Science 8Activity- Layers of the EarthInstructions

Purpose: to show the earth and its layers to scale.

Materials: large sheet of paper, string, cardboard, thumbtack, colored pencils, 0.5 meter stick

Background: The earth to an average person is large but few appreciate how big it is. We will draw it to scale.

Information:

Our scale earth radius will be about 50 cm. The earth has a radius of 6,371 km. Each of our measurements will relate to this proportion: 6371 km: 50 cm. Therefore: 127.42 km: 1cm

Layer / Density / Thickness / Temperature / Scale Cumulative Thickness
Inner Core / 13 g/cm3 / 1200 km / 6600 C / 9.4 cm
Outer Core / 10-12 g/cm3 / 2250 km / 3800 C / 27.0 cm
Mantle / 4.6-5.4 g/cm3 / 2900 km / 870 C / 49.8 cm
Crust / 2.5-3 g/cm3 / 5-40 km / varies / 50.0 cm

Procedures

1)Near a lower corner choose a starting point. Mark it with an X.

2)On the paper measure out from the X the scale cumulative thickness to show the boundaries for the inner core. Then measure the outer core and mantle.

3)Tie one end of the string to the thumbtack.

4)Push in your thumbtack with the string attached, through the paper at the X. Be sure to put the stacks of cardboard behind the paper so you don’t pierce the table.

5)Hold your pencil at the first point you made on the paper to mark the thickness of the inner core and wrap the string around the pencil. Carefully draw anarc with your point at the first mark you made from the X.

6)Repeat step 5 for the outer core and mantle.

7)By hand draw in the thickness of the crust. It can vary from less than .5 mm to 3 mm because of variances in the surface of the crust.

8)Use the information from the table aboveto label each layer. Be sure to include the thickness, density, and temperature. The information about composition should come from the textbook(pages 336-338).

9)Color appropriately using page 336 in the textbook.

10) We have never drilled through the crust, could we ever drill to the core?

BONUSAlong the surface of the earth, show the distance between Pickens and Columbia, SC and New York City to scale. Columbia- 160 km- 1.3 cm. NYC- 1000 km- 7.8 cm. How do these distances compare to the size of the earth or thickness of the crust?

Lab: Earth’s Layersver. 3.59/18/18