APPLYING NEAR-SURFACE GEOPHYSICAL PRINCIPLES (GPR) TO HELP UTAH FAMILIES

Ground Penetrating Radar (GPR) has become increasingly accessible and utilized by a variety of communities to detect below-surface features such as utilities, geologic features, and graves. Previous studies have explored the effectiveness of using GPR to locate graves using a multitude of techniques and scenario variability, creating a framework for other studies involving the search and recovery of gravesites.

This study used the NOGGIN GPR system with a 250 MHz sensor to perform grid surveys at locations in both Weber County and Sevier County, Utah, each with several sites, to search for a lost individual and a clandestine grave. The purpose of locating these individuals is to help provide a form of finality for family members by finding their loved ones who have been missing for a long period of time. Additionally, this study aims to answer why GPR is a suitable option for locating potential targets such as human remains. Lastly, it provides undergraduate students with experience in planning and executing a real-world GPR survey. Two undergraduate students have participated in the initial planning, surveying, and analysis of the GPR data, with mentoring by faculty/staff from the University of South Florida and Weber State University. They have also had the opportunity to work with Weber County Search and Rescue as well as an investigative reporter to better understand the significance of geoscience research to the public.

Reflexw software was used to process and analyze the radargram profiles for diffraction patterns that represent promising targets. The Sevier County GPR surveys were conducted over four sites in primarily dry, sandy-silty soils. Analysis resulted in one promising shallow target (70-80 cm depth) that was later excavated. The target was confirmed to be a large tree root system. The Weber County GPR surveys were conducted over three sites, each with its own challenging set of conditions. Two of the sites were in the flowing Weber River, and the third was on a predominantly cobble point bar. Preliminary analysis has resulted in one promising target (30-40 cm below river bottom) at Site 1, which used a Sensors & Software pulseEKKO Pro with 200 MHz antennas mounted on a raft (also used at Site 3). Analysis is continuing on data for Sites 2 and 3 with no promising targets identified as of yet.