What Is An Atoll?

An atoll is a unique marine feature comprising of an island formed of coral enclosing a lagoon within itself; atolls are mainly found in tropical parts of oceans where the conditions favor rapid growth of coral.

Atolls are usually situated at the site of submerged volcanoes and the commonly accepted theory regarding their creation is that as the volcanic islands gradually subside in the ocean due to geological forces within the Earth's crust or due to erosion and submergence of the island due to increased water level coral reefs which grow around the fringes of islands continue to exist forming atolls with a lagoon in the interior marking the site where the island had existed.

The majority of atolls are found in the Pacific Ocean in the Tuamotu Islands, Caroline Islands, Marshall Islands and the Kiribati and Tuvalu group of islands and in the Indian Ocean among the Maldives and Laccadives group of islands and the fringe islets of the Seychelles. Atolls are generally small in size with respect to land area with the largest individual atoll considered to be Kiritimati with a surface area of 321 sq km, located in the Pacific Ocean and included in the Kiribati group of islands.