chapter seven

3. Earth's magnetic field has flipped its polarity many times over the millennia.
7. Two plates sliding past each other convergent/plate-boundary two or more lithospheric plates collide subduction
9. is a continent that split
12. the formation of new areas of oceanic crust, which occurs through the upwelling of magma at mid-ocean ridges and its subsequent outward movement on either side
14. scientific theory that explains how major landforms are created as a result of Earth's subterranean movements
15. rigid outer part of the earth, consisting of the crust and upper mantle.

1. two tectonic plates move away from each other
2. is the gradual movement of the continents across the earth's surface through geological time
4. is the process by which the North pole is transformed into a South pole and the South pole becomes a North pole
5. state of having two opposite or contradictory tendencies, opinions, or aspects
6. lithosphere comprises a number of plates
8. the pulling force exerted by a cold, dense oceanic plate plunging into the mantle due to its own weight.
10. long, seismically active submarine ridge system situated in the middle of an ocean basin and marking the site of the upwelling of magma associated with seafloor spreading
11. movement caused within a fluid by the tendency of hotter and therefore less dense material to rise
13. sliding plate force is a proposed driving force for plate motion