A volcanic arc is a chain of volcanoes formed above a subduction zone, where one tectonic plate moves under another and sinks into the mantle. This process causes melting of the mantle material, leading to magma formation. The magma rises to the surface, resulting in volcanic activity. These arcs typically form along oceanic-continental or oceanic-oceanic plate boundaries. A well-known example of a volcanic arc is the Andes Mountains in South America, which is created by the subduction of the Nazca Plate beneath the South American Plate. Volcanic arcs can significantly impact local ecosystems and human settlements.