3C-3D seismic micro-survey at a Maya plaza ruin in Belize, Central America

Nicholas A. Kaprowski, Robert R. Stewart

Using seismic methods to image the very shallow subsurface is not yet common. The Applied Geophysics Group at the University of Calgary is involved in developing shallow seismic techniques and identifying their potential value in various disciplines, such as archaeology. To this end, we have conducted a number of seismic micro-survey field surveys including tests at the Maax Na Maya archaeological site in northwest Belize. In 2003, a 3C-3D seismic micro-survey (7m x 7m) was undertaken over a Maya plaza ruin at Maax Na. We recorded data up to about 300 Hz by using a hammer source and omni-geophones. 3-D refraction velocities ranged from about 300 m/s to 1300 m/s. Further results from the 3-D refraction analysis indicate shallow layers dipping to the southeast which may have archaeological significance in terms of water drainage. Reflection data were more difficult to process (largely because of source-generated noise), but showed structure consistent with the refraction results. Strata identified from a 1.2m deep test pit near the centre of the study are also consistent with the seismic data.