Frequency Time Analysis (FTAN) and Moment Tensor Inversion Solutions from Short Period Surface Waves in Cameroon (Central Africa)

ABSTRACT

Short period surface waves generated by a local earthquake recorded by broadband seismometers at distances of about 186 to 778 km from the earthquake’s epicenter located in Cameroon (Central Africa) were processed for group velocity maps and dispersion waveforms using the frequency time analysis (FTAN) method. The resulting group velocity fundamental modes of the extracted Rayleigh and Love waves were used for a joint amplitude spectral and P polarity inversion using moment tensor inversion. The corresponding group velocity dispersion curves, the residual as a function of depth, the amplitude spectra and the moment tensor solutions of the regions from the epicenter to the different stations up to a depth of about 10 km were obtained.

Cite this paper

E. Ndikum, C. Tabod and A. Tokam, "Frequency Time Analysis (FTAN) and Moment Tensor Inversion Solutions from Short Period Surface Waves in Cameroon (Central Africa),"*Open Journal of Geology*, Vol. 4 No. 2, 2014, pp. 33-43. doi: 10.4236/ojg.2014.42004.

E. Ndikum, C. Tabod and A. Tokam, "Frequency Time Analysis (FTAN) and Moment Tensor Inversion Solutions from Short Period Surface Waves in Cameroon (Central Africa),"

References

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[2] J. Boaga, “Seismic Noise and Controlled Source Surveys: Tools for Seismic Hazard Deterministic Approach,” Ph.D. dissertation, University of Padova, Padova, 2008.

[3] G. G. Euler, D. A. Wiens, P. Shore, F. W. Koch, R. Tibi, A. A. Nyblade and A. M. Reusch, “Shear Velocity Structure of the Cameroon Volcanic line Region from Rayleigh Wave Phase Velocities,” EOS, Transactions, American Geophysical Union, 89(53), AGU Fall Meeting Suppl., 2008, Abstract #S21C-1843.

[4] K. A. P. Tokam, C. T. Tabod, A. A. Nyblade, A. Julia, D. A. Weins and M. E. Pasyanos, “Structure of the Crust Beneath Cameroon, West Africa, from the Joint Inversion of Rayleigh Wave Group Velocities and Receiver Functions,” Geophyiscal Journal International, Vol. 183, No. 2, 2010, pp. 1061-1076. http://dx.doi.org/10.1111/j.1365-246X.2010.04776.x

[5] A. Levshin, V. F. Pisarenko and G. A. Pogrebinsky, “On a Frequency-Time Analysis of Oscillations,” Annales Geophysicae, Vol. 128, No. 2, 1972, pp. 211-218.

[6] A. Levshin, L. I. Ratnikova and J. Berger, “Peculiarities of Surface Wave Propagation across Central Eurasia,” Bulletin of the Seismological Society of America, Vol. 82, No. 6, 1992, pp. 2464-2493.

[7] A. Dziewonski, S. Bloch and M. Landisman “A Technique for the Analysis of Transient Seismic Signals,” Bulletin of the Seismological Society of America, Vol. 59, No. 1, 1969, pp. 427-444.

[8] L. I. Ratnikova, “Frequency-Time Analysis of Surface Waves,” In: Workshop on Earthquake Sources and Regional Lithospheric Structures from Seismic Wave Data, International Centre for Theoretical Physics, Trieste, 1990, pp. 1-12.

[9] C. Nunziata, G. Costa, M. Natale and G. F. Panza, “FTAN and SASW Methods to Evaluate vs of Neapolitan Pyroclastic Soils,” Earthquake Geotechnical Engineering (Balkema), Vol. 1-3, 1999, pp. 15-19.

[10] C. Nunziata, G. Costa, M. Natale, A. Vuan and G. F. Panza, “Shear Wave Velocities and Attenuation from Rayleigh Waves,” In: Pre-Failure Deformation Characteristics of Geomaterials (Balkema), 1999, pp. 365-370.

[11] C. Nunziata, G. Costa, M. Natale and G. F. Panza, “Seismic Characterization of the Shore Sand at Catania,” Journal of Seismology, Vol. 3, No. 3, 1999, pp. 253-264. http://dx.doi.org/10.1023/A:100 9861824955

[12] A. Z. Mostinskiy and B. G. Bukchin, “Moment Tensor & Source Depth Inversion Program Reference Manual, Surface Waves Processing & Seismic Source Inversion,” International Institute of Earthquake Prediction Theory and Mathematical Geophysics (Mitpan), On-Line Bulletin, 1998-2005. http://www.mitp.ru/en/soft/word_pdf_Manuals/MomTens_man.pdf?

[13] A. L. Levshin, “Effects of Lateral Inhomogeneity on Surface Wave Amplitude Measurements,” Annles Geophysicae, Vol. 3, No. 4, 1985, pp. 511-518.

[14] B. G. Bukchin, “Determination of Source Parameters from Surface Waves Recordings Allowing for Uncertainties in the Properties of the Medium,” Izvestiya Physics of the Solid Earth, Vol. 25, 1990, pp. 723-728.

[15] A. Z. Mostinskiy, B. G. Bukchin and A. A. Egorkin, “Software Packages for Data Base, Frequency-Time Analysis Program and Moment Tensor & Source Depth Inversion Program (FMT package), Surface Waves Processing & Seismic Source Inversion (Double-Couple Approximation),” International Institute of Earthquake Prediction Theory and Mathematical Geophysics (Mitpan), On-Line Bulletin, 1998-2005. http://www.mitp.ru/en/soft/mainIndex.html

[1] M. Natale, C. Nunziata and G. F. Panza, “FTAN Method for the Detailed Definition of vs in Urban Areas,” 13th World Conference on Earthquake Engineering, Vancouver, 1-6 August 2004, Paper No. 2694.

[2] J. Boaga, “Seismic Noise and Controlled Source Surveys: Tools for Seismic Hazard Deterministic Approach,” Ph.D. dissertation, University of Padova, Padova, 2008.

[3] G. G. Euler, D. A. Wiens, P. Shore, F. W. Koch, R. Tibi, A. A. Nyblade and A. M. Reusch, “Shear Velocity Structure of the Cameroon Volcanic line Region from Rayleigh Wave Phase Velocities,” EOS, Transactions, American Geophysical Union, 89(53), AGU Fall Meeting Suppl., 2008, Abstract #S21C-1843.

[4] K. A. P. Tokam, C. T. Tabod, A. A. Nyblade, A. Julia, D. A. Weins and M. E. Pasyanos, “Structure of the Crust Beneath Cameroon, West Africa, from the Joint Inversion of Rayleigh Wave Group Velocities and Receiver Functions,” Geophyiscal Journal International, Vol. 183, No. 2, 2010, pp. 1061-1076. http://dx.doi.org/10.1111/j.1365-246X.2010.04776.x

[5] A. Levshin, V. F. Pisarenko and G. A. Pogrebinsky, “On a Frequency-Time Analysis of Oscillations,” Annales Geophysicae, Vol. 128, No. 2, 1972, pp. 211-218.

[6] A. Levshin, L. I. Ratnikova and J. Berger, “Peculiarities of Surface Wave Propagation across Central Eurasia,” Bulletin of the Seismological Society of America, Vol. 82, No. 6, 1992, pp. 2464-2493.

[7] A. Dziewonski, S. Bloch and M. Landisman “A Technique for the Analysis of Transient Seismic Signals,” Bulletin of the Seismological Society of America, Vol. 59, No. 1, 1969, pp. 427-444.

[8] L. I. Ratnikova, “Frequency-Time Analysis of Surface Waves,” In: Workshop on Earthquake Sources and Regional Lithospheric Structures from Seismic Wave Data, International Centre for Theoretical Physics, Trieste, 1990, pp. 1-12.

[9] C. Nunziata, G. Costa, M. Natale and G. F. Panza, “FTAN and SASW Methods to Evaluate vs of Neapolitan Pyroclastic Soils,” Earthquake Geotechnical Engineering (Balkema), Vol. 1-3, 1999, pp. 15-19.

[10] C. Nunziata, G. Costa, M. Natale, A. Vuan and G. F. Panza, “Shear Wave Velocities and Attenuation from Rayleigh Waves,” In: Pre-Failure Deformation Characteristics of Geomaterials (Balkema), 1999, pp. 365-370.

[11] C. Nunziata, G. Costa, M. Natale and G. F. Panza, “Seismic Characterization of the Shore Sand at Catania,” Journal of Seismology, Vol. 3, No. 3, 1999, pp. 253-264. http://dx.doi.org/10.1023/A:100 9861824955

[12] A. Z. Mostinskiy and B. G. Bukchin, “Moment Tensor & Source Depth Inversion Program Reference Manual, Surface Waves Processing & Seismic Source Inversion,” International Institute of Earthquake Prediction Theory and Mathematical Geophysics (Mitpan), On-Line Bulletin, 1998-2005. http://www.mitp.ru/en/soft/word_pdf_Manuals/MomTens_man.pdf?

[13] A. L. Levshin, “Effects of Lateral Inhomogeneity on Surface Wave Amplitude Measurements,” Annles Geophysicae, Vol. 3, No. 4, 1985, pp. 511-518.

[14] B. G. Bukchin, “Determination of Source Parameters from Surface Waves Recordings Allowing for Uncertainties in the Properties of the Medium,” Izvestiya Physics of the Solid Earth, Vol. 25, 1990, pp. 723-728.

[15] A. Z. Mostinskiy, B. G. Bukchin and A. A. Egorkin, “Software Packages for Data Base, Frequency-Time Analysis Program and Moment Tensor & Source Depth Inversion Program (FMT package), Surface Waves Processing & Seismic Source Inversion (Double-Couple Approximation),” International Institute of Earthquake Prediction Theory and Mathematical Geophysics (Mitpan), On-Line Bulletin, 1998-2005. http://www.mitp.ru/en/soft/mainIndex.html