Layers of Earth
Earth and Space
Layers Of Earth
Part I: Modeling Layers Based on Chemical Composition
Earth can be categorized and divided into layers by understanding
what kind of material makes up each layer. The crust of Earth is
made mostly of the elements of silicon, oxygen, and aluminum.
There are two types of crust that make up this outermost layer of
Earth. We observe the oceanic crust of Earth when we look
underwater at ocean floors or the continental crust when we stand
on the ground and look out over the land. The crust is not very thick
when compared to the rest of Earth.
Create a model by starting with Earth’s crust, which contains all land
surfaces and ocean floors.
Procedure:
1.  Place the plastic wrap inside the half sphere mold. Smooth the
plastic so it sticks inside the half sphere.
2.  Press the yellow clay into the sphere, leaving an empty space in
the middle. This layer will be very thin.
3.  In your Student Journal, find the cross section diagram of Earth
and color the crust (the outermost circle) and the legend yellow.
Next is Earth’s mantle. The mantle is also made of silicates, but they
are denser than the silicates of the crust because mantle silicates
include elements like iron and magnesium.
4.  Press the red clay into the space on top of the yellow clay, still
leaving a space in the middle.
5.  In your Student Journal, use red to color the mantle of the cross
section of your diagram and the legend.
Finally, model Earth’s innermost area, the core. The core includes
the densest Earth materials, the elements of iron and nickel.
6.  Press the white clay into the center of the model to represent the
core.
7.  In your Student Journal, leave the inner most circle white to
represent the core.
Give your model to your teacher so it can dry, and answer the questions in your Student Journal.
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Layers of Earth
Earth and Space
Part II: Modeling Layers Based on State of Matter
We learned that different materials make up Earth and that
the layers of crust, mantle, and core are classified based on
their different chemical compositions.
We expect to find these Earth materials in a state of matter,
probably solid or maybe liquid, but the interior of Earth holds
surprises as we continue to investigate a different way to
classify layers of Earth.
We don’t sink as we stand on the surface of Earth or even on
the bottom of the ocean floor because we stand on cool,
solid material. All of the crust is in a solid state of matter. A
little bit of the outer part of the mantle is solid, too. This layer,
based on its solid state, is called the lithosphere.
Procedure:
1.  Wait to take the model out of the mold until it is
completely dry.
2.  Look at the cross section part of your model. Use a black
felt tip marker to draw a dotted line all the way around the
red mantle, almost on the edge, so just a little of the red
is outside of the circle, along with all of the yellow (see
Example A).
Example A
3.  Remember that all of the yellow and a little of the red is
cool and solid. This cool and solid layer is called the
lithosphere and your dotted line is its boundary.
4.  Return to the cross-section diagram that you colored in
Part I of your Student Journal. Use the marker to draw in
a dotted line on the diagram, just as you did on the
model.
5.  Use a pencil to draw an arrow to point out and label the
lithosphere layer on the cross-section diagram.
Continue with Part II of this Student Guide on the following page.
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Layers of Earth
Earth and Space
Part II: Modeling Layers Based on State of Matter, continued
Now explore the layer that lies just below the lithosphere. The dotted
line on your model represents the boundary that separates the
lithosphere and the layer called the asthenosphere. The
asthenosphere is classified based on its state of matter; it does not
behave like either a solid or a liquid. The best way to describe the
asthenosphere is that it is “a solid that flows.” Let’s see where the
asthenosphere is located using the model.
Procedure:
1.  Look at the red mantle of your model. Find the lithosphere
boundary dotted line that you added. Use a black felt tip marker
to draw in one more dotted line just below the dotted line for the
lithosphere boundary. The thin layer between your two dotted
boundary lines is the asthenosphere. (Example B)
2.  Return to the cross-section diagram that you colored in Part I of
your Student Journal. Use the marker to draw in a second dotted
line on the diagram, so that it matches your model. Remember
that the red between these dotted lines is classified as the
asthenosphere because the material of this layer behaves as a
“solid that flows.”
Example B
3.  Use a pencil to draw an arrow to point out and label the
asthenosphere layer on the cross-section diagram.
4.  The inner core and the outer core are in different states of matter.
Both layers experience extremely high temperatures but the
inner core is solid. Draw a dotted line in a circle within the interior
of the white core to show the separation between the outer core,
which is in the liquid state of matter, and the inner core, which is
in the solid state of matter. (Example C)
5.  Add the same dotted line to your cross section diagram and use
a pencil to point out and label the inner and outer core.
Example C
6.  Follow disposal and reuse directions for materials, and then
answer Part II questions in your Student Journal.
Peel off and throw away the plastic wrap. Return the reusable mold. Go to Part II Student Journal.
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Layers of Earth
Earth and Space
Part III: Investigating Solids that Flow
In the upper part of Earth’s mantle, we find the
asthenosphere which lies directly below the cool and
solid lithosphere. The asthenosphere is a solid, but it
has plasticity, which allows it to move and flex, kind of
like Silly Putty ©. Let’s explore what “plasticity” really
means.
1.  Measure 30 grams of cornstarch and place it in the
plastic bag. Add 20 mL of water.
2.  Zip the bag closed and squeeze the water until it
mixes with all parts of the cornstarch and is thick and
without clumps. You should not be able to see any
dry cornstarch in the bag.
3.  Explore this mixture with the bag zipped closed.
4.  Extension – Take out a handful of the mixture and roll
it into a small ball. Stop and let the mixture “melt” in
your hand. This is how the plasticity of the upper
mantle works.
5.  Clean up your materials and work space.
6.  Answer the questions in Part III of your Student
Journal about the asthenosphere plasticity model.
After final discussions, complete Reflection and Conclusion questions in your Student Journal.
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