An island arc is a curved chain of volcanic islands that forms at a tectonic plate boundary, typically where an oceanic plate subducts beneath another oceanic plate. This process creates magma that rises to the surface, resulting in volcanic activity. Island arcs are often found in regions like the Pacific Ocean, where they can create beautiful landscapes and rich ecosystems. These arcs are usually associated with deep ocean trenches, which mark the location of the subduction zone. Famous examples of island arcs include the Aleutian Islands in Alaska and the Japanese Archipelago. The geological activity in these areas can lead to earthquakes and eruptions, shaping the surrounding environment.