archipelagos

An archipelago is a group or chain of islands clustered in a sea or ocean, sometimes forming a distinct geographic region. The term derives from the Greek archì- “chief” and pelagos “sea,” later adopted into other languages to describe such island networks.

Archipelagos form through several geological processes. Some arise from volcanic activity, as magma builds islands above the ocean floor. Others consist of continental fragments that become islands through sea-level rise and tectonic movement. Still others are coral reef systems that accrete around submerged structures and atolls, creating rings or clusters of low-lying land.

Notable archipelagos include Indonesia and the Philippines, which together contain thousands of islands; Japan, the Caribbean islands, and the Aegean Sea archipelagoes; the Hawaiian Islands; New Zealand’s main islands; the Canary and Cape Verde islands; and the Seychelles and Maldives. They span diverse climates, from tropical to temperate, and occupy strategic positions in global trade, biodiversity hotspots, and cultural exchange.

Ecologically, archipelagos host high biodiversity and many endemic species due to isolation. Coral reefs and surrounding marine habitats support diverse life, but such systems are vulnerable to climate change, invasive species, habitat loss, and overfishing. Islands often exhibit unique ecological communities adapted to local conditions.

Humans use archipelagos for living, fishing, tourism, and transport. Governance recognizes archipelagic baselines under international law, with states claiming territorial seas and exclusive economic zones around island groups, reflecting the political and economic importance of these dispersed lands.