EGU23-15781, updated on 26 Feb 2023
https://doi.org/10.5194/egusphere-egu23-15781
EGU General Assembly 2023
© Author(s) 2023. This work is distributed under
the Creative Commons Attribution 4.0 License.

Rayleigh and Love wave tomography from seismic noise of the North African and South Iberian Peninsula lithospheric structure and collision zone

Alejandra Neri1, Said Badrane2, Beatriz Gaite3, Antonio Villaseñor1, Roberto Cabieces4, César R. Ranero1,5, and Arantza Ugalde1
Alejandra Neri et al.
  • 1Marine Sciences Institute, Barcelona Center for Subsurface Imaging , Barcelona, Spain
  • 2National Center for Scientific and Technical Research, Rabat, Morocco
  • 3Spanish National Geographic Institute, Madrid, Spain
  • 4Royal Spanish Navy Observatory, San Fernando, Spain
  • 5Catalan Institution for Research and Advanced Studies-Institute of Marine Sciences , Barcelona, Spain

With more than 40 years of study, there are still uncertainties about the structure, evolution, and geodynamics of the North African and South Iberian Peninsula lithospheric structure and collision zone. Models of the lithosphere of the region coincide in some anomaly zones, such as the subduction slab under the Gibraltar arc. However, they show discrepancies in the distribution and polarity of the velocity anomalies in the onshore and offshore of most of North Africa.

To contribute to the study of the lithospheric structure and to unveil the tectonics in this controversial region, we constructed an ambient noise tomography (ANT) of Love and Rayleigh waves from temporary and permanent broadband stations located in the Iberian Peninsula, North Africa, and Atlantic islands (Madeira, Canarias, Balearic Islands). 

The methodology employed contemplates phase cross-correlation of 14 months of ambient noise records and the subsequent stacking of the cross-correlograms to obtain the Empirical Green's Function (EGF). To measure the dispersion characteristics of surface wave EGFs present in the ambient noise, we implemented the Frequency-Time Analysis (FTAN). And finally, the inversion of the dispersion measures to get the surface wave tomography.

The distribution of the almost 100 broadband stations in North Africa, Portugal, Spain, and the Atlantic islands, results in a broad path coverage in the North African and South Iberian Peninsula lithospheric structure and collision zone, complementing the previous Rayleigh wave velocity models. Furthermore, current studies in this region are Rayleigh-waves based, so the integration of Love waves in this ANT yields new information on the media velocity anisotropy.

How to cite: Neri, A., Badrane, S., Gaite, B., Villaseñor, A., Cabieces, R., Ranero, C. R., and Ugalde, A.: Rayleigh and Love wave tomography from seismic noise of the North African and South Iberian Peninsula lithospheric structure and collision zone, EGU General Assembly 2023, Vienna, Austria, 24–28 Apr 2023, EGU23-15781, https://doi.org/10.5194/egusphere-egu23-15781, 2023.