Sediment velocity of the Yucatan Basin, Caribbean Sea from conventional CDP seismic data.
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| Other Authors: | , , , |
| Format: | Thesis Book |
| Language: | English |
| Published: |
1981.
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| Subjects: | |
| Online Access: | Link to ProQuest Copy Link to OAKTrust copy |
| Abstract: | Accurate estimates of the range-of-error of root-mean-square velocities (VRMS) and interval velocities (VINT) derived from conventional CDP seismic data acquired in deep-water ocean basins can be obtained routinely, provided that all artifacts of the acquisition and analysis routine are successfully accounted for. The error estimation technique derived herein, Precision Velocity Analysis (PVA), incorporates a nonlinear velocity increment into the hyperbolic-trajectory-search routine of a conventional computerized velocity analysis algorithm. The data are subsequently manipulated in terms of this nonlinear function. Low order polynomials are fit in the least-squares sense to error-normalized VRMS functions. Standard deviations of these fits are used to obtain reflection-time dependent quantitative error estimates of the predicted VRMS velocities. These error-limited VRMS values are inverted to obtain corresponding error-limited VINT values. For conventional CDP data the interval velocity solutions obtained approach the same order of accuracy as that of the average performance of variable angle reflection velocity determination techniques. Application of the PVA technique to multichannel seismic data from the Yucatan Basin has produced the first detailed picture of the velocity structure of the sediments of this little-studied Caribbean basin. On the basis of acoustic behavior the sedimentary section can be subdivided into three distinct and essentially undisturbed layers. Average interval velocity and thickness values for Layer I are: 1858 m/sec and 455 m; for Layer II: 2433 m/sec and 488 m; for Layer III: 3177 m/sec and 957 m. Comparison of subbottom velocity functions for the Yucatan Basin with similar functions for the Columbia and Venezuela Basins clearly establishes the uniqueness of the Yucatan Basin sediments. The undisturbed nature of the basin sediments suggests that the basin must have been tectonically stable during the time required to accumulate the 2000 m (average thickness) of observed sediment. |
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| Item Description: | "Major subject: Geophysics." 13 folded maps in pocket. Typescript (photocopy). |
| Physical Description: | xviii, 235 leaves : illustrations ; 29 cm |
| Bibliography: | Includes bibliographical references (leaves 148-156). |