Plate Tectonics

5. name for the crust and the upper mantle together, earth's tectonic plates.
7. transverse seismic wave that travels through earth
10. molten rock that has erupted onto earth's surface.
12. plate boundary where lithosphere is destroyed.
13. the centre of earth.
14. a zone where earth's crust and mantle are being pulled apart.
15. section of earth's crust that moves
16. where plates are moving apart from each other in opposite directions.
18. layer beneath earth's crust.
20. the separating of continents by drifting across earth's surface.
21. a layer of 'plastic' semi-solid rock in the lower mantle on which earth's tectonic plates move.

1. when one plate sinks below another plate during collision.
2. a depression in the ocean floor.
3. plate boundary where new crust is formed.
4. a deep channel in the ocean floor where crust is sinking downwards.
6. patterns of magnetism trapped in rocks on each side of plate boundaries.
8. crust that forms the ocean floor.
9. earth's outermost solid layer.
11. on earth's surface.
17. the process of continents breaking up, subsiding and allowing in water from the sea.
19. molten rock below earth's surface.