Simulation of Strong Ground Motion for the 7.6Mw Kashmir Earthquake Occurred on 8 Oct 2005

Abstract:

The Mw 7.6 Kashmir earthquake which struck the northern area of Pakistan , the Kashmir region on 8 October 2005.The epicenter was located 18km north-northeast of Muzaffarabad, with a focal depth of 26km and it occurred in the Hazara-kashmir syntaxial bend near Main Mantle Thrust (MMT). This is one of the most devastating earthquakes occurred along Himalayan Arc and brought more than 80,000 deaths and more than 5.2 billion USD economical loss. The earthquake had duration of 25s and 75km rupture length along the surface. In order to investigate the strong motion caused by this earthquake, we simulate the Kashmir earthquake by the Curved grid finite difference method (CG-FDM). The finite-fault rupture, real topography variations and modified crustal model are considered. Simulated results are compared with available records, showing good mutual agreement between the synthetic and observed ground motions. According to the Pakistan Meteorological Department (PMD), the intensity of four observed points had reached scale IX, whereas our simulated results show those points are located in the regions with our predicted intensity scale IX or VIII. Peak Ground Acceleration (PGA) and Peak ground velocity (PGV) are most important parameters for hazard analysis, and our results are sufficiently coincide with their observed values. Finally, we also discuss the significant effect of surface topography on ground motion resulting by the Earthquake.