Coda wave attenuation at Jalisco Block, Western Mexico

Abstract:

Coda waves are very important to study the properties of the continental crust. We analyze the coda wave attenuation at Jalisco Block through Simple isotropic scattering model proposed by Sato (1977). We measure coda Q using around 1700 seismograms recorded at the Mapping the Rivera Subduction Zone (MARS) seismic experiment and 1500seismograms at the Red Sismológica y Acelerométrica Telemétrica de Jalisco (RESAJ).The study provides new information on the statistical properties and spatial variation of coda Q, where present values of 23 ± 13 for 1-5 Hz, 60 ± 27 for 5-10 Hz, 94 ± 37 for 10-15 Hz, and 120 ± 40 for 15-20 Hz frequency band. The frequency-dependent quality factor is modeled in the form Q(f)=Q₀f ^α. We made Coda Q cartography in comparison with the region’s geology and seismicity. We observed a clear correlation of the coda Q anomalies with major tectonic features within the studied area. Large coda Q values correlate with the Colima Volcano Complex, the Colima Graben, and the Trans Mexican Volcanic Belt.