133 Application of Laser Scanning for Monitoring Coastal Cliff Instability in the Pozzuoli Bay, Coroglio Site, Posillipo Hill, Naples R. Somma, F. Matano, E. Marino, T. Caputo, G. Esposito, M. Caccavale, S. Carlino, S. Iuliano, S. Mazzola, F. Molisso, M. Sacchi, C. Troise, and G. De Natale Abstract This study presents a Terrestrial Laser Scanning (TLS) application to monitor the slope stability along tuffaceous cliffed coast of Pozzuoli Bay, at Coroglio test site, Naples, Italy. We tested TLS technique based on Time of Flight method in order to obtain a 3D model of the coastal cliff, along with a classification of the rock discontinuities on the basis of their spatial orientation. A high-resolution digital model of the study outcrop has been produced, with a cell dimension of 5 cm. The analysis of spatial orientation of planar-like surfaces derived from the digital 3D model shows an excellent correlation with the sets of fractures and faults actually measured in the outcrop by classic geo-structural analysis. The results obtained from the Coroglio test suggest that the use of TLS application is an effective method for the monitoring of instability and evolution of coastal cliffs in volcanic settings. Keywords Tuff cliff Á Rock fall Á Laser scanning Á Campi Flegrei Á Caldera Á Landslide monitoring 133.1 Introduction Landslides are regarded as a major geologic hazard and cause, every year, severe damage to urbanized areas and/or infrastructures. Landslides monitoring is a target for current research in the fields of geology, hydrogeology and geodesy, notwithstanding the dif ficulty posed by the inherent com- plexity and variety of landslide phenomena as well as by the lack of accurate reference morphologic data, in most cases. Among surveying techniques, Terrestrial Laser Scanning (TLS) can be successfully used to monitor landslide phenomena over wide areas with a high level of detail (Abellan et al. 2010; Fanti et al. 2013). This study presents a TLS application for landslides monitoring and analysis in the coastal zone of the Pozzuoli Bay, Eastern Tyrrhenian Sea margin, Italy. This area is a part of the Campi Flegrei, an active volcanic district character- ized by intense explosive activity during the latest Quater- nary and a well-known historical bradyseismic phenomenon. With a population of more than 300,000 inhabitants and numerous relevant infrastructures, Campi Flegrei district is one of the highest volcanic risk areas of the world, moreover its coastal zone is prone to a series of natural and anthro- pogenic hazards, including earthquakes, tsunamis, ground deformation, landslides, floods, storm surges, coastal erosion (Beneduce et al. 1988; Lirer et al. 2001). The area is also characterized by a dense road network that is often affected by landslide phenomena, thus causing interruption of transportation routes and/or damage to infrastructures, as already occurred in the past years. The coastal zone of the Pozzuoli Bay is represented by both rocky cliff and sandy beach segments. Cliffs mostly consist of welded pyroclastites, tuffs and ignimbrites. These coherent but relatively erodible volcaniclastic rocks are considerably R. Somma (&) Á T. Caputo Á S. Carlino Á C. Troise Á G. De Natale Istituto Nazionale di Geofisica e Vulcanologia Sez, Napoli via Diocleziano 328, 80124, Naples, Italy e-mail: renato.somma@ingv.it F. Matano Á G. Esposito Á M. Caccavale Á S. Iuliano Á S. Mazzola Á F. Molisso Á M. Sacchi Istituto per l’ambiente Marino Costiero – IAMC – CNR Calata Porta di Massa, Porto di Napoli, 80133, Naples, Italy E. Marino Stage srl, Viale Ghandi 128, 81025, Marcianise, Caserta, Italy G. Lollino et al. (eds.), Engineering Geology for Society and Territory – Volume 5, DOI: 10.1007/978-3-319-09048-1_133, © Springer International Publishing Switzerland 2015 687