SEISMIC HAZARD ANALYSIS OF ISLAMABAD

Abstract

Seismic Hazard Analysis (SHA) is carried out for the city of Islamabad using both deterministic and probabilistic approach. Earthquake catalogue compiled by National Engineering Services Pakistan (NESPAK) for the period of (1505-2006) has been used. All Quaternary faults in the vicinity of Islamabad have been considered for deterministic hazard analysis. Seismic zoning map of NESPAK has been utilized in the research. Earthquake catalogue contains total of 11,149 events. Earthquake events of moment magnitude (Mw>4.0) are taken for developing the recurrence relationships of selected four (04) seismic source zones. The attenuation equation of Boore and Atkinson 2008 next generation attenuation (BA08 NGA) has been used for the determination of the ground motion parameters. Maximum PGA of 0.49g by BA08 NGA obtained for Islamabad at rock site due to Main Boundary Thrust (MBT). In PSHA using the Crisis-2007 software, PGA values with 10% probability of exceedance in 50 years i.e. the return period of 475 years have been determined. The PGA results obtained at bedrock are 0.28g by BA08 NGA attenuation relation.