Primary Exploration on the Difference of the Automatic Picked P-Wave Onset between Three-Component Seismic Records

The determination of P-wave onset is important in built of seismic ground motion database for the construction of ground motion prediction equation, seismic site effect model, response spectra for the earthquake-resistant design and et al. Various P-wave onset automatic picking algorithm have developed for vertical seismic records. For horizontal seismic records, of which the P-wave onset are simply set the same as the vertical records. In this paper, the performance of one recently proposed P-wave onset automatic picking algorithm for horizontal and vertical seismic records has been tested using 3000 ground motion records of 51 earthquake events recorded by KiK-net and K-net of Japan Station Motion Observatory Networks in the Kanto Basin from 2000 to 2020. The results shown that the picked P-wave onset for North-South (NS) and East-West (EW) component are quite similar with the mean absolute difference equals 0.0918s. The mean absolute difference of picked P-wave onset between NS (EW) and UD component equals 0.9989s (0.9070s). Moreover, according to the picked P-wave onset, the P-wave arrival of NS and EW components are lagged behind that of UD component. Thus, the tested P-wave onset automatic picking algorithm, developed on basis of vertical component records cannot be directly applied for horizontal component records. Finally, the discussion of the variation of picked P-wave onset on the late computation of signal-to-noise ratio are included.