GEOLOGY

Detailed explanation-1: -An atoll is a ring-shaped coral reef, island, or series of islets. An atoll surrounds a body of water called a lagoon. Sometimes, atolls and lagoons protect a central island. Channels between islets connect a lagoon to the open ocean or sea.

Detailed explanation-2: -An atoll is a ring-shaped coral reef that forms as an old volcano erodes.

Detailed explanation-3: -When the island completely subsides beneath the water leaving a ring of growing coral with an open lagoon in its center, it is called an atoll. The process of atoll formation may take as long as 30, 000, 000 years to occur.

Detailed explanation-4: -Atoll which is also called as coral atoll is a ring shaped reef including rim which is present around a lagoon. These can be either circular or horse shoe shaped. Most of the world’s atolls are located in Pacific Ocean.

Detailed explanation-5: -Most of the world’s atolls are in the Pacific Ocean (with concentrations in the Caroline Islands, the Coral Sea Islands, the Marshall Islands, the Tuamotu Islands, Kiribati, Tokelau, and Tuvalu) and the Indian Ocean (the Chagos Archipelago, Lakshadweep, the atolls of the Maldives, and the Outer Islands of Seychelles).