Submarine Landslides in French Polynesia

摘要: Landslides are common features of oceanic islands and playa key role in their evolution. Caused by caldera collapse or flank collapses, they can be classified into three types: (1) rock falls, (2) slumps (3) debris avalanches (Moore et al. 1989). Rock superficial landslides, mainly related to erosion processes the subaerial parts island. The pieces less than 1 m size, surface is rippled. Flank collapses generally produce giant submarine with a horseshoe-shaped feature at head landslides due deep listric fault cataclysmic events producing fast moving avalanches. Deposits extend over several hundred kilometers away from an island characterized thicknesses 2 km, hummocky terrain lower part. Side-slip termed slump Fig. 6.1. Slumps slow-moving slope instabilities. thickness deposits as much 10 since primitive volcano shattered disrupted case avalanche. causes major lateral still matter debate, but most cases thought magma intrusion rift zones (Denlinger Okubo 1995; Keating McGuire 2000).