## 1 Introduction  
The Jinshajiang fault zone is an important fault located in the eastern part of the Qinghai-Tibetan Plateau. It is considered to be the western boundary fault zone between the Sichuan-Yunnan block and the eastern Xizang block and is characterized by reverse dipslip motion [1]. Since the Cenozoic, the collision of the Indian Plate with the Eurasian Plate has caused strike-slip motion along major faults and the significant uplift of the Tibetan Plateau, leading to intense fault activity and folding deformation in the eastern boundary region of the Xizang block [2, 3, 4]. The Jinshajiang fault is located at the forefront of the eastern Xizang block, and its activity since the Late Cenozoic has primarily manifested as intense east-west (EW) compression, which absorbed part of the movement of the eastern Tibet block toward the Sichuan-Yunnan block via EW shortening [5, 6, 7]. The geometric structure of the Jinshajiang fault zone is complex, intersected by the northeast (NE)-trending Batang fault and the northwest (NW)-trending Degin-Zhongdian-Daju fault, dividing the fault zone into northern, middle, and southern sections (Figure 1). Of these, the northern segment is NW trending with a relatively simple structure. The latest research indicates that the northern section reflects Late Pleistocene activity [8]; the central section of the fault is more complex, consisting of multiple fault branches oriented south-north (SN), NE, or north-northwest (NNW), and displays Holocene-Late Pleistocene activity. Meanwhile, the activity in the southern section of the fault is weak [6,9]. Views about the motion characteristics and slip rate of the Jinshajiang fault zone differ. [PERSON] et al. (2008) believe that the current activity of the Jinshajiang fault zone is weak, according to GPS data used to constrain and invert the current activity rates of major faults in the Sichuan-Yunnan region [10]. Conversely, the GPS inversion results of [PERSON] et al. (2020) suggest that the activity of the northern section of the Jinshajiang fault zone is not significant, while the middle and southern segments exhibit obvious right-lateral strike-slip movement, with slip rates of 4.9 mm/a and 5.5 mm/a, respectively [11]. On the basis of seismic geological surveys, [PERSON] et al. (2005) believe that the Hetaoping fault and the Hongjunshan fault in the middle segment of the fault zone exhibit left-lateral strike-slip movement, with the Yarigong fault in the middle segment exhibiting right-lateral strike-slip movement with a slip rate of 3.3-4.1 mm/a [6]. The current seismic activity along the Jinshajiang fault zone is unevenly distributed. Only the Batang fault within the fault zone has experienced an M7.3 earthquake (in 1870) since the beginning of historical records of strong earthquakes in the area [12,13]. There are no historical records of earthquakes stronger than M6 along the northern and southern sections of the main fault; however, the middle section has experienced multiple earthquakes ranging from 6.0 to 6.9 in magnitude [6,12]. [PERSON] et al. (2017) analyzed the focal mechanism solutions of the 2016 Litang M5.1 earthquake swarm and the 1989 Batang M6.7 earthquake swarm, both of which occurred in the middle segment of the Jinshajiang fault zone [12]. They found that these earthquakes exhibited normal faulting characteristics, which did not match the motion characteristics of the main faults in the fault zone. They suggested that the seismogenic structures were nearly EW-trending secondary faults within the fault zone. On the basis of GPS and minor seismic activity studies, [PERSON] et al. (2020) believe that the central segment of the Jinshajiang fault zone has a higher risk of strong earthquakes [11]. However, the structure of the middle section of the fault zone is complex, consisting of multiple Holocene-active faults, and the assessment of its seismic hazard still lacks confirmation via direct data from strong seismic activity.