# Hands-on Center

(Hot Spots: Hawaii and Yellowstone)
Lesson #9

The mantle's convection experiment
Modified and adapted from John Farndon's book
"How the Earth Works"

### The teacher must set up and run this experiment! The oil and dish will get hot!!!!!

Materials:

1. 1 heat proof glass dish
2. 1 tea candle
3. 3 cups of cooking oil
4. 1 book of matches
5. 1 bottle of dark colored food coloring
6. 1 eye dropper
7. 2 clay bricks
8. 4 small pieces of packing foam

1. Pour the 4 cups of cooking oil into the glass dish.
2. Place the glass dish onto the 2 clay bricks.
3. Light the tea candle and place it under the glass dish.
4. Put dark colored food coloring into the eyedropper.
5. Squeeze some of the food coloring into the cooking oil near the bottom of the glass dish.
6. When the food coloring begins to move lay some pieces of Styrofoam on top of the cooking oil and observe the movement. (The flowing of the Styrofoam will represent the movement of the Earth's plates) The cooking oil will heat up and convection currents will be generated. The food coloring will enable the students to see the movement of the convection currents. The oil and food coloring will rise as they heat up. The rising material will cool as it nears the surface of the liquid. The farther the material gets from the heat source the cooler it will become. As the material cools it will slowly desend.
This process of gaining energy (heat) and rising and then losing energy (cooling) will go on and on. These are convection currents. This rising and cooling sets up a current in the cooking oil. The teacher should explain that this is a theory of how the mantle "flows" and the plates (Styrofoam pieces) of the Earth are carried with these movements.
The students should draw and label a diagram of the experiment.

Magma Rising
Materials:
1. Cooking Oil
2. Squeeze Bottle (Example: dish soap bottle)
3. Large Clear Plastic Container
4. Water
5. Red Food Coloring
1. Have the students fill a plastic squeeze bottle full of cooking oil with red food coloring in it.
2. Place the squeeze bottle into a large clear plastic container full of water.
3. Tell the students to squeeze slowly the bottle full of cooking  oil.
1. Have the students record what they observe.
The students will observe the cooking oil rise through the water because the oil is less dense than the water. The same process causes magma in the Earth to rise from the bottom of the Mantle to the Earth's crust causing volcanism.