Theory of Plate Tectonics Theory of Plate Tectonics ““The Earth is like a cracked The Earth is like a cracked

eggshell!”eggshell!”

LithosphereLithosphere

The lithosphere is The lithosphere is broken into broken into separate sections separate sections called called plates.plates.

The plates carry The plates carry the continents, the the continents, the ocean floor or ocean floor or both.both.

Theory of Plate TectonicsTheory of Plate Tectonics Plate Tectonics is the Plate Tectonics is the

geological theory that geological theory that states that pieces of states that pieces of Earth’s lithosphere are in Earth’s lithosphere are in constant motion, driven by constant motion, driven by convection currents in the convection currents in the mantle.mantle.

The theory of plate The theory of plate tectonics explains the tectonics explains the formation, movement, and formation, movement, and subduction of Earth’s subduction of Earth’s platesplates

Plate MovementPlate Movement

No plate can budge No plate can budge without affecting the without affecting the other plates other plates surrounding it.surrounding it.

As plates move, the As plates move, the changes include changes include volcanoes, mountain volcanoes, mountain ranges, deep-sea ranges, deep-sea trenches, and trenches, and earthquakes.earthquakes.

Plate BoundariesPlate Boundaries

Transform BoundariesTransform Boundaries Along a transform Along a transform

boundary, crust is neither boundary, crust is neither created nor destroyed.created nor destroyed.

A place where two plates A place where two plates slip past each other, slip past each other, moving in opposite moving in opposite directions.directions.

Plate BoundariesPlate Boundaries

Divergent BoundariesDivergent Boundaries The place where two The place where two

plates move apart is plates move apart is called a divergent called a divergent boundary.boundary.

Most divergent Most divergent boundaries occur at the boundaries occur at the mid-ocean ridge.mid-ocean ridge.

On land, a divergent On land, a divergent boundary is called a rift boundary is called a rift valley.valley.

Plate BoundariesPlate Boundaries Convergent BoundariesConvergent Boundaries The place where two The place where two

plates come together, or plates come together, or converge.converge.

When two plates collide, When two plates collide, the density of the plates the density of the plates determines which one determines which one comes out on top.comes out on top.

The Moving The Moving PlatesPlates

The plates The plates are still are still moving at a moving at a rate of about rate of about 1-10 1-10 centimeters centimeters per year!per year!

Name the PlatesName the Plates