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

SummaryForensic geophysics should be an invaluable tool to assist search teams to detect and locate clandestine graves of buried murder victims. At present however, geophysics is underutilised and currently used techniques may not be optimal for specific targets or sites. There is a need for geophysical datasets to be collected over known burial sites for varying time periods post-burial.A study site was created with a naked and wrapped pig cadaver. The dimensions are based on available statistics of discovered burials. Monthly surveys using resistivity, Electrical Resistivity Tomography (ERT) and Ground Penetrating Radar (GPR) were performed postburial. Resistivity results show low anomalies over the naked pig and a smaller high anomaly over the wrapped pig with respect to background values. ERT time-lapse data shows optimum survey periods for the naked and wrapped pigs to be 9 and 3 months respectively. GPR 2D profiles detected both burials, with the wrapped pig exhibiting stronger reflection events. Lower frequency (110 MHz) antennae were found to be the optimal frequency to detect pig burials. Main Objectives:1. Detail time-lapse geophysical results over simulated clandestine graves.2. Determine optimal method(s) to locate a grave post-burial and if this changes over time.3. Determine which frequency GPR antennae is optimal.4. Compare GPR with ERT surveys.

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Fluvio‐glacial sand and gravel provide an important resource for the construction industry. The efficient and economic extraction of such geologically complex deposits requires a detailed understanding of their grade distribution. This is typically undertaken as point observations over the resource using a borehole drilling programme. We investigate the viability of using measurements of the elastic and electrical properties of the subsurface, derived from geophysical profiles, to determine the spatial variability of aggregate quality. A refraction seismic, surface wave seismic and resistivity survey was carried out over a fluvioglacial sand and gravel deposit at Scorton, Yorkshire, UK, on agricultural land adjacent to an active quarry. Two 190 m profiles, with borehole control at their extremes, were acquired with a 2 m source and receiver spacing. The P‐ and S‐wave velocities (Vp and Vs), together with resistivity and depth distributions were determined down to c. 20 m. The subsurface was divided into four layers: uncon‐solidated sand and gravel; dry consolidated sand and gravel; saturated sand and gravel; and basal clay. The work flow initially involved processing and interpreting the three geophysical techniques independently. Crossplots of the elastic and electrical parameters were used to distinguish unconsolidated from consolidated material; the water table; increased silt content; and recognize the basal clay. The Vp/Vs ratio proved very powerful at discriminating fine material (Vp/Vs ~ 3) from coarse material (Vp/Vs ~ 1.5). Regression analysis of crossplots produced P‐ and S‐wave relationships for the material, while electro‐acoustic relationships were less successful, especially below the water table. The results of the petrophysical analysis were used to set up guided inversions for the resistivity survey. Careful use of the refraction results as an a priori model for the resistivity survey was found to improve the resistivity inversion, though use of a sharp boundary introduced edge effects at the water table. The results from the integrated analysis were combined with the guided inversions into a final interpretation that enabled silt content, particle size and clay lenses to be mapped, which were not identified in the separately processed data.