Secondary/Shear)
cannot travel through any liquid
medium led seismologists to conclude
that the outer core is liquid

83. Seismic Waves movement

84. Seismic Waves and the
Study of the Mantle
Type Behavior Information
P-waves Compressional, travel
through solids and
liquids
Provide information
about the overall
structure and density
of the mantle.
S-waves Shear, travel only
through solids
Reveal the presence of
solid rock, helping
determine the depth
and composition of
different mantle layers.

85. Seismic Waves: Interior Part

86. Remember:
 P-waves are detected on the other side of
the Earth opposite the focus.
 A shadow zone from 103° to 142° exists
from P-waves
 Since P-waves are detected until 103°,
disappear from 103° to 142°, then
reappear again, something inside the
Earth must be bending the P-waves

87. Remember:
 existence of a shadow zone, according to German
seismologist Beno Gutenberg ( u t ən b k), could
ɡ ː ɛʁ
only be explained if the Earth contained a core
composed of a material different from that of the
mantle causing the bending of the P-waves
 To honor him, mantle–core boundary is called
Gutenberg discontinuity

88. Remember:
 From the epicenter, S-waves are detected until 103°, from
that point, S- waves are no longer detected
 S-waves do not travel all throughout the Earth’s body
 knowing the properties and characteristics of S-waves (that it
cannot travel through liquids), and with the idea that P-waves
are bent to some degree, this portion must be made of
liquid, thus the outer core

89. Remember:
 1936, the innermost layer of the Earth was predicted by Inge
Lehmann, a Danish seismologist
 discovered a new region of seismic reflection within the core
 Earth has a core within a core

90. Remember:
 the outer part of the core is liquid based from the
production of an S wave shadow and the inner part must be
solid with a different density than the rest of the surrounding
material
 size of the inner core was accurately calculated through
nuclear underground tests conducted in Nevada.
 echoes from seismic waves provided accurate data in
determining its size

91. "Exploring Earth’s interior reveals a
history written in stone, a record of
transformations that continue to shape
our future."