## 5 Results and Discussion  
By interpolating the final dataset, we mapped the surface deformation field of Riotinto for the period 2015-2017 (Figure 10). It shows the aforementioned 4 anomalies (other anomalies linked to the active Cerro Colorado pit are not analyzed in this work). Displacements in zones 1 and 2 happen in rock dumps and were not known before this study. Values go from less than 1 cm/y for most of the extension, up to 5 cm/y close to some steep slopes. These dumps are made up of disaggregated materials and therefore their mechanical behavior tends to plasticity (Figure 11), which could justify differences between vertical subsidence in the flat summit and along the slopes in steep zones that we interpret as debris slides [42]. It is important to take into account that some displacements in Zone 2 are in the northbound slope, a direction of low sensitivity for the DInSAR technique since it is oriented N-S.  
Figure 8: Displacement map integrating ascending and descending values. Velocity values quantify vertical displacement for slopes less than 13\({}^{o}\), and displacement along the slope for greater slopes. Negative values mean downwards. Outsider values are in black and “climber” artifacts are the “vector out” symbols. Figure 9: Boxplot of the joint dataset. Red circles show the outliers that have been removed because they conflict with neighboring values. Despite good coverage and consistent data, ground-level data is required to confirm these results. Nevertheless, we suggest increasing the control of these two passive dumps. On the other hand, Zone 3 shows a pattern of displacement consistent with subsidence and collapses observed at ground level. Atalaya Mining monitors terrain instability in this area to prevent any risk. Zone 3 is an old ore deposit first mined through galleries and then open pit, and finally filled with mining waste and abandoned. It is believed that the cause of the ground instability is failures in the abandoned galleries. Furthermore, this area is affected by the mining plan in Cerro Colorado, changing its status to an active zone. Figure 11: North-South view of the passive mining elements. The numbers are the four zones under discussion. Figure 10: Deformation map showing the velocity anomalies interpolated from the displacement map, blue dots (Figure 8). Negative displacements are downward in flat zones and along the maximum slope in steep zones. The numbers show the four zones under discussion. Atalaya Open-Pit, Zone 4  
Thanks to the terrestrial monitoring conducted by the mining company at the east of the Atalaya open pit, we have been able to make a detailed analysis of the observed displacements. As previously stated, in Zone 4 the Vlos vector has been projected not along the maximum slope but to the main displacement direction determined by the local GNSS network (Figure 12). The local topography in the east wall of the open pit is a narrow convergent slope crossed by a fault zone and the shale of the Volcano-sedimentary Complex and the Culm Group [27]. This conjunction weakens the wall structure and breaks it into blocks (Figure 12). We interpret the velocity values observed as block slide type displacement inside this weakened zone [42]. From the average of the displacement vectors measured using GNSS, we determined a direction with angles of 42\({}^{\circ}\) dip and 331\({}^{\circ}\) azimuth that we used to project Vlos in this area. Assuming that all points on the blocks are moving in the same sliding direction, we compared in a graph four coinciding GNSS and Sentinel-1 measurements (Figure 12). The correlation is high, getting velocities values up to 11 cm/y. The small correlation mismatches could be explained by scale differences, while GNSS measurements are at specific point locations, InSAR measurements represent pixel averages (-40 \(\times\) 40 m in flat Earth resolution). It is also worth saying that the GNSS survey markers are not cemented pillars but Feno-type nails, the integrity of which is more vulnerable to unexpected damages.