Fig. 4: Evidence for observed ASD originating from off-fault damage.

a The east–west interseismic displacement rate in the study region from InSAR time-series of 2014–2019 Sentinel-1 images, with a black square marking the reference point. Blue lines are the two fault ruptures on the Sürgü fault (SF) and the east Anatolian fault (EAF). Displacements along profile A–A* are shown in (c). b The east–west postseismic displacement rate obtained from 9 months of Sentinel-1 SAR images after the earthquakes. c Inter- and post-seismic displacement rates along profile A–A*, which are insufficient to compensate for the observed meter-level coseismic ASD. d ALOS-2 SAR interferogram (track 77) of the Narli fault and EAF junction showing distorted fringes and fringe discontinuities within and around the off-fault damage zone. e, f Two more examples of distorted fringes within the off-fault damage zone. These distorted and discontinuous fringes illustrate that off-fault damage (i.e., inelastic deformation and secondary fault offsets) occurred in these areas. The coverage of (d–f) is indicated in Fig. 2e, and a clear version of (d–f) without labels is shown in Supplementary Fig. 15. The shaded relief background map in (a–b) is derived from the shuttle radar topography mission (SRTM) 3-arc seconds data⁷⁶.