What causes tectonic plate movement?

Tectonic plate movement is primarily caused by the heat from the Earth's interior creating convection currents in the mantle.

The Earth's lithosphere, which includes the crust and the uppermost part of the mantle, is divided into several large and small tectonic plates. These plates float on the semi-fluid asthenosphere beneath them. The heat from the Earth's core causes the mantle to behave like a slow-moving liquid, even though it is solid rock. This heat creates convection currents within the mantle, where hot, less dense material rises, cools, and then sinks back down as it becomes denser. These convection currents act like conveyor belts, dragging the tectonic plates along with them.

In addition to convection currents, other forces also contribute to the movement of tectonic plates. One such force is slab pull, which occurs at subduction zones where one plate is forced under another into the mantle. The sinking plate pulls the rest of the plate along with it due to gravity. Another force is ridge push, which happens at mid-ocean ridges where new crust is formed. As magma rises and solidifies to form new crust, it pushes the older crust away from the ridge, causing the plates to move apart.

The interaction of these forces results in different types of plate boundaries: divergent (where plates move apart), convergent (where plates move towards each other), and transform (where plates slide past each other). These movements are responsible for many geological phenomena, such as earthquakes, volcanic activity, and the formation of mountain ranges. Understanding these processes helps geographers and geologists predict natural disasters and analyse the Earth's ever-changing landscape.