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

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.

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.

The Collisional Orogeny in the Scandinavian Caledonides project provides insights into the deep structure and bedrock of a ca. 400 Ma old major orogen to study deformation processes that are hidden at depth from direct access in modern mountain belts. This paper describes the successful operations at the second site. It provides an overview of the retrieved geological section that differs from the expected and summarises the scientific potential of the accomplished data sets and drill core.