## 5 Discussion  
Overall, the data confirmed the presence of a graben-like structure, the Sarno basin, in the inner sector of the Sarno plain, which was first suggested by [PERSON] et al. [20]. This area was the locus of relevant subsidence, both in the long-term (as suggested by the accumulation of around 20 m of lacustrine, traverting, and peat layers in the last 39 ka), and in the short-term (as suggested by geodetic data for the 1992-2020 time span). The comparison of all the datasets allowed for the distinguishing of the natural (e.g., tectonics) and larger anthropogenic (e.g., groundwater pumping) contributions to subsidence within the Sarno basin. The tectonic contribution to subsidence was indicated by geomorphological and stratigraphic datasets (Sections 4.1 and 4.2). Evidence of recent tectonic activity include the rectilinear scarps that ruptured the surface. These occurred both to the NE (e.g., in the surroundings of the Lavorate embayment and in the Sarno village) and to the SW (e.g., along the northern sector of the SVT) of the Sarno basin. Associated with these rectilinear scarps are, at depth, offset CI and post-CI deposits. As the CI is chronologically constrained at 39 ka [80], the fault slip rate during the last 39 ka may be derived. [PERSON] et al. [20] estimated the slip rates for both faults F1 and F2, which were named, in that paper, faults F3 and F4, respectively. Slip rates in the last 39 ka were found to be 0.2 mm/yr for fault F1 and 0.1 mm/yr for fault F2. Notably, the slip rate for the fault F1 was estimated near the Lavorate embayment. In the Sarno urban area, fault F1 caused a \(\sim\)10 m vertical offset of the top surface of the CI. This would result in an average slip rate of \(\sim\)0.25 mm/yr during the last 39 ka, slightly larger than that seen in the adjoining Lavorate basin. It must also be considered that the top surface of the CI may have experienced erosion after its deposition, thus the value of the slip rate may be slightly different. Unfortunately, borehole data in the hanging wall block near the Sarno village urban area does not reach the base of the CI. As a consequence, we could not evaluate the offset of the CI base surface, which could have provided a more robust estimation of slip rate. The slip rate variation along fault F1 was consistent with the often-observed variation in offset values along a normal fault [81], which are maxima in the central portion of the fault (e.g., a slip rate of 0.25 mm/yr in the Sarno urban area) and decrease towards its tips (e.g., a slip rate of 0.1-0.2 mm/yr in the Lavorate embayment). Furthermore, slip rate values around 0.1-0.25 mm/yr are consistent with the slip rate values detected in the inner sector of the Southern Apennines [40,82]. These data in combination suggest recent activity of the fault strands bounding the Sarno basin towards the NE (fault F1 in Figures 4 and 5) and the SW (fault F2 in Figures 4 and 5). Indeed, these faults are small and incapable of generating large earthquakes and breaking the surface in one single seismic event. The rectilinear scarps, however, can be interpreted as resulting from multiple low to moderate energy slip events. Furthermore, the orientation of the F1 and F2 faults is coherent with that of the more pervasive fault system cropping out in the adjacent Sarno Mountains (Section 4.3). Anthropogenic contribution to subsidence was indicated by the geodetic datasets and the hydrogeological data. DInSAR datasets also suggested the occurrence of a cluster of subsidence within the Sarno basin (Section 4.5). Hydrogeological data showed that piezometric variation was spread across the Sarno plain, with variable rates within the Sarno basin (Section 4.4). Furthermore, high values of lowering of the water table levels were observed both within the Sarno basin and outside of it (e.g., the area with values of \(-3/-5\) m in Figure 7).