Strong Motion Records of the 2002 Molise, Italy, Earthquake Sequence and Stochastic Simulation of the Main Shock

The far field radiation inferred from accelerometric data recorded by the Italian Strong Motion Network (RAN) during the October 31, 2002, Molise, Italy, earthquake indicates a strong anisotropy in PGA distribution that presents its maximum values in the eastern part of the epicentral area. This study explores an interpretation of source directivity using a stochastic approach to produce synthetic seismograms accounting for source dimensions and rupture evolution. An E-W strike-slip fault, with a dip close to 90 degrees and a fault plane size of (8x6) km(2), reproduces satisfactorily both peak accelerations and spectral shapes of the recorded data when the rupture enucleates from the western edge at a depth of about 20 km and propagates eastward. This approach allows us to put constraints on seismic source characteristics and can be used to simulate ground motion for the most damaged areas where strong motion data are not available. [DOI: 10.1193/1.1764784]