Friday, August 13, 2010

Family Science Night - Volcanoes

Before we get to the good stuff (namely the actual volcanic eruption) lets learn some facts about volcanoes and impress the kids.

  • There are approximately 1,510 "active" volcanoes in the world. Scientist currently know of about 80 volcanoes that are under the ocean.
  • A volcano is a land form (usually a mountain) that opens downward to a pool of magma (molten rock) below the surface of the earth. It is a hole in the Earth from which lava (molten rock) and gas erupts.
  • Magma is liquid rock that is inside of a volcano.
  • Lava is liquid rock (magma) that flows out of a volcano. Fresh lava ranges from 1,300° to 2,200° F and glows red hot to white hot as it flows.
  • The Earth's surface is made up of huge plates called slabs. These slabs sometimes move. When they move one plate is pushed below another plate and magma is pushed up between the two plates.
  • Somewhere around the world there are approximately 20 volcanoes erupting as you read this. The majority of these eruptions are happening under the ocean and geologists may not even know about them.
  • There are a total of 103 volcanoes in the United States. The breakdown is: Alaska (34), Arizona (8), California (9), Hawaii (10), Idaho (2), New Mexico (8), Oregon (21), South Dakota (1), Utah (2) Washington (6), and Wyoming (2).
Now on to the fun part, building your volcano!

A container to build in and to catch the "lava".
A disposable cup
Aluminum Foil
Dough ( we got our color by mixing together all of the red, blue, green and yellow doughs)

We used a mold for making stepping stones to build our volcano in but you can use a pie pan or a cake pan or any other container that you have handy. Put the cup in the middle of the container and then put a wadded up ring of foil around the cup. Next take sheets of foil and lay them over your cup, folding then into the inside of the cup by about half an inch. The rest of the foil will be molded around the wadded foil ring. Do this all the way around the cup.

Next you will take your dough and make it nice and pliable. I made mine into flat sheets and laid it over the foil form, lapping it into the inside of the cup again by about half an inch. Do this all the way around your volcano, covering all of the foil form. We let our volcano sit for a few hours before we proceeded onto the eruption, just to let the dough dry out a little bit. We used cheap dough and it was very sticky! This would also be a good time to put in some little plastic trees, animals or people if you wanted also. We did not do this as we did not have any cheap accessories that were available.

Now to make the eruption!
Baking soda (about 2-3 tablespoons per eruption)
Red food coloring
Vinegar (1/4 to 1/2 cup per eruption)

Put the baking soda in the cup (volcano). Mix the vinegar and the red food coloring in a separate container. Once it is a good color, pour it into the cup and then step back and wait for the eruption.

Pouring in the "lava" (vinegar & food coloring)

The eruption continues.

It begins to subside

The after picture.


  1. Thanks Almost Unschooling Mom, we enjoyed it a lot! It was fun to build and even more fun to erupt!

  2. Thanks for posting this on Science Sunday. It reminded me of how much fun it is to do this! We made one and gave credit to you on (to be posted on Monday)