Make a Volcano

Find out how volcanoes form and what causes them to erupt. Then click the planets in this interactive image to learn about volcanoes on planets throughout our solar system. Get inspired before you create your own volcano by checking out these images of volcanoes on Earth.

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Cut off the top of the paper cup so it's only about 0.5 inches (1-2 cm) tall. Place the paper cup at the center of your piece of paper and trace around the bottom to make a circle. The circle and the cup represent the crater inside your volcano. Tape the cup to the piece of cardboard or a cookie sheet. Mark north, east, south and west on both the paper and the cardboard or cookie sheet.

Fill the cup with a spoonful of baking soda. Then, slowly pour in enough vinegar to make the mixture foam up and flow out of the cup. This simulates an eruption and lava flowing out of your volcano.

If possible, use a colored pencil to trace around the edge of where the lava flew out of your volcano. Dab up the fluid with a paper towel. Then, cover the area inside the line you traced with a thin layer of one color of play dough to mark where the lava flowed.

On your graph paper, use a colored pencil that matches the color of the play dough you put down to draw the shape of your lava layer. This is the start of a map that will show where lava flowed during each eruption of the model volcano. Be sure the orientation of the cardinal directions on your map match the ones on your model volcano.

Repeat steps 3-5 three or four more times. Each time, put down a new layer of play dough and then map it out by drawing the shape of that layer on your graph paper. If you have more than one color of play dough, change colors between eruptions so it's easier to see the different layers.

Cut a plastic straw into thirds or fourths. Push an open end of the straw straight down through the play dough lava flows until you reach the bottom. Twist the straw in place and lift out a sample. This is what's called a core sample.

Looking through the clear straw, you can see the layers underneath the surface of the volcano. You can use this sample to investigate how the layers of the volcano formed over time. Repeat this step with each of your three or four straw pieces. Think about the best places to collect samples so that you can get as much information as possible.

On a blank piece of graph paper, draw a circle and cardinal directions like you did in Step 2. Use your core samples to make a prediction of where each layer of the volcano you’re studying begins and ends.

Then, use colored pencils that match the colors you find in the volcano to draw the layers on your graph paper. Try to get as close as you can with as few samples as possible!