Geodetic insights into the 2024 Wushi (North-Western China) seismic sequence: Mw 7.0 mainshock and Mw 5.7 aftershock from InSAR data

The 2024 Wushi seismic sequence started on 22 January 2024 (18:09 UTC) with a MW 7.0 event, followed by dozens of aftershocks, striking the southwestern sector of the Tian Shan Mountains in Wushi County (northwestern China) (Fig. 1), characterized by high geodetic strain rates (Wang & Shen 2020; Li et al. 2021). According to the United States Geological Survey (USGS), the earthquake's hypocenter was approximately 13 km deep, located in the Southern Tian Shan Mountains, about 130 km northwest of the city of Aykol. The earthquake was felt near the epicenter and across western Xinjiang Province, parts of eastern Almaty Region in Kazakhstan, and eastern Kyrgyzstan, resulting in damage and casualties. The subsequent seismic sequence included numerous aftershocks (8 events with magnitude between 5.0 and 5.7), located both ENE and WSW of the mainshock. The focal mechanism solution for the main events indicate transpressional faulting with reverse dip-slip and left-lateral kinematic components (USGS 2024), in agreement with the direction of active shortening of about 10 mm/yr in this sector of the Tian Shan Mountains (Molnar & Ghose 2000; Wang & Shen 2020). In addition, a recent study (Zhang et al. 2024) has highlighted a zone of surface ruptures (extending for about 2 km), possibly associated with a SE-dipping fault (thus dipping in the opposite direction compared to the main shock fault plane) that might be related to the MW 5.7 largest aftershock occurred on 29 January.