Interpreting Colin Zelt's "Shootout" Seismic Refraction Data Set using the Generalized Reciprocal Method.

Colin Zelt provided a synthetic seismic refraction data set for interpretation by “seismic tomography” methods for a special session at SAGEEP 2011. This data set is not designed for interpretation using the Generalized Reciprocal Method (GRM) as it lacks far shots and has a very dense number of interior shots. It is instead typical of data shot for tomographic interpretation methods. The data are interpreted here using GRM in spite of this; once using the original data and a second time using a trimmed data set, having discarded most sources and some receivers to make it look more like a typical spread designed for GRM. The comparison of the results with the original model used to generate the synthetic data set show that the major features of the original model are resolved within the expected capability of the seismic refraction method. The result obtained with the trimmed data set is not quite as good as the one with the dense data set and it requires a bit more effort on the part of the interpreter to bring out the features of the original model. However, this is more than made up for by the significantly lower field effort required to obtain the data. None of the calculations take more than a few seconds on a standard PC.