A linear programming approach to time-term analysis

Abstract

abstract A linear programming approach to time-term analysis of seismic refraction data, one that is more adaptable than previous methods, has been developed. The travel-time equations are constraints to a choice of objective functions, which produce different models that fit the data. As examples: a “best-fit” model can be obtained by minimizing the L1 norm of the misfit errors; by maximizing and minimizing the sum of the time terms, the deepest and shallowest models can be derived. In addition, the method can be adapted to allow for refractor anisotropy without any assumptions on the form of the anisotropy. Examples with sets of theoretical data illustrate the different ways in which the technique can be used. A set of travel times for the Pn phase from the northeast Pacific, previously interpreted to document compressional wave velocity anisotropy, exemplifies the application of the method.