chapter 7 vocab

1. plates moving away from the ridge
4. the cold and rigid outermost rock layer is called
7. drift continents are in constant motion on earth
9. where 2 plates slide past eachother
11. is the process by which new oceanic crust forms along a mid-ocean ridge and older oceanic crust moves away from the ridge
13. occurs and the magnetic field reverses direction
14. is a state in which magnetized objects point north
15. 2 plates collide

2. denser plate sinks below the more buoyant plate
3. earth surface is made of plates that move with respect to each other
5. forms when 2 plates separate
6. as a slab sinks it pulls on the rest of the plate with a force called
8. the circulation of material caused by differences in tempatureand density
10. ridges the mountain ranges in the middle of the ocean are called
12. all the continents were once part of a supercontinent called
16. is a state in which magnetized objects would reverse direction and point south