What is convection currents?
1. Convection currents are movements of heat within the mantle. Materials in the mantle are heated by the core. The heat will cause the mantle material to expand, rise and spread out beneath the plates.
Video animation of convection currents:
Describing the process:
2. The hot mantle material will cool slightly and sinks, pulling the plates along.
3.The sinking mantle material will heat up again as it nears the core and the whole process repeats.
4. As a result, plates will be dragged along or move away from each other.
A slab-pull force will cause a denser oceanic plate to be forced beneath a less dense continental plate or oceanic plate in a process called subduction.
As the plate subducts, it will pull the rest of the plates along.
Downward moving and rising portion of convection currents
The subducting plate will drive the downward moving portion of the convection currents.
At the other end of the convection current, the mantle material will drive the rising portion of the convection currents