Abstract
abstract Lateral inhomogeneities in the upper part of the Earth perturb the propagation of 20-sec Rayleigh waves and have generally significant and occasionally severe effects on amplitude and phase measurements. Rayleigh waves were traced over the globe by the laws of geometric optics using a grid of 20-sec phase-velocity values for four earthquakes with known source mechanisms. The ray tracing indicated that zones of intense focusing and defocusing, highly refracted paths, and multipath propagation to stations are not uncommon phenomena. The square root of intensity calculated by ray tracing correlated positively in most cases with observed amplitudes of 20-sec Rayleigh waves at LRSM sites, when corrected for other effects. Ray tracing was also applied to predict multipathing observed at LASA by means of wave number spectra; observations were matched by ray tracing in most cases. The full benefit of ray tracing for 20-sec Rayleigh waves can only be realized with an improved velocity grid, addition of an attenuation grid, and corrections for transmission losses at first-order velocity contrasts.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
