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How to Make a Model or Demonstration of the Earth's Layers

Earth has four layers: the crust, the mantle, the outer core and the inner core. The crust consists of solid rock varying in thickness from three to 44 miles. The mantle is 1,800 miles thick and comprises hot semisolid rock under high pressure; this layer is the source of the magma that erupts from volcanoes. The outer core is mostly liquid nickel and iron, with a thickness of 1,430 miles. The inner core is a ball of solid iron about 746 miles thick. You can easily produce a cutaway view of these layers with modeling clay.

2 sticks of orange modeling clay
6 sticks of red modeling clay
1 stick of blue modeling clay
Rolling pin or 1-inch wood dowel
Sharp knife
1-inch marble, preferably white or yellow

Instructions

- 1
  Roll a 3-inch ball of orange modeling clay to represent Earth’s outer core.
- 2
  Wrap multiple layers of red clay evenly around the orange ball until you have a large red ball with an orange ball hidden in its center. Roll this ball gently between your palms to make it round and smooth. This layer represents the mantle.
- 3
  Roll half of the blue modeling clay into a 1/8-inch “crust” and drape it over as much of the red ball as it will cover. Press the edges of the crust down carefully and smooth them. Repeat this process to cover the rest of the ball. Roll the ball gently between your palms to make it round and smooth.
- 4
  Cut a wedge from approximately one-third of the ball, starting each cut from the center. Remove the wedge to reveal the ball’s interior layers. Press the marble halfway into the center of the orange layer to represent the planet's inner core. Smooth the layers with your finger to obscure blade marks if necessary.

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