Empirical prediction of the ground shaking scenario for the Catania area

Simplified approaches for prediction of strong ground shaking, that can be efficiently implemented through a
Geographical Information System (GIS), are applied to constructing earthquake scenarios for the Catania municipal
area. Ground shaking maps in terms of peak ground acceleration and response spectral ordinates are developed
both for a repetition of the catastrophic 1693 earthquake (M7.3), and for a lower energy event, like that which
occurred in 1818 (M6.2). The maps account for amplification due to local site conditions. According to the
commonly used attenuation relations, the local amplification is taken into account either in a simpler way or in
a more detailed approach, derived from an extensive geotechnical zonation. The approximation introduced by the
simpler methodology, to be used whenever accurate data are not available, is estimated by a comparison with
damage distribution.