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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Applications of source signature deconvolution to airgun seismic profiling and the measurement of attenuation from reflection seismograms

Wrolstad, Keith H. 04 August 1978 (has links)
Deterministic source signature deconvolution is applied to the processing of marine wide angle and vertical profiler data with air-gun sources. Optimum results are obtained with a source signature measured by stacking the signal reflected from a relatively homogeneous abyssal plain sedimentary environment. This eliminates the need for the unstable inverse source-receiver ghost filter. Improved resolution of reflection event timing allows the computation of more reliable interval velocities by the T² - X² method, provided the layer thickness limitation of the method is not exceeded. Accurate timing of primary reflection events in the deconvolved vertical profiler data permits computation of frequency dependent attenuation by univariate least-squares regression in the Fourier transform domain. The technique successfully extracts input amplitude attenuation functions from model reflection coefficient sequences with additive random noise. This success is attributed to the stability of singular value analysis in solving the least-squares regression model. Statistical tests on the solution vectors for model and field data give criteria for evaluating their reliability. The model data studies suggest that multiple and primary events not included in the regression may be considered part of the noise term without seriously affecting the accuracy of the computed spectral ratios. The method is tested on field data from the following sedimentary environments off the coast of Oregon and northern California: a continental shelf basin, an abyssal plain environment, the base of the continental slope and two locations on the Astoria sea fan, one near the Cascadia sea channel and one north of DSDP site 174. Velocity versus depth and frequency dependent spectral ratio plots are determined for each environment. The computed surface layer interval velocity of 1.77 km/sec over a thickness of 455 m for the station north of DSDP site 174 is in good agreement with the average material type found in the drill core (sandy-silt with greater than 60% sand). Maximum attenuation coefficients are estimated from the spectral ratios for the upper sediment intervals of the study areas using typical acoustic impedance values of surface sediment types determined from nearby piston cores. Some maximum attenuation coefficients are too high suggesting the possibility of a stratigraphic component. The maximum attenuation in the upper interval for SB 46 over the Tufts abyssal plain where fine-grained material (silts and clays) is expected is 0.025 dB/m at 127 Hz compared with 0.004 dB/m at 80 Hz for the upper interval of the turbidite environment north of DSDP site 174. / Graduation date: 1979 / Best scan available for figures.
2

3D seismic surface multiple attenuation algorithms and analysis /

Alaslani, Abdulaziz Saleh, January 2001 (has links)
Thesis (Ph. D.)--University of Texas at Austin, 2001. / Vita. Includes bibliographical references. Available also from UMI Company.
3

Analysis and modeling of high-resolution multicomponent seismic reflection data

Guy, Erich D., January 2003 (has links)
Thesis (Ph. D.)--Ohio State University, 2003. / Title from first page of PDF file. Document formatted into pages; contains xxxviii, 372 p.; also includes graphics (some col.). Includes abstract and vita. Advisor: Jeffrey J. Daniels, Dept. of Geological Sciences. Includes bibliographical references (p. 362-372).
4

3D seismic surface multiple attenuation: algorithms and analysis

Alaslani, Abdulaziz Saleh, 1965- 14 March 2011 (has links)
Not available / text
5

Interpretation of Southern Georgia coastal plain velocity structure using refraction and wide-angle reflection methods

Harsha, Senusi Mohamed 05 1900 (has links)
No description available.
6

Structure and regional tectonic setting across the Atlantic Coastal Plain of northeastern Virginia as interpreted from reflection seismic data /

Pappano, Phillip A., January 1992 (has links)
Thesis (M.S.)--Virginia Polytechnic Institute and State University, 1992. / Vita. Abstract. Includes bibliographical references (leaves 52-54). Also available via the Internet.
7

A seismic reflection study over the Bane anticline in Giles County, Virginia /

Edsall, Robert William, January 1974 (has links)
Thesis (M.S.)--Virginia Polytechnic Institute and State University, 1974. / Includes bibliographical references (leaves 52-55). Also available via the Internet.
8

3D seismic surface multiple attenuation : algorithms and analysis /

Alaslani, Abdulaziz Saleh, January 2001 (has links)
Thesis (Ph. D.)--University of Texas at Austin, 2001. / Vita. Includes bibliographical references (leaves 192-200). Available also in an electronic version from UMI Company.
9

Analysis and modeling of high-resolution multicomponent seismic reflection data /

Guy, Erich D. January 2002 (has links)
No description available.
10

Deconvolution of seismic data using extremal skew and kurtosis

Vafidis, Antonios. January 1984 (has links)
No description available.

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