Conclusions

For the analyzed dataset, the velocity of seismic reflection events varies less than 100m/s with frequency across the usual exploration spectrum. There is no information available indicating greater variation for other datasets. Future wave-equation migration velocity analysis tools may allow for still greater variation, since the computational expense is not higher, and the inversion is more stable if the output of velocity analysis for low frequencies is taken as a starting model for higher frequencies. The dispersion in reflected waves does not warrant discarding proven velocity analysis and imaging software tools, but is worth considering when trying to build significantly more accurate ones.