Plate Tectonics

3. thinner, denser plates that are under the oceans
5. how volcanic eruptions are measured, Volcanic Explositivity Index
6. tectonic plates that move towards each other
8. theory devised by Alfred Wegener that the earth's continents drifted apart from a supercontinent
12. when an oceanic plate slides beneath a continental plate
14. the hot, molten rock layer of the earth the tectonic plates are on
16. rigid outer layer of the earth broken into tectonic plates
18. the name of the supercontinent in Alfred Wegner’s theory of Continental drift
19. openings in the earth's crust where molten rock, lava, ash and gasses erupt onto the surface
20. term used to measure earthquakes

1. heat from the earth’s core that causes the mantle to rise and lower as it warms and cools, moving the tectonic plates
2. Plate the smallest tectonic plate
4. tectonic plates that move away from each other
7. sudden violent movement of the earth's surface caused by the movement of tectonic plates
9. linear cracks in volcanoes caused by the earth's crust pulling apart
10. formed when tectonic plates collide, causing the crust to crumple and fold forming bumps on the surface
11. thicker, less dense plates that make up the continents
13. the largest tectonic plate
15. tectonic plates that slide past each other
17. a tectonic belt where most volcanoes and earthquakes happen