Plate Tectonic Theory

1. Plate tectonic theory

a) Earth’s internal structure consists of core, mantle and crust, including continental and oceanic crusts

b) explains how forces within Earth drives global plate movements

2. Convection currents

a) within the hot softened mantle below the crust

b) being the driving force of overlying plates

3. Slab-pull force

a) gravity-controlled subduction of denser oceanic plate

b) drags the rest of the plate along

Many movies have been made based on tectonic hazards - how true are these reflecting the hazards?

So what cause these tectonic hazards to occur? Let's look at the internal structure of our earth to find out more. 

How does convection current in the mantle cause the plates to move?

• The materials in the mantle are heated by the high temperature in the core.

• The heated materials becomes less dense and rise to the earth surface

• It spreads out below the crust and drags the plates above it, to move away from each other (divergent plates).

• The semi-molten rock cools, becomes denser and sinks towards the mantle and cause the plates above it, to move towards each other (convergent plates).

• The process continues and the convection current in the mantle causes the plates to move.

Watch this video on Plate Tectonics