The scattering of SH-channel waves by a fault in a coal seam

Journal Article · Thu May 01 04:00:00 EDT 1986 · Geophys. Prospect.; (United States)

DOI:https://doi.org/10.1111/j.1365-2478.1986.tb00471.x· OSTI ID:5651649

Buchanan, D J

The imaging of faults in coal seams by the in-seam seismic method has now become standard practice. In the UK over 300 surveys have been undertaken and the technique is now part of the exploration arsenal of colliery planners. From these users comes the pressure for two major improvements, namely an increase in range and target identification. This paper is directed towards the latter problem. It has long been recognized that the reflected channel waves must contain information on the fault structure that caused the reflection, and model experiments have been undertaken to investigate the reflection process. Only recently, however, have attempts been made to quantify the reflection process. Calculations using both the finite-difference and finite-element techniques have been carried out, and estimates of the reflection coefficient as a function of frequency have been obtained. The object of this paper is to extend these considerations by calculating analytically the scattering matrix of an SH-channel wave after interaction at a fault plane. The scattering matrix is calculated as a function of frequency, hade angle, and fault throw. The method employed is based on the decomposition of the incident SH-channel wave into Fourier components, the calculation of plane wave reflection and transmission coefficients within the constraints of geometrical acoustics, and finally the synthesis of the scattering matrix by application of the Helmholz-Kirchhoff integral. The calculation throughout is restricted to normal modes.

• Research Organization: National Coal Board, Technical Dept., Ashby Road, Stanhope Bretby, Burton-on-Trent Staffs DE15 0QD
• OSTI ID: 5651649
• Journal Information: Geophys. Prospect.; (United States), Journal Name: Geophys. Prospect.; (United States) Vol. 34:3; ISSN GPPRA
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
011000* -- Coal
Lignite
& Peat-- Reserves
Geology
& Exploration
58 GEOSCIENCES
580203 -- Geophysics-- Geophysical Survey Methods-- (1980-1989)
COAL DEPOSITS
COAL MINES
COAL SEAMS
DATA ANALYSIS
EUROPE
FINITE DIFFERENCE METHOD
FINITE ELEMENT METHOD
FOURIER ANALYSIS
FREQUENCY DEPENDENCE
GEOLOGIC DEPOSITS
GEOLOGIC FAULTS
GEOLOGIC FRACTURES
GEOLOGIC STRUCTURES
GEOPHYSICAL SURVEYS
IMAGE PROCESSING
INCIDENCE ANGLE
ITERATIVE METHODS
MATRICES
MINERAL RESOURCES
MINES
NUMERICAL SOLUTION
PLANNING
PROCESSING
REFLECTION
RESOURCES
SCATTERING
SEISMIC SURVEYS
SEISMIC WAVES
SURVEYS
UNDERGROUND FACILITIES
UNITED KINGDOM
WESTERN EUROPE