Volcanoes form from magma rising to the Earth's surface from hot spots in the crust. There are three main types of volcanoes - cinder cones which are small and steep-sided, shield volcanoes which are broad and dome-shaped, and composite volcanoes which are tall and cone-shaped. Volcanoes can be dangerous due to volcanic gases, tremors, lava flows, and pyroclastic materials such as ash flows. The distribution of volcanoes is not uniform around the world, with concentrations occurring in belts around the Pacific Ocean and Mediterranean Sea, as well as mountain ranges like the Cascades.

1. Earth’s Hot Spots Volcanoes

2. A naturally occurring process Magma rises to the surface At the surface, Lava and/or Pyroclastic Flow What is Volcanism?

3. Volcanic Gases Lava Flows Pyroclastic Materials Comp Contents of a Volcano

4. Cinder Cones Small, steep-sided Pyroclastic material Shield Volcano Dome-shaped Built up from lava flow Types of Volcanoes Fig. 5.9,b Fig. 5.10

5. Composite Volcano Lava Domes Fig. 5.11 Fig. 5.12

6. Dangerous gases Volcanic Tremors Forecasting volcanoes? Dangers of Volcanoes

7. Distribution of Volcanoes Fig. 5.14

8. Circum-Pacific belt Mediterranean belt Cascade range

9. Pyroclastic Flows. BBC, 12/10/2008. Youtube.com. BBC, Dec. 2008. Web. 12 Oct. 2010. <http://www.youtube.com/watch?v=XLmbnnh5OLs&feature=related>. Monroe, James S., and Reed Wicander. "Chapter 5:Volcanoes and Volcanism." GEOL. Student ed. Yolanda Cossio, 2011. 82-101. Print. http://www.google.com/imgres?imgurl=http://www.indianchild.com/images/valcanoe2.jpg&imgrefurl=http://www.indianchild.com/volcanoes.htm&usg=__ Works Cited