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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 1000-km-long Haiyuan fault system on the northeastern edge of the Tibetan Plateau contributes to accommodating the deformation in response to the India/Asia collision. In spite of its importance, the kinematics of the fault including the geometry and along-strike slip rate have not been completely defined. In this study, we use synthetic aperture radar data acquired between 2014 and 2021 by Sentinel-1 satellites to investigate the present-day strain accumulation on the Haiyuan fault system. We produce a high-resolution velocity map for the ∼300,000 km2 Haiyuan region using the Small BAseline Subset method. Our new velocity fields reveal deformation patterns dominated by the eastward motion of Tibet relative to Alaxan and localised strain accumulation along the Haiyuan, Gulang and Xiangshan-Tianjingshan faults. The western ∼300-km-long section of the Haiyuan fault, which was previously unmapped, seems to follow Tuolaishan and terminate at Halahu. We compute the along-strike slip rate using a Bayesian Markov Chain Monte Carlo inversion approach, and find that the overall strike-slip rate along the Haiyuan fault system gradually increases from the western end (1.8±0.3 mm/yr close to Halahu) to the east (6.4±0.5 mm/yr before entering Liupanshan), and further east, it decreases from 6.4±0.5 mm/yr to 1.3±0.7 mm/yr. The Haiyuan fault absorbs most of the left-lateral strike-slip motion with a rate of ∼4.2±0.4 mm/yr, and the Gulang and Xiangshan-Tianjingshan faults take up a fraction of 2.2±0.6 mm/yr. We re-map the previously identified shallow creeping zone on the Laohushan segment for a length of 45 km, slightly larger than the previous estimate of 35 km. The average shallow creep rate, 3 mm/yr between 2014–2021, is consistent with the rate before 2007 (2–3 mm/yr), implying that the shallow creep is a steady behaviour. • We produce a high-resolution InSAR velocity map for the ∼300,000 km2 Haiyuan region. • The western section of the Haiyuan fault follows Tuolaishan and terminates at Halahu. • Strike-slip rate gradually increases from the western end (∼1.8 mm/yr) to the east. • We re-map the shallow creeping zone on the Laohushan segment for a length of 45 km. [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]