Near-surface seismic imaging: refraction tomography and reflection imaging
David C. Henley, Robert A. Birch, Robert R. Stewart
Near-surface shallow seismic imaging techniques have been under development for a number of years and are used in an increasing number of applications. Concurrently, archaeological investigation has made increasing use of various geophysical techniques, principally potential field and electrical methods, to detect subsurface anomalies of potential archaeological interest. To date, however, seismic methods have received little attention for use in archaeological investigation. This chapter describes a recent application of two seismic imaging techniques at Ma'ax Na, a Mayan temple site in Belize. Three intersecting shallow seismic lines were acquired at this site. Analysis of the data is incomplete, but early results include reflection images for all three lines, as well as tomographic images obtained by applying the turning-ray model to first break time picks. All the images appear to tie reasonably well at intersection points, but for the shallowest section of the earth, the tomographic images appear to contain the most useful information for archaeological purposes.