An atoll (/ ˈæt.ɒl, - ɔːl, - oʊl, əˈtɒl, - ˈtɔːl, - ˈtoʊl /) [1] is a ring-shaped island, including a coral rim that encircles a lagoon. There may be coral islands or cays on the rim. [2][3] Atolls are located in warm tropical or subtropical parts of the oceans and seas where corals can develop.

Feb 28, 2025 · atoll, coral reef enclosing a lagoon. Atolls consist of ribbons of reef that may not always be circular but whose broad configuration is a closed shape up to dozens of kilometres across, enclosing a lagoon that may be approximately 50 metres (160 feet) deep or more.

Mar 19, 2025 · An atoll is a ring of coral that originally grew completely around the shoreline of an island, and which continued to grow upward on top of itself as the island subsided or eroded away. As reef building corals thrive only in warm waters, atolls are only found in …

Oct 19, 2023 · 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. Atolls develop with underwater volcanoes, called seamounts. First, the volcano erupts, piling up lava on ...

Apr 17, 2019 · The modern definition of atoll describes it as an annular reef that has enclosed a lagoon in which there is no raised mass of land projecting into the body of water. Atolls are mostly hidden by ocean waves, with some wrecking canoes and ships.

Apr 10, 2025 · Artwork representing coral islands, reefs, and atolls created by D. Caldwell for the National Park Service. Coral islands, reefs, and atolls are vital marine ecosystems found in both tropical and subtropical waters.

What is an “atoll”? For reef scientists, atolls are broadly defined as a large, ring-shaped coral reefs that surround a central lagoon. Coming up with a more specific and unambiguous definition of such reef formations is not all that easy however.

Apr 25, 2017 · An atoll is a ring-shaped coral reef or series of coral rims that encircle a lagoon either partially or wholly. Atoll and lagoons form a rim around an island that offers protection to the central island.

The meaning of ATOLL is a coral island consisting of a reef surrounding a lagoon. Did you know?

Oct 12, 2024 · Atolls are ring-shaped coral reefs surrounding a central lagoon, formed by the erosion and sinking of volcanic islands over millions of years. Approximately 440 atolls exist worldwide, with the majority located in the Pacific Ocean. Atolls are predominantly found in warm tropical or subtropical regions where coral growth is supported.