Despite the vast spread of the archipelago, it covers a total land area of only about . The climate is a
warm tropical one, without sharply distinct seasons. The average annual temperature is a relatively continuous . Water sources such as lakes or rivers are absent, leaving catchments of rain as the only source of fresh water. The annual average rainfall is . Although average rainfall is lowest in September and November, it does not vary markedly throughout the year. The archipelago is geologically highly stable, because it was created by the action of the
Easter fracture zone, which is only weakly active. There have been no volcanic eruptions during recorded history.
Flora and fauna The sparse soil of the coral islands does not support diverse vegetation. The
coconut palm, which is the basis of
copra production, is of special economic importance. On a few of the islands,
vanilla is also cultivated. Agriculture is generally otherwise limited to simple subsistence. Fruit and vegetable staples include
yams,
taro,
breadfruit, and a wide range of tropical fruit.
Pandanus leaves are traditionally woven together to make mats, hats, and roof
thatches. However, many of the roofs nowadays are made of corrugated sheet-metal. There are also mangrove forests in sheltered areas, though its less common around coral atolls. The species-rich reefs are home to a diverse range of underwater fauna. The surface creatures are primarily
seabirds,
insects, and
lizards. The Tuamotus have
86 species of birds, ten of which are
endemic, including the
Tuamotu kingfisher, the
Tuamotu reed warbler, and the
Tuamotu sandpiper. Thirteen species are globally threatened, and one has gone extinct.
Geology All of the islands of the Tuamotus are coral "low islands": essentially high sand bars built upon coral
reefs.
Makatea, southwest of the Palliser Islands, is one of three great
phosphate rocks in the
Pacific Ocean. (The others are
Banaba in
Kiribati, and the island nation of
Nauru.) Although the
Gambier Islands are
geographically part of the Tuamotus because they lie at the southeastern extreme of the
archipelago, they are
geologically and
culturally distinct. The ring-shaped atoll
Taiaro, which lies in the northwestern portion of the archipelago, is a rare example of a coral reef that has a fully enclosed lagoon. Taiaro has been officially designated a
UNESCO biosphere reserve since 1977. ==Island groups==