Seismic hazard analysis for Kuala Lumpur, Malaysia

Abstract

In the past, probabilistic seismic hazard analysis (PSHA) has been performed by researchers to assess the level of seismic hazard in Kuala Lumpur, Malaysia and its vicinity. However, the peak ground acceleration (PGA) values obtained are high due to unsuitable ground motion prediction equation (GMPE). This article is divided into two parts: development of a suitable GMPE and the PSHA for this region. Two main sources have been identified as the contributors to earthquake hazard in Peninsular Malaysia, namely the Sumatra strike-slip fault and Sumatra subduction zone. For the subduction zone, nine recorded large earthquake events are analyzed and regression analysis is performed to obtain a new GMPE for this region. In performing PSHA, the strike-slip fault is divided into 14 zones based on the individual fault segments, while the subduction is divided into 4 zones. Historical earthquakes of this region are collected, processed, and segregated according to the zones. PSHA has been conducted by modeling the source seismicity using Gutenberg-Richter and characteristic earthquake models. The developed GMPE has been used along with other attenuation models: Megawati and Pan [2010] and component attenuation model (CAM) by Balendra et al. [2002] for subduction; and Sadigh et al. [1997] and CAM for strike-slip fault. The peak ground accelerations in Kuala Lumpur for 10% and 2% probability of exceedances in 50 years are found to be 16.5 gal and 23.4 gal, respectively. From deaggregation analysis, the main contributor for the 10% probability of exceedance in 50 years is found to be a 7.5 Mw earthquake at 300 km, originating from the strike slip fault. Finally, the design response spectrum for Kuala Lumpur is developed for rock sites, which would be amplified further by local soil profile. © 2012 Copyright A. S. Elnashai & N. N. Ambraseys.