High-Frequency Maximum Observable Shaking Map of Italy from Fault Sources

Abstract

This study presents the innovative concept of maximum observable shaking (MOS) maps. Our approach makes use of the improved understanding of the Italian regional tectonic setting and uses composite seismic sources (CSS) taken from an Italian database of individual seismic sources. The CSS are merged with high-frequency scenario calculations of expected maximum shaking in a given area. For a given CSS, we consider the associated typical fault, and compute the ground shaking for a rupture model derived from its associated maximum credible earthquake. As the maximum credible earthquake and typical fault ‘float’along the CSS (i.e. the computational fault plane takes on different spatial positions), the high-frequency ground motion is computed at each point surrounding the given fault, and the maximum from the observable shaking according to that scenario is plotted on the MOS map.