Graduation Year

2005

Document Type

Thesis

Degree

M.S.

Degree Granting Department

Geology

Major Professor

Kruse, Sarah E.

Keywords

numerical models, laminations, high-resolution, radar wave, subsurface exploration

Abstract

Thin layers (layers that are not resolvable in terms of GPR wavelengths) are very common in sedimentary deposits. To better understand ground penetrating radar (GPR) wave behavior in sequences of thin layers with contrasting electromagnetic parameters, 1D FDTD simulations are run for simple layer distributions. Laminated (mm-scale) sequences can produce reflected energy with 10-20% of the amplitude of reflections from equivalent isolated contacts. Amplitude spectra from laminae packages are shifted toward higher frequencies. Such spectral shifts in radar profiles may potentially be used as indicators of fine-scale laminations. A comparative study of GPR records and models generated from core data from Waites Island, South Carolina, a Holocene barrier island, suggest that magnetite-rich laminae contribute significantly to radar profiles, but that some features in the radar traces cannot be associated with lithologic changes seen in vibracores.

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