What's Beneath Our Feet? Applications of Near-Surface Geophysical Methods
USU Student Showcase
We examine several geophysical methods for imaging the shallow subsurface including ground-penetrating radar and seismic refraction. Examples will be provided from New Mexico and Utah. Shallow subsurface geophysical methods, including ground-penetrating radar (GPR), provide a noninvasive technique for archaeological reconnaissance. In 2013 the Summer of Applied Geophysical Experience program surveyed two 30 by 30 m grids within the San Marcos Pueblo Archaeological Site near Santa Fe, New Mexico. The San Marcos Pueblo was inhabited from about 1300-1680 A.D. and has lain relatively undisturbed for the last three hundred years. GPR scattering of electromagnetic waves, expressed as diffractions sourced at a scattering body at 10-20 cm depth, is interpreted to indicate a midden or an old dump for domestic waste. Seismic refraction experiments were conducted on the USU Quad in February and March 2014. These experiments consisted of three lines of seismic geophones with 6, 2 and 4 m spacing, respectfully. The 2 m seismic line experiment included forward and reverse shots. The 2 m seismic line also included both stationary and mobile sources. From our data we modeled a second layer at about 1.2-1.3 m in depth, which we interpret to be the water table. We repeated the experiment in March with 4 m spacing, modifying the acquisition parameters to better visualize the primary wave arrivals.
Allred, Isaac, "What's Beneath Our Feet? Applications of Near-Surface Geophysical Methods" (2014). USU Student Showcase. Student Showcase. Paper 23.