Lapse-Time Dependence of Coda Quality Factor Within the Lithosphere of Northern Ecuador

Abstract

In the current study, a frequency-dependent attenuation relationship based on coda waves is developed for the Ecuador region. The single backscattering model developed by Aki and Chouet (J Geophys Res 80:3322–3342, 1975) is used to investigate the dependence of Coda-Q on lapse time frames. The waveforms of 49 local earthquakes recorded by a one-station local seismological network are used for the analysis. The frequency-dependent Coda-Q relations estimated for the region are: Qc = (65.75) f0.6302 (10 sec lapse time), Qc = (92.48) f0.6868 (20 sec lapse time), Qc = (18.17) f1.3337 (30 sec lapse time), Qc = (30.95) f1.2303 (40 sec lapse time), Qc = (88.22) f0.9117, and Qc = (125.19) f0.9342. Given that greater areas would be sampled by longer lapse time windows, the rise in Qc values with lapse time demonstrates the depth dependency of Qc. The increase in value of Q0 (QC at 1 Hz) with time depicts that the heterogeneities decrease with depth. The observed quality factor is highly variable with the lapse time and frequency. The more significant value of n shows that the area is seismically active. The observed Qc relation is found equivalent to other similar seismically active regions. © The Editor(s) (if applicable) and The Author(s), under exclusive license to Springer Nature Switzerland AG 2024.