Plate Tectonics

Plate Tectonics

This theory helps us to understand how land masses and ocean basins of the earth are arranged.

What are Plates?

Large sections of the earth’s crust that are able to move.

What is the Continental Drift?

The theory that the earth was one big landmass called ‘Pangea’ before it split into two pieces, to the North ‘Laurasia’ and to the South ‘Gondwanna’.

Evidence to the Continental Drift

1) The rock formations of the boundaries of continents near each other were similar.

2) It looked like a jigsaw puzzle.

3) Look alike fossils on different continents.

Convectional Current

When the magma in the mantle causes the plates to move.

Divergent Plate Margin

When two plates are moving away from each other.

Sea Floor Spreading

When two oceanic plates move away from each other, magma from beneath the earth rises to the surface where it cools and hardens to form a new strip of land.

Convergent Plate Margin

When two plates move towards each other.

Collision Zone

When two plates of the same mass converge.

Subduction Zone

When two plates of different masses converge.

Transform Plate Margin

When two plates move alongside each other.

Events Occuring at Plate Margins

1) Divergent: Earthquakes and Volcanic Eruptions

2) Convergent: Fold Mountains, Earthquakes and Volcanic Eruptions

3) Transform: Earthquakes

What is an Earthquake?

A sudden release of energy in the Earth's crust that creates seismic waves.

Features of an Earthquake

1) The Focus/Hypocentre: Where the earthquake originates.

2) The Epicentre: Where the waves are the strongest.