Xiong Dingyu

The first‐arrival tomographic inversion and its application to identify thick near‐surface structures

The stacking profile along a wide-line in the Tu-Ha area, West China, is still in poor quality after the field static correction is applied. The long wave length components of static corrections remain. In this study, we pick first-arrival times on shot-gathers and then perform first-arrival tomographic inversions to estimate the near-surface velocity model. From the model obtained, we find that under the normal low-velocity-layer (LVL), in the middle of the line, another LVL exists with the depth reaching to about 300 meters and the scope along the line spanned to several spread-lengths. Taking the two LVLs into consideration, we carry out the tests of datum static corrections. The final image on the tomostatic profile is much improved when the static problems are solved.