Attenuation of seismic waves in the Trinidad and Tobago area

• Published in: Tectonophysics 1996-03, Vol.253 (1), p.111-127
• Main Authors: Latchman, Joan L., Ambeh, William B., Lynch, Lloyd L.
• Format: Article
• Language: English
• ISSN: 0040-1951; 1879-3266
• DOI: 10.1016/0040-1951(95)00050-X

The attenuation of seismic waves from earthquakes located within the area bounded by 9–12°N and 60–63°W was estimated from short-period seismograms. Coda- Q, Q c, determinations were made for each of the six seismograph stations within the area, while spectral Q values from P-phases, Q α , were estimated for station TRN. The S-S single-scattering model was assumed for coda generation, and the ω −2 source model was assumed for the spectral Q determinations. The Q c values show a strong frequency dependence in the frequency range 1.5–12 Hz. The value of Q at 1 Hz, Q o, was found to lie within the range 107–132, while the rate of frequency dependence, n, extends from 0.80 to 1.06 for shallow events. For intermediate-depth events, Q o varies from 101 to 173 and n from 0.80 to 1.02. The Q α values obtained show a spatial variation within the region, the highest attenuation was obtained on land Trinidad.