%0 Journal Article %T Near-surface study at the Valhall oil field from ambient noise surface wave tomography %+ Institut de Physique du Globe de Paris (IPGP) %+ Institut des Sciences de la Terre (ISTerre) %A Mordret, A. %A Landès, M. %A Shapiro, N., M %A Singh, S. %A Barkved, O., I %A Roux, Philippe %< avec comité de lecture %Z The IPGP contribution number is 3342 %@ 0956-540X %J Geophysical Journal International %I Oxford University Press (OUP) %V 193 %N 3 %P 1627-1643 %8 2013 %D 2013 %R 10.1093/gji/ggt061 %K Europe %K Interface waves %K Seismic tomography %K Interferometry %Z Sciences of the Universe [physics]/Earth Sciences/Geophysics [physics.geo-ph]Journal articles %X We used 6 hr of continuous seismic noise records from 2320 four-component sensors of the Valhall 'Life of Field Seismic' network to compute cross-correlations (CCs) of ambient seismic noise. A beamforming analysis showed that at low frequencies (below 2 Hz) the seismic noise sources were spatially homogeneously distributed, whereas at higher frequencies (2-30 Hz), the dominant noise source was the oil platform at the centre of the network. Here, we performed an ambient noise surface wave tomography at frequencies below 2 Hz. We used vertical-component geophones CCs to extract and measure the Scholte waves group velocities dispersion curves that were then processed with a set of quality criteria and inverted to build group velocity maps of the Valhall area. Although Scholte wave group velocity depends on S wave, our group velocity maps show features similar to that was previously obtained from P-wave velocity full-waveform inversion of an active seismic data set. Since the dominant noise source at high frequency (above 3 Hz) was the oil platform, we determined a 2-D S-wave velocity model along a profile aligned with the platform by inverting group velocity dispersion curves of Love waves from transverse-component geophones CCs. We found that S-wave velocity down to 20 m was low and varied along the profile, and could be used to estimate S-wave static. %G English %2 https://insu.hal.science/insu-02277520/document %2 https://insu.hal.science/insu-02277520/file/ggt061.pdf %L insu-02277520 %U https://insu.hal.science/insu-02277520 %~ IRD %~ INSU %~ UNIV-PARIS7 %~ UNIV-SAVOIE %~ AFRIQ %~ UGA %~ CNRS %~ UNIV-GRENOBLE1 %~ IPGP %~ OSUG %~ ISTERRE %~ UNIV-PARIS %~ USMB-COMUE