Structure of the Earth
Chapter 3
Section 1
Layers of the
Earth
Objectives:
Describe and compare the crust, mantle,
and core
Describe the structure of the lithosphere
Explain why matter within the
asthenosphere moves
Make a model of the earth and its layers
Skills Warm-up
Layer by Layer
List different objects that are made up of
layers.
Classify them based on number, type, and
thickness of layers.
Do most of the objects contain soft or hard
centers?
Earth’s Interior
Earth’s surface is made up
of ______, ______, and
_______
At one time, people
thought earth might be
___________
In 1864, Jules Verne wrote
“Journey to the Center of
the Earth”
What do you think is
between earth’s surface
and its center?
Earth’s Interior
What would you find if you could bore a hole deep
into the earth until you reached its center?
1. The _________ __________of the materials changes
as you go __________
2. Materials increase in ________ as you go __________
3. __________ and _________ increase with depth, but
at different rates
The way that these factors ________ in the earth’s
interior produces ________ with different ________
__________ and different ________ __________
Layers of the Earth
3 Main Layers based on ___________ properties:
________ – outermost layer of the earth
________ – middle layer of the earth
________ – innermost layer of the earth
Activity
Watch parts of Journey to
the Center of the Earth
Chemical Makeup
of Layers
From _________ to _________:
Crust – contains rocky ________ (silicon/oxygen
compounds) rich in _________ (Al), _______ (Fe),
and ___________ (Mg)
Thickness varies from _______to _______
Mantle – dense, mostly _____ and ____ _________
Makes up ________ of Earth’s volume
Makes up ________ of Earth’s mass
Core – very dense, mostly two metals: ___ and ___
Makes up ________ of Earth’s mass
Makes up ________ of Earth’s volume
Physical Makeup of Layers
3 Main Layers based on
___________ ___________:
• The _____________
includes the crust and
outer mantle – it is
strong, cold and rigid
• The _____________ is
just below in the mantle
- it is hot, semi-liquid,
and easily deformed
(plasticity)
• The ______________
(mantle) below the
asthenosphere – very
strong and rigid
because temperature
isn’t high enough
Physical Makeup of Layers
______ ______– liquid
Temperature
overcomes pressure
Circulation of
molten Fe is source
of magnetic field?
______ ______– solid
Very high pressure
overcomes high
temperature
Physical Properties of Layers
____________________ deep inside the earth are
______ __________to melt the silicates and other
substances that make it up
But, most of the earth’s interior is not ___________
Why????
Physical Properties of Layers
_________ inside the earth offset the
high temperatures
_______ pressures will not allow the
earth’s matter to _______
Physical
Properties
• _________ between __________ and ________ varies
with depth of each of earth’s layers
• Depending on this balance, matter can be ________,
________, or ___ _________
• ___________ – condition where the right balance of
pressure and temperature makes _______ material
_______ and ___________, but not completely liquid
Questions So Far
Answer the following 10 questions on a sheet of paper
and hand them in at the end of class (use your guided
notes)
1. How thick is the crust and what does it contain?
2. What materials does the mantle contain?
3. How much of the earth’s volume does the mantle
make up? How much of the earth’s mass?
4. Which layer is more dense, the mantle or the core?
(Remember D = M/V)
5. What materials account for the density of the
earth’s core?
Questions So Far
6. Based on their characteristic physical properties, what
are the 5 zones of the earth?
7. What does the lithosphere include?
8. What is the hot, soft, and flowing condition of the
asthenosphere called?
9. What is the physical condition of the outer core? Why?
10. What is the physical condition of the inner core? Why?
Skills Warm-up
Crust:
What objects besides the earth have
crusts?
How are their crusts similar to and
different from the earth’s crust?
Structure of the ____________
Two distinct parts:
___________ _______
Less dense because of higher
percentage of silicon and
oxygen, has more aluminum
Contains rocks called
rhyolite and granite
___________ _______
More dense and darker in
color
Contains rocks called basalt
and gabbro
Which varies in thickness
more?
Movement in the ______________
Material is ________ and ________ – like hot tar
Intense heat from Earth’s core causes this material to
_____________
Matter ______ as it heats, then cools and slowly _______
The result – ___________, a circular flow of matter that is
very slow, but has important effects!
Living on Oceanic Crust
Most oceanic crust is covered with _________
But many islands and the surface of some continents
are made of oceanic crust
_________ __________
___________
___________ __________ (Idaho, Washington, Oregon)
Oceanic crust soil is not as ________ because of large
amounts of _______ and ____________
Can be used to grow _________, _________, and
____________ or to graze ____________
Hawaii
.
Iceland
Graphing Activity
Temperature Changes in then Earth
Each student should complete the graphing activity
using the data and the graph paper that I give out.
If it is not completed in class, it must be done for
homework.
Plasticity Activity
Section 2
Studying the
Earth’s Interior
Objectives:
Identify two types of seismic waves
Describe the movement of seismic waves
Explain how earth scientists make
inferences about the earth’s core
Infer the characteristics of an object
through indirect observation
Skills Warm-up
Boiling Over:
Without removing the cover from a pot
cooking on the stove, how could you
determine what was cooking inside?
How might your method of determining
the pot’s contents be similar to the way
scientists determine what is inside of the
earth?
Studying the
Earth
How do we know
that some parts
are liquid and
some are solid?
How do we
know it’s hot
in there?
How do we know what the
chemical makeup is?
Studying the Earth
The interior of the earth _______
be observed _________
Deepest mine is ___ ____ _______
Deepest hole ever bored into the crust went down
only ________ – still far from the mantle
Earth’s _________ does provide some clues
________ _______(magma) from volcanoes is evidence
for high temperatures inside the earth
But most knowledge has come from
________ ___________ of how _______
_________from earthquakes travel
Shock Waves
• You have all probably
experienced shock waves
• Have ever hit a baseball or
softball with a bat?
• The vibrations or shock
waves travel through the
bat to your hands
• Shock waves can also
travel through the _______
Seismic Waves
____________ – sudden movements in the crust that
can cause shockwaves
________ _____– shock waves from an earthquake
can pass from one side of the Earth to the other
__________ – instrument that detects seismic waves.
Located all over Earth’s surface
Scientists gain valuable information about the
interior of earth by comparing the ________ and
________ _______of waves
Types of Seismic Waves
The two types most useful for studying the Earth’s
interior are:
____ _______ travel in a _______________ movement
of rock particles. Particles are squeezed together,
then pulled apart.
____ _______ travel in an ______________ movement
of rock particles.
S waves cannot travel through __________
Speed and Bending of Waves
_______ at which waves
travel depends partly on
the ________ of the rock it
travels through
The higher the density,
the ________ the speed
As a wave passes
through the Earth and
encounters rock types
with different densities,
its speed __________
If a wave passes through
rock layers at a slight
_______, a change in speed
can cause it to change
_____________
Speed and Bending of
Waves
Most seismic waves
travel in a ________
path through the
Earth. This curving
is called _________
When a wave
passes into a rock
of a different
________, its path
may ______ sharply
Inferring from Seismic
Waves
With knowledge of how
seismic waves travel,
scientists have:
Located the
_________ between
earth’s ________
Inferred the
________/_________
__________ of layers
Andrija Mohorovicic
Croatian scientist
In 1909 he discovered
the boundary between
the earth’s ______ and
_________
The Moho
_________ ___________–
“Moho”, the boundary
between the crust and the
mantle.
At a depth of between
____and ____km below
the surface, seismic waves
suddenly ______ _____
At this depth, rocks
became much more
______, and probably of a
different ________
________
The Core
When an earthquake
occurs, it sends seismic
waves in ____ _______
P and S waves are
detected by
______________
At a certain distance
away from where the
earthquake occurs
starts a zone in which
____ _________can be
detected
Called the _________
_______ – caused by
the Earth’s ________
The Core
Note that __________
__________ from the
earthquake, only ____
________ are detected.
What does this tell you
about the core?
It suggests that at least
part of the core is
_______ since no ____
________ are detected
The size of the earth’s
core can be calculated
from the size of the
_________ ________
Answer the following questions:
Where do the seismic waves from an
earthquake go?
What happens as P waves strike the core? Why?
Which waves cross the core?
Which waves are detected in the shadow zone?
What can be used to calculate the size of the
core?
Activity – How Does
Matter in the Mantle
Move