Seismic velocity structure of the crust and the upper mantle beneath the island of Crete, Greece

Abstract Crete is located in the Southern Aegean, in the southernmost part of the Hellenic Trench. Given the elevated numbers of seismicity in the region generated by the convergence of the Eurasian and African tectonic plates, the research area is critical. More than 1400 manually revised events from 2018 to 2022 have been used in this work to construct both local and regional 1-D velocity models. These data were entered into Passive Seismic Tomography, which is using body-wave (P and S) travel-time data to analyze medium to large-scale (in km) anomalies linked to local neotectonic and regional tectonic processes. A complex shallow structure was revealed in Crete's central region, in contrast to a smoother and more continuous image at deeper slices (> 40km). This result was likely due to result of the subducted lithosphere triggering an upward migration of fluids. The final dataset analysis contributed to a better understanding of the research area's prevailing seismotectonic processes and the relationship between shallow and intermediate-depth earthquake activity.