Near-surface model building: Are first breaks enough?

Estimation of a near-surface model for the derivation of long-wavelength statics is one of the long-standing problems in land seismic data processing. First arrivals are currently the main source of information for building a near-surface model and computing the resulting statics. Alternatively, ground roll and guided waves can be used for near-surface model building. I present a case study on a data set from the south of Oman where both inversion methodologies are applied. While the statics maps are similar, the underlying near-surface models differ significantly, and the first-arrival model is not consistent with the near-surface wavefield arriving after the first breaks. Hence, if the near-surface model is to be used for any purpose beyond statics, additional information on the near-surface wavefield such as dispersion curves should be incorporated into the inversion.