Proceedings of the 12th International INQUA meeting on paleoseismology, active tectonic and archaeoseismology

412 PATA Days 2024 M E T H O D O L O G I C A L A P P R O A C H EuQuaGe performed its first survey, coordinated by the Disaster and Emergency Management Authority of Türkiye (AFAD), employing twenty researchers from four different countries. The aim was to investigate the co- seismic ruptures caused by the 06 February 2023, Mw 7.6 Elbistan (Kahramanmaraş) Earthquake, the second mainshock, occurred along the Çardak Fault, an E-W segment of the complex East Anatolian Fault System (Duman & Emre, 2013), running in a remote mountainous area that was previously not fully surveyed due to a persistent snow cover. The fieldwork allowed us to share and set up a common working methodology while collecting data on the impressive surface faulting through the classical morpho-tectonic and structural geological approaches. The detailed survey was carried out in thirteen key areas (Fig. 1), some of which show a clear relationship between long-term and coseismic deformation. Here we present five emblematic study cases of the near- fault deformational pattern and slip distribution of the Mw 7.6 Elbistan Earthquake surface faulting. Overall, along with ~2,000 photos acquired by professional digital cameras, more than 600 structural data points were gathered by digital mobile devices and shared in real time. Specific software allowed to collect information on the observed structural pattern elements, recording metadata on their typology, geometry, affected substratum, kinematics, offset components, etc., as well their exact spatial orientation and position. Furthermore, each study area was airborne surveyed employing two DJI Mini 2 and 3 UAVs equipped with a 12 MP-camera (1/2.3” CMOS sensor), which acquired more than 5,000 down- looking photos. These airborne surveys allowed reconstructing structure from motion (SfM) high-resolution (3-4 cm/pixel) digital surface models (DSMs), and relative orthophoto mosaics, Fig. 1: (a) Location of the surveyed key areas (white circles, this study). East-West and North-South co-seismic displacements for the 2023 Kahramanmaraş doublet (from Sentinel-2 optical satellite imagery). The Mw 7.6 and Mw 7.8 epicentres and focal mechanisms are represented (Lomax, 2023). The black lines show active faults (Emre et al., 2018). (b) Field measurements (circles; offsets in (c)) taken in May 2023 by Prevost et al. (2024). (d) Regional tectonic context (Duman & Emre, 2013). Modified from Prevost et al. (2024).