What lies beneath: The search for graves

BLOOMSBURG — October is the time for Halloween festivities. Hayrides, apple picking and, for some Bloomsburg University students, using ground-penetrating radar (GPR) to map soil and locate old graves.

Michael Shepard and Matthew Ricker, faculty members in the Department of Environmental, Geographical and Geological Sciences, take learning to whole new level. A soil level, to be exact. They combined their geophysics and soil management classes to start a new project and gather research.

Students use class time to study soil properties at various locations. On the university’s upper campus, there are six locations that, together, are longer than a football field. These sites are used particularly for soil research. There are two objectives during the soil research: finding the depth of each individual soil layer and using radar waves to determine different layers. Students can validate the radar waves by digging, but technology allows for the process to be quicker and more efficient.

This same technology is used in ongoing research to find old graves. Old cemeteries may lack records indicating where graves are located and vandals may move or remove tombstones. Both can cause difficulties for the placement of new graves. The most recent cemetery that was reviewed was Katy’s Church, Jerseytown.

Shepard sends out students with a GPR and other materials to “dig” up these unmarked graves. The GPR looks similar to a common lawnmower and is connected to a computer that transmits radar, reflecting back on various underground materials, such as old wooden caskets. When the radar bounces back from materials, it creates waves that display on the computer. The GPR creates an underground map for the students.

The students use two others techniques to measure soil properties – seismic geophones and current electrodes.

  • Geophones are placed in the ground within a straight line. A plate is hit with a sledgehammer, which creates sounds waves. The lag time of the sound waves reveals the layers of the soil.
  • Current electrodes are also placed in the ground and determine the electric current beneath the top layer of soil. The ease with which the electric current flows indicates the density of each layer of soil and what lies under the surface.

All of the research collected in the field is brought back to the classroom for review.