Plate TectonicsPlate Tectonics

The CrustThe Crust

• Outermost layer• 5 – 100 km thick• Made of Oxygen,

Silicon, Aluminum

The MantleThe Mantle

• Layer of Earth between the crust and the core

• Contains most of the Earth’s mass

• Has more magnesium and less aluminum and silicon than the crust

• Is denser than the crust

The CoreThe Core

•Below the mantle and to the center of the Earth•Believed to be mostly Iron, smaller amounts of Nickel, almost no Oxygen, Silicon, Aluminum, or Magnesium

PangaeaPangaea

The ancient (225 million years ago) supercontinent that split apart into the continents we know today.

Evidence of PangaeaEvidence of Pangaea

Continental DriftContinental Drift

The theory used to explain the movement of the continents on earth. It was first proposed by Alfred Wegner less than 100 years ago (1912)

animation

How Plates Move: How Plates Move: Convection CurrentsConvection Currents

Plate BoundariesPlate Boundaries

The term “plate boundary” refers to the edges where the different plates on earth are touching.

illustration

Each of the plates have a name.

There are Three Types of There are Three Types of Plate BoundariesPlate Boundaries

Convergent

areas of plates that are moving toward each other

animation

Indian and Eurasian Plates

Convergent Boundary

Convergent Boundary – Oceanic & Continental

Convergent Boundary – Oceanic & Oceanic

Convergent Boundaries - Continental

There are Three Types of There are Three Types of Plate BoundariesPlate Boundaries

Divergent

areas of plates that are moving away from each other

animation

Divergent Boundary - Oceanic

Divergent Boundary - Continental

Sea Floor SpreadingSea Floor Spreading

Sea Floor SpreadingSea Floor Spreading

• Mid Ocean Ridges – underwater mountain chains that run through the Earth’s Basins

• Magma rises to the surface and solidifies and new crust forms

• Older Crust is pushedfarther away from the ridge

There are Three Types of There are Three Types of Plate BoundariesPlate Boundaries

Transform

areas of plates that are sliding past each other; results in the largest and most destructive earthquakes

image

Transform Boundary – San Andreas Fault

Plate Boundary LocationsPlate Boundary Locations

click image to launch animation

Let’s ReviewLet’s Review

What are the three type of plate boundaries?

convergent

divergent

transform

Let’s ReviewLet’s Review

Which type of plate boundary results in the largest, most destructive earthquakes?

transform