Or This Wedgie Rocks! Or I D Like an Earth Wedgie, Please.

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.

1. Draw a light “center line” the length of the large sheet. About 2 inches from one end, make a dot labeled “Center of the Earth.” See Figure B. (To make a light line, do not stand on your pencil.)

1. Your scale is 1:10,000,000 (one to ten million), or 1 cm = 100 km. The Earth has a radius of about 6371 km. Hence, your “Slice” will be 63.7 cm long , or one 10 millionth as large as the Earth.

1. Make a mark on the “center line” which is 63.7 cm from the “Center of Earth” mark. See Figure B.

1. Have a friend hold one end of the string steady at the “Center” mark while you attach your pencil to the string at the 63.7 cm 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.

1. Use the “Table of Data” and the Construction Detail diagram (both on the next page) to determine the width of your slice. Measure that distance from the “Center Line” in both directions, and make a mark where that distance intersects the arc from step 5. See Figure B.

1. Now, use the meter stick to make straight “side lines” from the Center to your arc.

1. Complete your “Pizza Earth” by drawing arcs of the correct radius for each of the boundaries between Earth’s layers. To do this, use the table titled “Earth’s Interior.” You need to look for Radius and Boundary to determine what is what.
2. Then move on to “The Final Phase” (next page).

Table of Data for Width of Wedge

The Final Phase:

Once you have drawn all of your boundaries, label the layers using a dark pen. Color them in next! You choose the colors that you think are representative of the temperatures and compositions.

Next, cut out your “Pizza Earth” and connect it with the others in the class so we have a full circle. You have created a scale model of the interior of the Earth! (Note: the real Earth is a lot bigger! How many times bigger?)

Finally, answer the lab questions on that sheet.

Figure A: 8.5”

11”

Figure A: shows the four 8.5 x 11 sheets connected properly, or one large sheet.

Figure B: Earth’s Interior Structure Scale Model – Construction Detail

Four 8.5 x 11 inch sheets of paper taped together along their long edges.

63.7 cm

Width

center line

center

pointfaint “width marks”

63.7 cm

63.7 cm

1