Resumen

BEDOYA-GONZALEZ, Diego Alexander; VARGAS-JIMENEZ, Carlos Alberto  y  CHICANGANA-MONTON, German. ATTENUATION MODELS FOR A COLOMBIAN LLANOS FOOTHILLS AREA USING ATTENUATION OF CODA WAVES. bol.geol. [online]. 2014, vol.36, n.2, pp.91-100. ISSN 0120-0283.

Prominent seismic activity near to the Colombian Llanos Foothills was used for estimating the coda waves' attenuation in order to get a better understanding of the geological and structural setting of study area. The values of coda attenuation (Q_c^-1) were calculated by the Single Isotropic Scattering model - SIS proposed by Sato (1977) with the purpose of evaluating their spatial distribution and relationship with the geological structure of the crust. In this work were used about 4,000 earthquakes with M_L > 1.7 that were recorded by the Colombian National Seismological Network between 1993 and 2012. We used the SEISAN software by detecting the main seismic phases, then filtered in band pass centered on 2 (1-3) Hz, 8 (5-11) Hz, 12 (8-16) Hz, 16 (10-22) Hz and 25 (17-33) Hz to finally get the quality coda waves factors (Q_c) and the power law parameters Q₀ = 31.74 and ƞ = 0.92. Subsequently the results were plotted using Spatial inversion technique and with these map of anomalies, comparing the tectonic setting as well as the lithological and geothermal anomalies. Finally it was observed a dependence between Q₀ and ƞ values with areas where is observed active tectonics

Palabras clave : Colombian Llanos Foothills; Coda waves; Attenuation; Q_c; Q₀ ; ƞ.

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