Elastic Time-lag Full-waveform Inversion in Shallow Water

This technical report presents a study on the application of elastic time-lag full-waveform inversion (TLFWI) using ocean bottom node (OBN) data in shallow water environments. The study addresses the challenges posed by geological complexities and strong guided-waves that affect conventional full-waveform inversion methods. The authors propose a workflow that incorporates a time-lag cost function to enhance inversion results, particularly in the North Sea shallow-water dataset. The results indicate that elastic FWI significantly improves imaging quality compared to acoustic FWI, especially in areas with strong velocity contrasts, such as beneath a reflective chalk package. The report details the methodology, including data acquisition and processing techniques, and compares the outcomes of both acoustic and elastic TLFWI. The findings highlight the advantages of using elastic FWI for better event continuity and signal-to-noise ratios, suggesting future research directions to further optimize the inversion process. The study concludes that the proposed workflow enhances the resolution and accuracy of subsurface imaging.