Uncertainties in a probabilistic model for seismic hazard analysis in Japan

We developed a logic tree model for evaluating uncertainty in seismic hazard for Japan. The uncertainties in an attenuation model and a seismic source model with temporal dependence of large earthquake occurrence were represented by either discrete branches or continuous probability distributions associated with each node in the logic tree. The nodes for the attenuation model were distance measure, site correction coefficient, and standard error and those for the seismic source model were magnitude distribution, maximum magnitude, mean and variability of recurrence interval, seismic source location and geometry, and division of seismic source zones. Uncertainty in the hazard was evaluated using a Monte Carlo approach and displayed by 5-, 16-, 50-, 84- and 95-percentile hazard curves.