Automated measurement of teleseismic P-, SH- and SV-wave arrival times using autoregressive prediction and the instantaneous phase of multicomponent waveforms

Abstract

SUMMARY A new automated algorithm for picking the arrival times of the global P-, SH- and SV-wave phases from multi-component seismic waveform data is presented. This picker is based on a sequential approach using autoregressive prediction of the filtered waveform in a sliding time window, the Akaike Information Criterion and the Hilbert transform of the original waveform. The quality of the individual picks is computed by combining signal-to-noise ratios and higher order statistics into a single measure. Synthetic tests are used to find values for high and low quality thresholds. The algorithm is applied to a global data set of waveforms from teleseismic events with magnitude 6 or higher that occurred between 1990 and 2019. This resulted in approximately 4 million P-phase arrival times as well as approximately 3 million SH- and SV-phase arrival times each. These automatic picks are compared to approximately $830\, 000$ manual P-picks as well as approximately $70\, 000$ manual S-picks from the ISC-EHB catalogue. An upper bound for the picking errors of the automatic picks is estimated by using high quality picks of neighbouring stations. This upper bound is found to be 0.55 s for the P-picks and 4.3 s for the S-picks. If only high quality picks are considered, this represents 50 per cent of the P-picks and 25 per cent of the S-picks, then these errors decrease to 0.35 s for the P-picks and 1.5 s for the S-picks, respectively. As a by-product of the picking, the dominant periods of the arriving signals are determined as well.