Description
The World Stress Map (WSM) is the global compilation of information on the present-day tectonic stress field in the Earth’s crust. It is a collaborative project of university, industry and governmental organizations that aims at understanding the sources of stress in the Earth’s crust.
The WSM is now a key resource for scientists and engineers in both university and industry useful for understanding geodynamic processes, assessing seismic hazards and the stability of tunnels, and also for improving hydrocarbon production, safe subsurface disposal of waste and greenhouse gases, as well as geothermal power production.
The project was initiated in 1986 under the auspices of the International Lithosphere Program under the leadership of Mary Lou Zoback. Since 1995 the WSM is a research project of the Heidelberg Academy of Sciences and Humanities and is located at the Geophysical Institute of the University of Karlsruhe in Germany.
The WSM database release contains 13,853 data sets derived from a wide range of shallow to deep stress indicators, including earthquake focal mechanism solutions, well bore breakouts, drilling-induced fractures, hydraulic fracturing, strain relief measurements, and young (Quaternary) geological indicators. To integrate stress data from different sources into one common database, standardized quality-ranking procedures have been developed for all stress indicators. This quality ranking guarantees reliability and global comparability of the stress data.
Each stress record is assigned a quality between A and E, with A being the highest quality and E the lowest. A-quality data indicate the maximum horizontal stress orientation (SH) to be accurate to within ± 15°, B-quality data accurate to within ± 20°, C-quality to within ± 25°, and D-quality to within ± 40°. E-quality indicates data with insufficient or widely scattered stress information. More than 10,500 higher-quality (A-C) data sets are contained in the 2005 WSM release.
The WSM website also includes regional stress maps, software, stress interpretation guidelines, and the fast online data base interface “Create a Stress Map Online” (CASMO). CASMO allows WSM users to create high graphic quality stress maps to their own specifications that are delivered to the user via e-mail within a minute.
For the visualization of the WSM database the orientation of maximum horizontal compressional stress is displayed in stress maps. Data selected for the World map are from the WSM 2005 release from all depth (0-40 km) and all A-C quality data records except single focal mechanism solutions labeled in the database as Possible Plate Boundary events (PBE) or within 200 km distance to oceanic spreading ridges.
