Plate tectonics

By: Katelyn McHood

Three layers of earth

There are three layers of the earth- crust, mantle, core. The crust is the outer shell of the earth. The mantle is made up of rock and is the inner layer. The core is the center of earth.

Continental drift

Continental drift is a theory proposed by scientist, Alfred Wegener. Theory has it that the continents used to be one huge piece of land. However the piece of land moved apart by convection currents and are now called continents.

Evidence of continental drift

The evidence that Alfred Wegener used to create the theory of Pangaea (continental drift) was that the continents fit together like puzzle pieces. The other evidence was that animals and fossils of the same breed were being found on different continents.

Alfred Wegener

Alfred Wegener was born November first 1880 in Berlin, Germany. He died November 1930 in Clarinetania, Greenland. He got his education at Humboldt University of Berlin in 1905. He ha on child, Elsa Wegener. He had two siblings, Kurt Wegener, and Tony Wegener. His parents were Anna and Richard Wegener.

Sea floor spreading

Sea floor spreading is when two plates move away from each other causing volcanos that erupt which cause sea floor spreading. This is also known as the divergent boundary.

Harry Hess

Hess discovered sea floor spreading. He was born may 24 1906 in New York city, New York. He died august 25 1969. He got his education from Princeton and Yale university.

Sea floor spreading-continetal drift

Sea floor spreading helps explain continental drift in the theory of plate tectonics. When oceanic plates diverge, tensional stress causes features to occur in the lithosphere. This causes the continents to move farther apart.


Convection helps with plate movement the convection in the mantle: which moves the plates away (diverge).

Plate tectonics

Plate tectonics is convection in the mantle that cause the plates to diverge. Hot materiel rises as the cold materials drop and reheat. This a continuous cycle that causes the plate to move.

Plate boundaries

There are 5 types of boundaries- Transform, Divergent (on land), Divergent (in ocean), Convergent subduction, and Convergent continents. Trans form is when two plate slide past each other causing earthquakes and fault lines. Divergent (on land) is when to plates move away from each other causing rift valleys and volcanos. Divergent (in ocean) is when two plates move apart causing volcanos and sea floor spreading. Convergent subduction is when an oceanic plate goes down and a continental goes over it causing trenches and volcanic mountains. Convergent continents is when two continental plates collide causing mountains.

Ring of fire

The ring of fire is a large number of earthquakes and volcanic eruptions occur in the basin of the pacific ocean.