The 1600-km-long left-lateral East Kunlun fault (EKF) defines the northern boundary of the Bayan-Har Block, which is one of the most seismically active regions in the Tibetan Plateau, China (Li et al., 2011;. Over the past century, three destructive earthquakes (M > 7) ruptured some segments of the EKF, including the 1937 M7.5 Huashixia, 1963 M7.0 Dulan, and 2001 𝐴𝐴 Mw 7.8 Kokoxili earthquakes (Figure 1a), leaving two seismic gaps. One is the Maqin-Maqu seismic gap (Wen et al., 2007), where large earthquakes are expected to occur in the near future. Yet no related sign has been observed. In addition, the EKF is somewhat straight to the west of 98°E but bends ∼45° toward the southeast from 98°E to 99.5°E. Across such a fault geometry bending, the slip rate of the EKF decreases from ∼10 mm/yr in the west section of 98°E to ∼5-6 mm/yr along the Maqin-Maqu segment (Kirby et al., 2007;Van Der Woerd et al., 1998, 2002. Such a slip rate decrement suggests that the deformation is accommodated by some nearby structures and faults. Hence, some faults around the Maqin-Maqu segment, even though the slip rate is low, can be the location of large earthquakes. On May 22, 2021, an 𝐴𝐴 Mw 7.4 earthquake struck the Maduo county of Guoluo prefecture in Qinghai province, western China. This earthquake is another large earthquake (M > 7) that occurred in the Bayan-Har block since the 1947 M7.7 Dari earthquake. Until 30 May 2021, a total of 2979 aftershocks have been recorded by the China earthquake administration (Wang et al., 2021). This event caused severe damages to local buildings and

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The three-dimensional (3-D) deformation field associated with the 2016 Central Tottori earthquake is retrieved from advanced land observing satellite 2 interferometric synthetic aperture radar (InSAR) observations with four different viewing geometries, that is, ascending/descending tracks and left-/ right-looking modes. The strain model and variance component estimation (SM, VCE, SM-VCE) method is exploited and improved to integrate the InSAR observations with different viewing geometries so that the 3-D deformation field is not affected by the inconsistent coverage of SAR footprints or the gross errors in InSAR observations. The obtained results are consistent with GNSS observations, indicating that the improved SM-VCE method, known as SM-RVCE in this paper, is capable of retrieving an accurate and spatially complete 3-D deformation field for this earthquake. In addition, the precision of the InSAR observations and the estimated 3-D deformation are quantitatively assessed by the SM-RVCE method. Finally, on the basis of the estimated 3-D coseismic deformation, the source parameters of this event are inverted, revealing an asperity with a maximum strike-parallel slip of~1.1 m concentrated at depths between 2 and 10 km. The estimated seismic moment is 2.4 × 10 18 Nm, which corresponds to a Mw 6.2 event.