Application of Magnetic and Electromagnetic Methods to Metal Detection

Settimi

2011

Geophysical methods are increasingly used to detect and locate illegal waste disposal and buried toxic steel drums. This study describes the results of a test carried out in clayey-sandy ground where 12 empty steel drums had previously been buried at 4-5 m below ground level. This test was carried out with three geophysical methods for steel-drum detection: a magnetometric survey, electrical resistivity tomography with different arrays, and a multifrequency frequency-domain electromagnetic induction survey. The data show that as partially expected, the magnetometric and electromagnetic induction surveys detected the actual steel drums buried in the subsurface, while the electrical resistivity tomography mainly detected the changes in some of the physical properties of the terrain connected with the digging operations, rather than the actual presence of the steel drums.

Section: Magnetic Measurementsmentioning

confidence: 99%

Section: Magnetic Measurementsmentioning

confidence: 99%

Integrated geophysical measurements on a test site for detection of buried steel drums

Settimi

2011

“…From the comparison of the new map with the previous one, a strong decrement of anomalies due to the absence of the ferro-made of. Other techniques based on different physical properties of the inspected matter are also useful to detect different kind of waste (Gilkeson et al, 1992;Cochran and Dalton, 1995;Dahlin and Jeppsson, 1995).…”

Section: Magnetic Measurementsmentioning

confidence: 99%

“…The ratio between the amplitude of quadrature-component and the primary field depends on the electrical conductivity of the geologic materials. The ratio between the in-phase component and the primary field depends on the resistivity of the material and is more sensitive to metallic materials (Gilkeson et al, 1992).…”

Section: Electromagnetic Induction Measurementsmentioning

confidence: 99%

Ground magnetometric surveys end integrated geophysical methods for solid buried waste detection: a case study

Cafarella

Mauro

et al. 2009

The detection of illegal buried waste by means of geophysical techniques has recently become a major effort in shallow geophysical investigations. In particular, detection and location of underground metallic storage tanks can be accomplished using different instruments and techniques. In this paper we describe the results of an investigation carried out in a tuff quarry in Riano Flaminio (north Rome, Italy). A preliminary magnetometric survey revealed the existence of anomalous zones in the analysed region. Excavation in some of the selected areas confirmed that the anomalies were generated by underground magnetic material: over 160 steel drums were found. After their removal, a new magnetometric survey was performed. On the basis of the new map, a multifrequency induction survey, a geoelectrical profile and GPR measurements were taken to extend the characterization of the subsoil.

“…1967, Nettleton 1976, Telford et al 1976, Parasnis 1986, Robinson and Coruh 1988, Vogelsang 1994, Huang and Keiswetter 1997, Chianese et al 2006a, Chianese et al 2006b]. These applications can normally detect shallow iron or steel materials, and this influences the way the surveys are conducted and interpreted [Tyagi et al 1983, Frischknecht and Raab 1985, Gilkeson et al 1986, Jachens et al 1986, Gilkeson et al 1992, Pierce and De Reamer 1993, Godio et al 1999. Ravat et al [2007] critically tested the actual performance of several spectral magnetic depth-determination methods in terms of their capacity to determine the depth to the magnetic base for random and layered model magnetic sources of variable thicknesses.…”

Section: Introductionmentioning

confidence: 99%

Magnetic anomalies of steel drums: a review of the literature and research results of the INGV

Sapia

Settimi

2013

<p>The detection and evaluation of the status of disposal sites that contain hazardous waste materials is becoming an increasingly important element in environmental investigations. Close cooperation between the Istituto Nazionale di Geofisica e Vulcanologia (INGV; National Institute of Volcanology and Geophysics) in Rome and the Italian environmental police has resulted in numerous underground investigations of different buried materials. Among the geophysical investigation tools, magnetometry is the most effective, rapid and precise of all of the geophysical methods for localizing buried steel drums. Analysis of magnetic map anomalies can provide a variety of information about buried materials, including extension, distribution and depth, with processing of the acquired magnetic data. This information is also very useful in case of excavations that are aimed at the recovery of hazardous waste. This study determines the most relevant analyses reported in the literature, with modeling of magnetometric methods for environmental applications both theoretically and experimentally. Some studies and research results achieved by the INGV in relation to magnetic anomalies produced by buried steel drums are also reported, as found in field operations and as achieved from test sites.</p>