A volcanic outbreak is a sudden release of energy from a volcano, usually in the form of an ERUPTION. It is caused by the pressure of magma and gases within the volcano that build up until they are released explosively. The term 'ERUPTION' is used to describe the process of the magma and gases being expelled from the volcano. During an ERUPTION, lava, ash, and other materials can be thrown into the air, causing destruction and disruption to the surrounding area.