Seismic data acquisition to combine high-resolution seismic reflection and full-waveform inversion - A case study for overdeepened valleys

Abstract

In the context of the ICDP-project "Drilling Overdeepened Alpine Valleys", the integration of high-resolution seismic reflection (HRSR) and full waveform inversion (FWI) is used to enhance detailed near-surface imaging in heterogeneous glacial and post-glacial environments. To meet the specific requirements of both methods, dense P-wave and S-wave datasets were acquired over an overdeepened basin in the northern Alpine foreland, using a combination of vibratory and explosive seismic sources, as well as different receivers. Analysis of the datasets, as well as separate application of HRSR and FWI demonstrates the suitability of the acquired data. The FWI workflow applied to the P-wave data fits the recorded waveforms and converged successfully, yielding a consistent and physically reasonable model that correlates well with the HRSR images. These datasets are the basis for future methodological development of combining HRSR and FWI. The HRSR images reveal important information about the geology of the overdeepened basin near the town Schäftlarn (Germany). Using standard processing workflows, P-wave HRSR delineates detailed subsurface structures, including the base of the basin, intra-basin discontinuities, and subtle stratigraphic variations. Additional S-wave data provides superior resolution in imaging Quaternary basin sediments down to 200 m depth compared to P-waves and thus offers complementary information.