What drives the plates?

The new ELI today is 'What drives the plates? - using a pupil model to demonstrate that slab pull is the main plate-driving force'

Recent evidence has shown that the traditional view of mantle convection being the main driving force in lithospheric plate movement is probably incorrect. If it were the main driving force, then plates with the largest surface area would move fastest because they would have the largest area on which the mantle convection forces would act – this is not the case. However, those plates that have the longest subducting margins, with geophysical evidence of the deepest subduction slabs, do seem to be moving fastest – which is why this is now considered to be the main driving force. A fourth force that might be important is subduction suction where the old, cold oceanic plate subduction trench migrates towards the oceanic ridge pulling the over-riding plate behind it. Some geophysicists argue that this is an important driver of plate movement.
There are many plate tectonic ELIs on our website.