Probabilistic seismic hazard assessment for Singapore

Abstract

Seismic hazard assessment of metropolitan areas is an important topic in catastrophe risk management and disaster prevention. In this study, a probabilistic seismic hazard analysis (PSHA) is performed to estimate the seismic hazard for Singapore. The PSHA approach has been conducted based on the OpenQuake engine. An updated earthquake catalog for the neighboring region has been compiled from various sources, and three major source zones are identified using the updated earthquake catalog: Sumatra subduction zone, Sumatran strike–slip fault, and deformation–background zone. Also, 10 published ground motion prediction equations are incorporated in the logic-tree framework, which properly accounts for the epistemic uncertainty of ground motion intensity measures. The peak ground acceleration (PGA) values in the mean hazard maps at bedrock sites of Singapore for 10% and 2% exceedance probability in 50 years range from 0.04 to 0.05 g and from 0.14 to 0.15 g, respectively. The uniform hazard spectrum consisting of PGA and seven spectral accelerations is generated for rock sites in Singapore. Disaggregation analysis shows that the deformation zone identified contributes dominantly to the PGA hazard of Singapore, whereas the Sumatran strike–slip fault contributes dominantly to the long-period (spectral acceleration at 1.0 s) hazard. Besides, the seismic hazard maps for representative site conditions of Singapore are briefly presented.