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Reefs can form in a gradual, sporadic manner, with alternate vertical and horizontal growth episodes. In this type of fringing reef formation there are multiple separate reefs that are found parallel to the shore and the original fringing reef. These reefs become a single, large reef when reef sediments fill in the spaces between the different ...
Where the land is rising, fringing reefs can grow around the coast, but coral raised above sea level dies and becomes white limestone. If the land subsides slowly, the fringing reefs keep pace by growing upwards on a base of dead coral, and form a barrier reef enclosing a lagoon between the reef and the land.
Fringing reefs follow coastlines and can extend for many kilometres. [43] They are usually less than 100 metres wide, but some are hundreds of metres wide. [44] Fringing reefs are initially formed on the shore at the low water level and expand seawards as they grow in size. The final width depends on where the sea bed begins to drop steeply.
Reef types include fringing reefs, barrier reefs, and atolls. A fringing reef is a reef that is attached to an island. A fringing reef is a reef that is attached to an island. Whereas, a barrier reef forms a calcareous barrier around an island, resulting in a lagoon between the shore and the reef.
According to Charles Darwin's subsidence model, [5] the formation of an atoll is explained by the sinking of a volcanic island around which a coral fringing reef has formed. Over geologic time, the volcanic island becomes extinct and eroded as it subsides completely beneath the surface of the ocean.
Spur and groove formations are a geomorphic feature of many coral reefs. They are ridges of reef formed by coral ("spurs") separated by channels ("grooves") which often have sediment or rubble bed. Spur and groove formations vary in their size and distribution worldwide but are a common feature on many forereefs of fringing reefs , barrier ...
There are various types of shallow-water coral reef, including fringing reefs, barrier reefs and atolls; most occur in tropical and subtropical seas. They are very slow-growing, adding perhaps one centimetre (0.4 in) in height each year. The Great Barrier Reef is thought to have been laid down about two million years ago.
SMEs are characterized by carbonate reefs, which support many species. Estimates suggest that coral reefs alone may host between 1-9 million species. The three main types of reef formations are: [8] Fringing Reefs: attached to the shore; Barrier Reefs: separated from the mainland by a lagoon; Atoll Reefs: ring-shaped reefs surrounding a lagoon