TY - JOUR A1 - Heidbach, Oliver A1 - Rajabi, Mojtaba A1 - Cui, Xiaofeng A1 - Fuchs, Karl A1 - Mueller, Birgit A1 - Reinecker, John A1 - Reiter, Karsten A1 - Tingay, Mark A1 - Wenzel, Friedemann A1 - Xie, Furen A1 - Ziegler, Moritz O. A1 - Zoback, Mary-Lou A1 - Zoback, Mark T1 - The World Stress Map database release 2016 BT - Crustal stress pattern across scales JF - Tectonophysics : international journal of geotectonics and the geology and physics of the interior of the earth N2 - Knowledge of the present-day crustal in-situ stress field is a key for the understanding of geodynamic processes such as global plate tectonics and earthquakes. It is also essential for the management of geo-reservoirs and underground storage sites for energy and waste. Since 1986, the World Stress Map (WSM) project has systematically compiled the orientation of maximum horizontal stress (S-Hmax). For the 30th anniversary of the project, the WSM database has been updated significantly with 42,870 data records which is double the amount of data in comparison to the database release in 2008. The update focuses on areas with previously sparse data coverage to resolve the stress pattern on different spatial scales. In this paper, we present details of the new WSM database release 2016 and an analysis of global and regional stress pattern. With the higher data density, we can now resolve stress pattern heterogeneities from plate-wide to local scales. In particular, we show two examples of 40 degrees-60 degrees S-Hmax rotations within 70 km. These rotations can be used as proxies to better understand the relative importance of plate boundary forces that control the long wave-length pattern in comparison to regional and local controls of the crustal stress state. In the new WSM project phase IV that started in 2017, we will continue to further refine the information on the S-Hmax orientation and the stress regime. However, we will also focus on the compilation of stress magnitude data as this information is essential for the calibration of geomechanical-numerical models. This enables us to derive a 3-D continuous description of the stress tensor from point-wise and incomplete stress tensor information provided with the WSM database. Such forward models are required for safety aspects of anthropogenic activities in the underground and for a better understanding of tectonic processes such as the earthquake cycle. KW - Tectonic stress KW - Database KW - Stress tensor KW - Geomechanical modelling Y1 - 2018 U6 - https://doi.org/10.1016/j.tecto.2018.07.007 SN - 0040-1951 SN - 1879-3266 VL - 744 SP - 484 EP - 498 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Rajabi, Mojtaba A1 - Ziegler, Moritz O. A1 - Tingay, Mark A1 - Heidbach, Oliver A1 - Reynolds, Scott T1 - Contemporary tectonic stress pattern of the Taranaki Basin, New Zealand JF - Journal of geophysical research : Solid earth N2 - The present-day stress state is a key parameter in numerous geoscientific research fields including geodynamics, seismic hazard assessment, and geomechanics of georeservoirs. The Taranaki Basin of New Zealand is located on the Australian Plate and forms the western boundary of tectonic deformation due to Pacific Plate subduction along the Hikurangi margin. This paper presents the first comprehensive wellbore-derived basin-scale in situ stress analysis in New Zealand. We analyze borehole image and oriented caliper data from 129 petroleum wells in the Taranaki Basin to interpret the shape of boreholes and determine the orientation of maximum horizontal stress (S-Hmax). We combine these data (151 S-Hmax data records) with 40 stress data records derived from individual earthquake focal mechanism solutions, 6 from stress inversions of focal mechanisms, and 1 data record using the average of several focal mechanism solutions. The resulting data set has 198 data records for the Taranaki Basin and suggests a regional S-Hmax orientation of N068 degrees E (22 degrees), which is in agreement with NW-SE extension suggested by geological data. Furthermore, this ENE-WSW average S-Hmax orientation is subparallel to the subduction trench and strike of the subducting slab (N50 degrees E) beneath the central western North Island. Hence, we suggest that the slab geometry and the associated forces due to slab rollback are the key control of crustal stress in the Taranaki Basin. In addition, we find stress perturbations with depth in the vicinity of faults in some of the studied wells, which highlight the impact of local stress sources on the present-day stress rotation. KW - in situ stress KW - Taranaki Basin KW - New Zealand KW - plate tectonics KW - subduction zone Y1 - 2016 U6 - https://doi.org/10.1002/2016JB013178 SN - 2169-9313 SN - 2169-9356 VL - 121 SP - 6053 EP - 6070 PB - American Geophysical Union CY - Washington ER - TY - JOUR A1 - Ziegler, Moritz O. A1 - Rajabi, Mojtaba A1 - Heidbach, Oliver A1 - Hersir, Gylfi Pall A1 - Agustsson, Kristjan A1 - Arnadottir, Sigurveig A1 - Zang, Arno T1 - The stress pattern of Iceland JF - Tectonophysics : international journal of geotectonics and the geology and physics of the interior of the earth N2 - Iceland is located on the Mid-Atlantic Ridge which is the plate boundary between the Eurasian and the North American plates. It is one of the few places on earth where an active spreading centre is located onshore but the stress pattern has not been extensively investigated so far. In this paper we present a comprehensive compilation of the orientation of maximum horizontal stress (S-Hmax). In particular we interpret borehole breakouts and drilling induced fractures from borehole image logs in 57 geothermal wells onshore Iceland. The borehole results are combined with other stress indicators including earthquake focal mechanism solutions, geological information and overcoring measurements resulting in a dataset with 495 data records for the S-Hmax orientation. The reliability of each indicator is assessed according to the quality criteria of the World Stress Map project The majority of S-Hmax orientation data records in Iceland is derived from earthquake focal mechanism solutions (35%) and geological fault slip inversions (26%). 20% of the data are borehole related stress indicators. In addition minor shares of S-Hmax orientations are compiled, amongst others, from focal mechanism inversions and the alignment of fissure eruptions. The results show that the S-Hmax orientations derived from different depths and stress indicators are consistent with each other. The resulting pattern of the present-day stress in Iceland has four distinct subsets of S-Hmax orientations. The S-Hmax orientation is parallel to the rift axes in the vicinity of the active spreading regions. It changes from NE-SW in the South to approximately N-S in central Iceland and NNW-SSE in the North. In the Westfjords which is located far away from the ridge the regional S-Hmax rotates and is parallel to the plate motion. (C) 2016 Elsevier B.V. All rights reserved. KW - Iceland KW - Stress field KW - Stress pattern KW - Borehole image logs Y1 - 2016 U6 - https://doi.org/10.1016/j.tecto.2016.02.008 SN - 0040-1951 SN - 1879-3266 VL - 674 SP - 101 EP - 113 PB - Elsevier CY - Amsterdam ER -