Kinematic links between the Eastern Mosha Fault and the North Tehran Fault, Alborz range, northern Iran
- Kinematic interaction of faults is an important issue for detailed seismic hazard assessments in seismically active regions. The Eastern Mosha Fault (EMF) and the North Tehran Fault (NTF) are two major active faults of the southern central Alborz mountains, located in proximity of Tehran (population similar to 9 million). We used field, geomorphological and paleoseismological data to explore the kinematic transition between the faults, and compare their short-term and long-term history of activity. We introduce the Niknamdeh segment of the NTF along which the strike-slip kinematics of EMF is transferred onto the NTF, and which is also responsible for the development of a pull-apart basin between the eastern segments of the NTF. The Ira trench site at the linkage zone between the two faults reveals the history of interaction between rock avalanches, active faulting and sag-pond development. The kinematic continuity between the EMF and NTF requires updating of seismic hazard models for the NTF, the most active fault adjacent to theKinematic interaction of faults is an important issue for detailed seismic hazard assessments in seismically active regions. The Eastern Mosha Fault (EMF) and the North Tehran Fault (NTF) are two major active faults of the southern central Alborz mountains, located in proximity of Tehran (population similar to 9 million). We used field, geomorphological and paleoseismological data to explore the kinematic transition between the faults, and compare their short-term and long-term history of activity. We introduce the Niknamdeh segment of the NTF along which the strike-slip kinematics of EMF is transferred onto the NTF, and which is also responsible for the development of a pull-apart basin between the eastern segments of the NTF. The Ira trench site at the linkage zone between the two faults reveals the history of interaction between rock avalanches, active faulting and sag-pond development. The kinematic continuity between the EMF and NTF requires updating of seismic hazard models for the NTF, the most active fault adjacent to the Tehran Metropolis. Study of offsets of large-scale morphological features along the EMF, and comparison with estimated slip rates along the fault indicates that the EMF has started its left-lateral kinematics between 3.2 and 4.7 Ma. According to our paleoseismological data and the morphology of the nearby EMF and NTF, we suggest minimum and maximum values of about 1.8 and 3.0 mm/year for the left-lateral kinematics on the two faults in their linkage zone, averaged over Holocene time scales. Our study provides a partial interpretation, based on available data, for the fault activity in northeastern Tehran region, which may be completed with studies of other active faults of the region to evaluate a more realistic seismic hazard analysis for this heavily populated major city. (C) 2014 Elsevier B.V. All rights reserved.…
Author details: | Mohammad R. Ghassemi, Morteza Fattahi, Angela LandgrafORCiDGND, Mehdi Ahmadi, Paolo BallatoORCiDGND, Saeid H. Tabatabaei |
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DOI: | https://doi.org/10.1016/j.tecto.2014.03.007 |
ISSN: | 0040-1951 |
ISSN: | 1879-3266 |
Title of parent work (English): | Tectonophysics : international journal of geotectonics and the geology and physics of the interior of the earth |
Publisher: | Elsevier |
Place of publishing: | Amsterdam |
Publication type: | Article |
Language: | English |
Year of first publication: | 2014 |
Publication year: | 2014 |
Release date: | 2017/03/27 |
Tag: | Alborz range; Fault linkage and interaction; Mosha Fault; North Tehran Fault; Paleoseismology; Slip rate |
Volume: | 622 |
Number of pages: | 15 |
First page: | 81 |
Last Page: | 95 |
Funding institution: | Preparation of large scale fault zone map of Tehran area and guidelines for civil construction within the fault zone [BHRC-10-483]; Building and Housing Research Center (BHRC), Tehran, Iran |
Organizational units: | Mathematisch-Naturwissenschaftliche Fakultät / Institut für Geowissenschaften |
Peer review: | Referiert |
Institution name at the time of the publication: | Mathematisch-Naturwissenschaftliche Fakultät / Institut für Erd- und Umweltwissenschaften |