HR: 0800h
AN: GP31B-0838    [Abstracts]
TI: Estimating Magnetic Susceptibility and Frequency Dependent Susceptibility in Soils to aid Landmine Clearance
AU: * Hannam, J A
EM: hannam@liverpool.ac.uk
AF: University of Liverpool, Department of Geography University of Liverpool, Liverpool, L69 7ZT United Kingdom
AU: Dearing, J A
EM: jdearing@liverpool.ac.uk
AF: University of Liverpool, Department of Geography University of Liverpool, Liverpool, L69 7ZT United Kingdom
AB: Mine and UXO clearance using metal detectors is often hampered by the presence of strongly magnetic minerals in soils overlying targets that are known to significantly affect detector sensitivity and performance. Specifically, the concentration of frequency dependent superparamagnetic magnetic minerals, which have a time-dependent magnetic response, is shown to be correlated with impeded detector performance. Nanoscale iron oxides with frequency-dependent properties that form during soil development in topsoils are widespread and result from the interaction of soil forming processes at different scales. The development of a modelling tool was based on exploiting the known links between soil forming processes and the development of frequency dependent magnetic minerals in soils. The model was further refined using analogue information to determine likely magnetic contrasts between different soil types. The production of a national map of magnetic categories for soil types indicates areas where soils may be problematic for mine detection using metal detectors. Estimates of soil magnetic properties provide essential information for planning and deployment of mine clearance operations.
DE: 1512 Environmental magnetism
DE: 1540 Rock and mineral magnetism
SC: Geomagnetism and Paleomagnetism [GP]
MN: 2004 AGU Fall Meeting