Download Layers of the Earth

Layers of the Earth
Plate Tectonics Unit
Day 1 notes
Interior of the Earth
• What are the 4 layers of the Earth?
– Crust
– Mantle
– Outer core
– Inner core
• Which layer has the convection currents?
The Mantle
Lithosphere:
solid layer the
plates sit on
Asthenosphere:
plastic layer that
can flow with
convection currents
Lower mantle:
rigid layer
Asthenosphere Lab
• The asthenosphere is part of the
upper mantle, located directly below
the crust layer.
• Unlike the solid, rocky crust, the
asthenosphere is a semi-solid region
of melted rock.
• Because of the temperature and
pressure at this location, the magma
(melted rock) here can act both as a
rigid solid and a fluid liquid.
• Although the material in this
location is made from rock, it can
still be bent twisted, folded and/or
molded
Asthenosphere Lab
• In today’s lab, you will create a model substance that
acts like the asthenosphere
• The substance will sometimes act solid and sometimes
act liquid
(it has plasticity)
Asthenosphere Lab
• Put one “spoonful” of cornstarch into your glass beaker
• Fill the graduated cylinder with 10 mL of water
• Pour 5mL of water into the glass beaker with your
“spoonful” of cornstarch
• Stir the mixture together
• If the mixture is too thin and watery, add a little more of
the cornstarch
• If the mixture is too thick and gloopy, add a little bit more
water (less than the 5 mL left in your cylinder)
• When the mixture is just right, it will be a bit difficult to
stir. If you can’t tell if you’ve mixed it just right, raise your
hand and ask. 
• Try to pour the mixture from the beaker into your hands.
Do this over your plastic bin.
Plate Tectonics!
Heat is always moving from the interior of the Earth toward space!
1) What is happening on the left side of this animation (the yellow)?
2) What is happening on the right side of this animation (the blue)?
3) How is this like convection?
Convection currents in the Earth
• Molten rock is less dense
than solid rock so it wants
to move up and “float”
• As the rock moves further
up some gets forced out
onto the Earth’s crust.
• The remaining rock is
cooled (it is farther away
from its heat source) and
begins to sink.
• Then the whole process
begins again.
Reflection Questions
(answer on the bottom of your notes from yesterday)
1. How did the mixture act when you tried to pour it into your
hands?
2. How did the mixture act when you tried to roll it into a ball in
your hands?
3. How might the plasticity of the asthenosphere influence the
movement of the Earth’s lithospheric plates?
4. What provides the energy to move the plates in the
lithosphere? How does it work? (Hint: see page 310 in red book
if needed)
5. What if the mantle loses its plasticity? Predict what the
impact will be. (Hint: think interior and exterior of the Earth)
1.
2.
Measure the space you have on your paper (in cm)
Take the thickness of earth (6411km) and divide by your paper
size.
This is your scale factor (1 cm = ____km)
3. Use a calculator to divide each layer thickness by your scale factor
to figure out the distance of your drawing
4. Measure out each distance and sketch your pie wedge drawing
5. Color and label each layer of the earth in your drawing.
Earth Layer
Actual thickness
(km)
Inner Core
1216
Outer Core
2270
Mantle
2885
Crust
Total Earth
Layer thickness for
drawing (cm)
25
6411
(length of page)
Movement of Plates