SUBMARINE LANDSLIDES IN SOCIETY AND AUSTRAL ISLANDS, FRENCH POLYNESIA:

EVOLUTION WITH THE AGE OF EDIFICES

 Valérie CLOUARD 

Departamento de Geofísica, Univ. de Chile, Blanco Encalada, 2085, Casilla 2777, Santiago, Chile - valerie@dgf.uchile.cl

Alain BONNEVILLE

Géosciences Marines, CNRS, Institut de Physique du Globe,  4 place Jussieu, 75252 Paris Cedex 05, France - bonnevil@ipgp.jussieu.fr

 Abstract

 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 fragmental 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.

 Keywords: Submarine landslide, French Polynesia, Austral, Society, classification, oceanic islands

Clouard, V., and A. Bonneville, Submarine landslides in Society and Austral Islands, French Polynesia: evolution with the age of edifices., in Submarine Mass Movements and their Consequences, edited by J. Locat, and  J. Mienert, pp. 335-341, Kluwer Academic Publishers, 2003.