Author(s)

Jorge Luis de Souza^1*, Newton Pereira dos Santos¹, Carlos da Silva Vilar^1,2

¹Coordena?ao de Geofísica, MCTI/Observatório Nacional, Rio de Janeiro, Brazil.
²Departamento de Física da Terra e do Meio Ambiente, Universidade Federal da Bahia (UFBA), Brazil.

A large number of Rayleigh wave dispersion curves recorded at twenty three seismic stations was used to investigate the 3-D shear wave velocity structure of the northeastern Brazilian lithosphere. A simple procedure to generate a three-dimensional image of Mohorovicic； discontinuity was applied in northeastern Brazil and the Moho 3-D image was in agreement with several isolated crustal thicknesses obtained with different geophysical methods. A detailed 3-D S wave velocity model is proposed for the region. In the crust, our model is more realist than CRUST2.0 global model, because it shows more details either laterally or in depth than global model, i.e., clear lateral variation and gradual increase of S wave velocity in depth. Down to 100 km depth, the 3-D S wave velocity model in northeastern Brazil is dominated by low velocities and this is consistent either with heat flow measurements or with measurements of the flexural strength of the lithosphere developed in the South American continent. Our 3-D S wave velocity model was also used to obtain the lithosphere thickness in each cell of the northeastern Brazil and the results were consistent with global studies about the Lithosphere-Asthenosphere Boundary worldwide.

Rayleigh Waves, Group-Velocity Tomography, Three-Dimensional Shear Wave Velocity, Lithosphere, Spatial Resolution, Northeastern Brazil

Souza, J. , Santos, N. and Vilar, C. (2016) Three-Dimensional Shear Wave Velocity Structure of the Northeastern Brazilian Lithosphere. International Journal of Geosciences, 7, 849-872. doi: 10.4236/ijg.2016.76063.