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We use Sentinel‐1 Interferometric Synthetic Aperture Radar observations to derive the first complete map of slip‐rate distribution at km‐scale along the 1,000‐km‐long Haiyuan fault system, and further to analyze its earthquake potential. Rate distribution reveals four highly locked asperities (slip rate <1 mm/yr) and three creeping regions (slip rate ranges from 2 to 5 mm/yr) at depths of 0–20 km. Based on the rate distribution, we estimate seismic moment accumulation rate, and by combining historical earthquake records, we calculate the moment deficits on each fault segment. Results show that many fault segments have accumulated a seismic moment that equates to an Mw > 7.0 earthquake. The westernmost fault segment has been rarely mentioned in previous studies, but our calculations show evidently that it is capable of producing Mw > 7.0 earthquakes given the high seismic moment accumulation rate and a lack of small‐to‐moderate earthquakes. Plain Language Summary: Faults accumulate strains over long periods of seismic quiescence between great earthquakes, that is, interseismic strain accumulation, and release them either seismically by producing earthquakes or aseismically as creep. Studies of such strain accumulation and release processes are critical for understanding regional seismic hazard. We focus here on the 1,000‐km‐long Haiyuan fault system in northeastern Tibet. By using the most recent geodetic data sets, we quantify strain accumulation along the fault and evaluate its seismic potential. We derive fault slip rate distribution and calculate along‐strike seismic moment accumulation rate. Combining our knowledge of previous earthquake ruptures, including the time, extent and size, we compute the total seismic moment that has accumulated on each fault segment since the last major event. We find high seismic potentials along many fault segments, such as Lenglongling, Jinqianghe‐Maomaoshan and Gulang, which can generate an Mw > 7.0 earthquake anytime from now. Toward the western end, earthquake history remains poorly understood, but our analysis shows that the westernmost segment can produce Mw > 7.0 earthquakes, which deserves more attention. Key Points: Slip‐rate distribution at kilometer scale along the 1,000‐km‐long Haiyuan fault system is derived from high‐resolution Interferometric Synthetic Aperture Radar dataFine‐scale rate distribution reveals four highly locked asperities and three creeping regions at depths of 0–20 kmAlong‐strike seismic moment accumulation rate and deficits are computed based on rate distribution and earthquake rupture history [ABSTRACT FROM AUTHOR]

The 2019 Ridgecrest, California earthquake sequence ruptured along a complex fault system and triggered seismic and aseismic slips on intersecting faults. To characterize the surface rupture kinematics and fault slip distribution, we used optical images and Interferometric Synthetic Aperture Radar (InSAR) observations to reconstruct the displacement caused by the earthquake sequence. We further calculated curl and divergence from the north-south and east-west components, to effectively identify the surface rupture traces. The results show that the major seismogenic fault had a length of ~55 km and strike of 320 ° and consisted of five secondary faults. On the basis of the determined multiple-fault geometries, we inverted the coseismic slip distributions by InSAR measurements, which indicates that the Mw7.1 mainshock was dominated by the right-lateral strike-slip (maximum strike-slip of ~5.8 m at the depth of ~7.5 km), with a small dip-slip component (peaking at ~1.8 m) on an east-dipping fault. The Mw6.4 foreshock was dominated by the left-lateral strike-slip on a north-dipping fault. These earthquakes triggered obvious aseismic creep along the Garlock fault (117.3° W–117.5° W). These results are consistent with the rupture process of the earthquake sequence, which featured a complicated cascading rupture rather than a single continuous rupture front propagating along multiple faults. [ABSTRACT FROM AUTHOR]

The 12 November 2017 Darbandikhan earthquake (Mw 7.3) occurred along the converence zone. Despite the extensive research on this earthquake, none of this work explained whether this earthquake rupture was limited to the thick sedimentary cover or it extends to the underlying crystalline basement rock (or both). Besides, whether this region will generate devastating earthquakes again and whether there is a one-to-one correlation between these anticlines and blind-reverse faults need further investigation. In this study, we derived the co-seismic interferograms from the Sentinel-1A/B data and successfully described the surface deformation of the main seismic zone. The fringe patterns of both the ascending and descending interferograms show that the co-seismic deformation is dominated by horizontal movements. Then, using the along- and across-track deformation fields of different orbits, we retrieved the three-dimensional deformation field, which suggests that the Darbandikhan earthquake may be a blind thrust fault close to the north–south direction. Finally, we inverted the geometrical parameters of the seismogenic fault and the slip distribution of the fault plane. The results show that the source fault has an average strike of 355.5° and a northeast dip angle of −17.5°. In addition, the Darbandikhan earthquake has an average rake of 135.5°, with the maximum slip of 4.5 m at 14.5 km depth. On the basis of the derived depth and the aftershock information provided by the Iranian Seismological Center, we inferred that this event primarily ruptured within the crystalline basement and the seismogenic fault is the Zagros Mountain Front Fault (MFF). The seismogenic region has both relatively low historical seismicity and convergent strain rate, which suggests that the vicinity of the epicenter may have absorbed the majority of the energy released by the convergence between the Arabian and the Eurasian plates and may generate Mw > 7 earthquakes again. Moreover, the Zagros front fold between the Lurestan Arc and the Kirkuk Embayment may be generated by the long-distance slippage of the uppermost sedimentary cover in response to the sudden shortening of the MFF basement. We thus conclude that the master blind thrust may control the generation of the Zagros front folding. [ABSTRACT FROM AUTHOR]