1. Helps explain how continents moved apart (C.S.

2.  In WWI German scientists used sound waves to detect submarines on the seafloor

4.  In 1960 a Princeton University scientist suggest the idea of seafloor spreading  That hot, less dense material below Earth’s crust rises to the surface at mid-ocean ridges

5.  In 1968, the Glomar Challenger was sent with a drilling rig to obtain rock samples on the seafloor

7.  At these mid-ocean ridges there is a temperature increase that bring heat and chemicals to the center of these ridges  Gigantic clams, mussels and tube worms live there because it is so warm

8.  Earth has a magnetic field  A north pole  A south pole Magnetic lines, or directions, of force leave Earth near the south pole and enter Earth near the north pole

9.  Several times in history, Earth has had a magnetic reversal  Every 1000 years or so  Recorded in the rocks forming near mid-ocean ridges

10.  Magnetite is an iron bearing mineral  So what do we know about iron magnets?  These minerals align themselves with earths magnetic field

11. These rocks that contain the magnetite prove that earth’s magnetic field has reversed This helps show how the crust can move

12.  Bozeman Plate Tectonics Video Bozeman Plate Tectonics Video