Intro: Building Realistic Model Volcanoes
large (tall) plastic vial
lots of newspaper
black, white and brown spray-paint
1’X1’ cardboard pieces
Approximate Time Needed
No two volcanoes are exactly alike, but we can divide them up into four basic types.
Cinder cones are steep-sided, symmetrical cones formed by the eruption of mainly ash, cinders and other pyroclastic, or solid, ejecta. This is like Mount Vesuvius in Italy.
Shield volcanoes are broad, gently sloping domes formed by lava flows from a central vent or fissure. These can be found in Hawaii.
Composite volcanoes are formed from alternating lava flows and pyroclastic debris mixed with ash. They are somewhere in between shield volcanoes and cinder cones. Mount Saint Helen’s was a composite volcano.
Calderas are formed when the top of a composite volcano collapses following an explosive eruption. New cones can begin to build in the calderas, which sometimes have water in them. Crater Lake in Oregon is a caldera.
We can make a model of the different “class” volcanoes. This picture shows a shield, a composite and a caldera.
Tape the large vial to the center of your cardboard base. For a shield volcano use the film canister instead. This will be the magma conduit. Crumple up the newspaper into balls.
Wrap the newspaper balls with masking tape to help them keep their shape. Stack up the newspaper balls around the vial or canister in a general cone shape.
Wrap the balls with foil and mold into a volcano shape. For a shield volcano, the slope should be gentle and smooth. For a cinder cone the slope should be steep and smooth - a pure cone shape. For a composite volcano, the sides should be rough and steep. For a caldera, the sides should be rough and steep, but the central crater should be larger, like a big bowl. Tape the foil onto the cardboard, and tape the sides to help hold the shape.
Cut the foil away over the mouth of the vial or canister. Use spray-glue over the entire foil structure, and sprinkle lightly with sand. Once this is dry, spray paint the volcano with blacks and browns. For calderas and composite volcanoes you may want some white for a snow-cap.