f A 3D Elastic Hybrid Modelling Scheme

Full scale 3D elastic finite-difference modeling requires very large CPU times. A hybrid modeling scheme which combines an elastic cylinder-symmetric finite-difference modeling scheme with a 3D elastic finite-differente modeling schemes can reduce the CPU time considerably. The main limitation is that the overburden must be close to a plane-layer geology. The coupling of the two schernes is performed using an elastic representation theorem. Calibration of the hybrid scheme by comparison with the solution from a frequency-wavenumber algorithm give good results.