Tubuai Islands
The Tubuai Islands (Îles Australes/Austral Islands) are a long chain of remote islands located
in the far South Pacific, lying southwest of the Cook Islands (325 km northwest
of the Îles Maria), and 550 km south of the Society Islands. In all there
are 7 main islands (with a combined land area of 174 km²) within the 1,300 km long northwest to
southeast orientated chain.
Five of the islands are inhabited — Rimatara, Rurutu, Tubuai, Raivavae, and Rapa. The group also includes the uninhabited atoll of Maria (Îles Maria) and the rocky peaks of Marotiri (Îlots de Bass). The reef-ringed island of Tubuai, at 44 km² is the largest of the islands, followed by Rapa at 40 km².
The islands are the remains of former volcanic peaks,
thought to been have formed over a hot-spot,
in much the same way as the Hawaiian Islands. The islands at the southeast end of the chain are geologically
the youngest — the Îles Marotiri (Îlots de Bass) are a tight cluster of 4 rocky islands and
emergent rocks whose steep slopes support a scant vegetation. Maria, the most northeasterly of the islands
is the oldest of the Tubuai Islands. Its former volcanic peak has long since disappeared, but coral growth
has kept this last remnant above sea level, surviving as an atoll formation. Islands in the middle of the chain
have a more complex geological history — uplift processes and changing sea levels at islands such as Rimitara
and Rurutu have exposed once submerged fringing reefs, creating low limestone ridges around these islands.
