volcanic arc

A volcanic arc is a curved chain of islands or mountains associated with volcanic and seismic activity. These arcs typically form where two tectonic plates converge, and one plate is forced beneath the other into the mantle. This process, known as subduction, causes melting in the mantle wedge above the descending plate, generating magma.12

This magma rises to the surface, creating a line of volcanoes. If this occurs in the ocean, it forms an island arc, such as the Aleutian Islands. If one of the converging plates has continental crust, the volcanoes form on land, creating a continental volcanic arc, like the Andes Mountains. These arcs are often accompanied by deep-sea trenches on their convex side and are sites of frequent, deep-focus earthquakes.31