Hands-On Lesson #8

(Volcanic Cones and Eruptions)

Why Does Magma Rise??

Materials: Glass jar 9/10 filled with honey

small cork

Small steel ball (steel marble)


The students will place a small cork and a small steel ball into an empty glass jar. The students will then fill the jar with honey and watch what happens. They should write down their predictions as to what will happen after the honey is placed in the jar. The students should write down what they see occurring and why they believe it happened..  
The students will observe that materials made of less dense material (cork) will rise in a much denser medium (honey). The steel ball will remain on the bottom of the jar because it is denser than the medium that it is in (honey). Magma will rise in the Earth for the same reason, the magma is produced by the melting of the oceanic crust and the top layer of the mantle. The melting material is less dense than the surrounding mantle and that causes it to rise.

Cone Shapes

  1. modeling clay or playdough
  2. popsicle sticks for shaping cones
  3. wax paper

The students will construct a 3-d model of the three basic  
volcano cone shapes using modeling clay or playdough.

  1. shield cone
  2. cinder cone
  3. composite cone or stratovolcano