We compare seismometers with the 6C method, which combines rotational and seismometer data, determining signal directions and wave velocities for short and continuous low-frequency volcanic signals at Mt. Etna. Either the cluster or the rotational sensor reliably detect continuous signal directions, aligning with the observatory data. For short signals, 6C directions deviate more, likely due to a complex underground. Combining both methods' velocity results improves understanding volcanic waves.

We studied the crust beneath Celebes Sea and Makassar Strait in East Indonesia to better understand how the region formed and moves today. Using ocean-bottom and land-based seismometers, we discovered significant differences in crust thickness and unusual underground structures associated with major faults. These findings help explain past tectonic activity and may improve understanding of earthquake hazards in the area.

Curling stones often collide with each other during a game. Over time, these collisions cause damage in the striking bands on the sides of the stones. We determined experimentally how hard these stones collide into one another. We then looked at old curling stones to understand how damage builds up in these rocks. We found that early, fast impacts produce fractures until the striking band is saturated in fractures. Repeated impacts after this stage make fractures grow.

Contrary to current CCS (Carbon Capture and Storage) models, reaction experiments conducted at subsurface stress and temperature conditions reveal that feldspars, common, reactive grains in sandstone reservoirs, can undergo significant chemical and mechanical changes when exposed to CO₂ enriched water. These chemo-mechanical processes, including grain fracturing, dissolution, and clay precipitation, can modify fluid pathways and rock strength, potentially reducing reservoir productivity and increasing leakage risk.

The northwestern region of Bangladesh, an extension of India's ancient landmass, differs geologically from the sediment-covered rest of the country. Our research using gravity, magnetic, seismic, and drilling methods revealed distinctive magnetic anomalies suggesting gabbro rocks along fault lines, forming patterns of elevated and depressed blocks underground. This structural model, particularly in the Rangpur Saddle area, indicates significant potential for mineral resources.

We combined satellite radar and GPS data to model how the faults in El Salvador and nearby regions accumulate deformation. Motion across the central El Salvador Fault Zone is shared by several fault branches, while the offshore subduction zone appears to be weakly locked. These results improve the understanding of regional deformation and seismic hazard in Central America.

We applied fat ray travel time tomography to image the geothermal testbed at the BedrettoLab (Switzerland). An active seismic crosshole survey provided a dataset of 41’881 manually picked first breaks. The complex major fault zone was identified by a 3D velocity model and validated with wireline logs and geological observations. Induced seismicity from hydraulic stimulation experiments preferentially occurs in intermediate-velocity regions, possibly due to the presence of stress gradients.

We investigate how the spatial arrangement of normal faults in the Italian Apennines affects earthquake timing and size. Computer-based models show that wide networks with faults offset across-strike produce more irregular and variable earthquakes, while narrow networks with fewer across-strike faults lead to more regular events. Faster-moving faults are more sensitive to nearby positive stress interactions, highlighting the need to consider fault geometry in seismic hazard assessments.

LKAB (Luossavaara-Kiirunavaara Aktiebolag) is the largest iron ore producer in the EU, with the Kiirunavaara mine in northern Sweden as the main production unit. The company is now exploring the adjacent Per Geijer Deep iron mineralization, which is associated with rare-earth elements (REEs) and phosphorus, recognized to be of critical importance to EU. We present results from reflection seismic measurements and demonstrate that there is a distinct response from the Per Geijer Deep mineralization, and from the nearby Kiruna orebody.

We studied a deep fault zone in Switzerland to gain a better understanding of how water moves through faults and how this affects earthquake activity. Using field and laboratory tests, we found that flow is strongly controlled by open fractures and permeability changes significantly with scale. Small samples underestimate flow compared to larger tests. Our results show that faults are heterogeneous, highlighting the need for site-specific studies when assessing risks or planning experiments.

Near-surface imaging plays a crucial role in mine development, safety, efficiency, and environmental risk mitigation. Challenges in deep mining often stem from complex geological conditions and anthropogenic factors, such as undocumented historical mining activities. This study presents an integrated geophysical approach that combines multiple geophysical techniques to characterize the near-surface environment and delineate potential water conduits in a deep mining context.

We studied faults in Utah to understand how rock type controls fault dimensions. Using photogrammetry, field mapping, and mineral data, we found faults grow differently in weak and strong rocks because of variable mineralogy. For equivalent displacements, faults tend to be shorter in clay-rich layers and taller in rocks containing strong minerals. We built a model to predict hidden fault height from mineralogy and applied it to seismic data, showing fault dimensions are often underestimated.

Our study investigates ca. 1.78 Ga Jiguanshan diorite in the North China Craton. We found that Paleoproterozoic diorites across the craton share similar compositions and formed from melted deep crust, differing from volcanic and mafic rocks of the same age. Geochemical analysis reveals these diorites formed during crustal stretching, marking a tectonic shift from orogenic-related to within-plate settings. This provides key evidence for understanding how tectonic setting evolved after collisions.

We assess the fault impact on the stress field in northern Switzerland using 3D geomechanical models, calibrated with stress data. We see that faults affect the stresses only locally, with negligible impact beyond 1 km, suggesting that faults may not be necessary in reservoir-scale models predicting stresses of undisturbed rock volumes, such as for a geological repository. Omitting them can substantially reduce model set-up time and computational cost without compromising prediction reliability.

A method for shape quantification based on geometrical parameters is proposed alongside a set of regular geometries established as geomodeling benchmarks. Dimensions, gradient and curvature data is obtained on cross-sections. Data analyses provide insight into the main geometrical characteristics of the benchmark models and visualizes geometrical dis-/similarities between bodies. The method and benchmarks are usable in geomodeling workflows and structural comparisons based on sparse data.

We used sound waves to look beneath the surface in the Northern Cape of South Africa to search for hidden layers of rock that may contain valuable manganese deposits. Our study revealed nine distinct underground layers, including one likely to host manganese. This method helps locate buried resources without drilling, showing how advanced imaging can support mineral exploration in areas covered by thick sand.

We use analogue outcrops to predict orientations of the background fracture network in the subsurface. The novelty of our research is that we group different sets of fractures and stylolites into associations, based on the orientation of the stress field in which they formed. We apply this methodology to the Geneva Basin. Regional observations enable us to predict fracture orientations in the subsurface. 45 % of the fractures observed on image logs of two wells fit the prediction.