Atolls of Polynesia.
French Polynesia has an amazing diversity of islands, around 130 scattered over 2,500,000 square kilometers. Some of these Islands are "atolls", which are "ring-shaped ribbon reefs enclosing a lagoon".
(See below for a quick explanation on the formation of an atoll.)
In Polynesia, the Tuamotus form the largest chain of atolls in the world, spanning an area of the Pacific Ocean roughly the size of Western Europe. The most famous are Rangiroa, Fakarava, Tetiaroa, Tikehau, Maupiti, Manihi, Ahe or the heart-shaped Tupai, very noticeable from the sky and loved by Japanese newly-weds. It has become a very special honeymoon destination. On the other hand, the magical Tetiaroa will soon host the exclusive but eco-friendly Brando Hotel.
Atolls are very much part of the richness of Polynesian bio-diversity. Fakarava for example, Polynesia's second largest atoll, is presently being classified by UNESCO as a biosphere reserve. Rangiroa, the largest Polynesian atoll, spreads its elliptic shape over 80 km in length and 32 km in width. It is a favourite scuba diving area, offering some of the best dives in the world in and around the Tiputa Pass. Sedentary common bottlenose dolphins (Tursiops truncatus) regularly play in groups in the Pass. Large manta rays, green sea turtles and humphead wrasse can also be seen. Occasionally tiger sharks and hammerhead sharks can also be spotted. In January, large numbers of stingrays gather in the Tiputa Pass with the hammerhead sharks that feed on them.
From the sky, these atolls resemble exotic paintings, stripes of lush green coconut and palm vegetation contrasting with a striking palette of turquoise blue waters dotted with corals heads.
Have a look at Tim's selection of beautiful aerial Images of Polynesia's favourite atolls - the best Polynesian atolls from Polynesia's best aerial photographer.
Formation of an Atoll:
In 1842 Darwin explained the creation of coral atolls in the southern Pacific Ocean based upon observations made during a five-year voyage aboard the Beagle from 1831 to 1836. Accepted as basically correct, his explanation involved considering that several tropical island types—from high volcanic Island, through barrier reef island, to atoll—represented a sequence of gradual subsidence of what started as an oceanic volcano. He reasoned that a fringing coral reef surrounding a volcanic island in the tropical sea will grow upwards as the island sinks, becoming an "almost atoll", as typified by an island such as Bora Bora. The fringing reef becomes a barrier reef for the reason that the outer part of the reef maintains itself near sea level through biotic growth, while the inner part of the reef falls behind, becoming a lagoon because conditions are less favorable for the coral. In time, subsidence carries the old volcano below the ocean surface and the barrier reef remains. At this point, the island has become an atoll.