## 2 Dataset and Methods
### Geomorphological and Structural Survey  
A series of geomorphological surveys, organized between the spring and summer of 2019, were carried out for corroborating previous surveys [27; 30], which mainly focused on coastal processes and landforms, with particular attention on the detection of tidal notches and their morphovelutive significance. The surveys performed here aimed at refining the recognition and mapping of coastal and gravity-induced processes and landforms, as well as at enlarging this detection along the entire coastal slope between the Portonovo and the Due Sorelle sites (Figure 1).  
Figure 1: Geomorphological map of the Conero promutory showing the main geological and structural elements (map coordinates are in WGS84 cartographic reference system). Near-coast bathymetry (0-10 m below the sea level) is also indicated. 1: study area; 2: lake; 3: normal fault; 4: strike-slip fault; 5: Maiolica Fm.; 6: Marne a Fucoidi Fm.; 7: Scaglia Rossa Fm.; 8: gully erosion; 9: tidal notch; 10: plunging cliff; 11: landslide-toe compressional ridges; 12: rocky scarp; 13: landslide trench; 14: swamp; 15: alluvial fan; 16: stratified slope deposit; 17: sea stack; 18: beach; 19: shore platform; 20: slope debris and talus deposits; 21: debris flow; 22: debris avalanche; 23: rock avalanche; 24: rock fall; 25: rock slide; 26: diffuse gravity-driven slope deformations.  
The detection and mapping of the processes and landforms were based on the approach proposed by the new Italian Geomorphological Mapping guidelines [31], which suggest mapping each landform based on its genesis, evolution, and present dynamics. The peculiar amount of landslide phenomena affecting the coastal slopes imposed special attention on the detection and mapping of the gravity-induced processes and landforms, and their complex evolutionary scenarios. Geomorphological fieldwork was preceded by the interpretations of the panchromatic orthophotos visualized in the GIS platform and by the interpretation of the historical aerial stereopair images, which were helpful for a preliminary delimitation of both large landslide bodies and debris deposits. Results of these preliminary tasks were also helpful for tracing the main structural lineaments. The optical satellite images available in Google Earth, together with the ones available in ArcGIS 10.6 (i.e., TerraColor dataset) were consulted for planning fieldwork and for supporting the mapping of the largest landslide features, other than for delimiting the main cliff escarpments. The multitemporal remote sensing analysis was also useful for defining the recent activity of the main landslides. After the geomorphological fieldwork, final refining of the geomorphological mapping was completed through the 3D visualization of the topography at high-resolution, thanks to a hillshade map derived from the 2 m-cell-sized DEM in the GIS platform.  
Geostructural surveys, conducted together with the geomorphological ones, were carried out to detect and characterize the main tectonic structures that strongly control the rock mass behavior, as well as for refining the mapping of the lithological units composing the bedrock. The final aim was to unravel the connection between the local bedrock discontinuity frequency and distribution and the rock slope deformation and instability.  
The fieldwork was conducted using digital survey techniques, based on mobile devices that allowed for collecting field data in digital form, and its direct storage through remote cloud-uploading and real-time updating.