| 1. |
- Rashidi, Ahmad, et al.
(författare)
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Morphotectonic and earthquake data analysis of interactional faults in Sabzevaran Area, SE Iran
- 2020
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Ingår i: Journal of Structural Geology. - : Elsevier. - 0191-8141 .- 1873-1201. ; 139
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Tidskriftsartikel (refereegranskat)abstract
- We used satellite images, earthquake catalogues and field observations to study several active fault systems and their interactions in Sabzevaran Area in SE Iran. The focus of this study is to verify the link between the active faults, their kinematics and seismic activity. Field observations and geomorphological analysis highlight the interaction of the active faults. Moreover, most of the tectonic activity is observed in the area, related to the Chahmazrae- North Faryab shear zone. Most of the earthquakes in this shear zone are reverse and occur in the deeper crust while aftershocks dominantly occur in the shallower crust. The Main Zagros Reverse Fault (MZRF) is the source of reverse events and the Chahmazrae- North Faryab shear zone is source of left-lateral, oblique reverse faulting events, and strike-slip events. These types of the earthquakes in the study area confirm the idea of tectonic proximity of the root faults and shear zone. In the interaction area, minor fractures begin to develop and are progressively linked to the main faults. In the en échelon arrangement of the faults, the minor faults have grown and linked the en échelon segments of the faults. It seems that the earthquake ruptures can spontaneously propagate across both extensional and the compressional fault steps. This propagation occurs along strike-slip faults such as Sabzevaran fault and its branches.
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| 2. |
- Mehrabi, Ali, et al.
(författare)
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Spatiotemporal subsidence over Pabdana coal mine Kerman Province, central Iran using time-series of Sentinel-1 remote sensing imagery
- 2023
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Ingår i: Episodes. - : International Union of Geological Sciences. - 0705-3797 .- 2586-1298. ; 46:1, s. 19-33
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Tidskriftsartikel (refereegranskat)abstract
- Environmental monitoring of mining regions using satellite imagery is crucial for sustainable exploitation andnpreventing geohazards. Movements due to the failure of the roof in underground coal mining, by migrating upwards and outwards from the seam being mined, could eventually appear as ground deformation. To investigate the matter further, the surface deformation that occurred over the Pabdana mining area was monitored in three time periods, between October 2, 2014, and July 27, 2019. Persistent scatterer interferometry (PSI) was used based on 150 ascending and descending Sentinel-1A images. The maximum mining subsidence rate during the studied periods was about 30 to 35 mm/yr. The PSI analysis shows that the subsidence rate varied both temporally and spatially during the three studied periods. The time series and the displacement rate for various cross-sections highlight a clear quantitative relationship between coal extraction progress and subsidence, which proceeded southward throughout the three study periods. So, considering coal mining subsidence as a geohazard, land developments and structures over the mining area may be safeguarded. The approach used in this investigation can be implemented in other similar coal mining zones.
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| 3. |
- Rashidi, Ahmad, et al.
(författare)
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Strain rate and stress fields in the West and South Lut block, Iran: Insights from the inversion of focal mechanism and geodetic data
- 2019
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Ingår i: Tectonophysics. - : Elsevier BV. - 0040-1951 .- 1879-3266. ; 766, s. 94-114
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Tidskriftsartikel (refereegranskat)abstract
- The active tectonic deformation and hazardous earthquakes in the south and west of the Lut block have been investigated for a long time. In this study, we compute the geodetic and seismic strain rates using focal mechanism data from the Harvard CMT catalogue and various other sources including the published GPS velocities. Moreover, we also perform Focal Mechanism Stress Inversion (FMSI) to deduce a stress model for the region. Our study shows an expected correlation between the stress orientations, seismic and geodetic strain rates. Our results show that the south and west of the Lut block is generally exposed as a compressional strike-slip tectonic regime. The tectonic convergence in this area is taken up not only by motions along and across the faults but also by the rotation of those blocks which bounded by these faults. The maximum amount of rotation rate is observed where there are the main right lateral strike slip fault systems such as Sabzevaran, Gowk, Nayband, Bam, Kuhbanan, and Kahurak. The orientation of the mean stress direction, obtained from the FMSI results in the west and south of the Lut block, is approximated ~N19 E. In this area, faults are almost oblique relative to the tectonic motion direction. Moreover, there are right-lateral and left-lateral shears, in addition to the dip movements in different parts of the south and west of the Lut block. Our analyses show three main categories of the stress regimes including strike-slip faulting (43.2%), thrust faulting (38.6%), and unknown or oblique faulting (18.2%).We also calculated seismic and geodetic moment rates for this area, which indicate the seismic moment rate is relatively high between Bam and Shahdad where there are some segments of the Gowk fault.
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