Atoll - Wikipedia
As the volcanic island subsides, the coral fringing reef becomes a barrier reef that is detached from the island. Eventually, reef and the small coral islets on top of it are all that is left of the original island, and a lagoon has taken the place of the former volcano. The lagoon is not the former volcanic crater.
Atoll | Definition & Facts | Britannica
2024年11月27日 · 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.
Atoll Facts and Information - Coral Reef Info
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.
Atoll - Education | National Geographic Society
2023年10月19日 · 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 ...
What Is An Atoll? - WorldAtlas
2019年4月17日 · 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.
How a coral atoll forms - NOAA's National Ocean Service
How do coral reefs form? This animation shows the dynamic process of how a coral atoll forms. Corals (represented in tan and purple) begin to settle and grow around an oceanic island forming a fringing reef. It can take as long as 10,000 years for a fringing reef to form.
Atolls: The Ring-Shaped Coral Islands! - littleexplainers.com
2024年10月12日 · 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.
Scientists Say: Atoll - Science News Explores
2021年11月15日 · An atoll is a ring-shaped coral reef, island or chain of islands around a body of water called a lagoon. An atoll forms when an underwater volcano spills lava onto the seafloor. Over many eruptions, that volcanic rock piles up. Eventually, it rises above the …
Coastal And Oceanic Landforms: What Is An Atoll? - WorldAtlas
2017年4月25日 · 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.
Characteristics of atolls | Britannica
atoll, Coral reef enclosing a lagoon. Atolls consist of ribbons of reef that may not be circular but that are closed shapes, sometimes miles across, around a lagoon that may be 160 ft (50 m) deep or more.