Abstract
Based on compiled data during the period 1779-2010, 48,000 earthquake events exceeding M4 had occurred in Indonesia. Since the earthquake data are available in various magnitude scales, we converted all scales into moment magnitude. By using the catalogs compiled, we constructed area earthquake source model and estimated the frequency-magnitude relationship. From recorded data by accelerometers installed at four stations in Padang, we plotted observed data on the several existing attenuation equations and selected a suitable attenuation relationship for Indonesia. Peak ground acceleration on 10% probability of exceedance in 50 years for rock and soft soil condition were calculated. We compared the expected acceleration with existing ones and discussed. Based on the expected acceleration calculated, we proposed design spectra in several major cities in Indonesia.
