Plate tectonics

2. a long, narrow hole that is dug in the ground; ditch
3. a mountain with a hole in the top or side that sometimes sends out rocks,ash,lava, etc.
5. the action or process in plate tectonics of the edge of one crustal plate descending below the edge of another
7. actively deforming region where two or more tectonic plates more toward one another and collide
9. a current in a fluid that results from convection
13. a long, steep valley formed when two parallel rift form in the Earth's crust and the land between them sink
15. when 2 plates slide or move away from one another
17. a divergent tectonic plate located along the floor of the Atlantic Ocean
18. a shaking of a part of the Earth's surface that often causes great damage
19. relatively thick part of the Earth's crust that forms the large landmasses

1. a super continent that exist during the early ages
2. places where plates slide sideways past each other
4. a split or crack in the ground
6. an elevated region with a central valley on an ocean floor at the boundary between two diverging tectonic plates where new crust is formed
8. theory that states the lithosphere of the Earth is divided into small numbers of plates
10. a line of mountains connected by high grounds
11. each of several large landmasses thought to have divided to form the present continent
12. an area in the basin of the Pacific Ocean where several of earthquakes and volcanic eruptions occurs
14. an active strike-slip fault in West U.S. extending from San Franciso to South California
16. relatively thin part of the Earth's crust that underlies the ocean basins