Modelling the mobility and dynamics of a large Tahitian landslide using runout distance

Abstract

Runout distance was used here to determine whether the large landslide deposit formed several thousand years ago in northern Tahiti was caused by a single or multiple events. Using modelling to quantify the dynamics of this event suggested that a single event or a small number of events (n < 10) were responsible, and that the maximum slide velocity was high (>125 m/s) under partially submarine conditions. Such submarine propagation favoured a slower dynamic but a longer runout. The effective basal friction under submarine conditions ranged from 0.2 < μ < 0.3.