Open AccessTomography of the Alpine region from observations of seismic ambient noise
Author(s) -
Stehly L.,
Fry B.,
Campillo M.,
Shapiro N. M.,
Guilbert J.,
Boschi L.,
Giardini D.
Publication year - 2009
Publication title -
geophysical journal international
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.302
H-Index - 168
eISSN - 1365-246X
pISSN - 0956-540X
DOI - 10.1111/j.1365-246x.2009.04132.x
Subject(s) - geology , rayleigh wave , seismology , ambient noise level , seismic noise , group velocity , crust , azimuth , noise (video) , rayleigh scattering , passive seismic , geodesy , seismic tomography , surface wave , anisotropy , geophysics , mantle (geology) , geomorphology , optics , physics , sound (geography) , artificial intelligence , computer science , image (mathematics)
SUMMARY We use correlations of the ambient seismic noise to study the crust in western Europe. Cross correlation of 1 year of noise recorded at 150 three components broadband stations yields more than 3 000 Rayleigh wave group velocity measurements. These measurements are used to construct Rayleigh group velocity maps of the Alpine region and surrounding area in the 5–80 s period band. In the 5–10 s period band, the seismic noise recorded in Europe is dominated by surface waves originating from the Northern Atlantic ocean. This anisotropy of the noise and the uneven station distribution affect the azimuthal distribution of the paths where we obtain reliable group velocity measurements. As a consequence our group velocity models have better resolution in the northeast direction than in the southwest direction. Finally we invert the resulting Rayleigh wave group velocity maps to determine the Moho depth. Our results are in good agreement with the result of the numerous active experiments in the Alps and provide a continuous image of the Alpine structure.