## 5 Discussion and Conclusions
File E1: Relocated earthquake catalogue (1 June-18 October 2021). References [50; 51; 87; 88; 89] are cited in the Supplementary Materials. Conceptualization, E.V., J.A. and G.K.; methodology, E.V., G.K., V.K. ([PERSON]), J.A., N.V. and M.F. ; software, E.V., V.K. ([PERSON]) and E.P. ; validation, E.V., A.K., C.P.E. and S.P. ; resources, E.V., G.K., V.K. ([PERSON]), E.P., M.F., C.P.E., V.K. ([PERSON]), G.-A.T. and J.A. ; data curation, A.K., V.K. ([PERSON]), C.P.E. and E.P. ; writing--original draft preparation, E.V., G.K., V.K. ([PERSON]), E.P., M.F. and J.A. ; writing--review and editing, E.V., G.K., V.K. ([PERSON]), M.F., J.A. and N.V.; visualization, E.V., V.K. ([PERSON]) and M.F. ; supervision, E.V. ; project administration, J.A. and N.V.; funding acquisition, E.V., M.F., J.A., G.-A.T. and N.V. All authors have read and agreed to the published version of the manuscript. This research received no external funding. **Informed Consent Statement:** Not applicable. **Data Availability Statement:** Initial earthquake catalogues and arrival-time data are available at the database of SL-NKUA ([[http://www.geophysics.geol.uoa.gr/stations/gmapv3_db/index.php?lang=en](http://www.geophysics.geol.uoa.gr/stations/gmapv3_db/index.php?lang=en)]([http://www.geophysics.geol.uoa.gr/stations/gmapv3_db/index.php?lang=en](http://www.geophysics.geol.uoa.gr/stations/gmapv3_db/index.php?lang=en)); accessed on 7 November 2021) and GI-NOA ([[http://bbnet.gein.noa.gr/HL/database/database](http://bbnet.gein.noa.gr/HL/database/database)]([http://bbnet.gein.noa.gr/HL/database/database](http://bbnet.gein.noa.gr/HL/database/database)); accessed on 7 November 2021). Waveform data from permanent and temporary stations of the HUSN are available at the National EIDA Node hosted at GI-NOA ([[http://eida.gein.noa.gr/](http://eida.gein.noa.gr/)]([http://eida.gein.noa.gr/](http://eida.gein.noa.gr/)); accessed on 7 November 2021; [90]). Focal mechanisms of the mainshock from various agencies (Table S1) were acquired from [[https://www.seismicportal.eu/mtws/](https://www.seismicportal.eu/mtws/)]([https://www.seismicportal.eu/mtws/](https://www.seismicportal.eu/mtws/)) (accessed on 22 January 2022). Focal mechanisms for the aftershocks are from GI-NOA ([[http://bbnet.gein.noa.gr/HL/seismicity/mts/automatic-moment-tensor-gisola](http://bbnet.gein.noa.gr/HL/seismicity/mts/automatic-moment-tensor-gisola)]([http://bbnet.gein.noa.gr/HL/seismicity/mts/automatic-moment-tensor-gisola](http://bbnet.gein.noa.gr/HL/seismicity/mts/automatic-moment-tensor-gisola)); accessed on 7 November 2021). The relocated catalogue of this study is available in the Supplementary Materials. **Acknowledgments:** The authors would like to express their appreciation to the three anonymous reviewers for their constructive comments that helped improving the initial version of the manuscript, as well as the editors for giving us the opportunity to publish our work. We thank the scientists and personnel who have participated in the installation or maintenance of the permanent and temporary stations belonging to the HUSN and routine analysis of earthquake data. **Conflicts of Interest:** The authors declare no conflict of interest.