What is a theory developed by scientist to explain how forces deep within earth can cause seafloors to spread and continents to move?

The theory developed to explain how forces deep within the Earth cause seafloors to spread and continents to move is known as plate tectonics. This theory posits that the Earth's lithosphere is divided into tectonic plates that float on the semi-fluid asthenosphere beneath. Movements of these plates are driven by convection currents in the mantle, leading to phenomena such as seafloor spreading at mid-ocean ridges and continental drift. This process is responsible for the formation of various geological features and the occurrence of earthquakes and volcanic activity.