Reliability of Surface Wave Inversion

Surface wave seismic can be used to evaluate near surface geological information out. In order to get a reliable bedding model of the near surface loose soil layers the quality of the data and the inversion constraints are the most important influencing factors. This study discusses the influence of the thickness model as a boundary constraint doing data inversion according to MASW processed data (Park et al. 1999, Park et al. 2007). It can be shown that there is a relevant influence of the used thickness model of the uses SurfSeis sofware on the inversion results. A fixed depth model leads to unwanted stretching effects. The assessment of a free depth model using an equal or a variable thickness model gives good and comparable results. But there are high differences between the results if the profile was shot in opposite direction. The geological interpretation may vary according to the direction of the profiling. Forward and reverse measured profiles show significant differences in the inversion results, even there is only one geological setting. Therefore it is recommended to have a critical view of one dimensioned profile section.