## 3 Tectonic Setting  
The clockwise rotation of the Tibetan Plateau, as delineated by [PERSON] et al. [18], has fragmented the tectonic landscape into distinct sub-blocks [19] (illustrated in Figure 1). These sub-blocks are traversed by deep, major faults, each with unique kinematic attributes. The northward Bayan Har sub-block's eastward trajectory is halted by the stable South China sub-block, culminating in the formation of the thrust-type Longmen Shan fault zone at their interface [20]. This zone has witnessed significant seismic events--notably, the 2008 Wenchuan \(M_{W}\) 7.9 [21] and the 2013 Lushan \(M_{W}\) 6.6 earthquakes [22]. After these events, [PERSON] noted a decrease in stress levels in the Dayi area but an increase between Tianquan and Baoxin, suggesting dynamic stress redistributions, which have implications for future seismic activities [23]. South of Bayan Har, the Sichuan-Yunnan sub-block, emerging from the southeastern escape of the Qinghai-Tibet Plateau [24], is characterized predominantly be strike-slip and combined strike-slip with normal faults. The Xianshui He-Anning He-Zemu He fault zone, marking the northern boundary of the Sichuan-Yunnan sub-block's eastern edge, has been extensively studied due to its rich history of strong earthquakes [25]. [PERSON] discussed the locking and slip deficit of the Xianshuihe fault, indicating that the varying locking depths across this fault have significant implications for earthquake potential, suggesting that different segments might respond differently to tectonic stresses [26]. [PERSON] et al. examined the evolution of Coulomb stress over 200 years, noting that areas like Bamei, Selaha, and Kangding, which exhibit stress enhancement, are likely to experience strong earthquakes [27]. The Xianshui He fault belt (F1 in Figure 1b), commencing in Ganzi (GZ) and tapering off near Shimian (SM), stretches southeastward through Luhuo (LH), Daofu (DF), Kangding (KD), and Luding (LD), covering approximately 400 km. Since the late Cenozoic era, it has experienced notable sinistral strike-slip movement, amassing a total displacement of 60 km [28]. This fault belt is characterized by significant segmentation, with its slip rate diminishing from northwest to southeast, averaging around 10 mm/a [29; 30; 31; 32; 33; 34; 35]. To the north, the Anning He fault belt (F2 in Figure 1b) extends from Shimian (SM) and continues southwestward past Minamino (MN) to just south of Xichang (XC). Since the late Quaternary Period, it has displayed pronounced sinistral strike-slip and thrust movements. This 160 km long fault strikes north-south and dips either east or west, with angles ranging from 60\({}^{\circ}\) to 80\({}^{\circ}\)[33; 36]. [PERSON] et al. developed a three-dimensional finite element model to analyze the stress state and fault segmentation within the Anninghe-Zemuhe-Xiaojiang faults region [37], finding that some locations with higher stress correspond to low-\(b\)-value areas, suggesting a complex interplay of factors that influence fault behavior [38]. The northern and southern segments exhibit slip rates of approximately 2.8-3.7 mm/a and 5-8 mm/a, respectively, with six of the eight recorded \(M_{\rm S}\) > 6.0 earthquakes occurring in its southern segment [39]. The Zemu He fault belt (F3 in Figure 1b) continues the sinistral strike-slip pattern of the Xianshui He and Anning He faults. Starting from Xichang (XC) and extending to Qiaojia (QJ) in the south, GPS studies indicate a slip rate of about 6 mm/a [40]. Paleoseismic research suggests that eight \(M_{\rm S}\)\(\geq\) 7 earthquakes have occurred from the end of the Late Pleistocene Period to the present, with a recurrence interval estimated at approximately 1000 years [41]. Figure 1: **(a)** Map of tectonic units in the Qinghai–Tibet plateau (modified from [11]). The yellow solid lines indicate the boundaries of the blocks, while the blue ones illustrate the borders of the sub-blocks.