The central research topic of the GFZ Section 4.2 'Geomechanics and Scientific Drilling' is towards understanding the physical and physicochemical processes that control dynamics and mechanical properties in the Earth's crust and mantle lithosphere. This covers the entire spectrum of topics ranging from geomechanics and rock physics to the rheology of crust and uppermost mantle, ranging over the entire spatial bandwidth from the laboratory through mine and reservoir scale to the deformation of tectonic plate boundaries. The goal is a quantitative scale-invariant understanding of the mechanics of deformation and mass transport processes in the lithosphere (extremely brittle to fully ductile) and includes the analysis of their spatio-temporal changes and scale dependence from the atomic structure to the regional field scale (reservoir, plate margin). In our laboratories we conduct experiments on deformation and transport processes in reservoir and crustal rocks, for example on granites or porous storage rocks such as sandstone. In experiments in which we heat and pressurize rocks, we investigate seismic and aseismic deformation processes under controlled conditions and with optimal monitoring. From this we derive laws that we then study in nature in geological reservoirs or along tectonic plate boundaries under uncontrollable conditions. We also perform in-situ measurements in mines and in tectonically active areas along plate boundaries. Here we focus on the analysis of processes acting before, during and after earthquakes of different strengths. With our research, we not only discover fundamentals about the mechanical properties of rocks. We also provide physical basics for estimating a range of geo-risks and geomechanical issues in the exploration of the subsurface.