Island arc

The Ryukyu Islands form an island arc.

An island arc is a type of archipelago, often composed of a chain of volcanoes, with arc-shaped alignment, situated parallel and close to a boundary between two converging tectonic plates.

Most of these island arcs are formed as one oceanic tectonic plate subducts another one and, in most cases, produces magma at depths below the over-riding plate. However, this is only true for those island arcs that are part of the group of mountain belts which are called volcanic arcs, a term which is used when all the elements of the arc-shaped mountain belt are composed of volcanoes. For example, large parts of the Andes-Central American-Canadian mountain chain may be known as a volcanic arc, but they are not islands (being situated upon and along a continental area) and are thus not classified as an island arc. On the other hand, the Aegean or Hellenic arc in the Mediterranean area, composed of numerous islands such as Crete, is an island arc, but is not volcanic. Parallel to it is the South Aegean Volcanic Arc, which is the volcanic island arc of the same tectonic system.[citation needed]


There is some debate about the usefulness of the distinction between island arcs and volcanic arcs.[citation needed] The term "volcanic island arc" is merely a sub-classification of "island arc." Island arcs are tectonically created arc-shaped mountain belts that are partly below sea level. Essentially, they represent a specific geographic-topographic situation in which a mountain belt is partly submerged in ocean. Many of these are composed of volcanoes, and can thus be further classified as volcanic island arcs.

Other Languages
Afrikaans: Eilandboog
العربية: قوس الجزيرة
asturianu: Arcu insular
भोजपुरी: दीप चाप
català: Arc insular
čeština: Ostrovní oblouk
Deutsch: Inselbogen
eesti: Saarkaar
Ελληνικά: Νησιωτικό τόξο
español: Arco insular
français: Arc insulaire
한국어: 열도
हिन्दी: द्वीप चाप
Bahasa Indonesia: Busur kepulauan
עברית: קשת איים
Limburgs: Eilandjbaog
Nederlands: Eilandboog
日本語: 島弧
oʻzbekcha/ўзбекча: Orollar yoyi
polski: Łuk wyspowy
português: Arco insular
slovenčina: Ostrovný oblúk
slovenščina: Otoški lok
svenska: Öbåge
Türkçe: Ada yayı
українська: Острівна дуга
中文: 島弧