A user-friendly approach to NDSHA computations

Abstract We describe here the features of XeRiS, a web application aimed at the production of ground shaking scenarios based on the generation of synthetic seismograms, where the complexity and intricacies of the computational engine are hidden behind a user-friendly graphical interface. Scenarios can be generated with different levels of detail. At the regional scale, the comprehensive effect of all sources distributed within the active seismogenic zones or seismogenic nodes is considered. At the local scale, the amplification effects due to topography and to the soil subsurface complexity are taken into account. The characteristics of the source rupturing process can be modeled in detail controlling the position of the nucleation point on the fault plane, the rupture velocity, and the slip distribution. The modal summation technique is used to generate the synthetic seismograms very efficiently in the far field, and allows to generate tens of three-component seismograms in fractions of a second. To model wave propagation in near field conditions, the discrete wavenumber technique can be selected, allowing for the generation of the synthetic seismograms even on top of a finite fault. Parametric tests can be easily performed to check the effect of a model property on the obtained scenario. The time series generated can be downloaded and used by civil engineers in their quest for designing earthquake-resistant structures capable of surviving future earthquakes with limited damage.