plate tectonics

8. boundary between two colliding plates - keywords: ocean trench
9. the supercontinent that existed millions of years ago
13. the solid, outer layer of the earth that consists of the crust and the upper part of the mantle
15. an underwater chain of mountains.
16. currents in the mantle from the magma being heated by the core of the earth
18. the layer of rock that forms earth's outer surface
19. the deepest layer of the earth with an inner and outer version
20. created by two pieces of continental crust converging
21. where two or more plates meet

1. a deep valley that forms on land at a divergent boundary where two plates move apart
2. the man who came up with the theory of plate tectonics
3. a boundary where two plates are moving apart - hint: create new crust
4. Alfred Wegner's hypothesis that the continents were once a supercontinent
5. a vent on the earths surface where magma and gases are expelled
6. boundary between two plates that are sliding past each other
7. layer that the tectonic plates slide on, also before the crust
10. the process by which Earth's crust breaks apart
11. when one tectonic plates dives under another
12. a theory proposed by Alfred Wegener that explains how large pieces of land called plates move and change shape of the earth.
14. region around much of the rim of the Pacific Ocean where volcanoes and earthquakes occur frequently
17. creates midocean ridges, earthquakes, and volcanic activity