Earth-prints repository, logo   DSpace

About DSpace Software
|earth-prints home page | roma library | bologna library | catania library | milano library | napoli library | palermo library
Please use this identifier to cite or link to this item:

Authors: Akinci, A.*
Del Pezzo, E.*
Ibanez, J.*
Title of journal: Geophysical Journal International Volume
Series/Report no.: 2/121
Issue Date: May-1995
Keywords: Seismic scattering
Seismic attenuation
Abstract: We have obtained a separation of intrinsic and scattering attenuation in two tectonically active areas of the Mediterranean Basin, southern Spain and western Anatolia, using the Multiple-Lapse Time Window Method. In southern Spain, Q(s) is predominant over Q(i) for frequencies lower than 4 Hz; between 4 and 8 Hz, results show similar scattering and intrinsic attenuation. For frequencies higher than 8 Hz, intrinsic attenuation is clearly dominant over scattering. L(e)(-1) does not change uniformly with frequency; it increases until 8 Hz and decreases at frequencies greater than 8 Hz. The integrated energy curves of western Anatolia do not show regular change with distance. For the first energy window (0-15 s), there is a clear increase of the energy with distances between 0 and 80 km, and then a decrease after 80 km. The fit of the experimental data in the full hypocentral distance range is not good. We divided the experimental energy curves into two different segments, 0-80 and 80-170 km. In 0-80 km, B-0 is close to 1 and the L(e)(-1) values are low (0.004-0.013). In the second distance range (80-170 km) intrinsic attenuation is predominant over scattering. Q(s)(-1) is more frequency-dependent than Q(i)(-1):f(-1.47) against f(-1.29). We observed that coda Q(-1) is equal to the observed Q(i)(-1) for intermediate frequencies, in both regions. However, Q(c)(-1) is really similar to Q(s)(-1) for short distances and is between Q(i) and Q(s) for long distances in southern Spain at low frequencies. Q(c) is similar to the observed Q(t) in both regions at high frequencies. The poor fit of the simulated curves with experimental data can be explained by introducing geometrical spreading values different to those used here. It is necessary to improve the model used by taking into account phenomena like non-isotropic scattering, variation of attenuation with depth, the presence of surface waves or a geometrical spreading value different to the theoretical one used.
Appears in Collections:04.06.09. Waves and wave analysis
Papers Published / Papers in press

Files in This Item:

File Description SizeFormatVisibility
Geophysical Journal International 1995 Akinci121.pdfMain Article2.38 MBAdobe PDFView/Open

Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.

Share this record




Stumble it!



Valid XHTML 1.0! ICT Support, development & maintenance are provided by CINECA. Powered on DSpace Software. CINECA