Plate Tectonics

Plate Tectonics

Inner Core

Temperature: 5,000°C – 6,000°C

State: Solid

Composition: iron and nickel

Outer Core

Temperature: 4,000°C – 6,000°C

State: Liquid

Composition: iron, nickel, sulphur and oxygen

Lower Mantle

Temperature: 3,000°C

State: solid

Composition: iron, oxygen, silicon, magnesium and aluminium

Upper Mantle

Temperature: 1,400°C – 3,000°C

State: liquid / solid

Composition: iron, oxygen, silicon, magnesium and aluminium

Crust

Temperature: Around 22°C

State: Solid

Composition: Oceanic crust made up of iron, oxygen, silicon, magnesium and aluminium. (more dense)

Continental crust made up of granite, sedimentary rocks and metamorphic rocks. (less dense)

Multiple Choice

The outer core is solid.

• true

• false

Multiple Choice

The oceanic crust is more dense than the continental crust.

• true

• false

Plate tectonics

• The Earth's crust is broken up into pieces called plates.

• The crust moves because of movements deep inside the earth.

• The movement of the plates, and the activity inside the Earth, is called plate tectonics.

Convection currents

Heat rising and falling inside the mantle creates convection currents generated by radioactive decay in the core.

The convection currents move the plates.

Divergent plates:

Where convection currents diverge near the Earth's crust, plates move apart.

This is called a spreading center or rift valley.

Convergent plates:

Where convection currents converge, plates move towards each other.

The plate that moves under is subducted.

Plate boundaries

• Plate tectonics cause earthquakes and volcanoes.

• The point where two plates meet is called a plate boundary.

• Earthquakes and volcanoes are most likely to occur either on or near plate boundaries.

Multiple Choice

Convection currents move the plates.

• True

• False

Multiple Choice

The convection currents occur in the mantle.

• true

• false

Multiple Choice

When plate collide it is called a convergent plate boudary.

• true

• false

Multiple Choice

Subduction is the name given to the movement of the plates moving apart.

• true

• false

Multiple Choice

Earthquakes and volcanoes can occur at plate boundaries.

• true

• false

Multiple Choice

The outermost layer of the earth is the

• inner core

• outer core

• mantle

• crust

Pangaea

• About 300 million years ago, Earth didn't have seven continents, but instead one massive supercontinent called Pangaea, 

Multiple Select

Which of the following is evidence of Pangaea?

• fossils

• mountains

• puzzle like fit of continents