The 2023 M7.8 and M7.5 earthquake doublet near Kahramanmaraş, Turkey, offers insights into how large earthquakes rupture complex faults. Fault geometry was determined using surface ruptures and SAR measurements, while rupture kinematics were derived from joint inversion of high-rate GNSS, strong-motion waveforms, and GNSS static displacement. The M7.8 event initiated on a splay fault and propagated along the East Anatolian Fault (EAF) at 3.0–4.0 km/s. The M7.5 event showed bilateral supershear rupture (5.0–6.0 km/s) over 80 km. Sub-faults were optimally oriented relative to the local stress tensor for the mainshock, but the M7.5 event ruptured a fault misaligned with regional stress, suggesting local stress heterogeneity and potential free surface effects.

Kejie Chen, Guoguang Wei, Christopher Milliner, Luca Dal Zilio, Cunren Liang, Jean-Philippe Avouac