Vertical seismic profile synthetics by dynamic ray tracing in laterally varying layered anisotropic structures

Conference · Tue Jul 10 04:00:00 EDT 1990 · Journal of Geophysical Research; (United States)

OSTI ID:5455835

Gajewski, D ^[1]; Psencik, I ^[2]

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1. Stanford Univ., CA (USA)
2. Geophysical Institute, Prague (Czechoslovakia)

Dynamic ray tracing (DRT) is important in evaluating high-frequency seismic wave fields in complicated structures. Two formulations of the DRT equations for inhomogeneous anisotropic media are presented. One of them is represented by the classical DRT system, suggested by Cerveny 15 years ago. Both systems are specified in Cartesian coordinates. The DRT equations are supplemented with formulae for the transformation of DRT across a smoothly curved interface between two inhomogeneous anisotropic media. Cerveny's formulation of the DRT is applied to the computation of vertical seismic profile (VSP) synthetics. The results of DRT are used for the evaluation of the geometrical spreading and of the coefficients of the paraxial ray approximation for travel times and ray amplitudes. In addition, the DRT is also used in the interval ray tracing procedure, a procedure searching for rays staring from the source and terminating in a specified interval on a profile. Results of numerical modeling of VSP measurements in a three-dimensional laterally varying structure consisting of isotropic and anisotropic layers separated by curved interfaces are presented. Ray diagrams of selected elementary waves, time-distance curves, and multisource three-component VSP synthetics generated for two different source locations calculated for the anisotropic model are compared with the results determined for a reference isotropic model. The latter is obtained by averaging phase velocities of the anisotropic model. This comparison clearly shows the effects of anisotropy and the lateral variation of the model on seismic wave fields. The reliability of the ray synthetics is briefly discussed.

• OSTI ID: 5455835
• Report Number(s): CONF-880531--
• Conference Information: Journal Name: Journal of Geophysical Research; (United States) Journal Volume: 95:B7
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
580000* -- Geosciences
AMPLITUDES
ANISOTROPY
CALCULATION METHODS
CONTINENTAL CRUST
DATA ANALYSIS
EARTH CRUST
GEOLOGIC STRUCTURES
GEOPHYSICAL SURVEYS
ISOTROPY
MATHEMATICAL MODELS
MEASURING INSTRUMENTS
RELIABILITY
SEISMIC ARRAYS
SEISMIC DETECTORS
SEISMIC SOURCES
SEISMIC SURVEYS
SEISMIC WAVES
SEISMOGRAPHS
SIMULATION
SURVEYS
THREE-DIMENSIONAL CALCULATIONS