Sebastián Núñez-Jara from Patricia’s ERC QUAKEHUNTER group published a paper in Earth and Planetary Science Letters entitled “Unraveling the spatiotemporal fault activation in a complex fault system: the run-up to the 2023 MW 7.8 Kahramanmaraş earthquake, Türkiye”. The study builds on our earlier Nature Communications paper on the months-long seismicity transients before the Kahramanmaraş earthquake and extends the analysis to the six years preceding the mainshock. Sebastián combined deep-learning phase picking and association with classical location techniques to build an enhanced seismicity catalog. It contains more than six times as many events as the regional AFAD catalog, has a lower magnitude of completeness, and was carefully cleaned of quarry blasts. The catalog reveals three seismic transients near the future epicenter, most of them located off the main East Anatolian Fault, on the secondary Narlı Fault where the mainshock nucleated. Only the last transient, starting about eight months before the mainshock, shows a sharp b-value drop together with the strongest clustering and localization of seismicity. In December 2022, activity also migrated to a previously quiet branch aligned with the future rupture plane. The Narlı Fault also responded to the 2020 MW 6.8 Sivrice/Elazığ earthquake about 210 km away, pointing to its sensitivity to dynamic triggering. The cumulative rock damage produced by background seismicity indicates years-long weakening of the region between the Narlı Fault and the main fault. No clear acceleration of foreshocks was observed in the final days, which is consistent with the intermittent criticality concept rather than a deterministic run-up to failure. The enhanced catalog is available from GFZ Data Services (doi 10.5880/GFZ.ITSJ.2025.005).
Reference:
Núñez-Jara, S., P. Martínez-Garzón, G. Kwiatek, Y. Ben-Zion, G. Dresen, D. Becker, F. Cotton, and M. Bohnhoff (2025). Unraveling the spatiotemporal fault activation in a complex fault system: the run-up to the 2023 MW 7.8 Kahramanmaraş earthquake, Türkiye. Earth and Planetary Science Letters 669, 119570, doi 10.1016/j.epsl.2025.119570