Open AccessModelling the effect of seismic velocity gradients on the change in geometrical spreading across a boundary
Author(s) -
Baig A. M.,
Hron F.,
Schmitt D. R.
Publication year - 2001
Publication title -
geophysical journal international
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.302
H-Index - 168
eISSN - 1365-246X
pISSN - 0956-540X
DOI - 10.1046/j.1365-246x.2001.00482.x
Subject(s) - discontinuity (linguistics) , isotropy , amplitude , geology , boundary (topology) , space (punctuation) , plane (geometry) , geometry , seismic wave , physics , geophysics , optics , mathematical analysis , mathematics , computer science , operating system
SUMMARY This paper begins with a review on how rays may be traced though isotropic inhomogeneous media separated by curved interfaces. The results are applied to the case of a layer over a half‐space in which the seismic velocity varies linearly with depth and the interface is a horizontal plane. The presence of this type of velocity inhomogeneity will affect the observed amplitudes through its influence on the discontinuity in geometrical spreading at an interface. Analytical results will be compared to an approximate method for evaluation of geometrical spreading to ensure their accuracy. We show that the focusing effects due to the presence of velocity gradients become significant in our examples only for large angles of incidence.