Knowledge of the crustal stress state is important for the assessment of subsurface stability. In particular, stress magnitudes are essential for the calibration of geomechanical models that estimate a continuous description of the 3-D stress field from pointwise and incomplete stress data. We present the first comprehensive and open-access stress magnitude database for Germany, consisting of 568 data records. We introduce a quality ranking scheme for stress magnitude data for the first time.

Knowledge about the stress state in the upper crust is of great importance for many economic and scientific questions. However, our knowledge in Germany is limited since available datasets only provide pointwise, incomplete and heterogeneous information. We present the first 3D geomechanical model that provides a continuous description of the contemporary crustal stress state for Germany. The model is calibrated by the orientation of the maximum horizontal stress and stress magnitudes.

The influence and interaction of elastic material properties (Young's modulus, Poisson's ratio), density and low-friction faults on the resulting far-field stress pattern in the Earth's crust is tested with generic models. A Young's modulus contrast can lead to a significant stress rotation. Discontinuities with low friction in homogeneous models change the stress pattern only slightly, away from the fault. In addition, active discontinuities are able to compensate stress rotation.

The knowledge of physical properties of quartz as an abundant rock-forming mineral in the Earth’s crust allows for a better understanding of its dynamic processes. The thermal transport properties of single-crystal quartz are studied between –120 °C and 800 °C using a laser flash method. First, low-temperature data as well as the role of the low-to-high quartz phase transition (e.g. a transition-related non-ballistic radiative transfer) and size effects on thermal diffusivity are discussed.

Based on geophysical data integration and 3-D gravity modeling, we show that significant density heterogeneities are expressed as two large high-density bodies in the crust below the Sea of Marmara. The location of these bodies correlates spatially with the bends of the main Marmara fault, indicating that rheological contrasts in the crust may influence the fault kinematics. Our findings may have implications for seismic hazard and risk assessments in the Marmara region.

Subsurface engineering relies on sparsely distributed data points of the stress state of the earth's crust. 3D geomechanical--numerical modelling is applied to estimate the stress state in the entire volume of a large area. We present a multi-stage approach of differently sized models which provide the stress state in an area of interest derived from few and widely scattered data records. Furthermore we demonstrate the changes in reliability of the model depending on different input parameters.

A numerical model integrating the structure and mechanical properties of a sedimentary sequence in the Alpine foreland is presented to show that topography, tectonic faults and, most of all, spatialy variable rock properties affect the state of stress at depth. The tectonic forces acting on the sequence are primarily taken up by the stiff rock units leaving the weaker units in a stress shadow.