3D simultaneous seismic refraction and reflection tomography of wide-angledata from the central Chilean margin

We present an application of three-dimensional (3D) simultaneous seismic re fraction and reflection tomography for velocity and interface structure. Th e inversion technique and method for developing the starting model are spec ifically designed for relatively sparse wide-angle data acquired across str ongly-varying structure. The data were recorded in a region of seamount sub duction on the Chilean margin and consist of seven receivers and ten inters ecting airgun profiles over a 90x90 km area providing constraint to 25 km d epth. The tomographic method and the final model are assessed through a com parison with the large-scale geologic features of the margin and a resoluti on test. The 3D model shows the Valparaiso forearc basin, the accretionary wedge, the subducting plate, and possibly a subducted seamount. Our results show the potential of relatively sparse 3D wide-angle data.