The movement potential evaluation of the major Quaternary faults in Tehran Quadrangle

Introduction: Seismicity is closely related to active Quaternary faults. As a new parameter, FMP is defined to quantify earthquake risk along active faults. The landforms in Tehran quadrangle are mainly controlled by two sets of Quaternary faults, striking northwestsoutheast and east-west. The questions are: what are the activity levels of these faults? And will these faults cause destructive earthquakes? Aim: The present study evaluated the movement potential of the major Quaternary faults in Tehran Quadrangle. Materials and Methods: A new method is used to evaluate fault activity by considering the mechanical relationships between fault geometry and regional tectonic stress field. This method has been used to evaluate the fault movement potentials of all the major Quaternary faults in Tehran quadrangle. Result: The fault movement potential of the northwest striking fault set ranges from low to high, suggesting that some fault sets have the sufficient potential for generating destructive earthquakes, except the Telo-e-paeen fault, Kuh-e-Sorkh fault and Bayejan fault. The fault movement potential of the east-west striking fault set like North of Tehran fault is medium, suggesting that this fault set has not the sufficient potential for generating destructive earthquakes. Conclusions: According to this research, the contemporary movements potential along fault zones of various orientations are different under the action of present-day regional north – northeast compressive stress field in studied region. The Mosha fault zone, Niavaran fault, Pishva fault zone, Nava fault, EmamZadeh Davood fault and Pourkan-Vardij fault have high FMP (0.9 or 90%) and the Kuh-e-Sorkh fault zone has very low FMP (0.0 – 0.5).