Step-by-step explanation:
There are two main reasons for the movement of magma: heat and pressure. As magma is heated by the Earth's core, it expands and becomes less dense than the surrounding rock. This causes the magma to rise through the crust. In addition, pressure from the overlying rock can force the magma upward. This is similar to how a bottle of soda will explode if you shake it and then open the cap. In this case, the pressure from the carbon dioxide gas forces the liquid out of the bottle. The movement of magma is driven by similar forces.