SUBMARINE LANDSLIDES IN SOCIETY AND AUSTRAL ISLANDS, FRENCH POLYNESIA: EVOLUTION WITH THE AGE OF EDIFICES

摘要

This paper describes numerous submarine landslides in French Polynesia. This inventory shows an evolution of the landslide type with oceanic islands age. Submarine active volcanoes are subject to superficial landslides of fiagmental material whereas young islands exhibit marks of mass wasting corresponding to giant lateral collapses producing debris avalanche during the period of volcanic activity. Later, erosional processes generate fine grained debris avalanches and carving the stellate morphology observed on atolls and guyots. In addition, the shape of Tupai atoll and Rurutu Island have been deeply modified by giant slumps that deeply modify their shape.