• journal_title：Bulletin of the Seismological Society of America
• Contributor：Simanchal Padhy
• Publisher：Seismological Society of America
• Date：2009-
• Format：text/html
• Language：en
• Identifier：10.1785/0120080337
• journal_abbrev：Bulletin of the Seismological Society of America
• issn：0037-1106
• volume：99
• issue：6
• firstpage：3300
• section：Articles

The frequency-dependent attenuations of P and S waves in the crust beneath Bhuj are estimated using the extended coda-normalization method for varying the exponent, γ, in the geometrical spreading function, r^γ (r is the hypocentral distance). The analysis is based on the measurement of 378 aftershocks of the 2001 Bhuj earthquake (M_w 7.6). The events were recorded by six stations of the network in the frequency range of 1–24 Hz. The values of and , corresponding to spectral amplitude decays, show strong frequency dependence and are expressed as (0.052±0.019)f^-(1.1±0.06) and (0.02±0.01)f^-(1.0±0.04), respectively, when γ is fixed at unity. The ratio is found to be larger than unity for the whole frequency range. A model of random heterogeneity characterized by an exponential autocorrelation function with a root mean square fractional fluctuation ε of 6%–8%, a correlation length a of 0.4–1.2 km, and ε²/a≈10^-2–10^-3 km for the frequency range from 1 to 24 Hz can simulate the observed attenuation properties. This suggests that a scattering model well reproduce the frequency-dependent characteristics of and obtained in Bhuj.