Reliability of MASW profiling in near‐surface applications

Abstract

Pseudo‐2D surface wave profiling (MASW) has become a powerful state‐of‐the‐art tool for the characterization of near‐surface features in recent years. The rapid gathering and interpretation of surface wave data, i.e. Rayleigh waves, that this method offers is applicable to many investigations and environments. However, most studies only perform unidirectional active surface wave profiling, i.e. without data evaluation by measuring the same profile in the opposite direction. Uncertainties arising from using the MASW method are connected to the one‐dimensional inversion of a two‐dimensional subsurface. Moreover, the occurence of lateral inhomogeneities and dipping layers distort the flat‐layered 1D assumption used in surface wave inversion. In this study, we present data from two different MASW surveys. For both locations, we reveal shot‐geometrical effects and prove the necessity of bidirectional profiling, especially since these check shots can be implemented with only little extra effort. The results of this investigation show that, in general, more attention should be paid to data evaluation.