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Manual for Abandoned Underground Mine Inventory and Risk Assessment
Appendix A: Glossary of Terms

TERM DEFINITION
angle of draw: The angle subtended between the vertical and a line joining the extraction edge and limit of subsidence (Whittaker and Reddish, 1989)
bistatic: A term used to describe a Ground Penetrating Radar (GPR) antennae arrangement in which separate transmit and receive antenna are used.
conductivity A measure of the amount of free charge (electrons) comprising a material. Under the influence of an applied electric field these electrons move, generating an electric current which in turn produces a secondary electric/magnetic field. This secondary field provides information regarding the conductivity of the anomaly. (Munk and Sheets, 1997)
cropline: The general term "cropline", if not further defined, refers to the line along the ground surface where the mined mineral seam is exposed in the existing grade. The term "cropline", with further definition, can also be utilized to define the structural contour of the top of the mined mineral seam which is covered by a uniform depth of overburden. Example: One some ODNR abandoned underground mine maps, the notation on a map line may read "30 foot cropline". This indicates the line on the top on the mined mineral seam which was covered by 30 feet of natural overburden.
drift entry: A horizontal mine entry into the natural outcrop of the mined mineral seam.
electrical permittivity: A measure of the polarizability of a material, or the extent to which the molecules comprising a material distort when subjected to an electric field. When a material comprised of molecules with bound charge is subjected to an electric field a slight displacement occurs between the negative and positive charges of the atom/molecule. This displacement results in a secondary  electric/magnetic field which can then be measured (Kraus, 1992)
gob: Coal refuse commonly abandoned on the surface in piles at or near the mining operation.
haulage shaft: A mine shaft utilized for transport of the mined mineral to the surface.
manway: A mine opening utilized for worker access into and out of the underground mine. These shafts also can function at an integral part of the mine safety and mine ventilation plans. The term can refer to drift (horizontal), slope, or shaft (vertical) mine openings. This type of opening may also be referred to as a portal.
mine opening: A mine entry extending either vertically (shaft entry), horizontally (drift entry), or at an inclined angle (slope entry) to the mined interval.
monostatic: A term used to describe an antenna which is used to both transmit and receive GPR electromagnetic pulses.
portal: A mine opening utilized for worker access into and out of the underground mine. These shafts also can function at an integral part of the mine safety and mine ventilation plans. The term can refer to drift (horizontal), slop, or shaft (vertical) mine openings. This type of openings may also be referred to as a manway.
Rock Quality Designation
(ROD)
The ROD value is the percentage of the length of core run which is made up of the continuous pieces of core sample which are four (4) inches in length or greater.
shaft: A mine entry extending vertically from the ground surface down to the elevation of the mined interval.
slop entry: A mine entry which descends on an incline from the ground surface down to the elevation of the mined interval.
surface deformation: Areas of surface settlement, subsidence, or irregular drainage conditions
troughing: Linear surface deformation extending for some distance and having a gentle curvilinear profile when viewed in section.

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Updated: 06/27/2017
Federal Highway Administration | 1200 New Jersey Avenue, SE | Washington, DC 20590 | 202-366-4000