Strongly Frequency-Dependent Intrinsic and Scattering Q for the Western Margin of the Sichuan Basin, China, as Revealed by a Phenomenological Model
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Through applying the energy-flux model to teleseismic P-wave data, seismological scattering Q and intrinsic Q for the western margin of the Sichuan basin in southwestern China are estimated separately. The results exemplify the frequency-dependent Q values in the seismic frequency band. The scattering Q is heavily frequency-dependent and reaches a minimum at ~1.5 Hz. The intrinsic Q is nearly invariant for frequencies above 2 Hz and rapidly increases at lower frequencies. A major advantage of the energy-flux model is that it is a phenomenological model based on the conservation of energy and requires no geometrical spreading correction. The results are good counterexamples against the claim of a frequency-independent seismological Q.
KeywordsFrequency Band Phenomenological Model Sichuan Basin Spreading Correction Western Margin
Thanks to Prof. Michael Korn for discussions on the energy-flux model and to Prof. Brian Mitchell for his suggestions that improved the manuscript. This study was supported by the Key Projects of Chinese National Programs for Fundamental Research and Development (2004CB418402).
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