Geotechnical measurements to characterise slope sediments and to identify landslide mechanisms and their impact on ecosystems

Mass wasting processes are a common phenomenon along the continental margins. Observation and analysis of the mass wasting processes are of scientific and socio-economic interest due to the hazardous impact of offshore industry installations or Tsunamis, which endanger coastal cities and surrounding areas. The distribution of submarine landslides may be controlled by the interaction of morphology, sediment composition, sediment mechanical behaviour and external triggers. This study investigates the mechanics, mechanisms and factors governing slope instabilities of different submarine landslides sites evolved from active and passive continental margins. Results of geotechnical measurements from both the stable and the failed part of the landslides were compared to previously published geophysical and sedimentological data. The three different research sites are i) the passive continental margin of Mauritania, NW-Africa, ii) the active Ligurian margin (Southern France) and iii) the active margin of the Cretan Sea (Greece). A combination of several trigger mechanisms in interaction with preconditioning factors are requiered for destabilizing the investigated slope sediments.