Abstract Database


Davran Matkarimovich OTAJANOV
Supervisor: Bunichiro SHIBAZAKI
Country: Uzbekistan

The purpose of this study is to investigate the seismic activity and earthquake cycles on the thrust faults in the Main Pamir Thrust fault zone and the South Fergana Basin fault zones in Central Asia, through the numerical simulation of earthquake cycles. Firstly, we develop a numerical program for 1D spring slider model using a rate- and state-dependent friction law to investigate the recurrence times, stress drops of earthquakes. Shear stress is assumed to be accumulated by the delay of the fault slip from average slip rate of fault movement. The numerical results show that the recurrence interval decreases in proportion to the inverse of the average slip rate of the fault. The stress drop slightly decreases with the average slip rate. Next, we simulate earthquake cycles using 3D model of earthquake generation processes to investigate recurrence intervals of earthquakes.  We estimate the average slip rate for each fault zone based on GPS observations in this area. We use the average slip rate 15 mm/yr for the Main Pamir Thrust fault, the average slip rate 3 mm/year for the South Fergana Basin Thrust fault. By the numerical simulations, we obtain slip velocity distributions for each time step. The recurrence intervals increase by decreasing of the average slip rate of the fault. Estimation of recurrence intervals by this numerical simulation will be effective for macrozonation of earthquakes in Uzbekistan.