New Interpretation of Lemeglio Coastal Landslide (Liguria, Italy) Based on Field Survey and Integrated Monitoring Activities

Abstract

The Lemeglio landslide has been known since the end of nineteenth century because it represents a well-preserved coastal landslide in the Mediterranean environment. The landslide affects engineering structures: several drillings have been performed that allowed establishing the thickness and the bedrock nature; moreover they have been equipped with geotechnical and hydrogeological monitoring tools. It represents an active complex landslide, with a mean rate of movement up to 3 cm/y, whereas rapid phenomena like rockfalls occur at the landslide scarps. Recently, further information on ground movements has been collected through the radar interferometry technique PSinSAR. This monitoring activity, together with field surveys, allowed us to make a new delimitation of this large slope instability phenomenon. It now affects also the Lemeglio village and the north catchment of the hystorically-known area. On the basis of the collected data we can ascribe all the coastal area to a rock block slide or rotational sagging.