Landslides in stiff clay slopes along the Adriatic coast (Central Italy)

The slopes below the town of Petacciato are part of a landslide basin where several landslides, of different depth, are located. The study aims at investigating the overall sliding mechanism, focusing on both the recognition of the most active bodies and the interpretation of their interaction during the reactivation events. The combined analysis of geomorphic data, field investigation results and limit equilibrium back analyses results in the understanding that only the inland portion of the deep paleo-landslide has been repeatedly reactivated during the 20th century, followed by the formation of a new shear band at the toe of the slope, about the coastline. The reactivation starts with the mobilization of an intermediate depth body, lying upslope in the western portion of the basin, whose movement causes the mobilization of a deep body at the toe of the slope which in turn activates the inland portion of the deep paleo-landslide.