Volcanoes

9. When melted, these rocks are 70% silica and have high viscosity magma
10. Type of volcano that is large and built from pyroclastic material and lava
11. What the Hawaii islands were formed by
12. A depression at the top of a volcano
15. Volcano that has erupted at least once in the past 10,000 years
16. When melted, these rocks are 50% silica and have low viscosity magma
18. Volcano that has not erupted in at least 10,000 years
19. Pipe that brings magma to the Earth's surface

1. Volcano that is active but not currently erupting
2. Crater larger than 50 kilometers in diameter
3. Fast moving cloud of heated gas and rock fragments that occurs during violent eruptions
4. Secondary fissure where magma comes to the surface that is not the main vent
5. Large underground area of magma subjected to large amounts of pressure
6. Type of volcano that is small and built from pyroclastic material
7. Body of intrusive igneous rock formed by magma that cools before reaching the surface
8. Crack in the crystal rock caused by pressure
13. The ability of a liquid to resist flowing
14. Type of volcano that is wide, has a gentle slope, and forms from basaltic lava
17. Place where 452 volcanoes are located