## 4 Discussion  
The application of our working method to two study areas affected by coseismic surface faulting in 2016 Central Italy seismic sequence demonstrates that the virtual outcrop models represent an important tool for structural-geological and geomorphological research aimed at identifying and characterizing active tectonic structures. Furthermore, comparing the information obtained from the morphological analysis of the fault scarp of CAB, with configuration of the coseismic surface faulting of the 2016 Central Italy seismic sequence, it is possible to make inferences on the rupturing history of the studied faults. The good fit between the profile of the height of fault scarp and the 2016 coseismic slip profile (Figure 8b) suggests that the long-term fault scarp may have been formed as a result of several earthquakes, each causing a similar amount of surface displacement. It is also possible to infer for these events comparable values of magnitude. In particular, taking into account: (i) the height of the entire fault scarp (ii) the amount of the 30 October 2016 coseismic slip, (iii) the geometry of the slope profiles also including the possible eroded free face, and (iv) the assumption that earthquakes of equal/similar magnitude generated equal/similar dislocations (compared to 2016 one), we hypothesize that at least five events are needed to reach the observed values of fault scarp height. Previous paleoseismological works [16; 49; 50] have highlighted several seismic events, some of which caused the PTP reactivation, which occurred in the Pano Grande-Mt Vettore area. In particular, four events have been recognized in the last 8000 years, in addition to the earthquake of 2016. These four earthquakes, would have been occurred (from the oldest): (i) between IV and VI millennium BC, (ii) at the end of IV millennium BC, (iii) between II and III millennium BC, (iv) between the end of III and IV century AC (maybe in 270 AC). Furthermore, accepting the inferences, which implies that the 4.5 m outcropping fault scarp of the CAB was exhumed after the Last Glacial Maximum L.G.M. (-18.000 ky), a preliminary estimate of the slip rates, of 0.25 mm/y is obtained. Of course, the analyzed fault scarps might have recorded a higher number of coseismic slip events, which could have been followed by erosional episodes in a longer geological time; thus, the above estimate must be considered purely indicative. Several authors studied the causes/effects of the 2016 earthquakes from many points of view, as structural-geology, geophysics, seismology, paleoseismology, geomorphology, interferometry, geodesy, hydrogeology, engineering [31; 32; 34; 35; 36; 39; 40; 51; 52; 53; 54; 55; 56; 57; 58; 59; 60; 61; 62; 63; 64; 65; 66; 67; 68; 69; 70; 71; 72; 73; 74; 75; 76; 77; 78; 79; 80; 81; 82; 83; 84; 85; 86; 87; 88; 89; 90; 91], but only a few authors have provided and elaborated data acquired through drones [92; 93; 94; 95]. In addition, there are no author-produced image analyses of coseismic ruptures employing the techniques we propose here. Our results, obtained from the elaboration of high-resolution topography, fit well with the data published in [PERSON] et al. [36], [PERSON] et al. [15], and [PERSON] et al. [95], acquired through traditional or digital mapping techniques. At the same time, the present work has improved the details of the surveyed geological features, some of which were not appreciable directly in the field; among this latter, the degradation and erosion of the fault plane as well as the tilting of the topographic surface, the dip-angle, and the off-fault width of the tilted area. The here obtained results showed that the use of the drone-derived photogrammetry presents acceptable errors for all those structural-geological applications, also those that need high precision (near centimetric resolution), and that might be an integration to the traditional field survey. In Figure 13, three types of DEMs with different resolutions (10 m, 5 m, and 1 cm) are compared.