Download Earth Science - Center Grove Schools

Earth Science
“Pizza Earth”
(or “This Wedgie Rocks!” or “I’d Like an Earth Wedgie, Please.”)
Objective:
Students will gain an understanding and appreciation for the scale of the Earth’s inner layers by
constructing a scale model of a “Pizza Slice” of the Earth’s interior. The students will see the
relationship of the Earth’s large-scale structure to the phenomenon of Plate Tectonics.
Materials:
One big sheet of white paper
meter stick
string
pencil
colored pencils, crayons, etc.
Procedure:
1. Get the big sheet of paper
2. Fold the paper in half length ways.
3. Draw a l i g h t “center line” the length of the large sheet. Make a dot labeled “Center of the
Earth.”
32cm
4. Your scale is 1:20,000,000 (one to twenty million), or 1cm = 200km. The Earth has a radius of
about 6371 km. Hence, your “Slice” will be 63.7cm ÷ 2 or 32cm, or one 20 millionth as large as
the Earth.
5. Make a mark on the “crust” which is 32cm from the “Center of Earth” mark. See Figure Above.
6. Have a friend hold one end of the string steady at the “Center” mark while you attach your pencil
to the string at the 32cm mark. Carefully make an ARC with the string, making sure the string is
tight the whole time. This arc represents the outer edge of the Earth’s Crust.
7. Complete the Data Table to determine the length of each layer. Add these marks to your
“centerline” and use the same method as step 6 to make an ARC with the string.
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Calculate the LENGTH IN CM for each layer. Remember that 1cm = 200km
EXAMPLE:
6371km ÷ 200 = 32cm
Radius
(km)
Depth
(km)
Length
in CM
Layer
Boundary
Material
Average
Temperature
(°C)
air/solid
0 – 870°C
6371
0
Crust
Surface
6336
35
Upper Mantle
Crust-Mantle boundary
solid
1600°C
6221
150
Asthenosphere
LithosphereAsthenosphere boundary
solid
2200°C
5700
671
Lower Mantle
Transition Zone (base of
Upper Mantle)
solid
3700°C
3486
2885
Outer Core
Core - Mantle boundary
liquid iron
4300°C
1216
5155
Inner Core
Inner Core boundary
solid iron
7200°C
0
6371
Center of Earth
solid iron
7200°C
solid (SiO2)
rich
The Final Phase:
Once you have drawn all of your boundaries, label and color the layers. You choose the
colors that you think are representative of the temperatures and compositions.
Next, cut around the outside of your “Pizza Earth”. You have created a scale model of
the interior of the Earth! (Note: the real Earth is a lot bigger!)
Finally, answer the lab questions on that sheet.
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