The 3D thermo-rheological model of the Aegean Region

This note aims to present the latest updates on the 3D thermo-rheological model of the broader Aegean Region, which provide crucial constraints for the seismotectonics of the area. Indeed, the strong relationship between rheological behaviour and seismotectonic processes has been investigated, and the correlation between the brittle-ductile transition (BDT) and seismic/aseismic behaviour of the crust is well documented (Maggini and Caputo, 2020a; 2020b; 2021). At this regard, the BDT can be considered a reliable constraint for defining the base of the seismogenic layer of a tectonically active crustal volume. Following the above premise, Maggini et al. (2023) focused on the Aegean Region due to its intense seismotectonic activity and the availability of a large variety of geological, geophysical and geodynamic data useful to define the model and to validate the obtained results. Particular attention was paid to identifying the main rheological transitions, their regional trends and local aspects such as depth, strength and temperature. The resulting considerations on the thickness of the seismogenic layer were later used for fixing the maximum seismogenic depth of all seismogenic sources identified in the region (Caputo and GreDaSS WG, 2025), allowing to better constrain their width and especially their maximum expected magnitudes. Based on these results improving our knowledge of the Aegean seismotectonics it will be possible to perform more realistic seismic hazard assessment analyses.