Fig. 2: The absent surface displacement (ASD).

a–c Fully elastic deformation across a strike-slip fault during one earthquake cycle with (a) the total long-term block-like motion L(x) as the sum of b the interseismic deformation I(x) (an arctan behavior) and c the elastic coseismic deformation C(x). In a–c x is the distance from the fault, s₀ slip amplitude on the fault, and D locking depth during the interseismic period. d The quantification of ASD on a lateral profile of fault-parallel displacement observations (gray dots). The location of this profile is shown in (e) and Fig. 1b. The model (red curve) is obtained by fitting the observation with C(x). The residual (yellow dots) of the observation with respect to the model represents the ASD, which is also depicted as vertical lines between the model (red curve) and observations (gray dots). The total deformation is defined as the difference between two peaks of the model and the on-fault offset is the observed displacement jump across the fault (at x = 0). By fitting the residual with a logarithmic function (see “Methods”), the extent of the ASD (red squares) and thus the damage width can be determined. In the residuals, there is a signal with a length scale of ~5 km, which can be attributed to topography-related artifacts from the pixel-offset tracking process of non-orthorectified SAR images (Supplementary Fig. 2). e The ASD along the main ruptures (equivalent to the absolute value of yellow dots in (d) within the damage width) of all fault-perpendicular profiles. The gray bar in (e) represents the center position of the profile (gray dots) shown in (d), which we picked because its displacement pattern is fairly typical of the fault-parallel displacements with ASD in both complex and simple sections along the fault (Supplementary Movie 1). The uncertainty of the profile displacements is 5–9 cm, as indicated by the comparison of the SAR-based 3D displacements with GNSS observations (Supplementary Fig. 3). The arrow on the second rupture indicates the westward super-shear rupture^4,5,6,8,9,77. The shaded relief background map in (e) was derived from the shuttle radar topography mission (SRTM) 3-arc seconds data⁷⁶.