Extracted the book " Tahiti today and all these islands " by Arlette EYRAUD, with the editions J.A.
76 atolls and a multitude of reefs and small islands constitute Tuamotus that Roggeveen, navigator with the service of Holland, qualified islands " pernicious " after y to have lost one of its vessels in 1721. Bougainville which was deprived of valid charts and instruments of rather precise navigation, named them the dangerous archipelago and several times avoided some breaking them.
Scattered in the Pacific between 14° and 24° of southern latitude, 136° 5 and 149° of western longitude, over a length of more than 1500 km and a width of 500 km, Tumotus form a geographical whole of 20 000 km² (interior lagoon included/understood), clearly separated from the other archipelagoes and, with more close, to 320 km of Tahiti. The atolls are so many and certain so small, that their calculation remained a long time approximate. Among more extended, Rangiroa figure, Apataki, Fakarava, Makemo, Hao, but much are represented on the charts by a point and cover a few tens of hectares.
Except for the island raised for Makatea and rare filled atolls such Nukutavake and Tikei, they are all of the coral rings of which vastest spread out on three major alignments, directed north-western south-east, of Tikehau to Anaa, Aratikato Marokau, Taenga to Hao. The other atolls of North and the East are offset and often very insulated. The coral crowns cap underwater dorsals, born of eruptions whose age could be evaluated to 50 million years. Eroded by the rains, shaken by the oceanic movements and the slip of the plates lithospheric, the absorbed volcanos were used of sat for the madrepores which underline more or less circular contours of them.
To 3 or 4 m above the sea level, these grounds, subjected directly to the atmospheric disturbances and marine, were sometimes entirely submerged. The atolls of the West count, in general, one or more master keys which ensure the renewal of water, the good health of the corals, and facilitate the access of the coasters coming to supply the population with exchange of the copra harvest.
Those of the center and the East often have a closed vegetable crown and the marine exchanges are done in-depth. The life of the men who must accost in " surfing " on the reef is harder. A score of species of trees and shrubs related on the salted ground and the dry climate, formed the vegetable cover and brought food and the shelters, with fish and shells.
