plate tectonics

3. gravitational forces acting on the young, raised oceanic lithosphere around mid-ocean ridges
7. is the movement of the plates that make up earths crust lightest most buoyant rock layer
9. a theory that explained how continents shift position on Earth's surface
12. the pulling force exerted by a cold, dense oceanic plate plunging into the mantle due to its own weight
14. Two plates sliding past each other
15. a German polar researcher, geophysicist and meteorologist. During his lifetime he was primarily known for his achievements in meteorology and as a pioneer of polar research
17. Convective heat transfer, often referred to simply as convection, is the transfer of heat from one place to another by the movement of fluids
18. the upper layer of the earth's mantle below the lithosphere in which there is low resistance to plastic flow and convection is thought to occur
19. the rigid outer part of the earth, consisting of the crust and upper mantle

1. the sideways and downward movement of the edge of a plate of the earth's crust into the mantle beneath another plate
2. large-scale processes affecting the structure of the earth's crust
4. one of the plates oceanic crust and lithosphere mantle is pushed or subducted under the other it mixes with the overlying mantle and the addition of water to the hot mantle lowers the crusts melting point and leads to the formation of magma
5. oceanic crust is often forced down into the mantle where it begins to melt
6. volcanic activity or phenomena
8. a rigid layer of the earths crust is believed to drift slowly
10. the science that deals with the earth's physical structure and substance, its history, and the processes that act on it
11. a supercontinent that existed during the late Paleozoic and early Mesozoic eras
13. a feature on the Earth's surface that is part of the terrain
16. when two tectonic plates move away from each other