TS8.4Variation of crustal stresses in space and time
|Convener: Oliver Heidbach | Co-Conveners: Karsten Reiter , Mark Tingay|
The 3D stress state of Earth’s crust and its spatio-temporal changes is of key importance for industrial applications (e.g. hydraulic fracturing, borehole stability, induced seismicity) and scientific questions (e.g. earthquake cycle, slip tendency analysis) likewise. The amount of crustal stress information has increased substantially in the past decade indicating a more complex stress pattern related to regional/local variability due to crustal structures, fault zones, earthquake cycles or man-made stress changes from production or injection of fluids. 4D geomechanical-numerical models allow to quantify the contribution of natural and anthropogenic processes, rock properties, constitutive laws, inhomogeneities and anisotropies. However, to constrain such models, stress data from both, orientation and magnitude with a good spatial and time resolution are essential.
The main goal of the session is to bring together researchers from various geo-disciplines to contribute to a thorough understanding of crustal stress sources, stress variability during the seismic cycle and relation of observed strain with crustal stresses which leads to the observed complex stress pattern. The emphasis is on (1) stress data analysis and description of the spatio-temporal evolution of the stress field from geological and borehole data as well as seismological studies of earthquake focal mechanism solution and stress inversions, (2) application of stress information for geo-reservoir characterization in terms of productivity and safety aspects such as the re-activation of sealing faults and induced seismicity and (3) stress/strain accumulation and release within the seismic cycle and the role of Coulomb Failure Stress. Furthermore the focus of this session is also on (4) the plate-scale crustal stress pattern and its relation to mantle convection and the gravity field, (5) hydro-thermal-geomechanical models which provide a better process understanding and (6) the progress in paleo-stress measurements.