###### Abstract  
In this study, we defined screening maps for Italy that classify sites based on their potential for triggering landslides. To this end, we analyzed seismic hazard maps and hazard disaggregation results on a national scale considering four spectral periods (0.01 s, 0.2 s, 0.5 s, and 1.0 s) and three return periods (475, 975, and 2475 years). First, joint distributions of magnitude (\(M\)) and distance (\(R\)) from hazard disaggregation were analyzed by means of an innovative approach based on image processing techniques to find all modal scenarios contributing to the hazard. In order to obtain the \(M\)-\(R\) scenarios controlling the triggering of earthquake-induced landslides at any computation node, mean and modal \(M\)-\(R\) pairs were compared to empirical curves defining the \(M\)-\(R\) bounds associated with landslide triggering. Three types of landslides were considered (i.e., disrupted slides and falls, coherent slides, and lateral spreads and flows). As a result, screening maps for all of Italy showing the potential for triggering landslides based on the level of seismic hazard were obtained. The maps and the related data are freely accessible. earthquake-induced landslides; landslide triggering; seismic hazard; hazard disaggregation; triggering probability; Italy +
Footnote †: journal: Medical  
Following in the footsteps of many works in Italy devoted to the risk mitigation of natural hazards and land-use planning [13; 14; 15; 16; 17], the scope of the present work was the assessment and mapping of the potential for triggering earthquake-induced landslides on a national scale. The results can be useful for seismic microzonation purposes, guiding land-use planners in mitigating risks, and enhancing preparedness and emergency response within the framework of disaster risk management. Furthermore, they can be useful for subsequent assessments of landslide susceptibility. At least in principle, the evaluation of the seismic triggering of landslides implies the assessment of the exceedance of the critical acceleration at the site of interest, whose computation requires knowledge of site-specific geotechnical parameters (e.g., soil cohesion, friction angle, and unit weight). Alternatively, it can be achieved by analyzing the seismic parameters that are commonly related to landslide triggering, such as earthquake magnitude (\(M\)), source-to-site distance (\(R\)), epicentral intensity, peak ground acceleration (PGA) (in the present work, the terms \"peak horizontal acceleration\" and \"peak ground acceleration\" are used interchangeably), Arias intensity (\(I_{a}\)), and spectral acceleration (\(S_{a}\)) [1; 3; 4; 8; 19; 20; 21; 22; 23; 24; 25]. Nowadays, the values of most of these parameters can be easily obtained by querying national hazard maps through online web services, at least at the screening level. To deal with the critical role of seismicity in causing landslides, this study used data from the reference Italian seismic hazard maps [26; 27] and the results of the disaggregation of the hazard [28]. Specifically, the primary criterion that we used to define whether a site has the (seismic) potentiality to trigger a landslide is based on the comparison of the mean and modal \(M\)-\(R\) scenarios from hazard disaggregation with the upper bounds proposed by [PERSON] [1]. This criterion, which is better described in the next section, is also considered by the Italian Guidelines for Seismic Microzonation released by the SM Working Group [14; 15]. The disaggregation of spectral acceleration hazard corresponding to different spectral periods (\(T\) = 0.01 s, \(T\) = 0.2 s, \(T\) = 0.5 s, and \(T\) = 1.0 s) was also considered. As sites resonate at different fundamental periods depending on local geological characteristics [2], this allowed us to select the \(M\)-\(R\) pair controlling landslide triggering in relation to local geological conditions (through the use of the site classification system adopted by the Italian building code [29]).