Share This Article:

Spatial variation of coda wave attenuation using aftershocks of the Al Hoceima earthquake of 24 February, 2004, Morocco

Abstract Full-Text HTML Download Download as PDF (Size:1103KB) PP. 72-77
DOI: 10.4236/ns.2013.58A1009    3,367 Downloads   5,480 Views   Citations

ABSTRACT

On 24th February 2004 a significant earthquake (Md = 6.4) occurred in the north of Moroccocausing great damage in the vicinity of Al Hoceima region. This area is characterized by a complex faulting system as a result of compressional tectonic forces. Three short period seismic stations are set in this area of interest and recordings from these stations were used in this study. In order to complete our knowledge of attenuation, 60 local earthquakes are recorded a few days after the great earthquake with magnitude Ml 2.6 - 5.0 to estimate seismic attenuation. For this purpose, we applied the single backscattering model of Aki & Chouet 1975 inthe frequency range for 1 to 8 Hz. The study of coda waves was limited to a relatively short lapse time (20 Seconds) in order to sample the earth’s crust only. The values of Qc estimated for all the three stations show a strong frequency dependent relationship of the form Qc = Q0fn, where Q0 is Qc at 1 Hz , and n represents the degree of frequency dependence, and reflects the level of crustal heterogeneities to varying degrees. The average frequency dependent attenuation relationship has been obtained which indicates that the attenuation is high in this region. Finally to conclude our work, the values of Q0 suggest that Al Hoceima area is highly heterogeneous and the n parameter indicates a meaning frequency dependence of Qc.

Conflicts of Interest

The authors declare no conflicts of interest.

Cite this paper

Boulanouar, A. , Moudnib, L. , Harnafi, M. , Cherkaoui, T. , Rahmouni, A. , Boukalouch, M. and Sebbani, J. (2013) Spatial variation of coda wave attenuation using aftershocks of the Al Hoceima earthquake of 24 February, 2004, Morocco. Natural Science, 5, 72-77. doi: 10.4236/ns.2013.58A1009.

References

[1] Cherkaoui, T.E., Hatzfeld. D. and Jebli, H. (1990) Etude microsismique de la region d’Al Hoceima. Bulletin de l’Institut Scientifique, 14, 25-34.
[2] Medina, F. and El Alami, S.O. (2006) Focal mechanisms and state of stress in the Al Hoceima area (Central Rif, Morocco). Bulletin de l’Institut Scientifique, 28, 19-30.
[3] Sertcelik, F. (2012) Estimation of coda wave attenuation in the east Anatolia fault zone, Turkey. Pure and Applied Geophysics, 169, 1189-1204. doi:10.1007/s00024-011-0368-1
[4] Priyamvada, S. and Tripathi, J.N. (2012) Attenuation, coda Q, single backscattering model, lapse time window, garhwal himalaya. International Journal of Civil Engineering & Technology (IJCIET), 3, 279-291.
[5] Aki, K. and Chouet, B. (1975) Origin of coda waves: Source, attenuation and scattering effects. Journal of Geophysical Research, 80, 3322-3342. doi:10.1029/JB080i023p03322
[6] Aki, K. (1969) Analysis of the seismic coda of local earthquakes: Source, attenuation and scattering effects. Journal of Geophysical Research, 74, 615-631. doi:10.1029/JB074i002p00615
[7] Havskov, J. (1989) Coda Q for the state of Washington. Bulletin of the Seismological Society of America, 79, 1024-1038.
[8] Ma’hood, M. and Hamzehloo. H. (2009) Estimation of coda wave attenuation in East Central Iran. Journal of Seismology, 13, 125-139. doi:10.1007/s10950-008-9130-2
[9] Chandrani S. (2012) Spatial variation of coda wave attenuation in the Southern Indian Shield and its implications. Geologica Acta, 10, 309-318.
[10] Woodgold, C.R.D. (1994) Coda Q in the Charlevoix, Quebec, region: Lapse-time dependence and spatial and temporal comparisons. Bulletin of the Seismological Society of America, 84, 1123-1131.
[11] Rautian, T.G. and Khalturin, V.I. (1978) The use of the coda for determination of the earthquake source spectrum. Bulletin of the Seismological Society of America, 68, 923948.
[12] Jwngsar, B. (2012) Estimation of coda wave attenuation quality factor from digital seismogram using statistical approach. Science and Technology, 2, 1-7. doi:10.5923/j.scit.20120201.01
[13] Havskov, J. and Ottemoller, L. (2003) SEISAN: The earthquake analysis softwares for Windows, Solaris and Linux, version 8.0. Institute of Solid Earth Physics, University of Bergen, Norway.
[14] Paul, W. and Walter, S.H.F. (2013) The generic mapping tools version 4.5.9 technical reference and cookbook.

  
comments powered by Disqus

Copyright © 2019 by authors and Scientific Research Publishing Inc.

Creative Commons License

This work and the related PDF file are licensed under a Creative Commons Attribution 4.0 International License.