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

This chapter discusses the instability conditions of one of the largest landslide basins along the Adriatic coast, which is about 4 km² wide and is located just below the town of Petacciato. The landslides involve the stiff silty clays of the sub-Apennine Blue Clays, which outcrop in the lower part of the slopes. Several slopes along the Adriatic coast are affected by landsliding, despite being of low gradient. The slopes below the town of Petacciato are part of a landslide basin where several landslides, of different depth, are located. The surface fractures and fissures developing with sliding generally occur along pre-existing morphological elements recognizable as boundaries of landslide bodies. The 20th century sliding events at Petacciato represent reactivations of either deep paleo-landslides or old shallow landslides. The instability process is complex and composite and results from the mobilization of several landslides of different depth.