Plate tectonics

2. the innermost layer of the earth and hottest layer
4. when plates move towards each other
8. a sudden shaking of the earth's surface that often causes a lot of damage
10. the preserved remains of organisms that lived many years ago
12. the layer of the earth that lies below the lithosphere
14. a denser plate is pushed downward beneath a less dense plate when plates converge
17. magma from earth's mantle comes up at the mid-ocean ridge and create new oceanic crust
18. a circular movement of fluids caused by the rising of hotter, less dense fluid and the falling of cooler,denser fluid
19. when two tectonic plates move away from each other
20. the thick of the earth beneath its outer crust

1. a lowland region that forms where earth's techtonic plates move apart, or rift
3. continents were once connected but have drift apart
5. the solid, outer part of earth
6. the thin outermost layer of the earth
7. the eruption of molten rock onto the surface of a planet
9. the theory that the crust divided into large pieces
11. the outer layer of the core that is made of liquid iron and nickel
13. cracks in the earth's crust along which there is movement
15. when two tectonic plates slide past each other
16. deep and narrow depression in the seafloor where the subducted plate move into the asthenosphere