Materials of the International Conference
50th Anniversary of the International Geophysical Year
and Electronic Geophysical Year

16-19 September 2007 • Suzdal, Russia

Structure of lithosphere of Fennoscandia by seismic data

I. M. Aleshin1, G. L. Kosarev1, O. Yu. Riznichenko1, E. Kozlovskaya2, and I. A. Sanina3

1Institute of Physics of the Earth RAS, Moscow, Russia

2Sodankyla Geophysical Observatory/Oulu Unit, University, Oulu, Finland

3Institute of Geospheres Dynamics RAS, Moscow, Russia

Abstract

We present a 3-D model of absolute values of S-wave velocities and Vp/Vs ratios in the crust and upper mantle beneath the SVEKALAPKO temporary array that covered the transition from Archean to Proterozoic domain in the Fennoscandian Shield. The model was obtained using joint inversion of P-wave receiver functions, Rayleigh phase velocities and traveltimes of waves converted from the 410- and 660-km discontinuities. P-wave receiver functions were calculated for 30 broad band stations of the SVEKALAPKO station and short-period small-aperture RUKSA array in Russian Karelia. The data was inverted by the simulated annealing method. The inversion was stabilized using phase velocities of Rayleigh waves determined by surface wave studies (data was kindly provided be M. Bruneton) and traveltimes of converted Ps waves from the 410-km boundary determined from broadband records of the SVEKALAPKO seismic array. After that a 3-D S-wave velocity model and distribution of Vp/Vs ratio was obtained from 1D velocity distributions using special interpolation technique. The new 3-D seismic models demonstrate pronounced lateral variations of values of Vs and Vp/Vs ratio in the crust and upper mantle and of the depth to the Moho boundary. The depth to the Moho boundary varies from 51 to 63 km in our model, which agrees with the results of previous controlled-source seismic studies in the region.

Citation: I. M. Aleshin, G. L. Kosarev, O. Yu. Riznichenko, E. Kozlovskaya, and I. A. Sanina (2007), Structure of lithosphere of Fennoscandia by seismic data, in: Materials of the International Conference '50th Anniversary of the International Geophysical Year and Electronic Geophysical Year', GC RAS, Moscow, doi:10.2205/2007-IGY50conf.

© 2007 Geophysical Center RAS and authors


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