The baking soda volcano represents the quintessential science fair project. To construct a good model volcano, however, a student should understand how a real volcano works. The standard model volcano mimics the natural composite cone type of volcano and, as with real volcanoes, relies on a buildup of pressure to create an eruption.
Real volcanoes in nature commonly fit within three basic types. Shield volcanoes, considered the least dangerous type, have low, rounded appearances caused by hot, fluid lava formation. Shield volcanoes produce mostly lava and only a little ash and coarse material. Composite cone volcanoes present a very real danger. The lava forming these volcanoes runs thicker and has a tendency to pile up, creating the iconic conical volcano shape. Since these volcanoes spread out less than shield volcanoes, they often prove to be more explosive and less predictable. Aside from eruptions, landslides also present another hazard common to the composite cone volcano. Caldera volcanoes appear least often but pose the greatest danger. The thick magma flows very poorly and contains a large amount of gases. As a result, the magma gathers pressure, and as it reaches the surface, the gases blow the magma apart into large masses of volcanic ash and debris.
Volcanic eruptions behave in several different ways. Effusive eruptions pour lava of various shapes and thicknesses out onto the ground. Steam-driven phreatic eruptions result from magma, lava, hot rocks or volcanic deposits that heat water beneath the surface. Plinian eruptions form large, dark columns of gas that reach high into the stratosphere. Lava fountains spray jets of lava into the air upon the rapid formation and expansion of gas in molten rock. Pyroclastic flow creates an avalanche of hot ash, pumice, rock and gas that rushes down the side of the volcano. Strombolian eruptions cast out basaltic lava from a single vent intermittently.
Basic Volcano Project:: Chemical Reaction
Volcano science projects work by creating chemical reactions and using the resulting pressure to mimic effusive eruptions, lava fountains and pyroclastic flow from composite cone volcanoes. These projects use an acid -- usually in the form of vinegar -- and a base -- usually in the form of baking soda -- to create carbon dioxide gas. This gas builds up inside the project and the volcano erupts with a bubbly, fizzing liquid.
Basic Volcano Project:: Volcano Construction
A basic volcano science project requires either modeling clay or paper-mache to construct the model volcano. Paper-mache creates a light, portable volcano, while modeling clay creates a sturdier volcano that you can use multiple times. Glue a plastic bottle to a large piece of cardboard for a base. Mix your clay or paper-mache and build the volcano in the classic composite cone construction from the bottom up. Once the clay or paper-mache dries, paint the volcano and cardboard base as desired. Add any additional features, like rocks, twigs and plastic pine trees, to the base to complete the scene.