In-seam seismic Love wave scattering modeled by the finite element method

Journal Article · Wed Aug 01 04:00:00 EDT 1984 · Geophys. Prospect.; (United States)

DOI:https://doi.org/10.1111/j.1365-2478.1984.tb01711.x· OSTI ID:6184327

Asten, M W; Drake, L A; Edwards, S

The dynamic finite-element method allows frequency-dependent reflection and transmission coefficients to be computed for Love waves scattered by two-dimensional inhomogeneities in coal seams. Clean faults of zero hade angle show a throw-dependent cross-over frequency in reflection spectra, and throw-dependent conversion from fundamental to first higher mode energy in transmission spectra. Oblique faults show mode conversion in reflection spectra which is relatable to the fault hade angle by simple Huygens-theory models. Thin fracture zones or dykes normal to the seam show a reflection maximum when thickness of the zone is of order one quarter of the seam wave wavelength. Published field data from two known faults and a dyke are compared with the modeling results and support the belief that broad-band seam-wave data are capable of characterizing a seam discontinuity (throw, hade angle, dyke thickness) as well as locating it. Development of such procedures will require extensions to existing field practice and processing. 19 references.

• OSTI ID: 6184327
• Journal Information: Geophys. Prospect.; (United States), Journal Name: Geophys. Prospect.; (United States) Vol. 32:4; ISSN GPPRA
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
011000* -- Coal
Lignite
& Peat-- Reserves
Geology
& Exploration
COAL DEPOSITS
COAL SEAMS
DATA PROCESSING
DETECTION
DIKES
FINITE ELEMENT METHOD
GEOLOGIC DEPOSITS
GEOLOGIC FAULTS
GEOLOGIC FRACTURES
GEOLOGIC STRUCTURES
GEOPHYSICAL SURVEYS
LOVE WAVES
MATHEMATICAL MODELS
MINERAL RESOURCES
NUMERICAL SOLUTION
PROCESSING
REFLECTION
RESOURCES
SCATTERING
SEISMIC DETECTION
SEISMIC SURFACE WAVES
SEISMIC SURVEYS
SEISMIC WAVES
SURVEYS
WAVE PROPAGATION