oa Tomographic Imaging of the Common Dataset

Tomographic Imaging of the Common Dataset Don Zhao, Geogiga Technology Corp., Alberta, Canada Abstract A set of P-wave first-arrival times for a synthetic common dataset is analyzed with refraction Tomography to determine the two-dimensional seismic velocity structure. the refraction Tomography employs a hybrid ray-tracing scheme based on the shorted path method and the ray-bending method to efficiently obtain an accurate forward solution, and regularizes the non-linear iterative Inversion with vertical and horizontal smoothing constraints, damping contraints, and first-arrival picking errors. A vertcial gradient velocity model with lateral homogeneity is used as an Initial model to generate the velocity structure from the first-arrival times. the final result shows a non-flat bedrock structure overlaid with lower velocity layers and identifies two lower velocity zones within the structure.