Plate tectonics is the scientific theory that describes the large-scale motion of the plates making up Earth's lithosphere. One of the most dynamic areas of interaction is the subduction zone, which occurs when two tectonic plates collide and one is forced beneath the other into the mantle. This typically happens when a dense oceanic plate meets a less dense continental plate. As the oceanic plate descends, it encounters high temperatures and pressures, causing it to release water and other volatiles. These substances lower the melting point of the surrounding mantle rock, leading to the creation of magma. This magma eventually rises toward the surface, forming volcanic arcs. In addition to volcanism, subduction zones are associated with some of the world's most powerful earthquakes due to the intense friction between the grinding plates.