Spatially varying crustal stress along the Zagros seismic belt inferred from earthquake focal mechanisms

0567607 - GLÚ 2024 RIV NL eng J - Journal Article
Nouri, A. - Rahimi, B. - Vavryčuk, Václav - Ghaemi, F.
Spatially varying crustal stress along the Zagros seismic belt inferred from earthquake focal mechanisms.
Tectonophysics. Roč. 846, January (2023), č. článku 229653. ISSN 0040-1951. E-ISSN 1879-3266
Institutional support: RVO:67985831
Keywords : Zagros * Tectonic stress * Stress inversion * Earthquake * Focal mechanism
OECD category: Environmental and geological engineering, geotechnics
Impact factor: 2.9, year: 2022
Method of publishing: Limited access
https://www.sciencedirect.com/science/article/pii/S0040195122004474

We determine the stress field of the Zagros fold-and-thrust belt (ZFTB) in the collisional zone between the Arabian and Iranian plates. Using 898 mainshock focal mechanisms, which occurred along the belt between 1956 and 2021, we calculate stress at 32 locations. The results reveal that the crustal stress in the Zagros belt is heterogeneous with variations in the orientation of SH_max as well as in the stress ratio. The interpolation of the Simpson’s index Aϕ points to three distinct domains: northern, central and southern, which are characterized by wrench, compressional, and wrench-compressional to compressional tectonic regimes, respectively. Tectonic stress in the study area is characterized by a horizontal to sub-horizontal maximum compression axis in the ~NESW to ~NNW-SSE direction. The GPS measurements of the strain tensor and the SHmax direction inferred from the stress inversion indicate that both the deformation pattern and the seismicity along the ZFTB zone are primarily affected by convergence of the Arabian and Iranian plates.
Permanent Link: https://hdl.handle.net/11104/0347333