Slip complementarity and deficit of the East Anatolian Fault revealed by geodetic observations

Catastrophic earthquakes have struck along the East Anatolian Fault (EAF), including the 2020 Elaziğ earthquake and the 2023 Kahramanmaraş earthquake doublet. We integrated ground velocity from 2015-2020, together with co- and post-seismic deformation from the 2020 and 2023 earthquakes to investigate the fault slip evolution of the EAF, aiming to reveal the potential future seismic hazards. The spatiotemporally continuous deformation field allows us to derive complete slip distribution models throughout the earthquake cycle, including an interseismic period, two distinct postseismic periods, and three coseismic events. The results demonstrate that the slip patterns exhibit complementary characteristics across the interseismic, coseismic, and postseismic phases. Additionally, by integrating historical earthquake records with the strain accumulated and released during the observation period and quantifying the corresponding slip deficits, we evaluated the seismic potential of the EAF. Among these, the Palu segment emerged as having particularly high seismic risk, emphasizing the need for close monitoring. Geodetic observations suggest segments of the East Anatolian Fault which display interseismic slip deficits correlate with the rupture zones of the 2020 Elaziğ earthquake and the 2023 Kahramanmaraş earthquake doublet and may be useful to identify high risk regions.