Offshore windfarm foundations (UMASW)


Use the properties of marine surface waves, giving access to shear velocity values, in order to characterize the sediments at the location of the future foundations of offshore windfarm.


  • 48-channel seismic recorder
  • Hydrophones
  • 48-channel marine seismic streamers
  • Mini G Gun Sercel seismic source


The equipment is towed on the sea bottom and seismic shots are carried out at constant distance. The seismic data are recorded on board and an online quality control is carried out in order to modify, if necessary, on the acquisition parameters.

  • Acquisition set-up for marine surface wave (UMASW)

  • On-line in-house surface wave data processing software (signal and dispersion)


The results presented have been obtained for an offshore wind farm project, where a marine seismic campaign, using the surface wave and the refraction, has been achieved by SismOcean in order to estimate the shear wave velocity properties of the sediment.

These measurements were carried out using a dynamic acquisition with equipment dragged on the sea bottom by a vessel. A grid acquisition in different directions gave access to a 3D block of shear wave velocities data.

The objectives of this survey was to evaluate the shear properties of the sediment, to compare it with the geotechnical information before the installation of the monopiles of the offshore wind farm.