The study of forces within Earth that cause the crust to move is called plate tectonics.

Here's why:

* Plate tectonics is the theory that Earth's outer layer is made up of large, moving plates.

* These plates interact with each other at their boundaries, causing a variety of geological phenomena like earthquakes, volcanoes, and mountain formation.

* The forces driving plate movement are complex and include:

* Convection currents in the Earth's mantle

* Gravity pulling denser plates downward

* Ridge push at mid-ocean ridges

* Slab pull where dense plates sink into the mantle

So, while the study of plate tectonics encompasses many aspects, it's the central framework for understanding the forces that move the Earth's crust.