Geophysics, 68, 5, 1744–1748, 2003
Guido Russo andAldo Zollo
The knowledge of a viscoelastic model is required to simulate the propagation of seismic body waves in attenuating media. For computations in the time domain, the medium is modeled as a superposition of basic elements, each with a different relaxation time (Emmerich and Korn, 1987). Different strategies have been adopted to find relaxation times (Day and Minster, 1984; Emmerich and Korn, 1987; Carcione et al., 1988; Blanch et al., 1995; Xu and McMechan, 1998). Some of these strategies are based on the requirement that the quality factor Q, which is usually formulated as a function of angulary frequency (ω), must be nearly constant within an assigned frequency band, according to experimental results (McDonal et al., 1958; Hamilton, 1972; Newman and Worthington, 1982; Gibbs et al., 1994). We present a model based on the superposition of standard linear solids (SLS). The model is constrained by requiring that, for an assigned value Q0 of the quality factor, Q-1 (ω) ≈ Q0-1 over a given frequency interval. This condition is sufficient to determine the relaxation times and the other parameters. Numerical 1D tests are performed to assess the reliability of the model.