Plate Tectonics

1. (3)Specific regions on Earth with a high concentration of earthquakes and eruptions.
4. (3)Tiny powdery particles of pulverized rock exploded out of a volcano.
8. (2)Large hazardous chunks of hot molten rock thrown into the air during an eruption.
10. A volcano that scientists believe is completely dead and will never erupt again.
12. The thin, rocky outermost layer of the Earth.
13. Giant destructive ocean waves triggered by underwater earthquakes.
15. A sensitive instrument used to measure and record the vibrations of an earthquake.
16. To be completely swallowed up, buried, or covered over by lava or water.
17. Magma that has broken through the Earth's crust onto the surface.

2. The pipes or openings through which magma and gas escape a volcano.
3. (2)The lines or areas where two tectonic plates meet.
5. (3)A major horseshoe-shaped zone of volcanoes and earthquakes around the Pacific Ocean.
6. Large, rigid pieces of the Earth's crust that move slowly.
7. (2)A mathematical scale used to measure the absolute energy released by an earthquake.
9. A sleeping volcano that is currently quiet but expected to awaken in the future.
11. (2)Extreme naturally occurring environmental events that threaten human life and property.
14. Molten liquid rock that is trapped beneath the Earth's surface.