GNGTS 2024 - Atti del 42° Convegno Nazionale

Session 1.1 GNGTS 2024 The Preparatory Process of the 2023 Mw 7.8 Türkiye Earthquake. M. Picozzi 1,2 , A.G. Iaccarino 2 , D. Spallarossa 3 1 Isttuto Nazionale di Oceanografa e di Geofsica Sperimentale - OGS, Italy . 2 University of Naples Federico II, Italy. 3 DISTAV, University of Genoa, Genoa, Italy. To verify the existence of a preparatory process for the 6 February 2023, Mw 7.8 Kahramanmaraş earthquake, southern Türkiye, we analyze the temporal evoluton of seismic catalog informaton for ~7500 earthquakes with magnitudes ML ≥ 1.5, which occurred along the main segments of the East Anatolian Fault (EAF) since 2014. We fnd the EAF fault segments showing diferent temporal paterns in the proporton of nonclustered seismicity, which we interpret as temporal variaton of coupling. We also study the evoluton of the b-value, fractal dimension and energy rate. These seismic features show for the Amanos and Pazarcık fault segments a long-term trend during the period 2020 – 2022 that might correspond to a quiescence phase. The later is followed by a change in earthquake clustering and characteristcs that starts about eight months before the Mw 7.8 Kahramanmaraş event. Our observatons confrm the existence of a long-lastng preparatory phase for the 2023, Mw 7.8 Kahramanmaraş earthquake and can stmulate new investgatons on the East Anatolian Fault mechanic. Interceptng when a fault starts deviatng from its steady behaviour, might be the key for identfying the preparatory phase of large earthquakes and mitgate seismic risk. Corresponding author: mpicozzi@ogs.it