Slip rate of the Kazerun Fault and Main Recent Fault (Zagros, Iran) from 3D mechanical modeling

摘要

The aim of this work is, using GPS velocities and 3D mechanical modeling including preexisting faults with frictional properties that obey Coulomb-failure process to explore the long-term slip rates of the MRF fault and Kazerun Faults in the Zagros mountain of Iran. A model was constructed using spatially varying crustal thickness, geothermal gradient, and two major faults. Structural boundaries are derived from the several deep seismic soundings carried out in the area. Far field GPS velocities and late Quaternary fault slip rates are used to compare the model results. Rheological tests show that effective fault friction lower than 0.05 leads to high slip rates that fit with geologically and geodetically determined slip rates of MRF and Kazerun Fault. These results suggest that MRF and Kazerun Fault are weak faults like San Andreas and North Anatolian fault.