Abstract

Using envelopes of regional high‐frequency seismograms synthesized by an algorithm from 3D radiative transport theory (RTT), we investigate trade‐offs between the velocity fluctuation parameter ϵ, the corner parameter a of the von Kármán heterogeneity spectrum, and intrinsic attenuation. In the frequency band 1–4 Hz and range 100–1500 km, where S waves comprise the crustally guided Lg wave, the trade‐off between ϵ and a often lies between two regimes of scattering, one in which ϵ trades off with a such that either ϵ2a or ϵ2/a is approximately constant. We suggest methods for identifying the boundary between these regimes: (1) varying ϵ and a, and intrinsic attenuation Qint1 using RTT to synthesize waveform envelopes for a small number of frequencies, and/or (2) varying ϵ and a, and Qint1 in a larger series of simulations appropriate for multiple lapse‐time window analysis (MLTWA). A stable region for calibrating MLTWA plots, where the seismic albedo is close to 0.5, is helpful in reducing the uncertainties of intrinsic and scattering attenuation when one of the attenuations is much larger than the other.

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