What drives the movement of tectonic plates?

What drives plate tectonics

There are a number of competing theories that attempt to explain what drives the movement of tectonic plates. Three of the forces that have been proposed as the main drivers of tectonic plate movement are:

  • mantle convection currents— warm mantle currents drive and carry plates of lithosphere along a like a conveyor belt;

  • ridge push (buoyant upwelling mantle at mid-ocean ridges) — newly-formed plates at oceanic ridges are warm, and so have a higher elevation at the oceanic ridge than the colder, more dense plate material further away; gravity causes the higher plate at the ridge to push away the lithosphere that lies further from the ridge;

  • slab pull — older, colder plates sink at subduction zones, because as they cool, they become more dense than the underlying mantle. The cooler sinking plate pulls the rest of the warmer plate along behind it.

Recent research has shown that the major driving force for most plate movement is slab pull, because the plates with more of their edges being subducted are the faster-moving ones. However ridge push is also presented in recent research to be a force that drives the movement of plates.

Related topics

Elastic rebound Elastic rebound theory

The process of ground being subjected to a growing force until it snaps or breaks is explained in a theory called the elastic rebound theory.

Divergent boundary Plate tectonics

Tectonic plates can move relative to each in different ways. This movement gives rise to different types of plate boundaries with different properties and characteristic earthquakes.

Core structure The structure of the Earth

Studying the signals from distant earthquakes has allowed scientists to determine the internal structure of the earth.

Map of quakes Why and where?

Earthquakes do not occur randomly on the Earth. The pattern of earthquake locations can be explained by assuming the Earth's surface is made up from rigid plates that are in motion relative to each other.

Classroom activities | External links

What drives the plates? What drives the plates? | Earth Learning Idea

Using pupils to act as the lithosphere, this activity explains the competing theories of what forces drive the movement of tectonic plates.

Earth Learning Idea Plate tectonics through the window | Earth Learning Idea

If you were at a plate tectonic margin that was very active, what might you see? What might you hear? What might you sense? What might you feel?