Regional Seismic Hazard Posed by the Mentawai Segment of the Sumatran Megathrust

• DOI: 10.1785/0120080109
• Publication Date: 2009-03-19T18:53:45Z
• Authors: K. Megawati; T.-C. Pan
• Keywords: 01 natural sciences; 0105 earth and related environmental sciences

Several lines of evidence have indicated that the Mentawai segment Sumatran megathrust is very likely to rupture within next few decades. The present study investigate seismic hazard and risk levels at major cities in Sumatra, Java, Singapore, Malay Peninsula caused by potential giant earthquakes. Three scenarios are considered. first one an Mw 8.6 earthquake rupturing 280 km has been locked since 1797; second scenario, oc- curs along a 600 covering combined areas 1797 1833 historical events, producing 9.0 earthquake; third scenario same area as but with doubled slip amplitude, resulting 9.2 earthquake. Simulation results indicate ground motions produced hypothetical strong enough cause yielding medium- high- rise buildings many Sumatra. It vital ensure overall strength, stiffness, integrity structures maintained throughout entire duration shaking. However, ductile detailing current practice formulated based on assumption would last from 20 40 sec. This not tested for longer durations 3-5 min, expected In Singapore Kuala Lumpur, only high-rise buildings, especially those located soft-soil sites, risk. Given design required either city, thus relatively brittle, it crucial inves- tigate their performance under moderate-amplitude, long-duration, motions. also points out shifting response spectrum toward period range becomes significant sites far sources, which should be carefully considered formulation future codes.