GNGTS 2024 - Atti del 42° Convegno Nazionale

Session 1.1 GNGTS 2024 Table 1 Slip Tendency The slip tendency analysis (Figure 3 a, b) shows that both SRF and CF are under an almost unstable mechanical conditon in the given remote stress state. Concerning the SRF, Ts ranges from 0.35 to 0.85, with the most frequent values ranging from 0.6 to 0.7, while CF exhibits Ts ranging from 0.45 to 0.80, with the most frequent values ranging from 0.62 to 0.68. Moreover, Ts value distributon for CF is more clustered than that for SRF which exhibits Ts spreading on its overall plane with another highly frequent minor distributon between 0.48 and 5.4, located especially near its northern and deepest portons. Note that the calculaton was performed considering the saturated conditon of the surrounding medium in order to take into account the worst conditon for a potental reactvaton of the fault planes. Conclusion The instrumental seismicity, merged with structural feld investgaton and literature data, provided useful constraints to infer the geometry on surface and at depth of SRF and CF. The geometric parameters obtained through the model of these faults are compatble with the empirical relatonships (magnitude vs. rupture area and magnitude vs. fault length; Wells and Coppersmith, 1994; Leonard, 2010). Accordingly, we achieved the expected magnitude for CF and SRF and confrmed that these faults can be the probable sources of the mainshocks of the 1783 seismic sequence (5 February, 7 February, and 1 March, M = 6.9–7; Jacques et al., 2001). From the slip tendency analysis, we found that both fault planes are astride under the stable and unstable mechanical conditons in the given regional stress state. The response of the modelled fault planes