Plate Tectonics

Asthenosphere-  Under the lithosphere-  includes under the plastic mantle and the rest of the mantle-  What the plates sit on. 

 Continental Drift- Hypothesis that pieces of land broke apart and drifted apart over time.

Convection Currents- Movements where heat rises and cold sinks.  Cold moves to hot and the process repeats.  We believe that these currents occurred in the mantle to cause the cracking of the plates.

Pangaea- The ONE continent that was on Earth before they broke apart.

Lithosphere-  The layer that includes the Plastic Mantle and the crust.  It is the area that we live on. Composed of both Oceanic and continental plates

Plate- Pieces of the lithosphere that include continents and oceans.  They are divided by the cracks that occurred as a result of convection currents.

Sea floor spreading-  A theory that along an ocean ridge, a rift allows new magma to come up and push the two plates apart, which in turn moves the continents farther apart.