Use of geophysical and remote sensing technology to locate and delineate unmarked graves in clay-rich soils of Kansas.

Abstract

Maplewood Memorial Lawn Cemetery in Emporia, Kansas, contains a tract of land documented as containing approximately 705 unmarked graves. In 1870, this area was set aside as "Potter's Field" and used for burials of the underprivileged and minorities. Thesis research was carried out to determine the feasibility of locating unmarked graves in Potter's Field using geophysical and remote sensing technology. Positive identification of burials with an electromagnetic ground conductivity meter and kite aerial photography has provided evidence that both techniques can be successful in locating and delineating unmarked graves in clay-rich soils of Kansas. Research with the electromagnetic ground conductivity meter determined that extremely dry conditions and too wet soil moisture conditions were not favorable for the identification of anomalous values of geophysical data. It appeared that the electromagnetic ground conductivity meter required moderate soil moisture conditions for successful results for the location and delineation of unmarked graves. Geophysical field work was complemented with the use of a penetrometer which reinforced the conclusion that moderate soil moisture conditions were best for the location and delineation of unmarked graves. Different sessions of kite aerial photography revealed that late spring was better than early spring for the identification of patterned vegetative differences associated with possible graves. Furthermore, kite aerial photography detected vegetative differences outside of the study area contributing to a possible explanation for the location of numerous unmarked graves. Future research is necessary to determine how specific soil moisture conditions affect electromagnetic conductivity, however successful results may currently allow preservation and protection of unmarked graves.