Unit 7: Earth Systems

5. When lava gets erupted at the mid-ocean ridge axis it cools and turns into hard rock
7. the outer most layer of earth
8. the middle layer of earth
9. the rock closest tot he mid-ocean ridge
12. a lava type substance found deep int he earth
15. long narrow ditch
16. a seafloor mountain system formed by plate tectonics
17. the structure of earth divided into layers
21. person who came up with seafloor spreading
25. name of the one big continent when they were all together
27. one of wegeners 4 peaces of evidence
28. the rigid outer part of the earth, consisting of the crust and upper mantle

1. The rock farthest from the mid-ocean ridge
2. a current in a fluid that results from convection
3. the continents moving slowly
4. the force that moves the continents slowly causing continental drift
6. one of wegeners 4 peaces of evidence
10. a person who is studying or has expert knowledge of one or more of the natural or physical sciences
11. the inner most layer of earth
13. How old the rocks are
14. a long narrow hilltop, mountain range, or watershed
18. one of wegeners 4 peaces of evidence
19. one of wegeners 4 peaces of evidence
20. a theory explaining the structure of the earth's crust and many associated phenomena as resulting from the interaction of rigid lithospheric plates which move slowly over the underlying mantle
22. person who came up with the idea of continental drift.
23. nick name for Pangaea
24. a device used to calculate the ocean floor
26. the study of the continents