CONCLUSIONS

This paper presents an algorithm for picking the traveltimes of seismic events. We model seismic events as delayed wavelets and define the picking position as the first break of the minimum phase part of a wavelet. This definition accords with usual practice. For minimum phase wavelets, the first breaks are picked. For zero phase wavelets, the central peaks are picked. Two implementations of the algorithm are given. For isolated, noise-free events, the algorithm works well. But examples with field data reveal that the algorithm fails to pick the correct traveltimes when spiky noises are present.