High resolution seismic methods are increasingly being used to image the shallowest layers of the earth. Objectives include bedrock features, buried cultural structures such as pipelines, and even paleontological or archaeological anomalies. Shallow surveys are often performed under less than ideal conditions, however, and the resulting data may be poor in quality, sparse in fold, and limited in aperture. Furthermore, the elastic properties of near surface earth materials may differ considerably from those of more competent rocks at greater depth, creating further challenges for the imaging process. Presented here are the results of using some unconventional processing techniques to image seismic data constituting two components of a 3-C seismic survey conducted in the vicinity of an archaeological site in Belize during the summer of 2000 in order to locate interesting subsurface features prior to excavation. Useful images were obtained for both P-P reflected and P-S converted modes showing roughly coincident subsurface anomalies; but the raw 3-C data themselves proved to be surprisingly ambiguous, each component manifesting substantial levels of both vertical and inline horizontal particle motion.
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