1. Geology of the Oceans
Everything that happens on the surface of the Earth is a result of processes occuring inside the Earth

2. Plate Tectonics and the Ocean Floor
Alfred Wegner first proposed that continents move across the surface of the Earth in 1912
Continental drift has been operating for the last 3 billion years
Continents collide as they move and had formed one large supercontinent “Pangea”
200 MYA Pangea began to split apart and continents drifted to their present locations

3. Plate Tectonics
Present Continents have been found to fit together best when their continental shelves are matched up
Oceans are 4 billion years old but oldest ocean floor is 180 myo
New sea floor is created at mid ocean ridges and are volcanic in origin
Mid ocean ridges wrap one and a half times around the world
Oceanic crust is lost to subduction under thicker continental crust

5. Internal Structure of the Earth

6. Processes of Plate Tectonics

8. Plate Tectonics
Differences in the temperatures of mantle material cause convection currents in the mantle
Hotter mantle material rises up and scrapes along the bottom of the crust moving it and then cools and sinks deeper in the mantle
Continents are moved along by the process of sea floor spreading

9. Convection currents in Mantle

10. Temperatures within the Earth

11. Plate Tectonics
Earths crust is divided into 18 known plates 9 of which are larger
These plates act as huge rafts floating on the Earths mantle
Movement averages ¾ to 2 inches per year
Junctions between plates are called faults
Many Faults are geologically active as volcanos or earth quakes, Pacific rim “ring of Fire”

13. Hawaiian Island Chain

14. Islands, Seamounts, Tablemounts

15. Magnetic Field Reversal Record