Volcanoes

5. A type of volcano with broad, gentle slopes and built by the eruption of fluid basalt lava
7. Occurs where the edge of a continental plate collides with an oceanic plate
8. In 1980, this Washington State mountain gave North America its largest volcanic eruption
10. A string of islands formed by the volcanoes along a deep ocean trench
14. Marks a divergent plate boundary
18. Large ocean wave created by undersea earthquakes or volcanic eruptions
19. The eruption of Nevado del Ruiz with its devastating mud slides occurred in this South American nation in 1985
20. An opening or crack in the earth's surface through which lava flows

1. Active volcanoes on land
2. Mountains formed from the build-up of volcanic lava often take this shape
3. 1883 volcanic eruption in southeast Asia that killed 36,000 people
4. Adds new rock to existing land and forms near new islands
6. An area where magma from deep within the mantle melts through the crust like a blow torch
9. Molten rock that erupts from volcanoes
11. A volcano that is erupting or has erupted recently
12. A volcano that has not erupted recently, but may do so in the future
13. A vent at the earth's surface through which magma and gases erupt
15. A volcano that will not erupt again
16. The zone of earthquakes and volcanoes surrounding the Pacific Ocean
17. Molten rock that is found beneath the earth's surface