Convection currents

Stage 1

The heat of the earth’s core causes magma to heat up, become lighter and rise.

Stage 2

When the hot magma reaches the underneath of the crust it spreads out in all directions, dragging the crust with it.

Stage 3

The magma then cools slightly, as it’s farthest from the core. This makes it heavier.

Stage 4

The heavier magma sinks back down towards the core, where it is heated again.

Stage 5

the cycle is repeated again and again in a circular motion, causing convection currents.