An archipelago is a chain or cluster of islands that are formed by tectonic, volcanic, or erosional processes. Archipelagos can result from volcanic activity, as in the case of the Hawaiian Islands, or from the flooding of landmasses due to sea-level rise. These island groups are important for studying biogeography, evolution, and the impact of isolation on species development.
Reference: Gillespie, R. G., & Clague, D. A. (2009). Encyclopedia of Islands. University of California Press.