Moorea
- ISS006-E-39837
- 19 March 2003
- 18:31 UTC
Moorea, located 13 km off the northwest coast of Tahiti, is a steeply-eroded mountainous island of 132 km² in area — the second largest of the Windward Group after Tahiti. With a circumference of 61 km, the island consists of one major landmass, four small islets, a shallow lagoon averaging 3 m in depth and a well-developed fringing-reef that surrounds the entire formation. The highly dissected interior of the island reaches a maximum elevation of 1,207 m at Mount Tohivea.
Prominently marked by sharp shadows in the above image is the steep-sided, semi-circular ridge that sweeps through the central regions of the island, from the northeast coast to the northwest coast, dividing the southern coast from the partly enclosed depression of the centre and north. This tall rampart represents an ancient caldera wall and gives Moorea its characteristic "half a volcano" appearance when viewed from above. The northern depression is thought to have been produced by caldera subsidence and not by catastrophic caldera collapse as once thought. Now highly weathered and eroded, the caldera walls present a dramatic profile of steep slopes and sharp ridges, separating narrow ravines and valleys that slope to the coast. The northern side of the caldera floor is open to the sea and is cut by the two deep bays of Cook and Opunohu divided by Mount Rotui.
image: earth sciences and image analysis laboratory, nasa johnson space center.
