The failures of tailings dams have a major negative impact on the economy, surrounding properties, and people’s lives, and therefore the monitoring of these facilities is crucial to mitigate the risk of failure, but this can be challenging due to their size and inaccessibility. In this work, the deformation processes at Żelazny Most tailings dam (Poland) were analyzed using satellite Ad-vanced Differential SAR Interferometry (A-DInSAR) from October 2014 to April 2019, showing that the dam is affected by both settlements (with a maximum rate of 30 mm/yr), and horizontal sliding in radial direction with respect to the ponds. The load of the tailings is pushing the dam forward along the glacio-tectonic shear planes located at depth, in the Pliocene clays, causing horizontal displacements at a rate up to 30 mm/yr, which could lead to a passive failure of the dam. The measured displacements have been compared with the ones observed by in situ data from the 90s to 2013, available in the literature. The outcomes indicate that intense localized deformations occur in the eastern and northern sectors of the dam, while the western sector is deforming evenly. Moreover, although the horizontal deformation had a slowdown from 2010 until 2013, it continued in 2014 to 2019 with recovered intensity. The upper and the recent embankments are affected by major settlements, possibly due to a lower consolidation degree of the most recent tailings and a larger thickness of compressible materials.

Mining exploitation leads to slow or rapid ground subsidence resulting from deformation until the collapse of underground post-mining voids following excavation activities. Satellite SAR interferometry capabilities for the evaluation of ground movements allows the monitoring of intensive surface mine subsidence and can provide new knowledge about the risks in the mining industry. This work integrates both conventional and advanced Differential SAR Interferometry (DInSAR) to study the ground subsidence in the Legnica Glogow Copper District (LGCD, Poland) by processing about 400 Sentinel-1 images from October 2014 to April 2019. Even without field data and information on past and ongoing excavation activities, the DInSAR approach allowed us to identify 30 troughs of subsidence, ranging from 500 m to 2.5 km in diameter, which in some cases, took place several times during the analyzed time span. The cumulative subsidence in 4 years and 7 months exceeds 70 cm in several zones of the LGCD. The sub-centimetric precision achieved by advanced analysis (A-DInSAR), allowed us to monitor the real extent of the mining influence area on the surface, with deformation velocities of up to 50 mm/year. The ground deformation detected at LGCD can be due to both mining-induced tremors and roof subsidence above the underground excavation rooms. As deformations do not occur concurrently with tremors, this can be related to excavation activities or to degradation of abandoned mines.

<p>Earthquake-induced ground effects are strongly related to the presence and distance of active and capable faults, and they play an extremely important role in the mitigation of seismic risk. The Italian Seismic Microzonation Guidelines subdivide the active and capable faults in ‘certain and defined’ and ‘uncertain’, attributing to them microzones with defined landscape uses: ‘Respect’ and ‘Susceptibility’ zones respectively. In this work, we present the methodology used to map and analyze the Montereale basin’s faults, located in the highly seismic region of the central Apennines of Italy. The Montereale faults (MFS) pertain to two fault systems with an <em>en echélon</em> array, namely the San Giovanni and Capitignano fault systems. Yet the great scientific attention in this region, these faults still lack clear evidence of relationships with the major active and capable structures in the neighboring area that are considered responsible for the seismic events that affected central Italy in recent decades.</p><p>The San Giovanni fault cuts in heterogeneous deposits consisting of calcareous lithotypes, which expose well defined fault planes and easily recognizable fault scarps. Instead, the Capitignano fault occurs on softer arenaceous-pelitic deposits, which make hard to identify tectonic discontinuities.</p><p>The approach, by which we have mapped the Capitignano fault and defined Susceptibility and Respect microzones for the MFS, is divided into the following phases: 1. Identification of morphotectonic elements by the analysis of digital terrain models (DTM 10 m and LiDAR 1 m), morphological elements (linear slopes, non-degraded triangular facets, anomalies in the drainage network, linear valleys, saddles, alignments of slope breaks) represent the most evident expression of active tectonics. 2. Geological and geomorphological survey for the interpretation of the elements recognized by remote sensing data. 3. Geophysical surveys (tomography electrical resistivity and seismic reflection), planned based on the morphotectonic features, identified in the previous stages. 4. Paleoseismological trenches, located where geophysical investigations have confirmed the presence of subsoil’s discontinuities. 5. Dating of faulted soils.</p><p>Following this method, the recognition of active and capable faults was possible, even where their morphological expression was not evident or completely absent. Moreover, the study outcomes provided new pieces of evidence for a comparison with the neighboring and well-studied fault systems allowing to propose eventual structural relationships.  Finally, we believe that the proposed approach can be a powerful tool in regions densely affected by earthquakes. In fact, a deep knowledge of fault network and their mutual interactions allows to limit damage to people and inhabited centers and to plan reconstruction works in areas affected by seismic events.</p><p> </p>