Finite-difference computation of multivalued traveltimes

Finite difference algorithms devoted to computation of seismic traveltimes are becoming popular tools for seismic simulation in complex heterogeneous Earth models. All methods proposed up to now (e.g., Vidale, 1988, 1990, Podvin & Lecomte, 1991, Van Trier & Symes, 1991) are - explicitly or implicitly - limited to extracting first arrivals from the general (multivalued) solution of the eikonal equation.