SurfMin: Geophysics

NTIS Accession No: NTIS List Price:

Title of Report:

IDENTIFYING SUBSIDENCE HAZARDS USING A UNIQUE HIGH-RESOLUTION EM SYSTEM AND

NEURAL NETWORK INTERPRETATION (June 1995) 88pp.

Performing Organization Name and Address:

Laboratory for Add Subsurface Imaging, Dept. of Mining & Geological Engineering,

University of Arizona, Tucson, AZ 85721

Type of Report: Final Report

Abstract:

A high-frequency, high-resolution electromagnetic (EM) imaging system has been

developed for shallow geophysics surveys. Some key features of this system

include: (1) rapid surveying to allow dense spatial sampling over a large area,

(2) high-accuracy measurements which are used to produce a high-resolution image

of the subsurface, (3) measurements which have excellent signal-to-noise ratio

over a wide bandwidth (1 kHz to 1 MHZ), (4) rapid neural network interpretation

at the field site, and (5) visualization of earth models during the survey.

The EM system has been used to survey an area over the abandoned Union Pacific

#9 coal mine near Rock Springs, Wyoming. A portion of the mine is subsiding due

to a fire in the coal seam. The locations of subsidence-prone zones were

successfully mapped by the system.

Keywords:

Geophysics

High-resolution subsurface electromagnetic imaging system

Neural network interpretation

Data visualization software

Author(s)

Mary M. Poulton and Ben K. Sternberg