Estimations of Q{gamma}-1 from Seismic Rayleigh Waves

• Published in: Geophysical Journal International
• Main Author: Burton, Paul W.
• Format: Text
• Language: English
• Published: Oxford University Press 1974
• Subjects: Articles; Novaya Zemlya
• Online Access: http://gji.oxfordjournals.org/cgi/content/short/36/1/167; https://doi.org/10.1111/j.1365-246X.1974.tb03631.x

It is shown in this investigation that the Rayleigh waves from large nuclear explosions with an assumed circular radiation pattern, are very suitable data sources for determining the specific attenuation factor, Q γ −1. Welldetermined values of Q γ −1 are presented within the frequency range 0.015-0.11 Hz and a realistic upper limit to the frequency range, beneath which the Q γ −1 values are reliable, is estimated for each event by making particular use of the individual spectral phase curves of each seismogram. In general the higher frequency values of Q γ −1 are larger when determined from Novaya Zemlya than for the Lop Nor test site in China. The largest values of Q γ −1 are found at the lower frequencies for all the events. In other words the results indicate a degree of regional variation within the upper layers of the Earth overlying a consistent region of dissipation at depths around 100 km which is common to all the events analysed.