Abstract

Strong pulse-like ground motions excited by a causative fault with a rupture propagation close to the shear wave velocity can induce significant geological hazards. Despite recent advances in the observation and analysis of velocity pulses, the current understanding remains constrained by the small amount of pulse data, which to date have been investigated primarily in the horizontal direction. To address these challenges, we identify and extract large velocity pulses of continuous rotation records from three-component seismic data of 46 globally distributed earthquakes using a wavelet transform method. To better represent global seismic activities and disasters, we quantify the spatial pulse and spectral parameters that characterize pulse-like ground motion. The results indicate that the 3D rotation velocity pulse is significantly stronger than the original 1D and 2D pulse-like ground motion. Our study provides a quantitative framework to better assess and predict pulse-like ground motion in seismogenic regions.