ISSN:
1365-246X
Source:
Blackwell Publishing Journal Backfiles 1879-2005
Topics:
Geosciences
Notes:
The attenuation of the Lg waves for the Granada Basin has been analysed. This study has been done in the frequency domain, eliminating the influences of the source, the instrumental response and the local site response, using the Reverse Two-Station Method (RTSM). The average QLg value for the whole region, obtained for all the paths is: QLg= (105 ± 25)∞(0.93±0.14).The average values of QLg determined for this region are lower than those corresponding to other areas of Spain, and are similar to those of coda-Q obtained using local coda and single scattering methods, for some determined focal depth and for some lapse times (50 and 70 s). Small differences of the attenuation are observed between paths that cross the central part and the edges of the basin. A detailed analysis showed that the E-W and the N-S directions have differences between attenuation values; in the E-W direction Q0Lg (the QLg value at 1 Hz of frequency) is 131 ± 7 and in the N-S one Q0Lg is 88 ± 21. The frequency dependence is similar to the average QLg value. These values may indicate that the attenuation of the Lg waves, at least for this region, may not be affected by only the anelastic dissipation, but also by scattering process. The N-S direction is normal to the dominating fault systems and seems to provide a greater scattering effect than the E-W direction.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1111/j.1365-246X.1992.tb00576.x
