## 6 Conclusions  
This study presents the estimation of high-frequency attenuation of the spectral parameter \(\kappa\) and its local site-specific component \(\kappa_{0}\) for two seismological stations within the Zagreb seismic zone: Puntijarka-PTJ (situated on the peak of the Medvednica Mountains) and Zagreb-ZAG (situated in the city of Zagreb).  
Near-site attenuation kappa (or site kappa, \(\kappa_{0}\)) we estimated using traditional linear least-square regression and the linear regression suitable for data with errors (their differences is taken as 5% uncertainty). Site kappa is estimated by restricting the distance range for kappa, to ensure that local site attenuation at zero distance is not overwhelmed by the path component for larger distances.  
The main results and conclusions are:  
* Site \(\kappa_{0}\) values estimated from the extrapolation to zero distance (using traditional linear regression and error-in-variables regression) are within the range of the uncertainty (\(\pm 1\) standard deviation) with a constrained \(\kappa_{0}\) value;
* Estimated \(\kappa_{0}\) values for PTJ (0.0283-0.0360 s) and ZAG (0.0411-0.4750 s) correlated with \(V_{S30}\) values are within the range of existing \(\kappa_{0}\)-\(V_{S30}\) correlations, showing that \(\kappa_{0}\) has lower values for sites on harder rocks (lower attenuation) and higher \(\kappa_{0}\) values on softer rocks (higher attenuation);
* Comparison of the high-frequency coda attenuation values with frequency independent, \(Q_{c}\)(\(f\)) and \(Q(\kappa_{R})\) for both stations can be considered comparable when looking at average values with the assumption that they are affected by the same regional characteristics;
* The lowest \(\kappa\) values are spatially distributed within a few kilometres around the stations due to near-site effects;
* Variations in observed \(\kappa\) distribution between lower and higher attenuation subset areas is clearly under the influence of local and regional geological structures that are distributed predominantly within regional active faults and complex tectonic structure.  
Figure 8: A preliminary intensity map of the M5.5 earthquake of 22 March 2020 at 5:24 AM (UTC). The epicentre is 7 km north of Zagreb city centre and is marked with a black star.  
Attenuation of seismic waves is one of the key factors in seismic hazard assessment. Additionally, it is important for quantification of earthquakes and plays a significant role in studies of seismic source and crustal structure. Thus, this study is a step towards the better defining of input parameters for seismic hazard and risk assessment for the wider area of the city of Zagreb.  
Conceptualization: D.S., [PERSON] and T.K.; methodology: D.S.; software: D.S.; validation: [PERSON] and T.K.; formal analysis: D.S.; investigation: D.S.; data curation: D.S.; writing--original draft preparation: [PERSON] and [PERSON]; writing--review and editing: [PERSON], [PERSON] and [PERSON]; visualization: D.S. T.K. and J.J.; supervision: [PERSON] and [PERSON]; project administration: [PERSON]; funding acquisition: S.M. and D.S. All authors have read and agreed to the published version of the manuscript.  
This research received no external funding. The APC was funded by D.S.  
The authors wish to thank to [PERSON], [PERSON] (macrosicmic fieldwork) and the Croatian Seismological Survey, Department of Geophysics, Faculty of Science, University of Zagreb for the support with this study. The support is gratefully acknowledged. Copyright permission for using Figure 1[19] obtained through Copyright Clearance Center's RightsLink(r) service (order number: 496520553234).  
The authors declare no conflict of interest.