1. Volcanoes

2. Anatomy of a Volcano Lava erupts through an opening called a vent
As the lava flows onto the surface it cools and hardens around the vent
Over time the hardening lava can accumulate and form a volcano
At the top of the volcano a bowl shaped depression, called a crater forms
Large craters are called calderas

5. Shield Volcanoes
This has a mountain with a broad, gently sloping side and nearly circular base
They form when layer upon layer of basaltic lava during nonexplosive eruptions
Hawaii

8. Cinder-Cone Volcanoes
This forms when material ejected high into the air falls back to Earth and piles up around the vents
These have steep sides and are generally small
These are more explosive then shield volcanoes

11. Composite Volcanoes
These form when layers of volcanic fragments alternate with lava
These are much larger then cinder-cone volcanoes and can be very explosive
Mount St. Helens