Variations in uniform hazard spectra and disaggregated scenarios during earthquake sequences

Abstract Seismic hazard varies greatly during an earthquake sequence. Understanding this variation can be useful to end-users, such as emergency managers, it would enable them make more informed decisions about potential risk reduction measures. This article presents examples of how two commonly-used products probabilistic seismic assessments: uniform spectra and disaggregated scenarios, vary severe sequences in western Greece. These calculations are made using a recent time-dependent model based on Bayesian ETAS approach. The show that for short return periods (1 10 years) significantly higher than standard time-independent but the 475 2475 years similar those from assessments. generally converge within couple days spectra. also dominant scenarios evidenced by disaggregation assessment significant differences scenarios. is particularly true when sequence distant location interest aftershocks contribute overall hazard. To these changes clearly introduces new graphical representation results: contour maps showing magnitude or distance scenario with axes structural period response spectral acceleration.