Plate Tectonics

By: Gracen Long Period:6

The Three Layers of the Earth

There are three layers of the Earth:

-Crust: The outermost layer of the Earth on which we live

-Mantle: The middle layer takes up most of the earth. Mostly made of magma and hot rock.

-Core: The core is made up of liquid metals, and is the innermost layer.

Continental Drift

Continental drift is the theory that the plates beneath our feet are shifting and moving due to Convection Currents. Wegener believed that all of the continents were once one massive continent called Pangaea. The evidence for Pangaea is that they found fossils of the same species on different continents. Plus, the shore lines of South America and Africa fit together like puzzles.

Sea Floor Spreading

Sea floor spreading is when plates diverge in the ocean. It causes Ridges and Volcanoes. It was discovered Harry H. Hess. Sea floor spreading is evidence of Continental drift.

Plate Tectonics

Convection helps with plate movement, because it pushes the plates around. Plate Tectonics is the theory that the Earths crust is broken into plates, that are constantly shifting.

Plate Boundaries

There are 4 types of plate boundaries:

-Transform: Grind together. Causes Earthquakes

-Divergent: Pull apart. Cause Rifts, valleys, and volcanic activity.

-Convergent: Push together. Create mountains.

-Convergent Subduction: One plate goes down and the other goes up. Causes volcanic mountains, and trenches.

The Ring of Fire

The Ring of Fire is an area of volcanic activity in the Pacific Ocean.