2. Why do volcanoes erupt?

3. Deep in the earth it is very hot. It is so hot that rocks melt. The melted rock is called magma. The magma is lighter than the rocks around it so it rises. Sometimes it finds a crack or hole in the earth’s crust and bursts through. Molten rock at the surface is known as lava. This is how a volcano begins.

4. What are the different kinds of volcanoes?

5. Volcanoes do not all look alike. Their shape is based on what type of materials they erupt. There are three main kinds, or shapes, of volcanoes. These shapes are due to the two types of eruptions.

6. If there is little dissolved gas in the magma the eruption will take the form of a flow of lava. (flat soda) If there is a lot of dissolved gas in the magma the eruption will be exposive, pyroclastic. (newly opened soda)

7. Shield Volcanoes

8. Volcanoes that build up from many slow, steady, flows of hot lava, are called shield volcanoes. This kind of volcano is low and broad with gently sloping sides. They look like a warriors shield. These are not very dangerous, you just move out of the path of the flow.

9. Lava flow eruptions

12. Shield volcanoes

14. Cinder Cone Volcanoes

15. Cinder cone volcanoes form when solid rock and ash shoot up into the air and fall back around the volcano opening. This known as a pyroclastic eruption. These are very dangerous. The cinder cone volcano has steeply sloped sides.

16. Pryroclastic eruptions

19. Cinder cone volcanic mountains

21. Strato or Composite Volcanoes

22. Strato volcanoes, also called composite volcanoes, erupt with molten lava, solid rock, and ash. In other words, both lava flows and pyroclastic eruptions. The layers pile up much like layers of cake and frosting. The layers form into symmetrical cones, and the slopes are steep.

23. Composite volcanic mountains