Crescent‐shaped slab slides in a submarine canyon system, Arequipa fore‐arc basin, off southern Peru

SeaMARC II side‐scan imagery and bathymetry, seismic reflection, and free‐fall core sampling data reveal the morphology, structure, and hydrology controls on the formation and development of a series of crescent‐shaped slab slides along the submarine canyon walls in the Arequipa fore‐arc basin off southern Peru. The crescent‐shaped slab slides occur in a segment of an approximately 25‐km‐long canyon course and generally accord with the meandering of the canyon course. Most of the slab slides commonly consist of four distinctive zones: the fissured zone, scarp zone, voided zone, and frontal zone. The fissured zone is developed on the crown of the sliding walls; the scarp zone is marked by scars with crescent‐shaped slip surfaces and throws ranging from 50 to 120 m. The voided zone is characterized by 1–3 km wide terraces resulting from slab‐type excavating of the seafloor. The frontal zone is normally comprised of debris materials distributed on the seafloor near the canyon thalweg; however, there is lack ...