Passive seismic data were acquired along a 2.8 km long profile in the Sudret area of Gotland, Sweden, as part of a feasibility study for storage of CO₂ below the Baltic Sea. Virtual shot gathers were retrieved by seismic interferometry. Both the body waves and surface waves provide high-quality images of the top of the Ordovician formation and have a good consistency with the borehole section. Our results show that passive data can be used for mapping some general geological features in Gotland.

This study applied fat ray travel time tomography to image the geothermal testbed at the BedrettoLab. An active seismic crosshole survey provided a dataset of 42'843 manually picked first breaks. The complex major fault zone was successfully imaged by a 3D velocity model and validated with wireline logs and geological observations. Seismic events from hydraulic stimulation correlated with velocity structures, "avoiding" very high and low velocities, speculatively due to stress gradients.

Reflection seismic data can provide high resolution images of the Earth's crust and allow a better understanding of crustal structure on all continents. In this paper we revisit reflection seismic data that were acquired previously across the central part of the Scandinavian peninsula. Merging of individual components of the data set in a more optimal manner resulted in a new image of the crust below the Scandinavian Caledonides with a revised interpretation of the crustal structure in the west.

This study presents a new geological model of the Fano-Pesaro offshore area, refining its tectonic framework. We identified multiple fault detachments at different depths, influencing thrust system dynamics and deformation. This work highlights the importance of integrating seismic and borehole data, even legacy, to build reliable subsurface models. These findings contribute to improved seismic hazard assessment and support offshore energy development and carbon storage projects.

Geological storage of CO₂ has emerged again in recent years as a complement to reducing CO₂ emissions to the atmosphere. The Swedish government recently gave the task of further studying the potential for CO₂ storage within Swedish territory to the Geological Survey of Sweden. We report here on results from investigations on southern Gotland island. We find that we can map several geological formations of interest and that the rock is seismically anisotropic.

Two reflection seismic (semi-)regional profiles were acquired to map the regional reflectivity of the Koillismaa Layered Igneous Complex in north-eastern Finland. Several reflections up to a depth of 5–6 km are mapped. The top of the magma conduit associated with KLIC is successfully revealed and it is interpreted that there might be a second magma conduit below the exposed intrusion. The study helped in better understanding of the regional structural geology of the area.

The manuscript re-analyses seismic data from the UPPLAND profile in the Fennoscandian Shield, focusing on Vp and Vs velocity models. Significant differences between prior and present models emerge in the lower crust and mantle and in the Moho depth. The new model suggests Vp of 7.05–7.17 km/s in the lower crust and 8.05 km/s in the upper mantle, with Moho at 43–50 km. Two tectonic interpretations are proposed to explain these findings, emphasizing the complexities of seismic data interpretation.

Sub-surface geometries of ancient faults must be mapped using high-resolution geophysical surveys using reflected seismic waves. Several such surveys in southern Canada map faults, many of which host significant gold or nickel deposits. Reflectors are considered upper crustal brittle, lava flows if folded or broken or mid-crustal if mostly parallel. Steep fault zones formed first in ocean settings when the lavas erupted. Folds and horizontal shortening occurred during later mountain building.

The spatial correlation between crustal magma reservoir and seismicity is crucial for investigating the dynamics of the Wudalianchi volcanic systems. A high-resolution 3-D shear-wave velocity crustal model reveals a distinct low-velocity body located at depths of ~10–23 km below the Wudalianchi volcano. Together with the earthquake distribution, this provides new insights into the magmatic activity of the active Wudalianchi volcano.

Sinkholes and caves underground pose challenges for various industries in the karst area, particularly those dependent on stable ground conditions, such as construction, agriculture, and infrastructure development. In this study, we applied seismic reflection, a geophysical method, to delineate shallow subsurface complex geological structures and to better understand limestone cave formation.

Three seismic profiles were acquired in the Thinia valley, an isthmus connecting the main part of the island to the Paliki peninsula, to improve the subsurface knowledge of the tectonically peculiar Kefalonia island. Here the presence of a possible channel has been largely disputed to make Paliki the Homer’s Ithaca. Results from different analyses further constrain the recent tectonic history of the area and thus, the long-debated presence of an historic water channel in the valley.

Local seismic tomography yields the highest-resolution 3D Q_p model in CSES. Low Q_p anomalies along faults and basins indicate high medium fragmentation, thick sediments, or fluid richness. Tengchong volcano's westward dipping high attenuation suggests magma flow. Most M6+ earthquakes occur in low attenuation zones or anomaly boundaries. The 2008 Wenchuan M_S 8.0 and 2013 Lushan M_S 7.0 epicenters were separated by a low attenuation area, indicating future major earthquake risks.