archipelago

An archipelago is a group or chain of islands distributed across a sea or ocean. The islands in an archipelago may be closely spaced or spread over large distances, and the arrangement often reflects underlying geologic or oceanographic processes. The term is used for island systems such as the Japanese Archipelago and the Caribbean Archipelago.

The word archipelago derives from the Greek arkhi- "chief" and pelagos "sea", historically used to denote a sea containing many islands. In modern usage, it denotes any island group, regardless of size or configuration.

Archipelagos form through tectonic activity, volcanic processes, and sea level changes. Subduction zones and volcanic arcs create chains of islands; collision or fragmentation of continents can produce archipelagos along continental margins. Erosional and depositional forces, sea-level fluctuations during glaciations, and submarine volcanism contribute to the creation and distribution of islands.

Some of the world's largest or best-known archipelagos are the Indonesian Archipelago, the Philippine Archipelago, the Japanese Archipelago, the Caribbean Archipelago, and the Aegean Archipelago in Greece.

Archipelagos often host high biodiversity due to isolation and varied habitats; many species are endemic to individual islands or archipelagos. Human activity, trade routes, and island biogeography have shaped cultures and economies around archipelago systems, with shipping, fishing, and tourism playing major roles.

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