## 2 Methods and Data  
### Two Assessment Methods Based on the Newmark Model  
The Newmark model, which was introduced by [PERSON] in 1965, was originally developed to assess the stability of dams in response to seismic activity [14]. According to this method, when ground motion produces a peak acceleration surpassing the critical acceleration (\(A_{\rm c}\)) associated with the most precarious surface, a slider is initiated to slide along this surface, leading to cumulative displacement. Essentially, the model posits that a rock-soil mass with a higher \(A_{\rm c}\) value necessitates a greater peak ground acceleration (\(PGA\)) to induce cumulative displacement, indicating that a larger \(A_{\rm c}\) value generally corresponds to enhanced stability during seismic events. Therefore, after a critical acceleration distribution map of the regional rock-soil mass has been prepared, the value of \(A_{\rm c}\) can be combined with the \(PGA\) to quickly determine the earthquake-triggered landslide risk of the rock-soil mass within the seismic zone. To calculate \(A_{\rm c}\), we need to first calculate the static safety factor (\(F_{\rm s}\)) of the rock-soil body under non-seismic conditions. The static safety coefficient can be computed using the principle of limit equilibrium [41]. \[F_{\rm s}=\frac{c\prime}{\gamma t\sin\alpha}+\frac{\tan\varphi t}{\tan\alpha} -\frac{m\gamma\
u\tan\varphi t}{\gamma\tan\alpha} \tag{1}\]  
In Formula (1), \(F_{\rm s}\) represents the static factor of safety, while \(c^{\prime}\), \(\varphi^{\prime}\), and \(\gamma\) denote the physical and mechanical parameters of the rock-soil mass--specifically, the effective cohesion (kPa), effective friction angle (\(\lx@math@degree\)), and unit weight (\(\rm kN/m^{3}\)), respectively. The selection of the rock-soil physical mechanics parameters \(c^{\prime}\), \(\varphi^{\prime}\), and \(\gamma\) is detailed in the Data  
Figure 1: Geographic overview and earthquake-triggered landslides distribution map. Source Section. The variable \(t\) represents the slope-normal failure slab thickness, which, in the context of this earthquake, where landslides were predominantly small to medium-sized [37; 38; 39], is considered as 3 m. The slope angle (\({}^{\circ}\)), denoted by \(\alpha\), was determined using digital elevation models (DEMs) within the study area, while \(m\) signifies the proportion of the slab thickness that is saturated. Given the absence of rainfall during this seismic event, the value of \(m\) is assumed to be 0. After \(F_{\mathrm{s}}\) was calculated, we were ready to perform the calculation of \(A_{\mathrm{c}}\). \(A_{\mathrm{c}}\), representing the critical acceleration of the rock-soil mass in the study area, can be computed from \(F_{\mathrm{s}}\) using Formula (2). \[A\mathrm{c}=(F\mathrm{s}-1)g\sin\alpha \tag{2}\]  
By employing the difference method and cumulative displacement method, the seismically triggered landslide risk of the rock-soil mass in the study area was evaluated based on the critical acceleration (\(A_{\mathrm{c}}\)) and peak ground acceleration (\(PGA\)). The difference method involves treating the \(PGA\) and \(A_{\mathrm{c}}\) as distinct entities and utilizing their difference as the primary metric for assessing the risk of earthquake-triggered landslides. A larger difference indicates a heightened risk of such landslides, while a smaller difference suggests a lower risk. On the other hand, the cumulative displacement method involves fitting \(A_{\mathrm{c}}\) with the \(PGA\) to directly determine the permanent cumulative displacement of the rock-soil mass (\(D_{\mathrm{N}}\)) under the influence of ground motion. In the process of the permanent cumulative displacement method, \(D_{\mathrm{N}}\) serves as the basis for assessing the risk of earthquake-triggered landslides. It is important to note that the empirical formula used to calculate \(D_{\mathrm{N}}\) exhibits regional characteristics.