Advertisement

Acta Geodaetica et Geophysica

, Volume 48, Issue 1, pp 87–107 | Cite as

Shear-wave velocity structure of the northern part of the Iberian Peninsula from Rayleigh-wave dispersion analysis

  • V. Corchete
  • M. Chourak
Article

Abstract

The uppermost 50 km of the lithospheric structure of the northern part of the Iberian Peninsula is presented in this study, by means of a set of 2D images of shear-wave velocity for depths raging from 0 to 50 km. This goal will be attained by means of the inversion of the Rayleigh-wave dispersion. For this purpose, the 23 earthquakes occurred on the vicinity of the study area, from 2001 to 2003, will be considered. The dispersion curves of these earthquakes have been measured for periods from 2 to 45 s, by combination of two digital-filtering techniques: Multiple Filter Technique (MFT) and Time Variable Filtering (TVF). The resulting set of source-station averaged dispersion curves has been inverted according to the generalized inversion theory, to get S-wave velocity models for each source-station path. Finally, these models have been interpolated by kriging to obtain a 2D mapping of the S-wave velocity structure, for the northern part of Iberia. The results presented in this paper show that the crust of the study area consisted of three main layers of varying thickness with a clear S-velocity contrast, resulting in a Moho depth of 30 km that decreases to 25 km in the eastern border of the Iberian peninsula and to 20 km in the Valencia trough. The upper crust has a sedimentary cover of 2 km thick. This upper crust has a thickness of 8 km, showing a very small lateral variation. In the middle crust (from 10 to 20 km depth), the S-velocity increases from 3.4 km/s to 3.7 km/s for the whole study area except for the east and the Valencia trough, where the S-velocities reach values of 3.9 km/s. The lower crust (from 20 to 30 km depth), exhibits S-velocities of 3.8–3.9 km/s, which jump to 4.3–4.7 km/s in the upper mantle.

Keywords

FFT Inversion Rayleigh wave Shear velocity Lithosphere Iberian Peninsula 

Notes

Acknowledgements

The authors are grateful to Instituto Geográfico Nacional (Madrid, Spain), which has provided the seismic data used in this study.

References

  1. Badal J, Corchete V, Payo G, Canas JA, Pujades L, Serón FJ (1990) Processing and inversion of long-period surface-wave data collected in the Iberian Peninsula. Geophys J Int 100:193–202 CrossRefGoogle Scholar
  2. Badal J, Corchete V, Payo G, Serón FJ, Canas JA, Pujades L (1992) Deep structure of the Iberian Peninsula determined by Rayleigh wave velocity dispersion. Geophys J Int 108:71–88 CrossRefGoogle Scholar
  3. Badal J, Corchete V, Payo G, Pujades L, Canas JA (1996) Imaging of Shear-wave velocity structure beneath Iberia. Geophys J Int 124:591–611 CrossRefGoogle Scholar
  4. Chourak M, Corchete V, Badal J, Serón FJ, Soria F (2003) Imaging of the near-surface Shear-wave velocity structure of the Granada Basin (Southern Spain). Bull Seismol Soc Am 93(1):430–442 CrossRefGoogle Scholar
  5. Chourak M, Corchete V, Badal J, Gómez F, Serón FJ (2005) Shallow seismic velocity structure of the Betic Cordillera (southern Spain) from modelling of Rayleigh wave dispersion. Surv Geophys 26:481–504 CrossRefGoogle Scholar
  6. Corchete V, Badal J, Serón FJ, Soria A (1995) Tomographic images of the Iberian subcrustal lithosphere and asthenosphere. J Geophys Res 100:24133–24146 CrossRefGoogle Scholar
  7. Corchete V, Chourak M, Hussein HM (2007) Shear wave velocity structure of the Sinai Peninsula from Rayleigh wave analysis. Surv Geophys 28:299–324 CrossRefGoogle Scholar
  8. Corchete V, Chourak M (2010) Shear-wave velocity structure of the western part of the Mediterranean Sea from Rayleigh-wave analysis. Int J Earth Sci 99:955–972 CrossRefGoogle Scholar
  9. Corchete V, Chourak M (2011) Shear-wave velocity structure of the south-eastern part of the Iberian Peninsula from Rayleigh wave analysis. Int J Earth Sci 100:1733–1747 CrossRefGoogle Scholar
  10. Davis JC (1986) Statistics and data analysis in geology. 2nd edn, pp 383. Wiley, New York Google Scholar
  11. Cordoba D, Banda E, Ansorge J (1988) P-wave velocity-depth distribution in the Hercynian crust of northwest Spain. Phys Earth Planet Inter 51:235–248 CrossRefGoogle Scholar
  12. Marone F, van der Mejide M, van der Lee S, Giardini D (2003) Joint inversion of local, regional and teleseismic data for crustal thickness in the Eurasia-Africa plate boundary. Geophys J Int 154:499–514 CrossRefGoogle Scholar
  13. Mauffret A, Gorini C (1996) Structural style of the Camargue area and western Provencal Basin (south-eastern France), geodynamic consequences. Tectonics 15:356–375 CrossRefGoogle Scholar
  14. Meissner R, Wever T, Fluh E (1987) The Moho in Europe-implications for crustal development. Ann Geophys 5B:357–364 Google Scholar
  15. Morgan P, Fernandez M (1992) Neogene vertical movements and constraints on extension in the Catalan Coastal Ranges, Iberian Peninsula and the Valencia trough (western Mediterranean). Tectonophysics 203:185–201 CrossRefGoogle Scholar
  16. Navarro M, Corchete V, Badal J, Canas JA, Pujades L, Vidal F (1997) Inversion of Rg waveforms recorded in Southern Spain. Bull Seismol Soc Am 87(4):847–865 Google Scholar
  17. Paulssen H, Visser J (1993) The crustal structure in Iberia inferred from P-wave coda. Tectonophysics 221:111–123 CrossRefGoogle Scholar
  18. Payo G, Corchete V, Badal J, Serón F, Canas JA, Pujades L (1992) First two-station Rayleigh wave measurements for the northern Iberian region. Bull Seismol Soc Am 82(3):1434–1452 Google Scholar
  19. Sarrate J, Canas JA, Pujades L, Badal J, Corchete V, Payo G (1993) Shallow structure of part of north-western Iberia from short-period Rayleigh-wave observations. Tectonophysics 221:95–105 CrossRefGoogle Scholar
  20. Tejero R, Ruiz J (2002) Thermal and mechanical structure of the central Iberian Peninsula lithosphere. Tectonophysics 350:49–62 CrossRefGoogle Scholar
  21. Téllez J, Matias LM, Cordoba D, Mendes-Victor LA (1993) Structure of the crust in the schistose domain of Galicia-Tras-os-Montes (NW Iberian Peninsula). Tectonophysics 221:81–93 CrossRefGoogle Scholar
  22. Téllez J, Cordoba D (1998) Crustal shear-wave velocity and Poisson’s ratio distribution in Northwest Spain. Geodynamics 25:35–45 CrossRefGoogle Scholar
  23. Van der Meijde M, van der Lee S, Giardini D (2003) Crustal structure beneath broad-band seismic stations in the Mediterranean region. Geophys J Int 152:729–739 CrossRefGoogle Scholar
  24. Vegas R, Banda E (1982) Tectonic framework and Alpine evolution of the Iberian Peninsula. Earth Evol Sci 4:320–343 Google Scholar
  25. Zoetemeijer R, Desegaulx P, Cloetingh S, Roure R, Moretti I (1990) Lithospheric dynamics and tectonic-stratigraphic evolution of the Ebro Basin. J Geophys Res 95:2701–2711 CrossRefGoogle Scholar

Copyright information

© Akadémiai Kiadó, Budapest, Hungary 2013

Authors and Affiliations

  1. 1.Higher Polytechnic SchoolUniversity of AlmeriaAlmeriaSpain
  2. 2.Faculté Polidisciplinaire d’ErrachidiaUniversity of Moulay IsmaïlBoutalamineMorocco
  3. 3.NASG (North Africa Seismological Group)GelderlandThe Netherlands

Personalised recommendations