An archipelago (// (listen) ARK-ih-PEL-ə-goh), sometimes called an island group or island chain, is a chain, cluster or collection of islands, or sometimes a sea containing a small number of scattered islands.
Indonesia, Japan, the Philippines, New Zealand, Maldives, the British Isles, the Bahamas, the Aegean Islands (Greece), the Florida Keys, Hawaii, Puerto Rico, the Canary Islands, the Madeira and the Azores are all examples of well-known archipelagos.
The word archipelago is derived from the Ancient Greek ἄρχι- (arkhi-, "chief") and πέλαγος (pélagos, "sea") through the Italian arcipelago. In Italian, possibly following a tradition of antiquity, "Archipelago" (from medieval Greek *ἀρχιπέλαγος and Latin archipelagus) was the proper name for the Aegean Sea. Later, usage shifted to refer to the Aegean Islands (since the sea is remarkable for its large number of islands).
Archipelagos may be found isolated in large amounts of water or neighbouring a large land mass. For example, Scotland has more than 700 islands surrounding its mainland which form an archipelago.
Archipelagos are often volcanic, forming along island arcs generated by subduction zones or hotspots, but may also be the result of erosion, deposition, and land elevation. Depending on their geological origin, islands forming archipelagos can be referred to as oceanic islands, continental fragments, and continental islands.
Oceanic islands are mainly of volcanic origin, and widely separated from any adjacent continent. The Hawai'ian Islands and Easter Island in the Pacific, and Île Amsterdam in the south Indian Ocean are examples.
Sets of islands formed close to the coast of a continent are considered continental archipelagos when they form part of the same continental shelf, when those islands are above-water extensions of the shelf. The islands of the Inland passage off the coast of British Columbia are an example.
- Whittaker R. J. & Fernández-Palacios J. M. (2007) Island Biogeography: Ecology, Evolution, and Conservation. New York, Oxford University Press
- Indonesia. The World Factbook. Washington, DC: Central Intelligence Agency of the United States. 4 December 2008. Archived from the original on 10 December 2008. Retrieved 7 December 2008.