Spice Project R&T Workshop II, Smolenice castle, Slovakia, 2005
Maria Lancieri and Aldo Zollo
The Earthquake Scenario describes the ground motion and the effects generated by a large earthquake. In case of the occurrence of a strong event, it can be an advantageous tool for planning and coordinating emergency response and for civil protection agency alert. Therefore it can be decisive to rapidly estimate the strong ground shaking, in order to mitigate the destructive effect in urban areas and for critical facilities. To asses the seismic scenario for an event of given magnitude and hypocenter, the first step is to build a shake map that gives the ground motion level at sites throughout the examined region. The factors that affect the strong ground motion level are source mechanism, distance from the earthquake, the rock and soil condition at sites, and variation in the propagation of seismic waves from the earthquake due to complexities in the structure of Earth?s crust. The second step is to evaluate the earthquake severity using relationships between the ground motion parameters and the damage level. The seismic scenario can be then expressed in terms of Mercalli. Intensity maps or in terms of structural damages for different building class. For an optimal evaluation of those parameters it is important to take into account all the source effects that can influence their amplitude or spread, introducing the fault extension, the rupture directivity effects, the slip distribution over the fault plane. All these effect become more and more important as the rupture complexity grows. The objective of this work is to simulate earthquake scenario for complex normal fault events, using simplified source/propagation models, and to investigate the effect of complex source on damage distribution. This work represents the first step toward the development of a near-real time method for scenario map computations.