## 5 Conclusions  
Thanks to the improvement of the OT network, with the addition of two new stations in the northeastern sector of the GP, an enhanced dataset of microearthquakes was recently collected and released [27]. In this study, with this new dataset, the total \(Q_{c}\) of S-waves was studied for the GP area. \(Q_{0}\) values indicate that the Gargano area is tectonically active when compared with other regions as, for instance, the Central and Southern Apennines (Italy); the comparative results of \(\alpha\) indicate that the GP crust is strongly heterogeneous at a penetration depth of about 30 km in the lower crust, and this result agrees with the observed seismicity, which concentrates at that depth, indicating a high degree of fracturing of the GP's lower crust. In this work, using attenuation kernels, we present the first 3D \(Q_{c}\) maps of the Gargano (Southern Italy) area for different depths and frequencies. The geophysical knowledge of the area greatly benefits from this 3D approach, providing a marked improvement with respect to the averaged \(Q_{c}\) estimates alone. The imaging was performed at different frequencies and depths. Results at low and medium frequency indicate a fairly homogeneous \(Q_{c}\) at all depths, whereas, at high frequency, results indicate:  
1. The presence of a high \(Q_{c}\) body in the northern sector of the GP at a depth of up to 16 km, which would support the hypothesis of a high density/susceptibility body, as deduced by [PERSON] et al. [72] in the same sector and at the same depth (zone labeled B (Figure 8c));
2. The presence of a low \(Q_{c}\) area, down to a depth of 16 km, suggesting a ductile regime in the upper/intermediate crust in the northeastern sector of the GP (zone labeled C (Figure 8c));
3. The presence of a low \(Q_{c}\) area in the southwestern sector of the GP at depth down to 32 km that would support the presence of a ductile behavior in the lower crust [34], responsible for the absence of seismicity at that depths (zone labeled E (Figure 8c));
4. An increasing trend of \(Q_{c}\) with depth (Figure 8c), confirming that, at high frequencies, \(Q_{c}\) is dominated by the intrinsic attenuation of back-scattered body waves, as depicted in Figure 9.  
According to these interpretations, the GP area reveals many interesting features that are promising for further investigation. Figure 9: \(Q_{c}\) trend versus the source-to-receiver distance \(r\) (km) for \(f_{c}\) = 12 Hz and \(t_{L}\) = 30 s.  
**Author Contributions:** Conceptualization, M.F., E.D.P., S.d.L., G.P. and A.T.; data curation, S.L. ; formal analysis, M.F., S.L., E.D.P. and S.d.L. ; funding acquisition, E.D.P. and A.T.; methodology, M.F., E.D.P. and S.d.L. ; project administration, A.T.; resources, E.D.P. and A.T.; software, S.L. and E.D.P. ; supervision, M.F., E.D.P., S.d.L., G.P. and A.T.; validation, M.F., E.D.P. and S.d.L. ; visualization, M.F., writing--original draft, M.F., E.D.P. and S.d.L. ; writing--review and editing, M.F., S.L., E.D.P., S.d.L., G.P. and A.T. All authors have read and agreed to the published version of the manuscript. **Funding:** This work was partially supported by Project PRIN n. 201743P29 FLUIDS (Detection and tracking of crustal fluid by multi-parametric methodologies and technologies). E.D.P. was partially funded by the Spanish Mineco Project FEMALE, PID2019-106260 GB-I00. **Data Availability Statement:** Envelope data used in this study are described in the data paper Filippucci et al. 2021 (submitted to Data MDPI). Data are available online on Mendeley repository: [[http://dx.doi.org/10.17632/w9](http://dx.doi.org/10.17632/w9) hsj2 whzm.1]([http://dx.doi.org/10.17632/w9](http://dx.doi.org/10.17632/w9) hsj2 whzm.1).