Answer – Forces such the convection currents in the mantle, slab pull and ridge push cause tectonic plates to move.
Explanation:
The lithosphere is the outermost layer of the Earth, and it is this that is broken up into plates called the tectonic plates. These rest on the asthenosphere which is partially fluid, and thus a good conductor of convection currents originating from the heat at the core. The currents traveling through the asthenosphere disturb the plates above it and thus, produce movement in them.
Ridge push occurs when warm asthenospheric magma rises up as a ridge under the lithosphere. This causes the plates above it to slide downwards on either side, thus triggering movement in them.
Slab pull is when older, colder and denser plates sink downwards, as in the case of subduction. This is the result of gravitational pull (as is the downward slide of the plates in ridge push). This motion too contributes to tectonic movement. In fact, geologists regard this last as the most important factor causing tectonic plates to move.
