SummaryThis study provides forensic search teams with systematic geophysical monitoring data over simulated clandestine graves for comparison to active cases. Simulated 'wrapped' and 'naked' burials were created. Multi-geophysical surveys were collected over a three-year monitoring period. Bulk ground resistivity, Electrical Resistivity Imaging, multi-frequency Ground Penetrating Radar and grave 'soil water' conductivity data were collected. Resistivity surveys revealed the naked burial had consistently low-resistivity anomalies, whereas the wrapped burial which had small, varying highresistivity anomalies. GPR 110-900 MHz frequency surveys showed the wrapped burial could be detected throughout, with the 'naked' burial difficult to resolve after 18 months. 225 MHz frequency data was optimal. 'Soil water' analyses showed rapidly increasing (year one), slowly increasing (year two) and decreasing (year three) conductivity values. Results suggest resistivity and GPR surveys should be collected if target 'wrapping' is unknown, with winter to spring surveys optimal. Resistivity surveys should be collected in clay-rich soils.
Main Objectives:1. Systematically monitor the geophysical responses of clandestine graves over a three-year burial interval. The selected geophysical monitoring methods were electrical (both fixedoffset surveys and electrical resistivity imaging 2D profiles) and multi-frequency GPR surveys.2. To determine, of the geophysical techniques and configurations investigated, which would be optimal to detect buried human remains in the different burial styles (naked and wrapped) and if this changed over time.3. To determine which dominant frequency GPR antennae would be optimal for forensic search teams to utilize for the detection of similar clandestine burials.4. To measure changes in the conductivity of soil-water within a grave, in order to better understand the geophysical survey data collected over the graves.5. To generate and calibrate 2D resistivity models of the survey site at yearly intervals to explain the changing resistivity responses.6. Simultaneously collect appropriate site data (rainfall and temperature) to allow comparisons with other research studies and criminal search investigations.
New Aspects Covered:This study is the first to simultaneously collect multi-frequency GPR, fixed off-set and 2D ERI electrical surveys, grave 'leachate' conductivity measurements and site-specific factors (local climate, moisture content, porosity) etc over a three-year monitoring period. Results show surprising variations both temporally and seasonally, with winter surveys consistently