Effects of Propagation Paths on Surface-Wave Magnitude Estimates
TELEDYNE GEOTECH ALEXANDRIA VA SEISMIC DATA LAB
Pagination or Media Count:
The report investigates the effect of realistic propagation paths on the visual and spectral amplitudes of fundamental mode Rayleigh waves. It shows that the Harkrider amplitude response factor of a layered media should relate directly to a station correction it varies by a factor of nearly three between oceanic and continental sites. Attenuation due to effective Q losses may cause scatter, of over one-half magnitude unit, in teleseismic amplitudes but is unimportant at regional distances. Differences in recorded amplitude caused by dispersion over oceanic and continental paths are sufficient to warrant the application of path corrections to visually measured amplitudes. These differences can be avoided by computing spectra of the signals, or suppressed somewhat by using the results of stationary-phase approximations.
- Seismic Detection and Detectors