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High‐resolution interseismic strain mapping is important for studying faulting behavior and for assessing seismic hazards. Interferometric Synthetic Aperture Radar has been widely applied to measure interseismic deformation along active strike‐slip faults. However, phase unwrapping errors and over‐smoothing effects limit its ability to map the extremely‐high strain due to shallow creep. Here, without the involvement of ground‐based measurement, we perform phase‐gradient stacking on wrapped Sentinel‐1 interferograms to directly map the shear strain rates along the North Anatolian Fault (NAF) with unprecedented resolution. The derived high‐resolution strain‐rate map reveals five strain‐concentrated segments on the NAF, implying shallow creeps. We find that their spatial distribution coincides with the lower coseismic slip of previous earthquakes that occurred since 1939. The proposed method can be applied to other less‐studied strike‐slip faults to distinguish segments with shallow creep and strong coupling, and thus to better quantify the shallow strain budget and its associated seismic hazards.

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<p>High-resolution geodetic measurements of the accumulated strains along active faults are important for faulting dynamics studies and seismic hazard evaluation. InSAR has been widely applied to measure the interseismic strain along active strike-slip faults. However, phase unwrapping errors, tropospheric delays, along with over-smooth effects in calculating the strain from velocity limit its capability of mapping the highly localized strain along faults. Phase-gradient stacking that sums up the wrapped phase differences of adjacent pixels has been successfully applied to reveal localized deformation across coseismic fractures and slow-moving landslides, yet lacks application to reveal interseismic strain along faults. Here, we conduct phase-gradient stacking on Sentinel-1 SAR interferograms, for the first time, to map the interseismic strain along the North Anatolian Fault with unprecedented resolution. We reveal several segments with extremely high strain rates attributed to shallow creep of the fault. By comparing with historical earthquake ruptures, we find that the creeps are either related to afterslip of recent earthquakes, or related to slip deficits of earthquakes occurred decades ago, challenging the opinion that the NAF has a uniform surface strain rate, particularly along its eastern portion. Our results show that the phase-gradient stacking can not only reduce the computation burden from phase unwrapping and tropospheric correction, but also achieve a much higher spatial resolution strain map than the traditional InSAR method. The proposed method can be applied to other large strikes-slip faults for distinguishing segments with surface creep and strong coupling and therefore better quantify the shallow strain budget and its associated hazards.</p>