2014 年 79 巻 1 号 p. 63-70
We apply full waveform inversion (FWI) to a land seismic dataset acquired along a long crooked survey line in a geologically complex mountainous region in Japan. The conventional reflection processing has been difficult due to the acquisition parameters and weak reflection signals at near-offset traces. However the dataset contains clear wide-angle reflections and refractions. FWI exploits these waveforms, and successfully yields a P-wave velocity model for the survey area. The FWI velocity model images the geological structure for the area including a large thrust structure. We validate the velocity model by comparing with the previously obtained migration image and the sonic logs. In addition, the synthetic waveforms generated from the FWI velocity model agree well with the observed waveforms, further confirming the validity of the FWI velocity model. Our results suggest that FWI is potentially a good velocity imaging technique for a geologically complex area.