The shallow slip deficit (SSD) during strike-slip earthquakes raises a question of how the strain budget is accommodated over multiple cycles. However, the origin of variable SSD observed in different earthquakes is still under debate because each earthquake has its unique initial stress condition. Here, we derive the slip model of the 2021 M_W7.4 Maduo earthquake in Qinghai, China, using multi-track radar images. Our results revealed that, in contrast to the large SSD on segments close to the epicenter, a much smaller SSD was observed at the west terminus of the rupture, where aftershock distribution indicates that the fault changes dip direction at 6 km depth. The 2021 Maduo earthquake thus represents an extraordinary case of significant along-strike SSD variation. After accounting for interseismic, postseismic, and diffuse off-fault deformation, we find that this variation is likely contributed by the along-dipping geometrical variation, implying that a multi-segment earthquake may leave heterogeneous stress condition on the fault with different amounts of SSD.

Landslides accompanying earthquakes are essential in landscape evolution along active fault zones. However, most studies focus on the rapid, catastrophic coseismic landslides with surface scars; the role of slow-moving landslides and their relation with the coseismic landslides is poorly known. Combining radar interferometry, deep-learning network, and inventories of coseismic landslides, we show a clear complementary pattern between coseismic and slow-moving landslides distributed along the transition between the Qinghai-Xizang plateau and the Sichuan basin. Geomorphic analysis on areas dominated by coseismic and slow-moving landslides shows their distinct topographic fingerprints, suggesting that the coseismic landslides tend to occur on the top of the hill, while the slow-moving landslides erode the lower part of the slope. We infer that the coseismic landslides likely constrict the initiation and development of slow-moving landslides after large earthquakes by removing materials from slopes. Our results imply that the coseismic landslides may dominate the landscape feature close to active fault zones, where the lack of slow-moving landslides may indicate the historical occurrence of large-magnitude, landslide-prone earthquakes.

The surface velocity is one of the most important characteristics of glaciers. Monitoring and mapping glacier movements are of great significance for the studies of sea-level rise, glacier mass balance and dynamics, global warming, and the management of freshwater resources. It is also essential for the early warnings of hazards caused by ice avalanches. SAR imaging geodesy has been developed for measuring glacier velocity, especially the pixel-offset tracking method. This paper introduces some basic concepts of glaciology and principles of various SAR imaging geodesy methods, with a detailed presentation about the developments in the applications of the pixel-offset tracking method. Finally, the challenges and future prospects of SAR imaging geodesy in glacier monitoring are discussed.