## 2 Materials and Methods
### Synthetic Model  
The location of the seismometer network deployment should consider the concept of stress distribution. The stress concentration of the block caving mining method in the ore body in an incline intrusion geological setting is similar to the stress concentration encountered in the open-stope mining method in smaller veins, where the greatest stress concentration is on the hanging-wall side [30]. This stress imbalance arises due to a combination of compressional forces due to loading and tensional stress due to caving. The stress concentration zone in the base of underground mines is called the abutment. In this zone, if the strength of the rock mass is still able to withstand the stress, the rock experiences elastic deformation (elastic zone). When the elastic limit is exceeded, the rock undergoes crack initiation, which then spreads to fracture. The crack growth process triggers the emergence of microseismic events. Therefore, this zone is called the seismogenic zone [8; 10; 12; 31]. The zone under the seismogenic zone is the yielded zone, where rock is crushed and collapsed. The boundary between these two zones continues to propagate as cave propagation progresses (Figure 2). The growth and shape of the cave due to mining activities using the block caving method should be monitored and controlled. Growth of the cave that does not conform to the mine design will have an impact on its security, safety and economic aspects. Microseismics is a proven reliable method for monitoring cave propagation [26,32,33]. The conceptual model of stress redistribution for homogeneous rock masses during the undercutting and caving processes has been agreed upon and proven by empirical data based on the results of microseismic monitoring [10,33]. Based on this general model, during the undercutting process, the compressed stress in the abutment and rock in the cave parameter experiences tensional stress towards the air gap at the undercut level (Figure 2). We built a synthetic model with an incline intrusion geological setting with a slope of 49\({}^{\circ}\) consisting of three (3) different mining levels, the first mining level at an elevation of 1820-1880 mean sea level (msl), the second at 1600-1680 msl and the third at 1500-1560 msl (Figure 1). The depth of the block caving was 2000 m. Our abutment zone was set at an elevation of 1620 m and the top cave was at an elevation of 1740 m (Figure 3). The caving mine in this study was designed with a triangular pyramidal shape, with cave heights varying from 10 m on one side and increasing gradually to a height of 120 m on the other side (Figure 3). The abutment of the cave had an area of 50,000 m\({}^{2}\). Our synthetic model represents a block caving that rises vertically; abundant microseismic events would be observed in the abutment and the top cave. Therefore, imaging the velocity perturbations in the abutment and top cave becomes crucial in monitoring cave stability. The microseismic sources in this study are illustrated as divided into several clusters concentrated around the abutment area and seismogenic zone. This synthetic model is based on a conceptual model that has been proven by empirical data based on observations and experiences at a number of mining sites using the block caving method [10,33,34,35,35]. This model has also been validated by physical modeling conducted by previous researchers [32,36]. We set 1800 synthetic microseismic events to represent typical microseismic events distribution in a block caving area. The distribution of microseismic events was generally oriented to northwest-southeast (Figure 4). The data consisted of 400 events at an elevation of 1500-1600 msl (below the abutment zone), 1000 events at an elevation of 1600-1700 msl (in the abutment and seismogenic zones) and 400 microseismic events at an elevation of 1700-1800 msl (in the seismogenic zone).