First breaks—automatic phase pickings of P‐ and S‐onsets in seismic records

Abstract

We have developed, validated and extensively tested a fast and versatile processing scheme for picking with confidence P‐ and S‐ arrival times in local seismic records. Out of 300 local events analyzed accurate P‐ and S‐ arrival times were automatically picked for 90% of these recordings. Essential ingredients in the processing scheme were i) prewhitening, ii) wavelet transform, iii) polarization filtering, iv) envelope transform and v) finally function fitting by a simulated annealing method for picking first breaks in approximately noise free envelope records.