Intrinsic and scattering seismic wave attenuation in the Canary Islands

Abstract

Abstract. The Canary Islands volcanic complex is studied in terms of coda wave attenuation. A multiple lapse time window method, based on the hypothesis of multiple isotropic scattering with uniform distribution of scatterers, is applied to

S-wave envelope broadening characteristics of microearthquakes in the Canary Islands

“…These results are in agreement with Canas et al (1998) who found a low scattering attenuation in the Canary Islands and related the strong frequency dependence of the attenuation parameters obtained to the size of the heterogeneities in the region, which would be at least comparable to the wavelength of the lowest analyzed frequencies, or about 2.6 km.…”

“…This result may indicate that random inhomogeneity in the Canary Islands region is represented by a Gaussian ACF. An analogous conclusion was reached by Canas et al (1998) who separately estimated the contribution of intrinsic absorption and scattering to total attenuation using an independent data set in the same region. They found that the decrease of scattering attenuation was faster than with increasing frequencies, which implies that the medium may be characterized by a Gaussian ACF (Wu, 1985).…”

“…This means that, for the frequency range analyzed in this study and if we consider an average S-wave velocity of 4 km/s (e.g. Canas et al 1998) strong heterogeneities with a scale from several hundreds of meters to a few kilometers may be present in the region.…”

“…Canas et al (1995) and Canas et al (1998) magnitudes ranging between 2.0 and 4.1 and having hypocentral distances less than about 600 km and focal depths less than 80 km were analyzed. Table 1 band.…”

“…The scattering characteristics in this region were previously studied by Canas et al (1998), who estimated the intrinsic absorption and scattering loss by means of the Multiple Lapse Time Window method (Hoshiba et al 1991) within the framework of a model of multiple isotropic scattering in a medium with uniform distribution of scattering and absorption properties. They found that the intrinsic absorption is the dominant attenuation effect for all the studied frequencies in the region.…”