Check out this paper from the coast of Gabon, where the authors use repeat multibeam surveys to capture a large-scale slope failure very near the coast. They estimate that more than 2 million cubic meters of sediment were evacuated during 2005 (probably in an event that lasted less than a few days)! The authors also estimate that due to the dynamic nature of the seafloor in the area, that all evidence of this submarine slide scar will disappear from the seafloor in about 20 years. Spectacular!
off the shelf edge 