“…Methods to calculate the frequency dependence of attenuation have been given by several authors to suit low-and high-frequency applications (O' Connell and Budianski, 1978;Kjartansson, 1979). However, in nearly every experimental geometry attenuation is di⁄cult to measure (Jannsen et al, 1985;Tonn, 1989;Bromirski et al, 1995;Bowles, 1997;Richardson and Briggs, 1997). The processing technique by Frazer et al (1999), which we applied to our data, combines the standard spectral ratio method (e.g., Tonn, 1989) and Bayesian inverse theory (e.g., Tarantola, 1987).…”