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.