The process by which magma, volcanic ash, and gases are erupted from a volcano. Indonesia's high number of active volcanoes is a direct result of its position on the Ring of Fire.

Massive, irregularly shaped slabs of solid rock, composed of both continental and oceanic lithosphere, that form the Earth's outer shell. Their movement and interaction are responsible for earthquakes, volcanic activity, and mountain building.

A string of volcanoes and sites of seismic activity, or earthquakes, around the edges of the Pacific Ocean. Roughly 90% of all earthquakes occur here, and it is dotted with 75% of all active volcanoes, surrounding several major tectonic plates.