Sensitivity Analysis of the Interfrequency Correlation of Synthetic Ground Motions to Pseudodynamic Source Models

Given the deficiency of recorded strong ground?motion data, it is important to understand the effects of earthquake rupture processes on near?source ground?motion characteristics and to develop physics?based ground?motion simulation methods for advanced seismic hazard assessments. Recently, the interfrequency correlation of ground motions has become an important element of ground?motion predictions. We investigate the effect of pseudodynamic source models on the interfrequency correlation of ground motions by simulating a number of ground?motion waveforms for the 1994 Northridge, California, earthquake, using the Southern California Earthquake Center Broadband Platform. We find that the cross correlation between earthquake source parameters in pseudodynamic source models significantly affects the interfrequency correlation of ground motions in the frequency around 0.5 Hz, whereas its effect is not visible in the other frequency ranges. Our understanding of the effects of earthquake sources on the characteristics of near?source ground motions, particularly the interfrequency correlation, may help develop advanced physics?based ground?motion simulation methods for advanced seismic hazard and risk assessments.