@article{DurandBentzKwiateketal.2020,
  author    = {Durand, Virginie and Bentz, Stephan and Kwiatek, Grzegorz and Dresen, Georg and Wollin, Christopher and Heidbach, Oliver and Martinez-Garzon, Patricia and Cotton, Fabrice and Nurlu, Murat and Bohnhoff, Marco},
  title     = {A two-scale preparation phase preceded an M-w 5.8 earthquake in the sea of marmara offshore Istanbul, Turkey},
  series = {Seismological research letters},
  volume    = {91},
  journal   = {Seismological research letters},
  number    = {6},
  address   = {Boulder},
  issn      = {0895-0695},
  doi       = {10.1785/0220200110},
  pages     = {3139 -- 3147},
  year      = {2020},
  abstract  = {We analyze the spatiotemporal evolution of seismicity during a sequence of moderate (an M-w 4.7 foreshock and M-w 5.8 mainshock) earthquakes occurring in September 2019 at the transition between a creeping and a locked segment of the North Anatolian fault in the central Sea of Marmara, northwest Turkey. To investigate in detail the seismicity evolution, we apply a matched-filter technique to continuous waveforms, thus reducing the magnitude threshold for detection. Sequences of foreshocks preceding the two largest events are clearly seen, exhibiting two different behaviors: a long-term activation of the seismicity along the entire fault segment and a short-term concentration around the epicenters of the large events. We suggest a two-scale preparation phase, with aseismic slip preparing the mainshock final rupture a few days before, and a cascade mechanism leading to the nucleation of the mainshock. Thus, our study shows a combination of seismic and aseismic slip during the foreshock sequence changing the strength of the fault, bringing it closer to failure.},
  language  = {en}
}
@article{GholamrezaieScheckWenderothCacaceetal.2021,
  author    = {Gholamrezaie, Ershad and Scheck-Wenderoth, Magdalena and Cacace, Mauro and Bott, Judith and Heidbach, Oliver and Bohnhoff, Marco and Strecker, Manfred R.},
  title     = {Lithospheric strength variations and seismotectonic segmentation below the Sea of Marmara},
  series = {Tectonophysics : international journal of geotectonics and the geology and physics of the interior of the earth},
  volume    = {815},
  journal   = {Tectonophysics : international journal of geotectonics and the geology and physics of the interior of the earth},
  publisher = {Elsevier},
  address   = {Amsterdam [u.a.]},
  issn      = {0040-1951},
  doi       = {10.1016/j.tecto.2021.228999},
  pages     = {13},
  year      = {2021},
  abstract  = {The Sea of Marmara is a tectonically active basin that straddles the North Anatolian Fault Zone (NAFZ), a major strike-slip fault that separates the Eurasian and Anatolian tectonic plates. The Main Marmara Fault (MMF), which is part of the NAFZ, contains an approximately 150 km long seismotectonic segment that has not ruptured since 1766. A key question for seismic hazard and risk assessment is whether or not the next rupture along this segment is likely to produce one major earthquake or a series of smaller earthquakes. Geomechanical characteristics such as along-strike variations in rock strength may provide an important control on seismotectonic segmentation. We find that variations in lithospheric strength throughout the Marmara region control the mechanical segmentation of the MMF and help explain its long-term seismotectonic segmentation. In particular, a strong crust that is mechanically coupled to the upper mantle spatially correlates with aseismic patches, where the MMF bends and changes its strike in response to the presence of high-density lower crustal bodies. Between the bends, mechanically weaker crustal domains that are decoupled from the mantle indicate a predominance of creeping. These results are highly relevant for the ongoing debate regarding the characteristics of the Marmara seismic gap, especially in view of the seismic hazard (Mw > 7) in the densely populated Marmara region.},
  language  = {en}
}
@article{ZieglerHeidbachZangetal.2017,
  author    = {Ziegler, Moritz O. and Heidbach, Oliver and Zang, Arno and Martinez-Garzon, Patricia and Bohnhoff, Marco},
  title     = {Estimation of the differential stress from the stress rotation angle in low permeable rock},
  series = {Geophysical research letters},
  volume    = {44},
  journal   = {Geophysical research letters},
  publisher = {American Geophysical Union},
  address   = {Washington},
  issn      = {0094-8276},
  doi       = {10.1002/2017GL073598},
  pages     = {6761 -- 6770},
  year      = {2017},
  abstract  = {Rotations of the principal stress axes are observed as a result of fluid injection into reservoirs. We use a generic, fully coupled 3-D thermo-hydro-mechanical model to investigate systematically the dependence of this stress rotation on different reservoir properties and injection scenarios. We find that permeability, injection rate, and initial differential stress are the key factors, while other reservoir properties only play a negligible role. In particular, we find that thermal effects do not significantly contribute to stress rotations. For reservoir types with usual differential stress and reservoir treatment the occurrence of significant stress rotations is limited to reservoirs with a permeability of less than approximately 10(-12)m(2). Higher permeability effectively prevents stress rotations to occur. Thus, according to these general findings, the observed principal stress axes rotation can be used as a proxy of the initial differential stress provided that rock permeability and fluid injection rate are known a priori.},
  language  = {en}
}